Towards Novel Products and Processes
Programme Report 2010–2013
Towards Novel Products and Processes
Programme Report 2010–2013
High consistency forming of microfibrillated composite webs ................................................. 14
Foam Forming ............................................................................................................................................30
Fiber-based products for new applications ....................................................................................48
Microcelluloses and their characteristics .........................................................................................66
Resource-efficient papermaking concepts .....................................................................................90
Management of web uniformity based on imaging measurements .................................... 108
Expanded operating window for printing process enabling efficient use of
newly engineered fiber-web substrate ........................................................................................... 130
Optimizing structures and operation of entire production systems .................................... 146
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ISBN 978-952-67969-0-1 (paperback)
ISBN 978-952-67969-1-8 (PDF)
Layout: Brand United Ltd
Printing: Kirjapaino Lönnberg
The Finnish forest industry is undergoing radical changes. The decline of the graphic
paper sector means urgent efficiency improvements in existing products and processes are needed together with the establishment of a new earnings base from novel
products and processes. In 2008 these needs initiated the Forestcluster research programme Intelligent and Resource Efficient Production Technologies (EffTech), of which
the three-year research programme Efficient Networking towards Novel Products and
Processes (EffNet) was a direct extension.
The high business volumes of the forest industry’s existing products presents a big
challenge for any new product to reach similar volumes. Transformation of the industry
will, for this reason alone, take time. All possible means to improve the competitiveness
of current production must therefore be taken in the meantime, as it is this competitiveness that will enable the risky, but necessary, renewal of the industry.
The overall goal of EffNet was to improve the competitiveness of the whole forest
cluster by developing radically new energy- and resource-efficient production technologies and by finding means to reduce capital intensiveness. The focus was twofold:
firstly to develop new energy- and resource-efficient web production technologies and,
secondly, to re-engineer the product concept of fibre-based products with nanocellulose. The target was to develop and demonstrate new types of products manufactured
from wood-based fibre material and to expand the current product portfolio offered by
forest cluster companies.
New technologies always carry risk. Cooperating across the whole value chain in a common programme towards a common goal, however, gives us the combined force needed
to create and evaluate new ideas and to bear the development and implementation risks.
EffNet has created bright opportunities to improve raw material efficiency and develop
new products. Our goal now is to carry these forward as successful innovations.
Chairperson of Programme Management Group
FROM THE EFFNET PROGRAMME
Raw material, energy and water efficiency are
and use of new raw materials and novel fibre-
increasingly dominant drivers of forest indus-
based product concepts were created. Several
try investment. Incremental changes and lin-
technologies demonstrated at laboratory and
ear extrapolation of current practices will no
pilot scale show remarkable techno-economi-
longer guarantee a healthy and robust indus-
try. Future paper machine concepts will far outperform current technologies in resource and
capital efficiency. The most competitive prod-
Raino Kauppinen, Stora Enso:
ucts of today must be used to bridge the gap to
“The high applicability of the results reflects
the renewed forest industry of tomorrow.
the quality of the research and a clear
The EffNet programme addressed these
understanding of real-life challenges.”
challenges by exploring novel applications for
new materials, particularly nanocellulose. The
aim was to improve resource efficiency and
create a wider product space also within existing product categories.
Sharper competitiveness through foam
The technology with the highest value crea-
New ideas, successful product concepts
tion potential was foam forming. The method
was shown to significantly reduce capital inten-
The EffNet programme targeted research ar-
siveness and resource consumption and thus
eas of key strategic importance to the paper
improve the competitiveness and sustainabil-
industry, the renewal of which requires high-
ity of current paper and board products. The
risk research towards achieving radical devel-
technology also paves the way for forest in-
opment steps. EffNet succeeded in delivering
dustry renewal by enabling raw materials to be
this calibre of research.
combined in revolutionary new ways, creating
In the EffNet research programme new
knowledge, practicable ideas for new products
unique opportunities for companies to enter
new value chains.
The development of foam forming in EffNet
has opened up a totally new research track for
Novel tools to improve production
the development of novel products. This important achievement may not have been possible
Image-based measuring systems were devel-
without the combined force of a sizeable con-
oped to improve the process efficiency of both
sortium and public support. Foam forming pre-
existing and potential production systems,
sents exciting opportunities for the use of ex-
such as foam forming. The image-based quali-
isting raw materials and current production
ty monitoring technologies enable process op-
infrastructures, but also offers fertile ground for
timization and lead to direct improvements in
new, competitive applications beyond conven-
production efficiency. A developed new image
tional paper and board. Foam forming brings
analysis method for tissue paper provides fast
a fundamental change to the way fibre webs
and accurate information for optimizing crep-
can be formed and enables milestone improve-
ing in tissue production. The new method en-
ments in raw material efficiency. The technology
ables evaluation of the effect of chemicals in
opens up new product property windows and is
the creping process, thus leading to radical
set to make significant inroads in board making.
process efficiency improvements. Fast imaging technologies can improve competitiveness
in both current and future paper processes.
Knowledge and cost optimization
In today’s cost-pressure environment, the
need for new solutions is acute. In EffNet, the
Marjatta Piironen, Kemira:
“Innovative image-based technologies were
innovations in papermaking have
been achieved with high-filler concepts. Re-
developed in the EffNet programme. Without
search into microfibrillated cellulose filler ag-
EffNet this would have been very difficult or
gregates and starch-based biominerals also
showed high potential for achieving good paper properties and cost savings. The development of binding fillers and novel utilization of
cellulose fibrils opens opportunities to develop
new paper grades and bring cost benefits.
Big potential from microfibrillated
Printability research achieved important
new findings, expanding current knowledge
New technologies and utilization of microfibril-
and supporting the further development of
lated cellulose (MFC) in paper and board man-
printing papers. The printing efficiency results
ufacturing will impact the paper chemicals
have proven useful and practical. The partici-
industry in the future. The new knowledge cre-
pating companies have been able to utilize the
ated by EffNet will help companies design their
results in their existing business, for example
future chemical portfolios. MFC has consider-
by providing new pillars of customer support.
able application potential through combining
From the viewpoint of printing companies, one
various materials and techniques. One prom-
of the most promising results came from the
ising future application for MFC is in the fast-
development and test runs of a novel printing
growing industry of super-absorbent polymers.
paper. The test runs demonstrated good runnability of the new paper and the concept provides a firm basis for future development.
Power through networking
Creating value and new business
Close collaboration between companies and
The EffNet programme has contributed to new
EffNet researchers created new opportunities,
value and business creation in key areas of the
broader insight and networks for the future.
forest sector. These valuable results must now
According to the participants, networking has
be carried forward with further testing and eval-
been valuable and productive both within and
uation, for example at the pilot scale. Sever-
outside the research consortium. Close and
al participating companies have already based
open cooperation between key players and
their future business and development projects
experts generated a broad pool of expertise
on the research areas of the EffNet programme
and was considered an essential aspect of the
and will implement these projects in collabora-
tion with one or more EffNet partners.
The networks established in product safety
The results and technology concepts devel-
and characterization of nanocellulose were a
oped in the EffNet programme provide a sol-
valuable addition to the programme, and com-
id basis for further development towards new
pany seminars were also highly appreciated.
industrial solutions, generating value and new
Participants also gained insights into interna-
business opportunities for the forest industry.
tional research in several leading areas, such
as process design, image-based measurement,
nanocellulose applications and foam chemistry. The networking opportunities and contacts
built during the programme will be of significant
value in future development projects. Knowledge of the competence areas of researchers
in different universities and institutes will also
greatly facilitate future cooperation.
Jyrki Huovila, Metso:
“ Networking means having more power to
create new ideas and evaluate them throughout
the value chain, and to share the risks of new
The EffNet programme has had two impor-
Human technology, one of the strategic re-
tant strengths: effective networking between
search areas of the University of Jyväskylä,
partner companies, research institutes and
plays a central role in the interactive method-
academia in Finland, and a sufficiently long
ology for multi-objective optimization devel-
funding period. These have enabled serious
oped by the university’s industrial optimiza-
research efforts to generate radical solutions
tion research group. The research conducted
to improve the competitiveness of Finnish for-
in EffNet supports this major research area.
est industry companies.
The industrial optimization research group
The role of VTT Technical Research Centre of
participated in the Effnet programme in devel-
Finland in the EffNet programme has been cen-
oping and applying theory and methods and
tral and in line with VTT's objectives of creat-
software development for decision support.
ing high-level scientific and techno-economic
knowledge and know-how and generating technology and innovations for industry and society.
University of Jyväskylä, Department of
Mathematical Information Technology:
Erkki Hellén, VTT:
“The programme provided interesting and
“Without the five-year funding period, the next-
novel research problems and gave valuable
generation resource-efficient technology with
experience in dealing with the challenges of
the highest potential, foam forming, would have
complex real-world problems.”
not been developed to the level it is at now.”
The EffNet programme has demonstrated how
The research strategy of the Measurement In-
companies can collaboratively use Finnish
formation Group at Tampere University of Tech-
world-class research environments in effec-
nology is to develop generic design and oper-
tive and iterative ways to develop new prod-
ational methods for dynamic systems whose
ucts, leading to fruitful and continuous dia-
behaviour includes stochastic aspects. There
logue between researchers and industry. The
has been a strong synergy between programme
programme has activated international collab-
objectives and research objectives: the prob-
oration, built new contacts, educated young
lems specified by the programme have provided
researchers, created novel information and
practical test benches for generic research.
generated strategic opportunities for future
research and solutions development.
Risto Ritala, Tampere University of Technology:
“The combined scientific and application oriented research has provided us good opportunities for
publishing results and advancing the doctoral studies of our researchers.”
The National Research Strategy of the Finnish
The focus of the EffNet programme is on de-
forest-based sector was published in 2006.
veloping radically new energy- and resource-
To help implement the strategy, the public-
efficient web production technologies and
private partnership Forestcluster Ltd was es-
tablished in 2007 with the main goal of taking
concepts and novel, innovative products.
forward the research priorities outlined in the
The overall goal of the EffNet programme
strategy. Today, the Finnish Bioeconomy Clus-
was to develop sustainable solutions to en-
ter (FIBIC) has activities in three strategic fo-
sure the leading position of the Finnish for-
cus areas: Intelligent, Resource-Efficient Pro-
est cluster in the large-scale production of fi-
duction Technologies, Future Biorefinery and
bre-based printed and packaging products.
Sustainable Bioenergy Solutions.
The three-year research programme had total
Research programmes are the core of FIBIC’s
budget of 15 million euros. The Finnish Funding
operations. Their aim is to foster collaboration
Agency for Technology and Innovation (Tekes)
between end-users, companies and research-
provided 60% of the financing, with the re-
ers in creating opportunities for research and
mainder sourced from the participating com-
new business through open innovation and new
panies and research institutes.
ways of networking, and to speed the transition
from research results to commercial products.
Intelligent and Resource Efficient Produc-
2. Programme portfolio and goals
tion Technologies (EffTech) was the first research programme launched by Forestcluster
The Efficient Networking Towards Novel Prod-
in 2008. In the second phase (2010-2013), the
ucts and Processes (EffNet) programme aimed
EffTech programme was divided into two in-
to enhance the competitiveness of the whole
terlinked programmes in order to sharpen the
forest cluster by developing radically new en-
research focus and to diversify the number
ergy- and resource-efficient production tech-
of research participants. The three-year re-
nologies and by finding ways to reduce the
search programmes, Value Through Intensive
capital-intensiveness of the cluster. The pro-
and Efficient Fibre Supply (EffFibre) and Effi-
gramme portfolio for the three years included
cient Networking Towards Novel Products and
ten work packages (see Figure 1).
Processes (EffNet) together cover the whole
demonstrating new products and technolo-
EffFibre programme focuses on improving the
gies based on the utilization of microfibrillat-
availability and supply of high-quality raw ma-
ed cellulose (MFC). The main emphasis was on
terial from Finnish forests and developing new
production technologies for chemical pulping.
One half of the programme was targeted at
value chain from forest to printing press. The
technologies to expand paper and board prop-
erties and to allow the development of new fi-
solutions, most notably the printing process.
bre-based products outside traditional value
Concept generation by the participating com-
chains. The research focused on the two high-
panies orchestrated the detailed research or-
est potential technologies: foam forming and
ganized into studies on unit processes, quality
ultra-high consistency forming. In addition,
control and management, image-based meas-
the processability of microfibrillated cellulos-
urements, and the printing process.
es, development of binding fillers for paper
applications, and demonstration of new, value-added products were addressed. Special
attention was given to the sustainability and
3. Management of the
product safety of microfibrillated cellulose.
The second half of the EffNet programme
The EffNet programme was administered by
developed production system concepts for
a Management Group (MG) comprising repre-
the existing printed products and packaging
sentatives from industry and academia. The
markets. The concepts seek efficiency excel-
execution of was headed by Programme Man-
lence in total cost of ownership and sustain-
ager together with Industrial and Scientific Co-
ability performance, such as water and carbon
ordinators. The daily management tasks were
footprint. Three core concepts were identified
performed in each Work Package (WP) under
and analysed: novel fines-coated printing pa-
the leadership of the WP manager.
per, high filler content SC paper based on a
The main tasks of the Management Group
bindable filler concept, and reduced material
have been to supervise the progress of the
consumption in folding boxboard production
programme with respect to the objectives of
based on a foam-formed middle ply. The re-
the national forest cluster research strategy
search went beyond the boundaries of current
and the EffNet programme plan, and to assess
business models by analysing opportunities
the scientific progress and techno-economic
for optimal efficiency throughout the whole
feasibility of the results. In 2011, the MG’s main
supply chain, including intensive analysis of
tasks included mid-term evaluation of the pro-
the processes involved in producing customer
gramme, organization of the discussions with
Efficient Networking towards
Novel Products and Processes
New processes and product
based on nanocellulose
Verification of concepts
Efficient mill concepts
with new unit processes
Figure 1. EffNet programme portfolio.
the shareholder companies of Forestcluster Ltd in order to harmonize the EffNet pro-
4. Participants and international
gramme with the companies’ research strategies and to define the most important focus
The EffNet research programme brought to-
areas for the second period of the program.
gether the leading forest cluster companies
MG had the following members:
and research organisations related to papermaking technology, material science, modelling
• Jyrki Huovila, Metso Paper, Chairman
and simulation and machine vision research in
• Erkki Hellen, VTT, Scientific Coordinator
Finland. Eight companies and eight Finnish uni-
• Mika Hyrylä, UPM-Kymmene
versities and research institutes participated in
• Raino Kauppinen, Stora Enso
the programme. In addition, research was also
• Markku Leskelä, FIBIC
subcontracted from external partners.
(Lars Gädda until April 2012)
• Marjatta Piironen, Kemira
• Ari Pelkiö, Andritz
• Erkki Peltonen, Myllykoski
• Risto Ritala, Tampere University of
Tehnology, Scientific Coordinator
• Hannu Saarnilehto, Sanoma News
• Metsä Board
• Pauliina Tukiainen, VTT,
• Sanoma News
• Lauri Verkasalo, Metsä Board
• Stora Enso
(Ari Kiviranta until September 2011)
• Seppo Virtanen, UPM,
• Mikko Ylhäisi, Tekes
• Aalto University
Dissemination of EffNet programme resultsis
• Lappeenranta University of Technology
achieved with a number of different tools, the
• Tampere University of Technology
most important being the FIBIC research por-
• University of Eastern Finland
tal, accessible to EffNet programme partici-
• University of Helsinki
pants, and the FIBIC Ltd website (http://fibic.fi/
• University of Jyväskylä
programmes/effnet). Detailed project reports
• University of Oulu
and publications are available via the FIBIC por-
• VTT Technical Research Centre of Finland
tal. Programme seminars have also been held
annually, bringing together experts from ac-
International cooperation was built into the EffNet
ademic and industrial fields and providing a
programme and plays an important role in the de-
comprehensive overview of the programme’s
velopment of novel resource-efficient production
research activities and results.
technologies. Research organizations were encouraged to pursue international collaboration
for this purpose with the aim of strengthening
the position of Finnish research groups in international communities and opening up new
cooperation opportunities. The programme
participated in cooperation with six countries:
Canada, Germany, Ireland, Sweden, the UK
and the USA. Close links with the international scientific community are maintained, particularly in the areas of foam forming, multiparameter optimization, image analysis and
nanocellulose research. The cooperation initiated during EffTech was continued and broadened in EffNet.
Programme participants have been active
in presenting the programme results at international conferences and researchers have
arranged international workshops and conferences, such as the 21st International Conference of Multiple Criteria Decision Making,
at which EffNet research groups held a special
session on multi-objective process design for
systems with multi-objective operation. The
session generated valuable input from numerous international methodology experts. EffNet
participants have also been active participants
in international workshops aimed at promoting
the standardization of nanocellulose safety and
characterization test methods.
The EffNet programme was designed to minimize research overlap with related projects and
to maximize synergy between other research
activities. Many of the programme’s researchers were also involved in other related projects,
which ensured active information exchange
and rapid application of results. EffNet research
groups participated, for example, in the European Community's 7th Framework Programme
projects and several COST actions.
The EffNet programme’s core research also
supports several industry-driven projects aimed
at developing industrial applications. While many
of these projects are confidential, active participation of industrial partners within the programme has ensured active information flow, in
turn speeding the development process.
High consistency forming
c o n ta c t p e r s o n
Thad Maloney, email@example.com
pa r t n e r s
The purpose of this project was to develop a high consistency forming process
suitable for microfibrillated cellulose (MFC) composite webs and to outline a paradigm for manufacturing such webs. A MFC composite furnish was evaluated,
and a modular high consistency headbox and suitable approach flow system were
constructed. It was found that 8-10% solids was a suitable forming consistency.
Webs as low as 150 g/m2 were formed. It was also found that under certain conditions the web could be vacuum dewatered to as high as 33% solids with retention
close to 100%. Lab pressing studies showed a solids content of around 45% to be
achievable with a single shoe press. Excellent physical properties were attained,
including good formation, smoothness and light scattering. The results show it
should be possible to manufacture composites of this nature in large scale, both
the furnish cost and the investment costs look very attractive, and desirable product properties can be achieved.
This project demonstrates the manufacture MFC composite papers to be both
rational and feasible. The excellent intrinsic properties of MFC composite webs
means that it should be possible to find many viable new products in this category. The manufacturing solution is very different, and in many ways superior, to
traditional papermaking. There is ample value creation potential across the raw
material supplier–machinery manufacturer–producer–converter value chain.
microfibrillated cellulose composites, high consistency forming, MFC dewatering
must be removed, improve energy efficiency,
and simplify the manufacturing process. The
This project has its roots in the “Reengineer-
starting point of our investigation into the po-
ing Paper” philosophy. Simply put, this says
tential forming technology was a process pre-
that by rethinking the architecture of paper on
viously developed for traditional furnishes
a fundamental level we can design a new gen-
called ultra-high consistency forming (UHC), in
eration of paper products. More specifically,
which applied shear is used to deflocculate the
we are interested in the use of microfibrillat-
suspension before forming the web. The form-
ed cellulose, not as a functional additive, but
ing strategy investigated here has its origin in
as a major structural component in paper. The
the earlier UHC work of Professor Gullichsen
vast majority of current paper and board prod-
and co-workers. The possibility to use the UHC
ucts are essentially produced from mixtures
technology for a traditional furnish was also
of various pigments and pulp fibres. The func-
tional performance of paper is largely limited
by the relatively large size of fibres. Moreover,
the product and property space of the fibre/
pigment furnish approach has been largely exploited and existing products are mature. By
The objective was to develop a semi-pilot scale
including microfibrillated cellulose as a major
high consistency forming technology suitable
structural component in paper, the structure is
for forming MFC composite webs and establish
fundamentally altered and the potential prop-
a paradigm for manufacturing such webs. This
erty space is greatly expanded.
involved the following specific goals: 1) Construct a modular high consistency headbox and
By the time this project started it was already
approach flow system for the Aalto pilot ma-
clear that various MFC/pigment/fibre compos-
chine, 2) Develop the forming technology for
ites could achieve interesting properties. How-
MFC/pigment/fibre webs, 3) Outline a means
ever, it was not clear whether large-scale man-
for large-scale manufacturing, i.e., determine
ufacture of the composites would be possible.
the forming solids content and develop a water
removal strategy after forming, and 4) Test the
In order for MFC composites to become an
UHC concept on a folding box board (FBB) fur-
industrial reality, several problems must be
nish to identify any structural or potential pro-
solved. 1. The MFC must be manufactured in a
cess advantages to this forming method.
robust process with a rational cost structure;
2. Suitable forming technology must be found;
3. An energy efficient process must be devel-
3. Research approach
oped to dewater the web. This project did not
deal with point (1), but focused instead on the
1. Laboratory rheometer and former con-
forming technology. Sufficient evidence was
struction and tests. A lab device was built
gathered to show that dewatering was possi-
which allowed a suspension to be fluidized and
ble, and to outline a water removal strategy.
a web formed from the fluidized furnish. Several different slice arrangements for the lab
For composite webs containing a large amount
and energy values could be collected from the
therefore important to form at high consisten-
rheometer. This gave valuable information for
cy in order to reduce the amount of water that
former were constructed and tested. Torque
of MFC, dewatering is a potential problem. It is
the construction of the headbox. The objec-
tives of this study were to determine the upper
and increase bulk. Two MFC composite trials
solids content at which webs could be formed,
were carried out at the end of the project. A
identify possible speed limitations, quantify
bent blade bevelling system was added to the
web characteristics, and investigate 3-phase
headbox for the last trial.
systems to determine whether dispersed air
could help web forming.
The combination of lab and pilot studies was
used to determine whether the manufacture
2. Design and construction of the headbox. A
of pigment/MFC/fibre composites was rational
modular UHC headbox was designed and built.
and feasible and, if so, how it could be done.
The headbox has segments that can be taken off, modified and reattached. Two slice arrangements were constructed, and a third was
4.1 Defining the property space
3. Design and construction of the approach
flow. An approach flow was added that al-
In traditional papers, the main structural com-
lowed handling of the high consistency fur-
ponents are fibres, with length dimensions of
nish, introduction of gas or other chemicals
1-5 mm and pigments usually in the range of
and in-line high shear mixing.
1-3 µm. The forming concept, dewatering strategy and unit operation design are all based on
4. Lab studies on composite sheet structure.
this broad raw material concept. In this pro-
The property spaces for combinations of pig-
ject, we introduce the use of microfibrillated
ment/MFC/fibre blends were examined. Need-
cellulose as a major structural component. In
ed sheet preparation methods were devel-
doing so, we are fundamentally changing the
oped. From this work a 70/20/10 mixture was
furnish characteristics, the product proper-
defined as the test furnish for process devel-
ties and the needed manufacturing concept.
A key problem faced is the fact that the range
of furnish mixtures is almost infinite, leading
5. Lab studies on the dewatering/rheology
to very different rheological and dewatering
of MFC composite furnish was carried out
characteristics and thus different forming and
using an immobilization cell rheometer. The
manufacturing strategies. In order to narrow
idea was to better understand factors govern-
the 3-component furnish to a more workable
ing the rheology at high consistencies and de-
concept, a laboratory study on various pig-
termine how MFC swelling and other factors
ment/MFC/fibre mixtures was carried out. For
control dewatering. Lab pressing studies were
this work the usual laboratory sheet forming
done with a press simulator.
method was modified by: increasing the forming solids, using a very fine wire, adding over-
6. Pilot studies with the UHC former. The first
pressure to the sheet mould, and using a press
pilot studies were done with traditional fibre
drying method to prevent sheet shrinkage.
furnishes – bleached hardwood (BHW) and
BHW/BSW blends. Here we learned to use
The raw materials used were scalenohedral
the equipment and ironed out many practi-
PCC with 2.4 µm average particle size, VTT
cal problems. 3-phase systems were also in-
coarse MFC, bleached birch Kraft, lightly re-
vestigated in which 10% dispersed air was
fined. The experimental design is shown in
used to reduce viscosity, improve formation
Figure 1. A sample of the results for certain
strength properties is shown in Figure 2. The
It should be noted that in this study we are tak-
important conclusions from this study are:
ing a snapshot of only one particular solution.
There are a huge range of pigments, fibrillated
• There are non-obvious synergistic effects
celluloses and fibres that can be brought to-
of the components, such as maximum
gether to meet various end-use requirements.
stiffness at 20/60/20 pigment/MFC/fibre.
We would also like to emphasize that the role
• There are synergistic optical effects
and requirements of each of the main compo-
between the MFC and pigment.
nents can be very different to classical paper-
Scalenohedral precipitated calcium
making systems. In this project, the idea was
carbonate (SPCC) prevents the MFC from
to find a furnish concept that would allow web
collapsing in consolidation, thus leading to
formation and dewatering and lead to a prod-
high light scattering for certain mixtures.
uct with desirable intrinsic properties. This
• MFC contributes to bonding, light scattering
puts certain restrictions on the needed com-
and surface smoothness; pigment to light
ponents and the workable mixtures. For ex-
scatter and surface properties; fibre mostly
ample, a high degree of pigment structure is
to tear strength.
desired to give bulk and to maintain poros-
• The combination of high pigment/modest
ity throughout water removal (a requirement
MFC quantity/low fibre was of specific
for efficient dewatering, pressing and drying).
interest to our study. This combination
Thus, highly structured PCC was chosen. Even
delivers excellent optics, high smoothness,
with suitable components, not all mixtures will
reasonable tensile and tear strength and
be workable. For example, in cases where the
very good bulk/smoothness. We therefore
fibre content becomes too high the formation
specified a composite mixture of 70/20/10
may deteriorate, and if the MFC content is too
SPCC/MFC/fibre. The furnish cost structure
high, water removal can be a limiting factor.
is also attractive due to the high amount
of pigment. In later work, the BHW was
4.2 Headbox design
changed to a previously dried, unrefined
bleached softwood Kraft to further improve
Our initial hypothesis was that when high
tear strength and dewatering properties.
amounts MFC are used, dewatering limitations
Figure 1. The experimental design used to define the property space of pigment/MFC/fibre composites.
were likely to be the most serious obstacle to
certain simplifications to the headbox design
developing an industrially feasible process.
and made the headbox modular in nature. The
This implies that the forming process should
headbox design is shown in Figure 3.
be carried out at high consistency. The higher
the consistency at which we could form, the
The basic idea in UHC forming with classical
less water that needed to be removed in sub-
furnishes is to deflocculate the pulp suspen-
sion with a spinning rotor. If enough energy is applied, the viscosity of the suspension
As a starting point, we focused on the earlier
approaches that of water and the fibre flocs
work of Gullichsen et al., who developed ultra-
completely break up. This, in principle, pro-
high consistency forming (UHC). This concept
vides a route for forming webs at high consist-
has its roots in the development of medium
ency with good formation. The difficulty is that
consistency pulp technology, which is based
it is rather challenging to form a coherent web
on the deflocculation of a fibre suspension by
with an even velocity profile from a highly tur-
the application of sufficient shear. In several
bulent suspension. Thus, the design and relat-
projects, UHC headboxes were constructed
ed flow phenomena around the slice are cru-
and tested with traditional furnishes of up to
10% solids content. The technology met with
some degree of success. Based on this earlier
Two different slice arrangements were con-
work a UHC headbox was designed which was
structed for evaluation (Figure 4). The “wedge”
suitable for the Aalto pilot machine. We made
arrangement was conceived by Gullichsen et al.
Figure 2. Results for strength properties from the experimental design.
In this arrangement, the distance from the fluid-
a coherent free jet which would then impinge on
ized suspension to the slice is very short, which
the forming wire. The distance from the turbu-
has a potential benefit in minimizing the refloc-
lent zone to the slice exit should be sufficient to
culation time. With the wedge assembly, the web
attenuate disturbances and create the required
is formed in the gap between the bottom of the
pressure drop to ensure an even flow profile. The
headbox and the moving wire. The shear from
design was based on the best results of lab tri-
the wire can potentially rearrange the fibres and
als where, somewhat surprisingly, a converging
improve formation. The wedge space also effec-
slice gave the best free jet formation for both fi-
tively attenuates disturbances arising from the
bre and MFC composite furnishes.
turbulent mixing conditions inside the headbox.
The rotor in the headbox is capable of a maxThe second slice geometry constructed was a
imum speed of 4500 rpm and is driven by a
converging geometry with an adjustable slice
22 kW motor. The pattern on the rotor is 3mm
opening. The idea in this arrangement is to form
Figure 3. The high consistency headbox. The headbox is modular and can be taken apart and refitted.
Figure 4. The two slice arrangements. Right: A converging geometry with controllable slice profile; Left:
The “wedge” concept.
4.3 Approach flow and wet end
tion only and pressing and drying of samples
would be done in lab devices. The UHC experi-
The approach flow that was designed and
ments with BHW furnish also utilized the press
built is shown in Figure 5. A 1-cubic metre,
and dryer section of the pilot paper machine.
well-mixed delivery tank is used as both the
It was originally planned that the forming ex-
make-down and machine chest. A number
periments would be done at low speed, 5-10
of pumps were tested. The most suitable for
m/min. It was our initial hypothesis that the
our system was a flexible impeller pump with
forming dynamics would be fairly decoupled
variable speed control. This system can han-
from the machine speed, since the turbulence
dle fibre furnishes in the range 1-5% and MFC
is generated by external means. However, this
composite furnishes up to 10% solids. A high
turned out not to be correct – the forming me-
shear mixer was installed before the headbox.
chanics were strongly coupled to speed and
Prior to the mixer, gas or chemical additives
generally improved as the speed increased.
could be added. A recirculation line after the
The operating speed was thus often 30-40 m/
mixer could be used for basis weight control or
min. A method for capturing samples off the
for mixing the furnish before the trials. Three-
wire at this higher speed was developed.
phase forming experiments can be done by
adding air and a suitable surfactant and then
4.4 Lab-scale forming studies
forming microbubbles either in the high shear
mixer or directly in the headbox.
The above concept presented a number of design challenges. Various mechanical designs
The headbox contact and position relative to
needed to be tested with different furnishes,
the wire can be adjusted. Furthermore, the
each with different rheological characteris-
vacuum box positions can be adjusted to allow
tics. This required focusing in from a range of
forming either directly on the vacuum zone, or
furnish characteristics and possible headbox
prior to vacuum. Since the main experimental
design solutions to a more narrowed forming
work will be done at elevated consistencies, no
and furnish concept. To facilitate the design of
provision for capturing or recirculating white
the pilot headbox and investigate web forming
water was made. It was planned that MFC
mechanics for a range of furnishes, a small-
composite trials would utilize the former sec-
scale lab former was constructed.
The principle of the former was that several li-
Figure 5. Approach flow for the UHC former.
tres of stock could be fluidized in a chamber.
number of different furnishes (Figure 7). The
The torque, rotor speed and temperature were
experiments with BHW explored whether small
recorded. The suspension could then be ex-
amounts of dispersed air could be used to im-
truded through a slice (different slice geom-
prove the flow and web forming characteristics.
etries were constructed) forming a free jet.
The MFC composite furnish experiments con-
The condition of the free jet could be exam-
centrated on finding the upper solids content
ined with a high speed camera. A system for
at which jet forming was still achievable. At this
evaluating the quality of the free jet was put
stage we were certain that dewatering the fur-
in place. With this set-up it was possible to ex-
nish would be extremely difficult, so emphasis
amine what types of furnishes, conditions and
was placed on maximizing the solids content.
slice geometries would lead to the best qual-
The main findings from the experiments are:
ity jets (Figure 6). The limitations of the device
were that it did not allow web capture, the web
• From the BHC furnishes coherent jets
speed could not be controlled, and the flow
could be achieved at 6% and lower solids.
duration was short, so that steady-state con-
The presence of 10% dispersed air (0.02%
ditions were not really achieved.
sodium dodecyl sulphate SDS dispersant)
improved jet formation.
The lab rheometer/former was used to test a
• The jet speed was 200-300 m/min,
Figure 6. Schematic and actual lab rheometer/forming device. The various possible slice openings are
shown on the right (slice opening 2mm). On average, the “modified long narrowing lip” gave the best
web forming characteristics.
Figure 7. Examples of free jets formed under high shear conditions from the lab rheometer. On the left is
a poor jet formed from a BHW suspension at 6% solids with one of the less successful slice geometries.
On the right is an excellent coherent jet of MFC composite furnish at 9.3% solids.
indicating that sufficient machine speed is
ological properties and dewatering can be
needed to form good webs. Pilot trials later
gathered. In these studies, a couple of differ-
ent MFC grades were used, with either high or
• The application of high sheer generally
improved jet formation.
• The jet quality of the 70/20/10 MFC
low swelling. The influence of the fibre fraction
was studied, as was the solids content. A sample of the results is shown in Figure 8.
composite furnishes was excellent.
• The highest solids content at which web
The main findings from these experiments are
forming was possible for MFC composite
summarized below (note that further descrip-
furnish was 15% in the case of PCC as a
tion of this work and related publication can be
filler and 18% in the case of dispersed filler-
found in the Processability and preservability
grade ground calcium carbonate (GCC).
of microcelluloses section of this report).
Because the GCC had poorer dewatering
properties than PCC, the pilot trials were
conducted with 2.4 µm SPCC.
• While these experiments show that
• The furnish behaves as a gel and is highly
• The gel rheology is governed by its water
maximum forming solids could be as high
binding, which in turn is controlled by the
as 15-18%, practical pumping difficulties
swelling of the MFC. Thus, although MFC
limited the pilot trials to around 10% solids
is only 20% of the furnish, it governs the
in the case of MFC composite furnishes.
• MFC swelling also strongly influences
4.5 Lab rheology/dewatering studies
Common experience is that the addition of just
a few per cent of MFC to a handsheet or pilot
paper machine can often have a severe negative impact on all stages of water removal.
In deploying 20% MFC, we therefore expected water removal to be highly problematic.
Indeed, handsheets formed for the 70/20/10
furnish required overpressure and several
minutes to drain the water. However, forming
and removing water from a high consistency
furnish is very different to a handsheet and the
furnish is so completely different to traditional
fibre stock that poor water removal could not
be assumed. Practical experience proved this
to be the case.
The first clues that the 70/20/10 furnish could
be dewatered came from studies performed
with a Physica MRC-300 rheometer. This instrument allows simultaneous application of
shear and vacuum dewatering, so that information about the relationship between rhe-
Figure 8. Immobilization cell dewatering experiment with different composite furnishes. Lower gap position corresponds to easier dewatering. The upper curves use a highly swollen grade
of MFC (24 ml water/g solids swelling), the lower
curves a less swollen grade, VTT course MFC (9
ml/g swelling), used in machine trials. The closed
simples show the effect of 10% fibre in the furnish,
which increases dewatering for the furnish with
VTT course MFC.
dewatering of the furnish. The VTT coarse
tion, the PCC does not bind any water. The net
MFC with a network swelling of 9 ml/g
bound water in the web is less than traditional
(measured in a modified WRV test) had
paper, even when considering that MFC has a
much better dewatering characteristics
higher bound water content than Kraft fibres.
than a fine oxidized MFC with a swelling
Although our wet pressing research is still in
power of 24 ml/g.
its early stages, it is worth commenting that
• The application of shear helps dewatering
the pressing characteristics of the composite
• The presence of pulp fibres appears to have
web material are very different to traditional
a small positive influence on dewatering by
paper. The composite web is compressible to
helping to open flow channels.
the point where the filler network does not allow further compression and does not re-ex-
Further studies were begun at the end of the
pand. In ordinary paper, the web is highly com-
project to examine the press dewatering of
pressible, but expands and draws water back
the composite furnish. These studies are being
into the structure in the nip-rewetting phase.
carried out with a MTS press simulator which
It is clear from both the vacuum and press
can simulate fairly realistic pressing condi-
dewatering experiments that water remov-
tions. The results are shown in Figure 9. The
al from this kind of furnish can be surprisingly
results show that for this furnish at 100 g/m2
easy if the furnish characteristics and appro-
and 20% initial solids content, 45% solids con-
priate water removal strategy are understood.
tent can be achieved with a single shoe press.
Clearly, this is an area for further research.
Thus, if the web can either be formed at about
20% solids or at lower solids and vacuum de-
4.6 FBB trials
watered to 20% solids then pressing is completely feasible. Although we have not yet be-
The aim of this part of the project was to test
gun the drying experiments at the time of this
the UHC forming method with a fibre fur-
report, it is unlikely that the drying will be a
nish to determine whether suitable formation
problem. If the web permeability is sufficient
could be achieved and bulk could be improved.
to allow water transport in wet pressing, then
About 10 trials were run with a BHW or BHW/
it will allow steam transport in drying. In addi-
BSW furnish. Overall, the technology proved
Moisture ratio after
pressing for a 100 g/m2
70/20/10 MFC composite
web with 20% initial
solids content. The MFC
used was MF-Daicel.
challenging with fibre furnishes. However, the
• Based on these trials it was decided that
the headbox needed to be rebuilt with a
following findings were also made:
free jet geometry and that the furnish flow
• Several trials were conducted with the
and flocculation characteristics should be
wedge arrangement shown in Figure 4. In
improved. This was achieved by dispersing
these trials, it was found that a web could
10% gas into the furnish stabilized with
be formed in the solids range 1-5%, but the
formation of the web was not acceptable.
0.01% SDS dispersant.
• The use of the free jet improved the
Figure 10 shows that when the headbox is
forming, but low machine speed was still
lifted from the wire and the rotor is on, the
a problem. When 10% air was dispersed
condition of the jet is chaotic. The wedge
in the headbox with the high shear mixer,
attenuates pulsation, but formation is
the formation and bulk improved markedly
limited if the velocity flow through the slice
and were at a good level for this machine
is not even. In these trials the application of
type (Table 1). In our opinion, the 3-phase
shear helped the forming somewhat.
forming solution has potential and further
• The low speed of our pilot machine gave a
improvements can be made by adjusting
somewhat misleading picture, especially at
the headbox turbulence conditions and
higher solids contents. Forming conditions
attenuating flow disturbances.
clearly improved as the machine speed
Figure 10. Left: Jet condition with the headbox lifted from the wire; Right: The web formed with the headbox against the wire.
Table 1. Sheet bulk and formation for 3-phase forming at 1.8% solids content with free jet arrangement.
Samples were pressed and dried on machine.
4.7 MFC composite trials
als require about 0.5 m3 of material, so a considerable quantity of MFC is needed. Note that
The aim of this project was to demonstrate the
we have made some modifications that allow
feasibility of producing MFC composite webs in
trials to be made with about 200 litres of stock.
a reel-to-reel operation. The lab work, equip-
Sample capture is a further challenge.
ment construction and the fibre furnish trials
were conducted in preparation for the com-
Three trials were conducted, as summarized
posite forming trials. The industrial realization
of MFC composite products requires broader
research beyond the lab scale. Furthermore,
Trial 1: The furnish was 70/20/10 PCC/VTT
pilot-scale experiments are needed to identify
course MFC/BSW unrefined. Machine speed
the fundamental issues for in-depth research.
5-10 m/min. Grammage was about 500 g/m2.
Our first MFC trials validate this point.
Free jet arrangement. Solids 7-8%.
The MFC trials entailed numerous practical
• A web could be formed that was not
challenges, especially as the target was a highconsistency process. The MFC is produced locally at about 3% solids content, the PCC from
a decanter is at 30-35% solids, and ordinary
visually very even. Low speed was also a
limiting factor here.
• Samples were collected by applying blotting
paper to the web to remove samples
chemical pulp is available at 4%, unless thick
(Figure 11). This proved cumbersome.
stock is used. This limits the solids of the furnish
• Retention was close to 100% and some
to 9-10%, unless the MFC solids content can be
raised. Furthermore, the components must be
dewatering was achieved on the vacuum
section with couch solids at 10.5%.
brought together and thoroughly mixed. Mixing
• When the sample was pressed-dried, bulk
is of paramount concern when using any nano-
was 1.30 cm3/g and smoothness 3.5 PPS.
material, especially MFC-type products. The tri-
Formation was also good, showing that the
Figure 11. Taking samples in the first MFC composite trial.
gelatinous characteristic of the web means
• The web is still quite plastic even after wet
that the structure can be greatly altered
pressing. Final surface smoothness will
after forming the web, contrary to a normal
likely be controlled by the drying section
papermaking furnish. Fibres in the gel,
when well dispersed, do not reflocculate
like a normal papermaking suspension.
Trial 3. The purpose of this trial was to reduce
the Grammage further to the 100-200 g/m2
Trial 2: The purpose of this trial was to push
range, to test the bent blade concept, and to
the solids content to 10%. At this point we
examine wire section dewatering. The furnish
were still convinced that a high forming solids
was the same as in Trial 2, but the solids con-
content was needed due to dewatering limita-
tent was lowered to 7%.
tions. The furnish composition was the same,
• A bent blade with adjustable contact angle
except that Daicel MFC was used. 400 g/m2
and blade flexibility was added to the
headbox, as shown in Figure 13.
• The first suction box was moved under the
• At 10% solids, trial conditions were
considerably more difficult, e.g. pumping,
flow through headbox.
• Recirculating 1 hour through the high
shear mixer proved a good way to mix
• A methodology for capturing samples was
developed (see Figure 12).
• Bevelling experiments indicted that
both the grammage and profile could
be controlled and any formation issues
corrected by appropriate use of a bent
blade system after web formation.
• The role of both the wire and felt were
of apparent importance. It seems that
different forming fabrics than are normally
used for traditional furnishes will be
• The slice opening was reduced to achieve
a target grammage of 200 g/m2. The
grammage in the trial ranged from 150 g/m2
to 250 g/m2.
• The lateral spread of the furnish was
remarkable at high blade pressure: a 15 cm
wide web of 300 g/m2 spread to 30 cm and
• Couch solids content varied in the trial
considerably from 12% to as high as 33%.
Ash retention also varied from 92-100%.
• The basic forming concept is moving in a
promising direction, though considerable
development is still needed to test and
adjust various aspects.
• Based on observations during the trial, we
required. This aspect should be included in
do not believe there are any restrictions on
producing low-grammage webs.
Figure 12. Left: The sampling method of placing wire on wire. Right: Bent blade experiments demonstrate the plasticity of the furnish and that extreme lateral movement of the furnish is possible.
A major aim of this project was to outline a para-
tained through the consolidation process, other-
digm for manufacturing MFC composites of the
wise efficient water removal will not be possible.
type investigated here. Shortly stated, the forming consistency should be 8-10% solids content.
The forming should include high shear mixing
either before or in the headbox, as component
5. Exploitation plan and impact
mixing and the shear thinning behaviour of the
suspension are essential. A bevelling blade or
Nanocellulose is one of the most promising devel-
other means can be used to adjust the profile
opments in the forest cluster in recent years. The
and grammage. The web can be vacuum dewa-
development of industrial processes to produce
tered to a suitable solids content for press entry.
high-volume composites or next-generation pa-
Pressing can be done with existing press technol-
per and board products from fibrillated cellulos-
ogy, though attention must be paid to the press
es represents one of the most important manu-
fabric. The web can be smoothed prior to drying
facturing challenges of our time. This project did
to achieve good surface properties. Since web
not, and could not, develop such a manufacturing
shrinkage and planar deviation are an issue, re-
process. This requires a project of much greater
straint during drying via Condabelt technology or
scope. However, we did obtain strong evidence
some other approach is warranted. The furnish
that it is very possible to manufacture MFC com-
must be designed such that porosity is main-
posite webs on a large scale and that it is rational
Bent blade used to
bevel the furnish after
Figure 14. The bentblade UHC former in use.
Under some conditions
the web had a high
solids content, was
surprising strong and
could be peeled off the
table. The web had the
feel of a fabric. The trials
gave many surprising
and fascinating insights
into the nature of the
and feasible to do so – both from the product and
Dimic-Misic, K., Puisto, A., Gane, P., Niemin-
process point of view. While further research is
en, K., Alava, M., Paltakari. J. and Maloney, T.
required, we obtained considerable evidence that
The role of MFC/NFC swelling in the rheologi-
we are on the right track and gained useful expe-
cal behavior and dewatering of high consist-
rience in dealing with MFC furnishes and forming
ency furnishes, Submitted to Chemical Engi-
on a somewhat larger scale.
neering Journal, 2013.
The successful development of MFC compos-
Rantanen, J., Lahtinen, P. and Maloney, T.
ite manufacturing technology should not be
(2013): Property Space for Fibre, Microfibrillar
viewed as an instrument to improve cost struc-
Cellulose and Precipitated CaCO3 Composite
ture, but rather as a gateway to an entirely new
Sheets, Int. Paperworld IPW,(5).
industry. The bulk of the results have not been
widely published yet. Despite this, several inter-
Rantanen, J., Lahtinen, P. and Maloney, T.
national companies are interested in exploiting
(2012): Property space for fibre, microfibril-
the results and continuing development work in
lar cellulose and precipitated CaCO3 Compos-
this area. Discussions are underway.
ite sheets, Zellcheming annual conference and
expo, June 26.-28. 2012, Wiesbaden.
Rantanen, J., Lahtinen, P. and Maloney, T.
(2012): Strength property space for fibre, mi-
The project was carried out in cooperation with
crofibrillar cellulose and precipitated CaCO3
Aalto University and Finnish forest cluster com-
Composite sheets, PaPSaT annual seminar
panies. The pilot former was built at the Depart-
2012, October 2.-3. 2012, Espoo, 48-52.
ment of Forest Products Technology, Aalto University. The project was headed by Thad Maloney
Rantanen, J. and Maloney, T. (2011): Novel
at the Department of Forest Products Technol-
manufacturing method for nanocellulose con-
ogy. Professor Kuosmanen at the Mechanical
taining web based products, PaPSaT annual
Engineering department lead the former con-
seminar 2011, August 22.-24. 2011, Lappeen-
struction. Professor Mika Alava at the Phys-
ics Department lead the furnish rheology work.
Each of the above is located at Aalto University.
Rantanen, J. and Maloney, T. (2011): Ultra high
consistency forming research using novel raw
7. Publications and reports
materials, COST Training school - New technologies for treatments in the end-of-use of
packaging materials, September 12.-15. 2011,
Dimic-Misic, K., Puisto, A., Paltakari, J., Alava,
M., Maloney, T. The influence of shear on the
dewatering of high consistency nanofibrillated
cellulose furnishes, Cellulose, 8/6/2013.
Dimic-Misic, K., Sanavane, Y., Paltakari. J.,
and Maloney, T. Small scale rheological observation of high consistency nanofibrillar material based furnishes. Journal of Applied Engineering Science, ISSN, 1451-4117, 2013
c o n ta c t p e r s o n
Petri Jetsu, firstname.lastname@example.org
pa r t n e r s
Foam forming shows high resource efficiency potential and great promise as
a next-generation technology in the manufacture of fibre products. It enables
production of lightweight structures (high bulk) from various raw materials,
gives excellent formation independent of fibre length and shows excellent
dewatering properties for furnishes containing MFC. All of these offer ways
for forest industry companies to improve their competiveness, reduce capital
costs, significantly save resources, and promote sustainability. A semi-pilot
foam forming environment, built at the Technical Research Centre of Finland
(VTT), enables the production of structures with grammages from 15 to 150g/
m2 and forming at speeds up to 300m/min with consistencies as high as 4-5%.
The results indicate that in the case of folding box board, foam technology
together with advanced raw materials (here MFC as the strengthener) could
reduce manufacturing costs by 25% and carbon and water footprints by 45%
and 38%, respectively. The estimated reduction in total cost of ownership is
about 35%. Currently, the technology is being scaled up to pilot scale in another project to ease the adoption of the technology by industry. The potential
is huge, but several technological issues, such as an optimal foaming aid
concept, automation and control systems, and suitable processes to achieve
excellent printing surfaces while maximizing bulk, have to be tackled before
foam technology can be transferred to production scale.
Foam forming, folding box board, microfibrillated cellulose
refining. Forming structures from a wide variety of raw materials ranging from nanomaterials
The foam forming research continues the work
to centimetre-long fibres and materials of lower
started within the Re-Engineering Paper (REP)
density than water make this an attractive tech-
project during the first two years of the Ef-
nology for new fibre-based products. For exam-
fTech programme. The REP project originally
ple, foam forming naturally provides excellent
aimed at developing resource-efficient means
formation even with long fibres as well as the
of paper production utilizing microcellulose
possibility to form high-bulk structures. It also
and at developing advanced multi-scale mod-
enables forming of multilayered structures with
els to support this aim. The main findings of
excellent layer purity even for lightweight prod-
REP related to foam forming were:
ucts. The technology is already used for nonwoven applications on an industrial scale.
• Foam forming has been identified as the
most potential resource-efficient and
sustainable technological alternative
to produce microcellulose-containing
products. It enables efficient dewatering
Objectives of the study were to expand paper
and production of fibre-based products
and board properties with new resource-effi-
not achievable with current papermaking
cient furnish and technology concepts and to
offer ways to radically improve energy, water
• Lightweight packaging board is the product
and raw-material efficiency by utilizing foam
concept with highest potential in terms of
forming technology with microfibrillated cellu-
market size and growth and product value.
lose containing furnishes.
• Microcelluloses have been demonstrated
to give various novel product properties
(e.g. high stretch). These properties
3. Research approach
have been shown to depend strongly on
both microcellulose quality and process
The work is based on the competencies de-
veloped in the EffTech programme. In the ReEngineering Paper (REP) project, two main
The main technical challenges in utilizing mi-
advantages of foam forming were identified:
crocelluloses in product manufacturing re-
1) Possibility to generate extremely uniform
lated to forming and dewatering. Since mi-
webs (very good formation) and 2) Potential
crocelluloses bind water efficiently, they are
to make bulky structures. In the REP project
not compatible with current paper machines,
some demo structures were generated, but
where high wire section drainage is important.
very little attention was put to control of pro-
Therefore, forming at high solids content is a
cess and product properties such as forma-
crucial step in solving the dewatering prob-
tion, orientation and strength.
lems inherent in nanomaterial applications.
In the EffNet programme, a semi-pilot scale
Foam forming is a potential technology for next-
gle and multi-layer features was constructed
forming of web structures at high consistency
at VTT’s KISU facility. Controllability of sheet
with closed water systems and offers high en-
structure, product properties and process lim-
ergy saving potential in pumping, drying and
foam forming research environment with sin-
generation paper and board making. It enables
its, such as jet-to-wire ratio, consistency and
vacuum levels, were studied in dynamic condi-
The following improvements were carried out
tions. Laboratory-scale experiments were also
during the first modernization of the single-
carried out. The main focus was utilization of
layer foam forming environment:
foam forming technology combined with microcellulose (MFC) containing furnishes in mul-
• New headbox
ti-layered board making. The target was to in-
• New headbox feeding pump
crease the bulk of the folding box board (FBB)
• Improved foam recovery capacity through
middle ply by 50-100%, which offers radical en-
additional exhaust pump
ergy, water and raw material savings and considerably reduces carbon and water footprints.
As the new headbox and forming section is a
Other studied cases were SC and fine paper.
closed unit, there is no free slice jet in the head-
Development work also included foam chem-
box area. The headbox was designed on the ba-
istry research together with the SP Technical
sis that the same headbox could also be used
Research Institute of Sweden. Research related
for forming multi-layered web structures. The
to manufacturing of MFCs was excluded, so all
new headbox feeding pump enables pumping
utilized MFC grades were developed elsewhere.
of foamed suspensions at high consistency levels (up to 5%). Start-up of the single-layered
The foam forming results were highly promis-
web forming environment took place in No-
ing. Significant potential was identified for raw
vember 2011. The single-layer foam forming en-
material and energy savings in the manufacture
vironment modernization was finalized in May
of folding box board. Changing from water-laid
2012 and provides the following features:
technology to foam forming reduces manufacturing costs and carbon footprint by 25% and
• Improved foam recovery capacity
45%, respectively. Investment costs are also
• Improved pumping capacity
reduced by 25% in greenfield installations. In
• Improved mixing conditions in the feeding
addition, foam forming broadens the range of
product properties and products, creating new
business opportunities for the forest industry.
• Improved approach system for foamed
• Measurements for process control
A schematic picture of the single-layer foam
forming process is presented in Figure 1. The
4.1 Dynamic foam forming environment
main principle of the foam-laid forming process
consisted in the process foam being recirculat-
The objective was to construct a dynam-
ed within the flow loop and the raw materials
ic foam forming research environment to en-
being mixed with the process foam in a pulper.
able the forming of single and multi-layered
The quality of new and recovered process foam
web structures at speeds of up to 200 m/min
is controlled on-line by adjusting mixing condi-
to be studied. During the project a new foam
tions within the foam generator. Mixing condi-
forming research environment was designed
tions are then adjusted on the basis of these
and constructed around an existing semi-pi-
foam conductivity measurements. In single-
lot scale forming environment at VTT. Devel-
layer mode, both open and closed headbox-
opment work was divided into two phases: 1)
wire geometries are possible to run (Figure 2).
construction of single-layer facilities and 2)
construction of multi-layering facilities.
Figure 1. Schematic diagram of the single-layer foam forming process.
Figure 2. Left: Single-layer open headbox based forming unit; Right: Closed headbox based forming unit.
Figure 3. Schematic diagram of the multi-layer foam forming process.
The modernization of the multi-layer foam
forming environment was finalized in June
2013 and includes a manifold, a feeding chest
and a feeding pump for each layer. The layered
web structure is generated within the headbox. A schematic diagram of the multi-layer
foam forming process is presented in Figure 3.
Achievements of the developed dynamic
foam forming environment:
Single-layer structures in a continuous process
• Grammages up to 150 g/m2
• Headbox consistency up to 4-5%
Figure 4. Formation in foam forming is independent of fibre type and of superior quality to water
• Speed up to 300 m/min
• Open and closed headbox-wire geometry
Multilayer structures in batch mode
• Forming of two- and three-layer web
formed samples typically starts to decrease
when the grammage decreases below a cer-
4.2 Enhanced product properties
tain value (typically 50 – 60 g/m2) as the flocks
start to dominate the lateral strength behav-
One of the inherent properties of foam-formed
iour. As foam prevents flocculation to a great
products is their excellent formation. Figure 4
extent, the tensile index remains constant
illustrates this for three types of fibres. Most
even at very low grammages. This can have an
notable is that with foam forming the forma-
important impact on low-grammage products.
tion is independent of fibre type. Especially,
The experiment was conducted with both dy-
the specific beta formation was enhanced by
namic foam and water formers.
69% when spruce chemithermomechanical
pulp (CTMP) was used. The experiments were
Sheets made in the laboratory (static forming)
done with a dynamic, single-layer former.
were compared with dynamic foam and waterformed samples and sample data from the Finn-
One consequence of the excellent formation
ish Pulp and Paper Research Institute (KCL) pilot
is enhanced strength at low grammage, as
paper machine. The data for the static and dy-
shown in Figure 5. The tensile index of water-
namic samples is shown in Table 1.
Table 1. The data for the static and dynamic foam and water formed samples.
Static (laboratory sheet mould)
Pulp: CTMP spruce
MFC: Daicel MFC
Grammages: water 230 g/m2; foam 75, 105 and 150 g/m2
Pressing: no pressing, 1 pin roll and 10 pin roll
Disintegration: hot and cold
Pulp: CTMP spruce
Grammage: 105 g/m2
Pressing: no pressing, 0.5, 1.5 and 3.5 bar
When MFC is added to the foam-forming furnish we enter brand new territory in terms of
the bulk – Scott Bond relationship. We can make
lightweight structures that are strong enough
with high bulk. Such structures are unattainable with water forming because high bulk levels cannot be reached. Figure 7 further illustrates this by showing that with a 10% addition
of MFC, all of the critical strength properties of
Figure 5. At low grammages the tensile strength
of foam-formed sheets is clearly higher due to improved formation.
the 54% lighter laboratory-scale sheets are at
the same level as the water-laid reference.
As a consequence of the positive effect of MFC,
a test series using six different grades of MFCs
The most important outcome of our research
were run at the laboratory scale in order to de-
is shown in Figure 6: structures with the same
termine their effect on both z-directional and in-
strength can be produced with half the raw
plane strength properties. The pulps used in the
material. Without MFC a clear trend can be
study were pine kraft and spruce CTMP pulp and
seen. Scott Bond values decrease rapidly as
the amount of MFC added was 0% (a reference),
bulk increases from 2 cm3/g to 4 cm3/g. Howev-
5% and 15%. The sheets prepared were dried
er, if the bulk is greater than 4 cm3/g, increased
after forming without wet pressing. The results
bulk lowers the Scott Bond values only slowly.
from the test series are shown in Figure 8.
Very high bulk (> 6 cm3/g) can be achieved only
with foam forming. Thus, without any strength
According to the results, different MFC grades
additives, the only way to obtain a strong
seem to behave rather similarly in bulk vs.
enough structure (Scott Bond > 100 J/m2) is to
strength comparisons. However, in the case of
compress the structure sufficiently.
modified Scott Bond, the coarser and cheaper
Figure 6. Scott Bond values of CTMP sheets as a function of bulk. Board properties can be expanded
through a combination of foam forming (for high bulk) and strength additives. The green triangles are
typical values for CTMP sheets made on the KCL pilot paper machine. The blue squares and brown diamonds are values from static and dynamic water-formed and foam-formed studies, respectively. The
circles show the values of the foam-formed samples with different Daicel MFC contents.
Figure 7. With a combination of foam forming and MFC it is possible to make sheets at the laboratory
scale that are 54% lighter but have the same strength values as water-formed, heavier sheets. Water-formed sheets of grammage 230g/m2 (red squares), foam-formed sheets of grammage 105g/m2
with MFC (purple circles) and without MFC (blue diamonds). The green triangles indicate the estimated
strength values achievable with wet pressing for foam-formed sheets.
Figure 8. Effects of addition of six different MFC grades to pine and spruce CTMP pulps. Above: Modified
Scott Bond as a function of bulk. Below: Tensile index as a function of bulk. The right end points of the
lines equate to 5% addition and the left end points to 15% addition.
VTT MFC gave slightly higher values compared
ter laboratory wet pressing (3.5 bar, 5+2 min).
to the more refined and expensive VTT MFC.
The shrinkage potential study was based on
On the other hand, the more refined VTT MFC
a free shrinkage drying method allowing in-
gave a higher tensile index value. This exam-
plane shrinkage, but partly constraining curl-
ple illustrates that the choice of MFC should
ing (drying between wires). The results of the
depend on the required paper properties.
shrinkage potential measurements are shown
in Figure 9 (Left). According to the results,
In order to study the dimensional stability
the shrinkage potential of foam-laid papers is
of water-laid and foam-laid papers and sol-
smaller compared to water-laid papers. Foam-
ids content, the next test series were run us-
laid papers are also not as sensitive to MFC
ing pre-refined pine kraft pulp and VTT coarse
content as water-laid papers. The dryness lev-
MFC. The characteristics were measured af-
el of foam-laid papers is also higher after wet
Figure 9. Left: Foam-formed samples shrink less in free drying than water-formed samples at MFC contents of 0, 2.5, 5, 10, 15 and 20% and wet pressing conditions 0, 1.5 or 3.5 bar. Right: The solid content of
foam-formed sheets is higher after wet pressing (3.5 bar 3+2 min) than that of water-formed sheets at
MFC contents of 0%, 2.5%, 5% and 10%. The MFC used in the test series was VTT coarse MFC.
Figure 10. Left: In-plane strength properties of foam and water-laid samples (geometric average of tensile index values of foam samples) as a function of bulk (variables: MFC content and wet pressing pressure). Right: Z-directional strength of unpressed foam and water-laid samples as a function of bulk (variable: VTT coarse MFC content).
pressing (Figure 9, right). The MFC amounts
namic water-laid and foam-laid forming meth-
used can be reasonably high due to the open
ods are presented in Figure 11. Water is removed
structure of the foam-formed samples. This is
more easily than viscous foam, leading to lower
not an option in water forming, because the
vacuums in water-laid forming. Corresponding-
water drainage properties would be deterio-
ly, vacuums were higher in the removal phase
rated excessively. In our foam forming stud-
of process foam. After the removal phase, vac-
ies the solids content after wet pressing varied
uums were approximately at the same level in
from 45 to 55% also at high levels of MFC ad-
both forming methods. In the closed headbox
dition (10%, 15% and 20%).
based forming process vacuum levels were still
higher. This was mainly because most of the
In summary, foam-laid technology enables the
process foam was dewatered under the deck of
production of high-bulk structures. When this
the closed headbox and the quality of the paper
is combined with its good water drainage prop-
web was better with the closed headbox, thus
erties, allowing the addition of high levels of
leading to higher vacuum levels.
strengthening agents such as MFC, products
with both very high bulk and adequate strength
The tensile strength ratio and specific beta-
can be made. Figure 10 shows the possibili-
formation behaviour in the case of the closed
ties for strength compensation in foam-formed
headbox former is presented in Figure 12. The
samples for different wet pressing levels.
results show that a wide tensile strength ratio
can be achieved. The minimum tensile strength
4.3 Process research
ratio was around 3 and, correspondingly, the
maximum tensile strength was around 8. The
In the process research, refined chemical pine
achieved maximum tensile strength ratio was
pulp was used as the fibre raw material and the
exceptionally high compared to normal wet-
average grammage of the samples was 80 g/m2.
forming values. The specific-beta formation
values were also at a very good level, varying
The vacuums in the forming section for dy-
between 0.35 √g/m – 0.60 √g/m.
Figure 11. Vacuums in the forming section.
Figure 12. Tensile strength ratio can be controlled extensively in foam forming by altering the jet-to-wire
ratio without affecting the excellent formation.
Figure 13. Geometric tensile index and specific beta-formation as a function of forming consistency.
Figure 14. Geometric tensile index and specific beta-formation as a function of density of the process foam.
The geometric mean of tensile index and spe-
ing agents and papermaking raw materials in
cific beta-formation as a function of forming
aqueous foam-fibre systems was of great inter-
consistency is shown in Figure 13. As can be
est. The research was carried out in close coop-
seen, paper quality deteriorates with higher
eration between SP (Technical Research Insti-
consistency. The maximum forming consist-
tute of Sweden, formerly YKI) and VTT.
ency achieved was ~ 4.5%. The limited mixing
capacity in the foam chest (foam pulper) and
Foaming aid screening and foaming tests
the limited dewatering capacity in the form-
The foaming behaviour of pulp formulations, in
ing section prevented the attainment of higher
the presence of three ionic and four non-ion-
ic foaming aids, was tested with a tailor-made
foaming testing device and procedure devel-
The geometric mean of tensile index and specif-
oped by VTT. Foaming aids for testing were
ic beta-formation as a function of density of the
chosen based on their reported good foam-
process foam is shown in Figure 14. Paper qual-
ing properties, availability as bulk chemicals,
ity was weakened significantly when the aver-
as well as insensitivity to changes in tempera-
age density of the process foam was increased.
ture and pH within limits relevant to the foamforming process. The results from foaming
4.4 Foam chemistry
tests indicated that, of the foaming aids tested, three enabled relatively rapid generation
Much is known about the properties of pure
of the required foam-fibre volume. The list and
aqueous foams. However, extremely little is
molecular structure of the most rapidly foam-
known about the chemical interactions be-
ing chemicals are shown in Table 2.
tween foaming agents and papermaking raw
materials in aqueous foam-fibre systems. The
Foam-formed handsheets with different fur-
objective of the study was to increase under-
nish recipes (44 different recipes) were made
standing of the basic mechanisms related to
and tested to evaluate the effect of the select-
fibre-foam chemistry, foamability and foam
ed foaming agents on the formation and re-
stability. In particular, gaining an understand-
tention processes, the technical properties of
ing of the chemical interactions between foam-
the handsheets and the performance of other
Table 2. The most rapidly foaming chemicals and their molecular structures.
chemicals used in paper/board manufacturing
(see Figure 15, left). Furthermore, at AKD
in the presence of the foaming aids. The results
dosages ≥ 3 kg/t, the water absorbency of
obtained from the handsheet tests showed
water-formed handsheets was higher than
that the type of foaming aids used has signifi-
that of foam sheets made using the non-
cant effects on the mechanical properties and
quality of paper. The main findings of the handsheet tests can be summarized as follows:
5. Foam-formed sheets gave higher dryness
after forming and wet pressing than waterformed sheets. Foaming type and dosage
1. Foam-formed handsheets are bulkier than
had a significant impact on dewatering (see
water-formed handsheets after constant
Figure 15, right). Foaming aid dosage had no
wet pressing conditions. The type of
effect on the mechanical properties of the
foaming aid has a significant effect on bulk.
2. The formation of foam-formed sheets was
better than that of water-formed sheets. In
the presence of ionic polymers, the charge
of the used foaming aid has a significant
effect on formation.
3. The in-plane mechanical properties (tensile
strength) of foam-formed samples were
6. Filler retention was significantly higher with
foam-formed sheets utilizing a non-ionic
foaming aid than an anionic foaming aid.
7. The effect of cationic strength additives on the
strength increase of foam-formed handsheets
was lower in the presence of anionic foaming
aids than with non-ionic foaming aids.
somewhat similar to water-formed sheets at
a given bulk level. However, the out-of plane
The potential of utilizing the selected foaming
properties (Scott Bond delamination energy
aids in the practical foam forming of paper was
and Z-directional strength) of foam-formed
verified in a semi-pilot trial based on a fine pa-
samples, which are crucial for the functionality
per recipe. The results obtained during the tri-
of board, were clearly lower than for water-
als indicated that the findings made in the lab-
formed sheets at a given bulk level.
oratory tests were also valid in more dynamic
4. Sizing with alkyl ketene dimer (AKD) was
surroundings. It was also noticed that the se-
greatly dependent on the type of foaming
lection of utilized foaming aids must be done
aid used. Ionic sodium lauryl ether sulfate
together with the selection of the utilized re-
(SLES) and SDS required significantly higher
tention system. In conclusion, understanding
AKD dosage to achieve similar Mini-Cobb30
and control of fibre-foam chemistry is a key for
values to non-ionic alkyl polyglucoside
successful tailoring of final product properties.
Figure 15. Left: The effects of AKD dosage on Mini-Cobb30 value of foam- and water-formed handsheets. Right: The effects of foaming aid type and dosage on dryness after wet pressing for foam (and
water) formed handsheets.
4.5 Foam forming concept and
sumptions underneath of figure 17, a 25% reduction in production costs can be expected
(Figure 17). The calculations are based on the
The financial impacts and costs of adaption of
laboratory and semi-pilot scale results. Pro-
the foam technology are discussed in this sec-
duction in square metres is assumed to be the
tion. Folding box board (FBB) is used as a ref-
same, i.e., the volume of the reference water
erence case. The main changes required to re-
forming machine is 400,000 t/a and the foam
build a FBB machine are illustrated in Figure
forming machine 245,000 t/a (same speed,
16. A foam forming rebuild costs in the region
width and efficiency).
of EUR 10 million. The main changes to the
system are the conversion to a closed head-
Assumptions to achieve these results are:
box (which might, in some cases, not even be
Fibre: Reduction of basis weight from 270 g/
necessary) and installation of a foam genera-
m2 to 166 g/m2. Basis weight of the middle lay-
tor for mixing and dispersing, vacuum pumps
er is reduced from 192 g/m2 to 88 g/m2. MFC is
and a vacuum line for foam removal. In addi-
considered as fibre, a dosage of 20% is used
tion, minor automation updates are expected.
in calculations. It is also assumed that MFC re-
The consistency is assumed to increase from
places chemical pulp. This results in a total fi-
1% to 2.5%, so existing tank volumes are suf-
bre cost of 496 €/t.
ficient. Fresh water intake and outgoing water quality are assumed to remain unchanged.
Energy: Total energy consumption reduction
is estimated to be 20% (per tonne). This arises
There were two main outcomes of the FFB
from higher consistency (2.5%) as lower mass
case. Firstly, significant resource savings were
flows are needed but also due to lower basis
expected for both new forming technologies,
weight needed for the final product. Use of the
especially if microcellulose was used to in-
same energy levels in forming results in higher
crease the strength properties. Secondly, the
solids content before pressing. For example, for
savings potential is realized only if the value is
the reference case an increase from 19% to 24%
calculated per unit area (€/km2). Using the as-
is obtained using the same pulp mix (Birch/pine/
Figure 16. Foam rebuild
FBB concept with changes
CTMP). The same energy used in pressing re-
38%. Reductions are realized mainly through re-
sults in higher solids content after pressing. This
duced basis weight. For water footprint, the wa-
results in a total energy cost of 31 €/t.
ter scarcity is different in different regions of
the world; in Finland, where water resources are
Water: 13 m3/t water needed for production
readily available, the water scarcity footprint is
(4€/t). This is based on forming at higher con-
low in both cases (reference and foam FBB).
sistency (2.5%) and improved retention.
During the estimated 20-year lifetime of a maChemicals: Chemical cost per tonne for the
chine line, with 9% interest, the reduction in
reference are assumed to be 86 €/t. For foam-
total cost of ownership (TCO) can be about
ing chemicals the cost is assumed to be 8€/t
35%. This estimation arises from savings in
(SDS: 0.31% dosage, 2700€/t)
operating, investment, interest (shorter payback of machine when operating cost savings
For carbon footprint, the reduction is 45%, as
are assumed to be used to reduce loans fast-
shown in Figure 18. Water footprint reduction is
er), logistics and insurance costs.
Figure 17. Estimated savings potential for foam-formed folding box board.
Figure 18. Carbon (left) and water footprints (right).
5. Exploitation plan and impact
jects. Based on the results, we strongly believe
that foam forming will lead to a new manufacturing platform for fibre-based products as it 1)
Foam forming technology can significantly im-
requires significantly less raw materials, water
prove competitiveness, reduce capital intensive-
and energy than conventional manufacturing,
ness, reduce consumption of resources and im-
2) remarkably improves many product proper-
prove the sustainability of current products. At
ties, 3) enables exploitation of new raw mate-
the same time, it paves the way for the renew-
rial combinations, 4) offers a sustainable solu-
al of the forest industry by enabling raw materi-
tion for manufacturing a wide range of products,
als to be combined in new ways, thus opening
such as paper, board, tissue, hygiene products,
up opportunities for companies to create novel
insulation materials, filters and other added val-
value chains. This will create new business op-
ue products from bio-based, long fibres and 5)
portunities for large companies as well as small
offers possibilities for both large companies and
and medium sized enterprises (SMEs). Within
SMEs to create novel value chains.
this programme the concept was demonstrated
at the laboratory and semi-pilot scale. The next
step – validating the achievements at the pilot
scale – has already started in one project, SMEs
are seeking value-added applications in another
The research was carried out jointly by VTT
project, and several companies are also taking
and Finnish forest cluster companies. Table 3
active steps in this area through their own pro-
presents the research partners and their roles.
Table 3. Partner organisations and their research roles.
VTT Technical Research centre of Finland,
Fibre Process Knowledge Centre
Foam forming research, demo products manufacturing, fibre network modelling and concept
Process knowhow, demo products specifications, commercialization perspective
Demo products specifications, concept evaluation, commercialization perspective
Demo products specifications, concept evaluation, commercialization perspective
Demo products specifications, concept evaluation, commercialization perspective
SP Technical Research Institute of Sweden
Foam chemistry research, understanding of
basic mechanisms related to fibre-foam chemistry, foamability and stability
7. Publications and reports
Hellén, E., “Lightweight fibre materials through
Al-Qararah, A. M., Hjelt, T., Kinnunen, K., Be-
dustrial Applications –seminar, Espoo, 2013.
foam technology”, Biomaterials - Towards Inletski, N., Ketoja, J. A., Exceptional pore size
distribution in foam-formed fibre networks.
Hellén, E., “Renewal by combining novel form-
Nordic Pulp Paper Res. J. 27, 226-230 (2012).
ing technologies with advanced raw materials”, EffFibre&EffNet Workshop, 2012.
Al-Qararah, A. M., Hjelt, T., Koponen, A., Harlin, A., Ketoja, J. A., “Bubble size and air content
Hellén, E., “Beyond paper and board - Leap
of wet fibre foams in axial mixing with macro-
in resource-efficiency with nanocellulose and
instabilities, Colloids and Surfaces A: Physic-
new forming techniques”, Forestcluster Annu-
ochemical and Engineering Aspects, Volume
al seminar, 2011.
436, 5 September 2013, Pages 1130-1139.
Hjelt, T., Kinnunen, K., Lehmonen, J., Beletski,
Lappalainen, T. and Lehmonen, J., “ Determi-
N., Hellén, E., Liljeström, V., Serimaa, R., Miet-
nations of bubble size distribution of foam-fi-
tinen, A., and Kataja, M., ”Intriguing structur-
bre mixture using circular Hough transform”,
al and strength behaviour in foam forming”,
Nordic Pulp and Paper Research Journal, 2012,
PPPS 2011, Graz.
Vol 27, no. 5, 930-939.
Lehmonen, J., Jetsu, P., Kinnunen, K. and
Lehmonen, J., Jetsu, P., Kinnunen, K. and
Hjelt, T., ”Potential of microfibrillar cellulose in
Hjelt, T., “Potential of foam-laid forming tech-
water-laid and foam-laid papers” 2013 Tappi
nology in paper applications”, approved to
International Conference on Nanotechnology
Nordic Pulp and Paper Research Journal.
for Renewable Materials.
Kinnunen, K., Lehmonen, J., Beletski, N., Jet-
Mira, I., Andersson, M., Boge, L., Blute, I.,
su, P. and Hjelt, T., “Benefits of foam technol-
Salminen, K., Lappalainen, T., Kinnunen, K.,
ogy and its applicability in high MFC addition
“Foaming behaviour of cellulose pulp fibre-
structures”, approved to FRC.
surfactant systems used for novel production
of fibre-based materials”, Formula VII, 1 July 13
- 4 July 2013, Université de Haute Alsace, Mul-
Al-Qararah, A. M., Hjelt, T., Kinnunen, K., Belet-
Poranen, J., Kiiskinen, H., Salmela, J., Asi-
ski, N., Ketoja, J. A., “Exceptional pore size distri-
kainen, J.,Keränen, J., Pääkkönen, E., “Break-
bution in foam-formed fibre networks”, Int. Pa-
through in papermaking resource efficiency
per Physics Conf. 2012, Stockholm, Sweden.
with foam forming”, PaperCon, Atlanta, 2013.
Hellén, E., ”Resource efficiency with foam
Poranen, J., “Resource efficiency with foam
forming”, Tissue World, Barcelona, 2013.
forming”, EffFibre & EffNet Seminar, 2012.
Lappalainen, T., Salminen, K., Kinnunen, K.,
Järvinen, M., Mira, I., Boge, L., Andersson, L.,
M. and Carlsson, G. ”Laboratory scale investigation of foam forming”, EffFibre & EffNet
Lehmonen, J., Kinnunen, K., Hjelt, T., “Significant process improvements using foam forming”, Forestcluster Annual seminar, 2011.
Kinnunen, K., Lehmonen, J., Hjelt, T., Jetsu, P.,
“Foam forming facilities and demonstrations”,
EffFibre & EFFNet Seminar, 2012.
Kinnunen, K., Hjelt, T., Lehmonen, J., Jetsu,
P., Hellén, E., Kiiskinen, H., Poranen, J., ”Foam
forming - renewal of fibre products”, SHOK
Salminen, K., Lappalainen, T., Kinnunen, K.,
Andersson, M., Isabell, M., ”Foam chemistry”,
EffFibre & EFFNet Seminar, 2012.
for new applications
c o n ta c t p e r s o n
Erkki Hellén, email@example.com
pa r t n e r s
Tampere University of Technology
effnet Programme report
Demonstrations of new fibre-based products focussed on utilizing microfibrillated or microcrystalline celluloses in various applications and determining the
potential of foam forming technology to manufacture value-added products.
Filler-MFC composites were shown to offer a cost-effective substrate for printed
electronics applications with a superior temperature tolerance that only special
plastics can compete with. The performance of four different demonstrators
printed on the composite were comparable to those printed on plastic reference
substrates: conductors by inkjet, a LC resonator by screen printing, a near field
communication RFID tag by screen printing, and transistors by flexo printing.
Lightweight structures (densities 8-26 kg/m3; bulk 38-120 cm3/g) having thermal
conductivities comparable to commercial mineral and stone wool insulation materials were made from basic papermaking raw materials using foam forming.
Similar structures were also shown to perform well as lightweight, sustainable
sound absorption materials at challenging low frequencies (~500Hz). The best
structures were comparable to commercial sound insulation materials with
a density as low as 20 kg/m3. Finally, it was demonstrated that a new type of
microcellulose, namely carboxymethyl cellulose grafted microcrystalline cellulose, can act as an efficient strength additive in paper.
Foam forming clearly has the highest value creation potential of the concepts
studied in this section. Foam forming opens the way for a new manufacturing
platform for fibre-based products, as it 1) enables exploitation of unprecedented
raw material combinations 2) offers a sustainable solution for the manufacture
of a wide range of products like paper, board, tissue, hygiene products, insulation
materials, filters and other added value products from bio-based, long fibres, and
3) offers possibilities for both large companies and SMEs to create novel value
chains. The substrate for printed electronics also shows good value creation potential but, although the market potential for printed electronics is high, the market itself is still most probably too small for large companies to enter. The same
applies to the other demonstrations, which, however, may offer viable market opportunities for small and medium size enterprises. Overall, these demonstrations
show that it is possible to manufacture value-added products from wood fibres.
printed electronics, MFC, foam forming, sound absorption, lightweighting, thermal insulation
effnet Programme report