INDRESMAT is an innovation project for the development of a disruptive extrusion technology which was presented at the Networking Activities of the International Plastics and Rubber Event in Barcelona (EQUIPLAST 2017). The designed technology aims to introduce new extruded products into the market made from thermosetting resins such as polyurethane, polyester, phenolic and epoxy resins, among others. This novel reactive extrusion technology will enable a high productivity of bars, tubes, pipes, profiles, trays, plates, blocks and similar products to be used in low to high tech applications for different industrial markets and especially in construction. These materials will incorporate new features of plastic thermosets into the new
products mainly related to their resistance to temperature, to chemical agents and to mechanical stress.
INDRESMAT - Novel Reactive Extrusion Technology for Thermosetting Resins in Products within Construction and Industrial Markets
NOVEL REACTIVE EXTRUSION TECHNOLOGY FOR THERMOSETTING RESINS IN PRODUCTS
WITHIN CONSTRUCTION AND OTHER INDUSTRIAL MARKETS
INDRESMAT is an innovation project that will present the design of a new extrusion technology
at the Networking Activities of the International Plastics and Rubber Event from October 2nd
in Barcelona (EQUIPLAST 2017). The designed technology aims to introduce new extruded
products into the market made from thermosetting resins such as polyurethane, polyester,
phenolic and epoxy resins, among others. This novel reactive extrusion technology will enable
a high productivity of bars, tubes, pipes, profiles, trays, plates, blocks and similar products to
be used in low to high tech applications for different industrial markets and especially in
construction. These materials will incorporate new features of plastic thermosets into the new
products mainly related to their resistance to temperature, to chemical agents and to
Key words: extrusion, plastics, thermosetting resins, thermosets, innovation, industrial,
construction, pipes, sheets, profiles.
- Market context
In the world of plastic, conventional thermoplastic materials today represent a market share
around 85% of the world's demand for all plastics (1)
, with extrusion being the transformation
process with highest volume of production followed by the injection molding process. In
particular, the new extrusion technology will find numerous applications in the construction
market, where the European pipe and profile segments accounted around 55% of the
consumption for all plastics in this sector during 2015 (2)
. Taking PVC as reference for the most
demanded plastic in the construction market, the manufacture of pipes and profiles with this
thermoplastic (Figure 1) accounted for approximately 60% of total plastics consumption in that
sector during 2015 (3)
, being the rigid PVC pipe the application with the greatest turnover,
standing around 2.000 M€ for this year in Europe (4)
Figure 1. PVC extruded pipes and profiles
Despite the controversy generated by some studies indicating the possible existence of a
stagnant demand for PVC and even some of them forecast a contraction for the next years in
, the fact is that PVC remains the world's leading material choice by manufacturers of
pipes and profile products. Nevertheless, there is a potential growth in demand related with
an increase in the global economic activity, not only for PVC but also for all plastic materials in
this market segment. Linked to this, it is well known that in the pipelines segment, and in
general for extruded products, there is a favorable trend to the introduction of new materials
in all sectors since raw materials such as metals, concrete and ceramics, among others, are
giving way to the entrance of products made with new plastic materials.
In the context of the market described, it is very interesting to extend the extrusion model to
the thermosetting resins since this situation represents a business opportunity for these
materials, given the size of the market and available segments that may be accessible to
products with high technical performance features. Thermosetting resins offer new
advantages in extruded products for high-added value applications, which include the
possibility of channeling hot fluids, solvents or even corrosive liquids while maintaining the
integrity of their structure. In addition, there is also a market opportunity in applications
where thermoplastics, due to their own nature, have not yet entered and where products with
thermoset properties could have a great chance as those enabled by the extrusion technology
designed by INDRESMAT.
- Technological context and basis of the new thermosetting extrusion process
The extrusion of thermosetting resins is a process that today is technically underdeveloped
due to its difficulty, lack of efficiency and low performance of the devices designed until today.
In the past there have been several proposals for the development of this type of products (6,7)
which have not been very successful as evidenced by the scarce supply of commercial devices
for the continuous processing of resins. In addition, extrusion products manufactured with this
family of plastic materials are also not on the market. Commercially, the most similar to these
products are those obtained by pultrusion processes, although this process is slow and its
design is necessarily associated with the reinforcement of these materials with fibers.
The technology designed by INDRESMAT (8)
has taken into account the technical limitations of
conventional screw extruders for thermoplastics to process resins and the advantages offered
by piston injectors. While the screw extruders are designed to transport solids that melt at a
certain temperature to achieve an extrusion process after solidification, the extruder designed
for thermosetting resins is based on the existence of more than one piston compartment,
where the reactive liquid resin is pushed by synchronized pistons, creating alternating flows of
material converging in a single flow at the outlet of the extrusion head forming the extruded
The basis of this new hybrid extrusion technology, which combines the operability of the
injection process with the functionality of an extrusion process, lies in the generation of a
constant flow rate of resin, which curing reaction is controlled by the adjustable dosage of a
catalyst system and the application of a temperature profile along the basic elements that
configure the extruder (Figure 2).
Figure 2. Basic elements of the thermosetting resin extruder designed by INDRESMAT
An additional functionality of the thermosetting resin extruder is the possibility of coupling
similar devices usually employed in the conventional extrusion of thermoplastics, which will
allow the coating and lamination of other materials.
- Boundaries and high-added value applications of the new technology
The introduction on the market of the extrusion technology of thermosetting resins will not
only bring advantages associated to the properties of the new materials to be extruded, but
also will provide important process advantages. At the process level, the extrusion of
thermosetting resins will allow the following results to be achieved:
Fast processing rate.
High production capacity.
High energy efficiency.
Simplification and versatility of the extrusion process.
Low cost technology.
High product customization capability.
Reduced need for process additives.
Advantages at the process level include the real-time modification of the resin formulation
without the need for long stops to exchange and clean internal elements, as the entire
machine can be cleaned with circulation of a catalyst-free resin, avoiding material losses since
this can be recirculated to the feeding system. In addition, by modulation of the incoming
flows of raw materials, the properties can be changed to obtain products with regular section
lengths with different performance features by means of a programmed task.
At product level, the introduction of thermosetting resins will provide the following main
features to the extruded products:
High thermal resistance.
High chemical resistance.
High mechanical resistance.
High resistance to weathering.
High resistance to abrasion.
Thermosetting materials offer numerous advantages despite the current underdeveloped
technology for continuous processing of resins. The higher cost, mainly due to the slow
processing rates achieved for thermosetting resins manufacturing compared to thermoplastic
materials, has been so far an obvious disadvantage in applications where technical
requirements are not a must. However, the development of this new technology will represent
a significant advance in the extruded plastics sector due to the high productivity and versatility
of the extruder. In addition, taking in consideration the wide range of properties that can be
obtained with the different thermosetting resins, this technology will allow the entrance of
these products in different markets, which some examples are indicated below.
Applications in construction and building markets
The high resistance to chemical agents, corrosion and weathering of resins in general, will
allow the manufacturing of pipes and underground pipelines for liquids with a greater
durability. In addition, in case of leakage due to small breaks or perforations, the pipe can be
repaired in situ by sealing said leaks using the same resin which was used when manufactured
and without the need for removing, discard and replace the entire length. Another application
is the manufacture of pipes resistant to landslides or small earthquakes by combining rigid and
flexible segments on a regular basis length since the extruder can modify the formulation in
real time varying the incoming flows of the raw materials to achieve said properties. The
foaming capacity of some of the resins also will enable the manufacture of very light pipes of
large diameter for breathing or ventilation ducts applications.
Applications in industrial markets
The high thermal resistance of certain resins will allow the canalization and conduction of hot
fluids, maintaining its structure in industrial applications that currently do not allow the use of
thermoplastic materials. In addition, the high chemical resistance of these resins will allow the
conduction of solvents, certain corrosive fluids and aggressive chemical agents that currently
use non-plastic materials.
Applications in the transport, nautical and aeronautical markets
The high chemical resistance and foaming capacity of some of the resins available on the
market will allow the manufacture of light pipes and pipes resistant to oils, fuels and other
chemical agents present at the engines areas or transportation of hydrocarbons.
Applications in the electric market
The high temperature resistance of certain resins will allow the production of ducts and
profiles with superior fire protection as these materials do not melt and maintain their
structure at high temperatures. In addition, employing coating devices coupled to the
extruder, the electrical wiring can be coated with flexible thermoset material to improve its
insulation to external agents, enhancing the resistance to weathering and minimizing the risk
of short circuits.
- Market segments, product lifecycle and sustainability
As any development that involves the creation of a new manufacturing technology, the
technical difficulty in upscaling is a very important limiting factor for the access of the products
to the different market segments. The construction is probably the market with the largest
roadmap, which is represented in Figure 3 the main segments and sequence of access to them.
Figure 3. Market segments in construction and building for extruded products
In addition to the technical difficulty in upscaling, for each segment and application there are
regulatory considerations according to the sector that new materials must be adjusted to
satisfy a level of compliance during the lifecycle of the product. The sustainability of materials
from manufacturing to elimination, once its life cycle has been exhausted, is another main
consideration. In this regard, recycling is an important part in any material development that
has been foreseen and the phases are schematically represented in Figure 4.
Figure 4. Recycling process of thermoset products
The thermoset materials can be reused by reincorporation in the form of microparticles. This is
does not represent any additional problem because these materials do not melt during the
micronization process, avoiding the use of cryogenization as it happens in many
The incorporation of microparticles will not only reintroduce the recycled thermosets into the
manufacturing process at end-of-life, but also fillers from other materials of any origin,
recycled or not. In this regard, microparticles do not show problems in compatibility since
these fillers are embedded inside the crosslinked matrix without migration capacity. This is an
important advantage for these materials because it allows incorporating high contents of
fillers, reducing the cost of the product and also providing reinforcement to the polymer
matrix. Taking advantage of this particularity, the sustainability of the products is more evident
if one takes into account that, in addition to the incorporation of a large amount of recycled
fillers, there are resins which raw materials contain a very high percentage of Carbon from
Also related to the sustainability of the products, it is important to mention that in the
extrusion process of thermosetting resins, the use of process additives is practically
unnecessary. Many of process additives are usually toxic and able to migrate to the
environment, so this technology can also avoid problems of contamination.
There is now a very favorable situation for the introduction of new materials and the
development of new applications in different segments of the market for extruded products.
Thermoset materials made from thermosetting resins will offer a wide range of exclusive
properties, and this means a business opportunity in line with the current trend of replacing
non-plastic materials in applications with high technical requirements.
The reactive extrusion technology designed by INDRESMAT will make possible to massively
produce rigid, flexible, compact, foamed, reinforced or non-reinforced thermoset plastic
products for low to high value-added applications. These products will show unique properties
of thermal resistance, chemical resistance and mechanical resistance that gives them the large
variety of thermosetting resins available today.
The combination of efficiency and productivity of the reactive extrusion technology, added to
the versatility in properties of thermosetting resins, will undoubtedly be of interest to the
plastic manufacturer since it will allow the customization of a wide range of extrusion products
according to customer requirements. In addition, due to the simple configuration of the
extruder, plastic manufacturers will not need a large infrastructure of machinery and accessory
elements related with the process and type of material, situation that nowadays is very
common in thermoplastics manufacturing companies.
(1) Plastics Europe Market Research Group; Plastics – The Facts 2016
(2,3) Gonçalves, M. C., & Margarido, F; Materials for Construction and Civil Engineering:
Science, Processing and Design. Springer 2015
(4) Plasticsinsight.com; Top 10 Countries for Production of Rigid PVC Plastic Pipe, Tube,
and Hoses in Europe, 2016
(5) Thomas Washington, Amar Carmody; Contraction of Europe’s PVC market 2015
(6) Edward R. Jex; Patent US4240997
(7) Kjell Sand; Patent EP0494222B1
(8) Pablo R. Outón; Utility model ES1181409
Pablo R. Outón
MSc. High Specialization in Plastics and Rubbers
Founder at INDRESMAT (Barcelona)
Rev. Plastic. Modern. ISSN: 0034-8708, volume: 725