Medical Textiles Project Report

Created By – Rizwan Rajik Qureshi

Project Report
On
Submitted by
Miss. Yashaswi N. Bhongade
(Bachelor of Textile Science, III Year)
Under the Guidance of
Mrs. Snehal Rohadkar
“MEDICAL TEXTILES”
BACHELOR OF TEXTILE SCIENCE
MAHALAXMI JAGDAMBA COLLAGE OF LIBRARY & INFORMATION SCEINCE
RASHTRASANT TUKDOJI MAHARAJ NAGPUR UNVIVERSITY,
NAGPUR.2018-2019
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“MEDICAL TEXTILE”
CERTIFICATE
Is a record of dissertation work
Carried out by
Miss. Yashaswi N. Bhongade
Submitted in the partial fulfilment of requirement
For the degree of Bachelor of Textile Science
Of R.T.M. Nagpur university.
MAHALAXMI JAGDAMBA COLLAGE OF LIBRARY & INFORMATION SCEINCE
RASHTRASANT TUKDOJI MAHARAJ NAGPUR UNVIVERSITY,
NAGPUR.2018-2019
Mrs. Snehal Rohadkar
Guide
Mrs. Janvi Nandanvar
Principal
Mrs. Meghna Polkat
Head of
Department
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Acknowledgements
It was golden opportunity for these project and each step is a learning
process of one life. Each opportunity that we get adds something to our
personality. I take this opportunity to express my profound gratitude
towards every who helped me through the making of this project.
To being with I must acknowledge the wholehearted support I received
from Mrs. Snehal Rohadkar.
I am also thankful to Principle Janvi Nandanvar for their valuable
guidance. Mahalaxmi Jagdamba Mahavidhylaya Nagpur.
I would like to express thanks to Mrs. Sunita Wanaskar My outmost
thanks to all the staff members for their valuable support,
encouragement, guidance and suggestion during the Project
Finally I thank to all my friends and each and every member for their
unfailing, valuable suggestion, support & assistance.
Miss. Yashaswi Bhongade
B.T.S Final Year
Mahalaxmi Jagdamba Mahavidhylaya
Nagpur
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Contents
INTRODUCTION
TECHNICAL FABRIC
STRUCTURE
TYPES OF TECHNICAL
TEXTILE
1
2
3
4
5
6
7
8
MEDICAL TEXTILE
F I B R E USED IN
MANUFACTURIG
APPLICATION OF TEXTILE
IN MEDICAL F E I L D
CHARACTERSTICS OF MATERIAL IN
MEDICAL USED
CONCLUSION
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pg. 2
TECHNICAL TEXTILES
Introduction
Although ‘technical’ textiles have attracted considerable attention, the use of fibers,
yarns and fabrics for applications other than clothing and furnishing is not a new
phenomenon. Nor is it exclusively linked to the emergence of modern artificial fibers
and textiles. Natural fibers such as cotton, flax, jute and sisal have been used for
centuries (and still are used) in applications ranging from tents and tarpaulins to ropes,
sailcloth and sacking. There is evidence of woven fabrics and meshes being used in
Roman times and before to stabilize marshy ground for road building – early examples
of what would now be termed geotextiles and geogrids.
What is relatively new is a growing recognition of the economic and strategic potential
of such textiles to the fiber and fabric manufacturing and processing industries of
industrial and industrializing countries alike. In some of the most developed markets,
technical products (broadly defined) already account for as much as 50% of all textile
manufacturing activity and output. The technical textiles supply chain is a long and
complex one, stretching from the manufacturers of polymers for technical fibers,
coating and specialty membranes through to the converters and fabricators who
incorporate technical textiles into finished products or use them as an essential part of
their industrial operations. The economic scope and importance of technical textiles
extends far beyond the textile industry itself and has an impact upon just about every
sphere of human economic and social activity.
And yet this dynamic sector of the textile industry has not proved entirely immune to
the effects of economic recession, of product and market maturity, and of growing
global competition which are all too well known in the more traditional sectors of
clothing and furnishings. There are no easy paths to success and manufacturers and
converters still face the challenge of making economic returns commensurate with the
risks involved in operating in new and complex markets. If anything, the constant need
to develop fresh products and applications, invest in new processes and equipment,
and market to an increasingly diverse range of customers, is more demanding and
costly than ever.
Technical textiles have never been a single coherent industry sector and market
segment. It is developing in many different directions with varying speeds and levels of
success. There is continual erosion of the barriers between traditional definitions of
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textiles and other ‘flexible engineering’ materials such as paper and plastics, films and
membranes, metals, glass and ceramics. What most participants have in common are
many of the basic textile skills of manipulating fibers, fabrics and finishing techniques
as well as an understanding of how all these interact and perform in different
combinations and environments. Beyond that, much of the technology and expertise
associated with the industry resides in an understanding of the needsand dynamics of
many very different end-use and market sectors. It is here that the new dividing lines
within the industry are emerging.
An appreciation of the development and potential of technical textile markets
therefore starts with some clarification of the evolving terminology and definitions of
scope of the industry and its markets. This chapter goes on to consider some of the
factors – technical, commercial and global – which are driving the industry forward.
It also considers how the emergence of new geographical markets in China and other
rapidly industrializing regions of the world look set to be one of the major influences on
the growth and location of technical textiles manufacturing in the first 10 years of the
21st century.
Definition of technical textiles
The definition of technical textiles adopted by the authoritative Textile Terms and
Definitions, published by the Textile Institute is ‘textile materials and products
manufactured primarily for their technical and performance properties rather than
their aesthetic or decorative characteristics’.
Such a brief description clearly leaves considerable scope for interpretation,
especially when an increasing number of textile products are combining both
performance and decorative properties and functions in equal measure. Examples are
flame retardant furnishings and ‘breathable’ leisurewear. Indeed, no two published
sources, industry bodies or statistical organisations ever seem to adopt precisely the
same approach when it comes to describing and categorizing specific products and
applications as technical textiles.
It is perhaps not surprising that any attempt to define too closely and too rigidly
the scope and content of technical textiles and their markets is doomed to failure. In
what is one of the most dynamic and broad ranging areas of modern textiles,
materials, processes, products and applications are all changing too rapidly to define
and document.
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TECHNICAL FABRIC STRUCTURES
1. Woven fabrics
2. Knitted fabric
3. Non-woven fabrics
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WOVEN FABRICS
Introduction
Technical textiles1 are textile materials and products manufactured primarily
for their technical performance and functional properties rather than their aesthetic
or decorative characteristics. Most technical textiles consist of a manufactured
assembly of fibers, yarns and/or strips of material which have a substantial surface
area in relation to their thickness and have sufficient cohesion to give the assembly
useful mechanical strength.
Textile fabrics are most commonly woven but may also be produced by
knitting, felting, lace making, net making, nonwoven processes and tufting or a
combination of these processes. Most fabrics are two-dimensional but an increasing
number of three-dimensional woven technical textile structures are being developed
and produced.
Woven fabrics generally consist of two sets of yarns that are interlaced and lie
at right angles to each other. The threads that run along the length of the fabric are
known as warp ends whilst the threads that run from selvedge to selvedge, that is
from one side to the other side of the fabric, are weft picks. Frequently they are
simply referred to as ends and picks. In triaxial and in three-dimensional fabrics yarns
are arranged differently
Woven technical textiles are designed to meet the requirements of their end
use. Their strength, thickness, extensibility, porosity and durability can be varied and
depend on the weave used, the thread spacing, that is the number of threads per
centimeter, and the raw materials, structure (filament or staple), linear density (or
count) and twist factors of the warp and weft yarns. From woven fabrics higher
strengths and greater stability can be obtained than from any other fabric structure
using interlaced yarns. Structures can also be varied to produce fabrics with widely
different properties in the warp and weft directions.
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KNITTED FABRICS
Introduction
Hand and machine knitted fabric is created by interlocking a series of loops. The loops
(stitches) are interlocked using a needle to hold the existing loop while a new loop is
formed in front of the old loop.
The old loop is then brought over the new loop to form the fabric. Knitting differs
from weaving in that a single piece of yarn can be used to create fabric. The fabric
consists of horizontal rows known as courses and vertical columns of loops known
as Wales.
Knitted fabric has useful properties that make it suitable for a range of garments
including tights, gloves, underwear and other close-fitting garments. The loop
structure of knitted fabric stretches and moulds to fit body shapes. The air trapped by
the loops keeps the wearer warm.
Terms and Definitions
Warp knitting is a method of making a fabric by normal knitting means, in which the
loops made from each warp are formed substantially along the length of the fabric. It
is characterized by the fact that each warp thread is fed more or less in line with the
direction in which the fabric is produced. Each needle within the knitting width must
be fed with at least one separate and individual thread at each course. It is the fastest
method of converting yarn into fabric, when compared with weaving and weft
knitting.
Weft knitting is a method of making a fabric by normal knitting means, in which the
loops made by each weft thread are formed substantially across the width of the
fabric. It is characterized by the fact that each weft thread is fed more or less at right
angles to the direction in which the fabric is produced. It is possible to knit with one
thread only, but up to 144 threads can be used on one machine. This method is the
more versatile of the two in terms of the range of products produced as well as the
type of yarns utilized.
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NONWOVEN FABRICS
Introduction
It is an unfortunate fact that there is no internationally agreed definition of
nonwovens, in spite of the fact that the International Standards Organization
published a definition in 1988 (ISO 9092:1988). Many countries, particularly those that
have played an active part in the development of nonwovens, still prefer their own
national definition, which is generally wider in its scope than the very narrow defi-
nation of ISO 9092.
As it is essential to be clear on the subject matter to be included in this chapter, I
have decided to use the definition of the American Society for Testing Materials
(ASTM D 1117-80). This definition is as follows: ‘A nonwoven is a textile structure
produced by the bonding or interlocking of fibers, or both, accomplished by
mechanical, chemical, thermal or solvent means and combinations thereof. The term
does not include paper or fabrics that are woven, knitted or tufted.’ It has to be
admitted that this definition is not very precise, but it has been chosen because it
includes many important fabrics which most people regard as nonwovens, but which
are excluded by ISO 9092. Nonwovens are still increasing in importance; production is
increasing at the rate of 11% per annum.
One of the major advantages of nonwoven manufacture is that it is generally
done in one continuous process directly from the raw material to the finished fabric,
although there are some exceptions to this. This naturally means that the labor cost of
manufacture is low, because there is no need for material handling as there is in older
textile processes. In spite of this mass-production approach, the nonwovens industry
can produce a very wide range of fabric properties from open waddings suitable for
insulation containing only 2–3% fibers by volume to stiff reinforcing fabrics where the
fiber content may be over 80% by volume. All nonwoven processes can be divided into
two stages, the preparation of the fibers into a form suitable for bonding and the
bonding process itself. There are a number of different ways of fiber processing, each
producing its own particular characteristic in the final fabric. Equally there are a
number of different bonding methods which have an even bigger effect on the
finished fabric properties. Almost all the fiber processing methods can be combined
with all the bonding methods, so that the range of different possible manufacturing
lines is enormous, allowing a great range of final properties.
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However, this does raise a difficulty in describing the nonwoven process. We know that
the process is essentially a continuous one in which the fiber processing and bonding
take place in two machines tightly linked together, but it is impossible to describe the
combined machines together owing to the wide number of machine combinations that
are possible. Instead it is necessary to explain the methods of fiber processing and the
methods of bonding separately.
In fiber processing it is common to make first a thin layer of fiber called a web and then
to lay several webs on top of each other to form a batt, which goes directly to bonding.
The words web and batt are explained by the previous sentence, but there are cases
where it is difficult to decide if a fibrelayer is a web or a batt. Nevertheless the first
stage of nonwoven processing is normally called batt production.
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Technical Textiles Classification
 Agrotech
 Buildtech
 Hometech
 Indutech
 Oekotech
 Geotextiles
 Meditech
 Clothtech
 Protech
 Packtech
 Mobitech
 Sportech
Agrotech: These are the Agro-textiles, also known as Agrotex, that are used in
agricultural applications related to growing and harvesting of crops and animals. Not
only crop production, they are also used in forestry, horticulture, as well as animal and
poultry rearing including animal clothing. Agro-textiles have to be strong, elongated,
stiff, bio-degradable, and resistant to sunlight and toxic environment.
Buildtech: These are the Construction Textiles, also known as Buildtex, used in
construction and architectural applications, such as for concrete reinforcement, facade
foundation, interior construction, insulation, air conditioning, noise prevention, visual
protection, protection against sun light, building safety etc. The field of textile
architecture is also expanding as textile membranes are increasingly being used for
roof construction. Such fabrics as PVC coated high tenacity PES, Teflon coated glass
fiber fabrics or silicone coated PES are used extensively in football stadia, airports and
hotels.
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Indutech: These are the Industrial Textiles, also known as Indutex, used in different
ways by many industries for activities such as separating and purifying industrial
products, cleaning gases and effluents, transporting materials between processes and
acting as substrates for abrasive sheets and other coated products. They range from
lightweight nonwoven filters, knitted nets and brushes to heavyweight coated
conveyor belts
Oekotech: These are the Eco-friendly Textiles, also known as Oekotex or Ecotex. They
are mostly used in environmental protection applications - floor sealing, erosion
protection, air cleaning, prevention of water pollution, water cleaning, waste
treatment/recycling, depositing area construction, product extraction, domestic water
sewerage plants. They are even gaining unimaginable popularity in other sectors of
textile industry. Clothing, home furnishings, fashion accessories etc. all now come in
eco-friendly versions made of Oekotech.
Geotextiles: These are the Geotextiles, also known as Geotex, which are woven,
nonwoven and knit fabric used for many functions such as support, drainage and
separation at or below ground level. Their application areas include civil and coastal
engineering, earth and road construction, dam engineering, soil sealing and in drainage
systems. Geotech have good strength, durability, low moisture absorption and
thickness. Synthetic fibers such as glass fiber, polypropylene and acrylic fibers are used
to prevent cracking of the concrete, plastic and other building materials.
Medtech: These are the Medical Textiles, also known as Medtex. They include all the
medical fabrics that are used in health and hygiene applications in both consumer and
medical markets. They are generally used in bandages and sutures that are used for
stitching the wounds. Sutures and wound dressing uses fibers like silk fibers and other
synthetic fibers. Hollow synthetic fibers are used with nano particles (very small
particles) for delivery of drugs to any specific part of the body. Cotton, silk, polyester,
polyamide fabrics are also used in medical applications.
Clothtech: These are the Clothing Textiles, also known as Clothtex, including all those
textile products that represent functional, most often hidden components, of clothing
and footwear such as interlinings, sewing thread, insulating fiberfill and waddings. They
are the 'high performance' garment fabrics whose demand is increasingly rising with
time.
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Protech: These are the Protective Textiles, also known as Protex, that are used in the
manufacturing of protective clothing of different types. Protection against heat and
radiation for fire fighter clothing, against molten metal’s for welders, for bullet proof
jackets or for chemical protective clothing- all depend on the use of Protech. The
protective textiles are made with the help of specialty fibers such as aramid fiber used
in making of bullet proof jackets, glass fibers used in fire proof jackets etc. Sometimes
the protective textile is also coated with special chemicals, for example, when used in
manufacturing astronaut’s suits.
Packtech: These are the Packaging Textiles, also known as Packtex. Textiles have been
used for packaging since ages. It ranges from heavyweight woven fabrics used for bags,
packaging sacks, Flexible Intermediate Bulk Carriers (FIBCs) and wrappings for textile
bales and carpets to the lightweight nonwovens used as durable papers, tea bags and
other food and industrial product wrappings.
Mobitech: These textiles, also known as Mobiltex, are used in transport industry,
such as in construction of automobiles, railways, ships etc. Truck covers and restraints
are significant textile end-uses in the transportation sector. They can range from simple
ropes and tarpaulins to highly engineered flexible curtain systems and webbing tie-
downs. Other examples include seat covers, seat belts, non-woven for cabin air
filtration, airbags, parachutes, inflatable boats, air balloons am
Sporttech: These are the Sports Textiles, also known as Sporttex, used mainly for
making sportswear including sports shoes and other sports accessories. Increasing
interest in active sports and outdoor leisure activities such as flying and sailing sports,
climbing, cycling, etc. has led to immense growth in the consumption of textile
materials in manufacturing sporting and related goods and equipment. Synthetic fibers
and coatings have largely replaced traditional cotton fabrics and other natural fibers in
the making of Sporttech.
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Medical Textile
Introduction
Medical textiles or Medtech is one of the most important continuously expanding and
growing fields in technical textiles. Medical textiles represent structures designed and
accomplished for a medical application. The number of applications is diverse, ranging
from a single thread suture to the complex composite structures for bone
replacement and from the simple cleaning wipe to advanced barrier fabrics used in
operating rooms. Textile material and products, that have been engineered to meet
particular needs, are suitable for any medical and surgical application where a
combination of strength, flexibility and sometimes moisture and air permeability are
required. The medical textile industries have diversified with new materials and
innovative designs .Recently , application of textiles has started going beyond the
usual wound care , incontinence pad , plasters etc., Latest innovation i.e., wide variety
of woven , Non-woven , knitted forms of textiles increasingly finding their way into a
variety of surgical procedures.
Anation’senconomic power and quality of life of the people depend on the ability of
the industrialists to innovate and manufacture socially products. One does not need to
be a great to be a great scientist to innovate and discover new things, sometimes
simple techniques developed using common sense can be used to make high value
products. Medical Textile is an exciting and rewarding field that has great potential to
positively transform how people live their daily lives. Medical Textile industries in India
are still taking baby steps, compared to the international scenario. Medical Textiles
are known as Healthcare Textiles. Medical Textiles is one of the most rapidly
expanding sectors in the technical textile market. It is one of the major growth areas
within technical textiles and the use of textiles materials for medical and healthcare
products ranges from simple gauze or bandage materials to scaffolds for tissue
culturing and a large variety of prostheses for permanent body implants. Textile
products are omnipresent in the field of human hygiene and medical practice. Their
use is based on a number of typical basic textile properties like softness and lightness ,
flexibility, absorption , filtering etc., Advanced medical textiles are significantly
developing area because of their major expansion in such fields like wound healing
and controlled release , bandaging and pressure garments , implantable devices as
well as medical devices , and development of new intelligent textile products several
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researching works are going on all over the world in medical textile materials and
polymers. Nano-technique has acquired tremendous impulse in the last decade. Nano-
fiber based products as well as nano-coated materials are present innovations in the
field of medical .Nano-fibres are very attracted due to their unique properties , high
surface area to volume ratio , film thinness , nano scale fiber diameter porosity of
structures , lighter weight . Nano fibers are porous and the distribution of pore size
could be of wide range so they can be considered as engineered scaffolds with broad
applications in the field of tissue engineering. some other applications like wound
dressings , bone regeneration and nano-fibres to be the carrier of various drugs to the
specific sites , etc., Biomedical textiles are branch of technical textiles which are
manufactured from wide range of processes. The main attribute of biomedical textiles
is that it should fulfill the purpose for which it is designed. To fulfill this purpose
various synthetic and natural fibers each with its unique properties are used to
construct biomedical textiles.Polycaprolactone, Polyglcolic acid and Polylactic acid are
some synthetic fibers used in sutures and tissue engineering structures. Natural
biological fibers include chitin, collagen and alginate fiber.Sorbalgaon a non-woven
dressing material obtained from alginate fibers facilities a permeable moist wound
treatment woven and knitted materials are used extensively in vascular grafts and
hernia meshes. A specialized area of medical textiles is the extrusion of hollow fiber
membranes used in extracorporeal devices. Braided textiles are used for sutures and
to replace tendons and ligaments. Thus the textile sector has most commonly
emerging advanced application in medical textiles .The application of fiber has now
been extend for the manufacturing of artificial internal organs like kidneys, lungs,
heart valves, and thread for surgical purposes and other medical materials. As
innovative approach was made to utilize the eco-friendly renewable source of herbal
treated medicated textiles material to simple products. The results proved that the
herbal medicated products.
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Classification of Medical Textiles
Depending upon use of medical textile products they are classified as
follow-
Non-implantable
medical textiles
Implantable medical
textiles
Extracorporeal
medical textiles
Healthcare & hygienic
medical textiles
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Non-Implantable Materials
These materials are used for external application on the body and mal application
on the body and may not contact with skin. They are made from co-polymer of two
amino acids. They are employed as covering, absorbent, protective and supports for
injured or diseased part. They are different types of non-implantable material which is
wound dressing, plaster etc. A number of wound-dressing type is available for a variety
of medical and surgical applications. The functions of these materials are to provide
protection against infection, absorb blood and exudates, promote healing, and, in
some instances, apply medication to the wound. Common wound dressings are
composite materials consisting on an absorbent layer held between a wound-contact
layer and a flexible base material. The absorbent pad absorbs blood or liquids and
provides a cushioning effect to protect the wound. The wound contact layer should
prevent adherence of the dressing to the wound and be easily removed without
distribution new tissue growth. The base materials are normally coated with an acrylic
adhesive to provide the means by which the dressing is applied to the wound. Textile
materials used for wound-dressing applications include gauze, lint, and wadding. Gauze
is an open-weave, absorbent fabric, which, when coated with paraffin wax, is used for
the treatment of burns and scalds. In surgical applications, gauze serves as an
absorbent material when used as a protective dressing for first-aid and mild-burn
applications. Wadding is a highly absorbent material, which is covered with a non-
woven fabric to prevent wound adhesion or fiber loss.
Bandages are designed to perform a wide variety of specific functions, depending
upon the final medical requirement. They can woven, knitted, or nonwoven and are
either elastic or non-elastic. The most common applications for bandages is to hold in
place over wounds. Such bandages include lightweight knitted or simple open-weave
fabrics made from cotton or viscose, which are cut into strips and then scoured,
bleached, and sterilized. Elasticated yarns are incorporated into the fabric structure to
impart support and conforming characteristics. Knitted bandages can be produced in
tubular form in varying diameters on either warp or weft knitting machines. Woven
light-support bandages are used in the management of sprains or stains, And the
Elasticated properties are obtained by weaving cotton crepe yarns that have a high
twist content. Similar properties can also be achieved by weaving two warps together,
one beam being under a normal tension and the other under a high tension.
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Non-Implantable Materials
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A. Wound Dressing
A number of wound dressing types are available for variety of medical and
surgical application. The functions of these materials are to provide protection against
infection, absorb blood and exudates, promote healing and, in some instances, apply
medication to the wound. Common wound dressings are composite materials
consisting of an absorbent layer held between a wound contact layer and flexible base
material. The absorbent pad absorbs blood or liquids and provides a cushioning effect
to protect the wound. The wound contact layer should prevent adherence of the
dressing to the wound and be easily removed without disturbing new tissue growth.
The base materials are normally coated with an acrylic adhesive to provide the means
by which the dressing is applied to the wound. Developments in coating technology
have led to pressure sensitive adhesive coatings that contribute to wound dressing
performance by becoming tacky at room temperature but remain dry and solvent
free. The use of collagen, alginate, and chitin fibers has proved successfully in many
medical and surgical applications because they contribute significantly to the healing
process. When alginate fibers are used for wound contact layers the interaction
between the alginate and the exuding and the exuding wound creates a sodium
calcium alginate gel. The gel is hydrophilic, permeable to oxygen, impermeable to
bacteria, and contributes to the formation of new tissue.
Other textile materials used for wound dressing applications include gauze, lint,
and wadding. Gauze is an open weave, absorbent fabric that when coated with
paraffin wax is used for the treatment of burns and scalds. In surgical application
gauze serves as an absorbent material when used in pad form (swabs); yarns
containing barium sulphate are incorporated so that the swab is X-ray detectable. Lint
is a plain weave cotton fabric that is used as a protective dressing for first-aid and mild
burn applications. Wadding is a highly absorbent material that is covered with a
nonwoven fabric to prevent wound adhesion or fiber loss. A dressing should posses
the following properties:
 Healing properties, regulated mainly with the substances which are applied to
dressing
 Causing no mechanical injury of a granulating wound.
 Decreased adherence surface.
 Eliminating a possibility of loose fibers getting caught in the wound.
 Stable and spatial structure
 Easy penetration of wound secretion to the absorbing dressing.
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 Not-interrupted process of wound healing - as only the outer gauze compress is
changed.
 Painless changing of the dressing.
Wound dressing are used for protection against infection, absorption, exudation of
blood and excess fluids, healing and medication. Traditionally, wound dressing are
often made of cellulosic fiber such as cotton and viscose rayon fibers in the form of
woven or non-woven gauzes. The advantage was that they were highly absorbent. But
since the fibers structure is chemically, physically and biomedical inert to the wound-
healing environment, the fibers remain integral during the course of the treatment.
Due to rapid progress in the textile field, now days a number of natural polymers such
as chitin, chitosan, alginate, pectin, etc. are used.
Sorbalgaon is a supply, non-woven dressing made from high-quality calcium alginate
fibers with excellent gel-forming properties. The dressing offers a number of practical
therapeutic advantages for wound healing over any other commonly used textile
material.
Sorbalgaon dressing absorb approximately 10 ml exudates per gram dry weight and
are thus provided with a very high absorption capacity. They in addition differ from
textile dressing with respect to the applied mechanism of absorption. Whereas, cotton
gauze holds the absorbed fluid mainly between the fibers, the calcium alginates take
up wound secretions directly into the fibers, i.e. using intracapillary forces. Germs and
detritus are retained within the gel structure as the fibers swell during subsequent
gelatinization. The wound is thus effectively cleansed and a con-siderable reduction of
micro-organisms can be attained. The gel remains permeable to gas so that
Sorbalgaon represents dressing materials that facilitates a permeable moist wound
treatment. Sorbalgaon may generally be used for the treatment of all external wound,
but its application is mainly recommended for bleeding and secreting injuries that
support the wound-healing effects of gel formation. Sorbalgaon offers an especially
painless and a traumatic dressing’s change, which is of great importance with this type
of wound.
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Wound Dressings
SAMPLES
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B. Bandages
Bandages are mainly used for orthopedic purpose. There is a wide range of bandages
available for various purposes. Although bandages tension and sub-bandages pressure
are determined in the initial stages by the user during the time of application, the
ability of bandages to maintain this tension is determined by electrometric properties
under conditions of use. Bandages are designed to perform a whole variety of specific
functions depending upon the final medical requirement. They can be woven, knitted,
or non-woven and are either elastic or non-elastic. The most common application for
bandages is to hold dressing in place over wound. Such bandages include lightweight
knitted or simple open weave fabrics made from cotton or viscose that are cut into
strips then scoured, bleached, and sterilizes. Elasticated yarns are incorporated into
the fabric structure to impart support and conforming characteristics. Knitted
bandages can be produced in tubular from in varying diameters on either warp or weft
knitting machines. Woven light support bandages are used in the management of
sprains or strains and the Elasticated properties are obtained by weaving cotton crepe
yarns that have high twist content. Similar properties can also be achieved by weaving
two warps together, one beam under a normal tension and the other under a high
tension. When applied under sufficient tension, the stretch and recovery properties of
the bandages provide support for the sprained limb. Compression bandages are used
for the treatment and prevention of deep vein thrombosis, leg ulceration, and
varicose veins and are designed to exert a required amount of compression on the leg
when applied at a constant tension. Compression bandages are classified by the
amount of compression they can exert at the ankle and include extra-high, high,
moderate, yarns or warp and weft knitted in both tubular and fully fashioned forms.
Orthopedic cushion bandages are used under plaster casts and compression bandages
to provide padding and prevent discomfort. Nonwoven orthopedic cushion bandages
may be produced from polyurethane foams, polyester, or polypropylene fibers and
contains blends of natural or other synthetic fiber. Nonwoven bandages are lightly
needle-punched to maintain bulk and loft. A development in cushion bandages
materials includes a fully engineered needle punched structure which possesses
superior cushion properties compared with existing materials.
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BANDAGES SAMPLES
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Implantable Medical Textiles
These materials are used in internal body parts for repairing or healing internal wound
like stitching the wound part during surgery. The common examples of such type of
material are sutures, vascular grafts, artificial joints, etc. sutures are located after a
surgical operation has been performed so as to hold the basic structural elements in
their required sites. These provide the necessary strength and the usually retained for
a period of one to two weeks. They are both natural as well as synthetic ones. A
suture should have the properties, like good tensile strength, easy handling, good
knotting security and minimal reaction with the body area in contact. Two types of
sutures are presently available. They are the assimilated type such as catgut and the
non assimilated type such as silk or polyester filament. Catgut, the most used
assimilated type and the oldest one is made from collagen, extracted from Ox bones.
Silk is another natural material, which is used due to its biocompatibility. Now days
synthetic polymers area also used as suture material.
Polygly colic acid is used to make the multifilament or blended type of suture. It is
normally coated with a plasticizer. Currently, it is used for heart surgery in order to
withstand the high pressure within the heart. The most popularly used suture is poly
butyleneterephthalate because of its acceptable strength and smooth surface.
Recently a bi-directional barbed suture has been developed which obviates the
necessity to tie a knot. It has ability to put tension in tissue distortion. The barbed
suture with slippage in wound, as well as to more evenly distributes the holding forces
there by reducing tissue distortion. The barbed suture with a steeper cutangle and a
median cut depth have a higher tissue holding capacity than those with a moderate
cutangle and a nominal cut depth. Transplantation is not always possible due to some
reasons like availability, performance requirements, etc. Therefore doctors and
physicians have to go far artificial substitutes. A foreign or synthetic materials or parts
which are used to replace a body parts are referred to as prosthesis. Normally, the
common prosthesis is artificial tendon, corneas and skin patches. Tendon helps in
connecting muscular to bone while ligaments connect bone to bone. The expected
properties of tendon are tensile strength compatibility, porosity and flexibility. Chitin
fiber, a polysaccharide is also used in manufacturing of non-woven fabric and it is used
because of its good Adhesion to human body and its value in stimulating new skin
formation. It is used in area of cosmetic surgery in repairing breast abnormalities as
well as the women who are suffering from breast cancer. With this new development,
it is possible to control size as well as shape various body parts. The category includes
artificial bones implant, bone cement and artificial joints. Fracture of bone sometimes
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May results in implantation of a fixation device currently used are made of metals,
which may damage reinforced plastic. The heart has one –way valves to maintain the
forward flow of blood as it is pumped out of the heart. These valves may be abnormal
at birth, or it may become damaged as a result of damage such as rheumatic fever or
calcification due to aging. In addition, it should be resistant to infection and linkage
around the valve. A property prosthesis valve is developed in this regards and it is
constructed using textile materials and textile process already in use in other textiles
prosthesis. The valve is designed to mimic the human heart valve as closely as
possible. The performance test shows that the vascular action resembles the action of
natural heart valve and large effective opening area. In the case of repair of the
rotator cuff of the shoulder, knitted hoods made out of polyester are now days used
but they are now slowly and steadily changing to wove ones. Graft may be defined as
an artificial veins or arteries which are used to replace segments of natural
cardiovascular system that are blocked or weakened. They are inserted in order to
bypass the blockages and restore the circulation. Fibers used for vascular grafts are
polyester and polytetrafluroethylene in the form of knitted and woven structure and
for heart valve polyester. Fiber is used in the form of knitted and woven structure.
Sutures
Surgical suture is a medical device used to hold body tissues together after an injury or
surgery. Application generally involves using a needle with an attached length of
thread. A number of different shapes, size, and thread materials have been developed
over its millennia of history. Surgeons, physicians, dentists, podiatrists, eye doctors,
registered nurses and other trained nursing personnel, medics, and clinical
pharmacists typically engage to secure the suturing. Surgical knots are used to secure
the sutures.
A. Needles
Eyed or reusable needles are needles with holes called eyes which are supplied
separate from their suture thread. The suture must be threaded on site, as is done
when sewing at home the advantage of this is that any thread and thread and needle
combination is possible to suit the job at hand. Swaged or atraumatic, needles with
sutures comprise a pre-packed eyeless needle attached to a specific length of suture
thread. The suture manufacturer swages the suture thread to the eyeless atraumatic
needle at the factory. The chief advantage of this is that the doctor or the nurse does
not have to spend time threading the suture on the needle, which may be difficult for
very fine needles and sutures. Also, the suture end of a swaged needle is narrower
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than the needle body, eliminating drag from the thread attachment site. In eyed
needles body on both sides, and at best causes drag. When passing through friable
tissue, the eye needle and suture combination may thus traumatize tissue more than
a swaged needle, hence the designation of the latter as “atraumatic”.
There are several shapes of surgical needles. These include:
 Straight
 1/4 circle
 3/8 circle
 1/2 circle. Subtypes of this needle shape include, from larger to smaller size, CT, CT-
1, CT-2, and CT-3.
 5/8 circle
 Compound curve
 Half curved (also known as ski)
 Half curved at both ends of a straight segment (also known as canoe)
The ski and canoe needle design allows curved needles to be straight enough to be
used in laparoscopic surgery, where instruments are inserted into the abdominal
cavity through narrow cannulas.
Needles may also be classified by their point geometry; examples include:
 Taper (needle body is round and tapers smoothly to point)
 Cutting ( needle body is triangular and has a sharpened cutting edge on inside curve)
 Reverse cutting ( cutting edge on the outside)
 Trocar point or taper cut (needle body is round and tapered, but ends in small
triangular cutting point)
 Blunt points for sewing friable tissues
 Side cutting or spatula points (flat on top and bottom with a cutting edge along the
front to one side) for eye surgery
Finally, atraumatic needles may be permanently swaged to the suture or may be
designed to come off the suture with a sharp straight tug. These “pop-offs” are
commonly used for interrupted sutures, where each suture is only passed once and
then tied.
Eyed surgical needles which are semicircular, in different sizes. Sutures can withstand
different amounts of force based on their size; this is quantified by the U.S.P. Needle
Pull Specifications
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B. Thread
Micrograph of a H&E stained tissue section showing a non-absorbable multi-filament
surgical suture with a surrounding foreign-body giant cell reaction
Further information: suture materials comparison chart
Suture thread is made from numerous materials. The original sutures were made from
biological materials, such as catgut suture and silk. Most modern sutures are
synthetic, including the absorbable polyglycolic acid, Polylactic acid, monocycle and
polydioxanone as well as the non-absorbable nylon, polyester, PVDF and
polypropylene. The FDA first approved triclosancoated suture in 2002; they have been
shown to reduce the chances of wound infection. Sutures come in very specific sizes
and may be either absorbable (naturally biodegradable in the body) or non-
absorbable. Suture must be strong enough to hold tissue securely but flexible enough
to be knotted. They must be hypoallergenic and avoid the “wick effect” that would
allow fluids and thus infection to penetrate the body along the suture tract.
Soft Tissue Implants
The strength and flexibility characteristics of textile material make them particularly
suitable for soft-tissue implants. A number of surgical applications utilize these
characteristics for the replacement of tendons, ligaments, and cartilage in both
reconstructive and corrective surgery. Artificial tendons are woven or braided porous
meshes or tapes surrounded by a silicon sheath. During implantation the natural
tendon can be looped through the artificial tendon and then sutured to itself in order
to connect the muscle to the bone. Textile materials used to replace damaged knee
ligaments (anterior cruciate ligaments) should not only posses’ bio-compatibility
properties but must also have the physical characteristics needed for such a
demanding application. Braided polyester artificial ligaments are strong and exhibit
resistance to creep from cyclic loads. Braided composite materials containing carbon
and polyester filaments have also been found to be particularly suitable for knee
ligaments replacement. There are two types of cartilage found within the body, each
performing different tasks. Hyaline cartilage is hard and dense and found where
rigidity is needed; in contrast, elastic cartilage is more flexible and provides protective
cushioning. Low density polyethylene is used to replace facial, nose, ear, and throat,
cartilage; the material is particularly suitable for this application because it resembles
natural cartilage in many ways. Carbon fiber reinforced composite structures are used
to resurface the defective areas of particular cartilage within synovial joints as a result
of osteoarthritis.
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Anterior Cruciate Ligament Prostheses
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Orthopedic Implants
Orthopedic implants are those materials that are used for hard tissue applications to
replace bones and joints. Also included in this category are fixation plates that are
implanted to stabilize fractured bones. Fiber-reinforced composite materials may be
designed with the required high structural strength and biocompatibility properties
needed for these applications and are now replacing metals implants for artificial
joints and bones. To promote tissue in growth around the implant a non-woven mat
made from graphite and PTFF (e.g. Teflon) is used, which acts as an interface between
the implant and the adjacent hard and soft tissue. Composite structures composed of
poly (D, L-lactide urethane) and reinforced with polyglycolic acid have excellent
physical properties. The composite can be formed into shape during surgery at a
temperature of 60 C and is used for both hard and soft tissue applications. Braided
surgical cables composed of steel filaments ranging from 13-130um are used to
stabilize fractured bones or to secure orthopedic implants to the skeleton.
Cardiovascular Implants
Vascular grafts are used in surgery to replace damaged thick arteries or veins 6mm,
mm, or 1cm in diameter. Commercially available vascular grafts are produced from
polyester or PTFF with either woven or knitted structures. Straight or branched grafts
are possible by using either weft or warp knitting technology. Polyester vascular grafts
can be heat set into a crimped configuration that improves the handling characteristic.
During implantation the surgeon can bend and adjust the length of grafts, which,
owing to the crimp, allows the graft to retain its circular cross-section. Knitted vascular
grafts have a porous structure which allows the graft to become encapsulated with
new tissue but the porosity can be disadvantageous since blood leakage can occur
through the interstices directly after implantation. This effect can be reduces by using
woven grafts but the lower porosity of these grafts hinders tissue in growth; in
addition, woven grafts are also generally stiffer than the knitted equivalents.
In an attempt to reduce the risk of hemorrhage, knitted grafts have been developed
with internal and external velour surfaces in order to fill the interstices of the graft.
Another method is to seal or preclot the grafts with the patient’s blood during
implantation. This is a time-consuming process and its effectiveness dependent upon
the patient’s blood chemistry and the skill of the surgeon. Resealed grafts have zero
porosity when implanted but become porous allowing tissue ingrowths to occur. The
graft is impregnated with either collagen or gelatin that, after a period of 14 days,
degrades to allow tissue encapsulation. Artificial blood vessels with an inner diameter
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of 1.5 mm have been developed using porous PTFF tubes. The tube consists of an
inner layer of collagen and heparin to prevent blood clot formation and an outer
biocompatible layer of collagen with the tube itself providing strength. Artificial heart
valves, which are caged ball valves with metal struts, are covered with polyester
fabrics in order to provide a means of suturing the valve to the surrounding tissue.
Vascular Prosthesis
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Other Implants
Evolution of cochlear implant technology resulted in enhanced hearing, speech and
cost-effectiveness for children. Binaural cochlear implantation has been used in
children. Developed of perimodiolar electrodes, implantable microphones and
rechargeable batteries promise fully implanted devices in future.
Intraocular sustained drug release using implantable devices has been investigated to
treat vitreoretinal diseases. Possible targeted diseases include those in which
repeated intraocular injections are effective (cytomegalovirus retinitis, uveitis),
diseases requiring surgery (proliferative vitreoretinopathy) and chronic diseases
(macular oedema, retinitis pimentos). Hydrophobic or hydrophilic polymers shaped
into sheet, disc, rod, plug or a larger device can be implanted into the subretinal
space, intrasacleral space, vitreous space or peribulbar space or at the pars plane.
Solid biocompatible implantable devices for sustained or controlled intravitreal drug
delivery to the posterior segment of the eye have been developed employing diverse
approaches and include osmotic mini-pumps, nonbioerodible and bioerodible drug-
loaded pellets, configured capillary fibers, biodegradable sclera plugs, sclera discs,
polymeric matrices and scaffolds of various geometries providing unique mechanisms
of drug release for the delivery of drugs to the posterior segment of the eye.
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Extracorporeal Medical Textiles
Extracorporeal devices are mechanical organs that are used for blood purification and
include the artificial kidney (dialyser), the artificial liver, and the mechanical lung
(blood oxygenator). Blood purification is an effective therapy for incurables such as
end-stage renal failure. It is used to correct the abnormality of blood quality and
quality is treating sickness. Use of an artificial organ is a life saving treatment which
can restore the spring that does not function, and a dynamic balance can be obtained
by organ transplantation to recover health again. The function and performance of
extracorporeal devices benefit from fiber and textile technology.
Principles of Blood Purification
Principles of blood purification therapies are dialysis, filtration and adsorption.
Separation membranes and adsorbents are used in blood purification devices. The
membrane separation depends on membrane pore size. Purification methods are
hemodialysis (dialysis, membrane pore size 1-8 nm), hemofiltration (filtration,
membrane pore size pore size 3-60 nm), plasma exchange (filtration, porous
membrane pore size 02-0.6 micrometer) and hemoadsorption. Hemodialysis accounts
for more than 90% of the blood purification treatment in the world which corresponds
to 30 million treatments per year keeping 3,00,000 patients alive. Hemodialysis
includes removal of metabolic substances, adjustment of electrolytes and Ph, removal
of excess water by ultra filtration and, dialysis which is usually a membrane separation
process. During the process, blood contact with dialysate through a membrane.
Ultrafine membrane with blood on one side and dialysis fluid on the order, the urea
molecular which are much more smaller than blood plasma get separated from blood
by using ultra filtration.
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Textiles Materials for Extracorporeal Devices
Extracorporeal fibers are those used in mechanical organs such as hemodialysis
(artificial kidney), artificial live and mechanical lung. Fiber material design by copying
fibers within the living body is very important in order to protect human health in an
ever ageing society. Varieties of artificial internal organs are used as shown. The human
body is larger user of fiber material such as artificial kidney and artificial blood vessels.
Of course, the human body is itself a fiber manufacturer and produces various kinds of
fiber to protect our health. The communication between nano-fibres in a cell(DNA) and
nano-fibres in clothes will be possible by the middle of the century.
A good example is the artificial kidney used for hemodialysis. Historically regenerated
cellulose fibers in the form of cellophane have been utilized to retain waste products
from blood. Japan is the world leader in fiber technology to make ‘Hollow fiber’ for the
artificial kidney. Over the past 20 years, cellulosic membranes have improved
considerably due to the ability form: (1) Thinner membranes. (2) Controlled pore size
(3) Improvement of surface properties. These are now the basis of the production of a
range of artificial kidneys for treatment of chronic renal failure, and for this purpose
the membranes are made from cuprammonium solution and saponified cellulose
triacetate.
Artificial Kidney
The kidneys serve as filtering devices of the blood. The nephrons, the working units of
the kidney, filter waste materials out of the blood and produce urine to secrete toxins
from body. The kidneys also maintain normal concentrations of body fluids, which play
a key role in homeostasis. In the natural kidney, ultra filtration of the blood occurs
through the glomerular capillaries leading to the removal of waste products and the
purification of blood. In an artificial unit a membrane dependent ultra filtration
achieves essentially the same result. Hemodialysis is indispensable for people
suffering from kidney disease.
The function of the artificial kidney is achieved by circulating the blood through a
membrane, which may be either a flat sheet or a bundle of hollow regenerated
cellulose fibers in the form of cellophane that retain the unwanted waste materials.
Multilayer fibers composed of numerous layers of needle-punched fabrics with varying
densities may also be used and are designed to remove the waste materials rapidly
and efficiently. The synthetic polymer substitute being experimented with is a
polyethylene glycol-polyethylene terephthalate block copolymer membrane which can
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selectively filter. The material used in dialysis membranes are regenerated cellulose,
cellulose triacetate, acrylonitrile copolymer, poly (methyl methacrylate), ethylene-
vinyl alcohol copolymer, polusulfone and polyamide which can be grouped as cellulose
and synthetic polymer systems. Eighty per cent of the dialyzers use cellulose materials
which have excellent permeability for low molecular substances. Pore sizes of
membranes vary between 1-3 nm for conventional membranes and 4-8 nm for large
pore membranes.
The development of artificial kidneys depends on the development of hollow fiber
membrane. Polymer can be spun into hollow fiber membrane as shown. Artificial
dialysis is accepted as reliable. The purpose of the development of artificial kidney
dialysis membrane is to mimic the ability of kidney to completely remove wastes like
urea and albumin. One of the side effects of long-term dialysis is a shoulder injury
caused by β2-microalbumin accumulating so that the joint cannot move. Big pores are
effective in removing waste.
However, other necessary components are also removed. The problem can be solved
by making a monomolecular layer fiber, which is controlled by the relation of surface
structure to waste blood. There remain problems to be solved in controlling of
material and holes on the surface of hollow fiber. To improve dialysis membrane
development, it is necessary to make fiber more identical to the organ itself. At
present, heparin is used to prevent clotting of blood. If the patient who undergoes
dialysis is a diabetic, the amount of heparin used must be decreased. Therefore,
biocompatibility of the material needs to be achieved.
An external artificial kidney, a hemodialysis, is used which can perform many of the
functions of a kidney. It is attached to the blood circulation via, an artery and a vein.
Since the dialyser is a foreign substance to the human body, when the blood is
circulated through the dialyser, the leucocytes count in the blood decreases over the
first 20 minutes of dialysis, but recovers to its original value after 1 hour. It is made up
from a bundle of hollow fibers through which the blood circulates. The objective is to
improve the surface of hollow fibers so that the leucocytes decrease does not occur.
Kidney troubles, it is believed, can be caused by proteins of molecular weight in
between 10,000 to 30,000. The blood also contains substances that must be retained,
such as albumin with molecular weight of about 70,000. Each hollow fiber
manufacturing is now developing a suitable membrane, through which the harmful
proteins of molecular weight around 20,000 pass but not the proteins of the molecular
weight around 70,000. These could have much practical benefits.
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Artificial Kidney Manufacturing Medical Textile
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Mechanical lung
Mechanical lungs use micro porous membranes that provide high permeability for
gases (both O2 and CO2) but low permeability for liquid flow and functions in the
same manner as the natural lung allowing oxygen to come into contact with the
patient’s blood. During the flow, oxygen, which is maintained at a high partial
pressure, displaces carbon dioxide, thus effecting purification. In this devices, oxygen
flows around hollow fibers at extremely low pressure. Blood flow inside of the fiber.
The oxygen permeates the micro pores of the fiber and comes in contact with the
blood. The pressure gradient between the blood and oxygen is kept near zero to
prevent mixing of oxygen and blood. Red blood cells capture oxygen by diffusion
process.
The mechanical lung was first developed as a device to replace lung function during
heart surgery, and is now extensively used for this purpose in the USA (about 250,000
per year) and Japan (20,000 per year). A never form of artificial lung can also be used
as a supplementary respiratory device over a longer term to assist the breathing of
patients suffering from acute lung or heart failure, or older people with weak lung
function. Silicone or polypropylene hollow fibers are used for the fabrication of the
mechanical lung to allow permeation of gases. It ideally should function for at least 1
to 3 weeks. But the present mechanical lungs can function only for a week, because,
its ability to remove carbon dioxide falls off. The lung is a form of gas exchange to
supply oxygen to blood and remove carbon dioxide. The best membrane material
available and in extensive use is silicone, which not only has a high permeability to
gases and low permeability to water but can also be autoclaved.
Mitsubishi Rayon Co (Japan) has developed micro porous polypropylene hollow fiber
for the manufacture of an artificial lung, and is currently supplying the fiber to medical
device manufactures. Here gases freely pass hydrophobicity of PP membrane. As a
result, the artificial lung of the gas bubble type is rapidly being replaced with the
membrane type. PP hollow fiber exhibits good compatibility with blood and excellent
gas permeability. Its use allows the design of a compact artificial lung that is easy and
safe to operate. However, its long-term use cause a leak of blood plasma components,
and an investigation is underway to improve the membrane material in order to
eliminate this disadvantage. The progress in developing an artificial lung has been slow
due to difficulties in engineering problems and limitation of required materials.
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Artificial lung manufacturing medical textile
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Artificial liver
The artificial liver utilizes hollow fibers or membranes similar to those used for the
artificial kidney to perform their function. Organ cells are placed around the fibers and
blood flows inside the fiber. Blood nutrients pass through the fiber wall to the oxygen
cells and enzymes pass from the cells to the blood. The metabolism of the liver is very
complicated which poses problems for the artificial liver. This can be solved by using
double lumen structure with a hollow fiber within hollow fiber. Blood runs outside and
in contact with liver cells and blood, and after purification it runs inside the fiber.
The liver is a remarkable organ; like the skin, it can regenerate after severe trauma. In
fact, a patient can recover with only 20% of his or her liver still functional, as the liver
grows back. However, there is a point of ‘No return’ after which the liver cannot
regenerate, and there are underlying disease conditions that, in some cases, make a
transplant the only alternative. Unlike the heart, lung or kidneys, which have one
primary function, the liver has multiple functions essential to maintain life including
carbohydrate metabolism, synthesis of proteins, amino acid metabolism, urea
synthesis, liquid metabolism, drug biotransformation and waste removal. Therefore the
preferred artificial liver support system would perform these various liver functions.
Hepatocytes carry out many vital biological functions, such as synthesis and catabolic
reactions, detoxification and excretion. Due to their ability to restore a tissue- like
environment, hollow fiber bioreactors show great potential among different system
used to culture hepatocytes. Currently the major use of Hepatocyte Hollow Fiber
Bioreactors is as bio artificial livers to sustain patients suffering from acute liver failure,
but they can also be used to synthesize cell products and as cellular models for drug
metabolism and transport studies.
The artificial liver utilizes the functions of separating, disposing & supply of fresh
plasma in hollow viscose fibers or membranes similar to those used for artificial kidney
to perform their function. In the case of extracorporeal devices, cells are grown to
confluence in devices resembling dialysis cartridges, and then inserted into a ‘Circuit’
outside the patient’s body, where blood from the patient flows through the cartridge
the cells, and then back into patient. Extracorporeal liver assist device (ELAD) or bio
artificial liver (BAL). The principal goal of the ELAD is to circulate a patient’s plasma
extracorporeal through a bioreactor that contains metabolically active hepatocytes.
Such devices are expected to increase life of patient, improve the care and quality of
life of patients, and improve the care and quality of life of patients and to reduce care
costs. ELAD cartridge is hollow fiber dialysis cartridge that contains a semi-permeable
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membrane with a low molecular weight cut-off. This allows for the physical separation
of cells from certain, but not all, components found in the patient’s blood, as well as
permitting the cells to secrete vital molecules back into the patient. Membranes used
in BAL: Cellulose acetate, cuprophan, Homophone, Polyamide, Polypropylene,
Polusulfone.
Artificial liver manufacturing medical textile
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Healthcare and Hygiene Material
Healthcare and hygiene products are an important sector in the field of medicine and
surgery. The range of products available is vast but typically they are used either in the
operating theatre or on the hospital ward for the hygiene, care, and safety of staff and
patients. The range of products used in this category and includes the fiber materials
used and the method of manufacture.
Textile materials used in the operating theatre include surgeon’s gowns, caps and
masks, patient drapes, and cover cloths of various sizes. It is essential that the
environment of the operating theater is clean and a strict control of infection is
maintained. A possible source of infection to the patient is the pollutant particles shed
by the nursing staff, which carries bacteria. Surgical gowns should act as a barrier to
prevent the release of pollutant particles into the air. Traditionally, surgical gowns are
woven cotton goods that not only allow the release of particles from the surgeon but
are also a source of contamination generating high levels of dust. Disposable nonwoven
surgical gowns have been adopted to prevent these sources of contamination to the
patient and do often composite materials comprise non-woven and polyethylene films
for example.
The need for a reusable surgical gown that meets the necessary criteria has resulted in
the application of fabric technology adopted for clean room environments, particularly
those used for semiconductor manufacture. Surgical masks consist of a very fine middle
layer of extra fine glass fibers or synthetic microfibers covered on both sides by either
an acrylic bonded parallel-laid or wet-laid non-woven. The application requirements of
such masks demand that they have a high filter capacity, high level of air permeability,
are lightweight and non-allergenic. Disposable surgical caps are usually parallel-laid or
spun-laid nonwoven materials based on cellulosic fibers. Operating room disposable
products and clothing are increasingly being produced from hydro entangled
nonwovens. Surgical drapes and cover cloths are used in the operating theatre either
to cover the patients (drapes) or to cover working areas around the patient (cover
cloths).
Nonwoven materials are used extensively for drapes and cover cloths and are
composed of films backed on either one or both sides with nonwoven fabrics. The film
is completely impermeable to bacteria while the nonwoven backing is highly absorbent
to both body perspiration and secretions from the wound. Hydrophobic finishes may
also be applied to the material in order to achieve the required bacteria barrier
characteristics. Development in surgical drapes has led to the use of loop-raised warp-
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knitted polyester fabrics that are laminated back to back and contain micro porous
PTFE films in the middle for permeability, comfort and resistance to microbiological
contaminants.
The second category of textiles materials used for healthcare and hygiene products are
those commonly used on hospital wards for the care and hygiene of the patient and
includes bedding, clothing, mattress covers, incontinence products, cloths and wipes.
Traditional woolen blankets have been replaced with cotton leno woven blankets to
reduce the risk of cross-infection and are made from soft-spum twofold yarns which
posses the desirable thermal qualities, are durable and can be easily washed and
sterilized. Clothing products, which include articles worn by both nursing staff and
patients, have no specific requirements other than comfort and durability and are
therefore made from conventional fabrics. In isolation wards and intensive care units,
disposable protective clothing is worn to minimize cross infection. These articles are
made from composite fabrics that consist of tissue reinforced with a polyester or
polypropylene spun-laid web.
Incontinence products for the patient are available in both diaper and flat sheet forms
with the latter used as bedding the disposable diaper is a composite article consisting
of an inner covering layer (coverstock), an absorbent layer, and an outer layer the inner
covering layer is either a longitudinally orientated polyester web treated with a
hydrophilic finish, or a spun-laid polypropylene nonwoven material a number of weft
and warp knitted pile or fleece fabrics composed of polyester are also used as part of a
composite material which includes foam as well as PVC sheets for use as incontinence
mats cloths and wipes are made from tissue paper or nonwoven bonded fabrics, which
may be soaked with an antiseptic finish. The cloth or wipe may be used to clean
wounds or the skin prior to wound dressing application, or to treat rashes or burns.
Surgical hosiery with graduated compression characteristics is used for a number of
purposes, ranging from a light support for the limb, to the treatments of venous
disorders. Knee and elbow caps, which are normally shaped during knitting on circular
machinces and may also contain elastomeric threads, are worn for support and
compression during physically active sports, or for protection.
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Healthcare/Hygiene Products
Surgical Garments
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Fibers Used In Manufacturing
Commodity Fibers
Fibers used in medicine and surgery may be classified depending on whether the
materials from which they are made are natural or synthetic, biodegradable or non-
biodegradable. All fibers used in medical applications must be Non-toxic, Non-
allergenic, non-carcinogenic, and be able to be sterilized without imparting any change
in the physical or chemical characteristics.
Commonly used natural fibers are cotton and silk but also included are the regenerated
cellulosic fibers (Viscose rayon); used in non-implantable materials and
healthcare/hygiene products. A wide variety of products and specific applications
utilize the unique characteristics that synthetic fibers exhibit. Commonly used synthetic
materials include polyester, polyamide, and polytetrafluroethylene (PTFE),
polypropylene, carbon, glass, and so on.
The second classification relates to the extent of fiber biodegradability. Biodegradable
fibers are those which are absorbed by the body within 2-3 months after implantation
and include Cotton, Viscose rayon, Polyamide, Polyurethane, Collagen, and Alginate.
Fibers that are slowly absorbed within the body and take more than 6 months to
degrade are considered non-biodegradable and include Polyester, Polypropylene, PTFE
and Carbon.
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Speciality Fibers
A variety of natural polymers such as Collagen, Alginate, Chitin and Chitosan have been
found to be essential materials for modern wound dressings.
Collagen, which is obtained from bovine skin, is a protein available either in fiber or
hydrogel (gelatin) form. Collagen fibers, used as sutures, are as strong as silk and are
biodegradable. The transparent hydrogel that is formed when collagen is cross linked in
5-10% aqueous solutions, has high oxygen permeability and can be processed into soft
contact lenses.
Calcium alginate fibers are produced form seaweed. The fibers posses healing
properties, which have proved to be effective in the treatment of a wide variety of
wounds. Dressings comprising calcium alginate are non-toxic, biodegradable and
haemo-static.
Chitin which is obtained from crab and shrimp shells, has excellent anti thrombogenic
characteristics, and can be absorbed by the body and promote healing. Chitin
nonwoven fabrics used as artificial skin adhere to the body stimulating new skin
formation which accelerates the healing rate and reduces pain.
Treatment of chitin with alkali yields chitosan that can be spun into filaments of similar
strength to viscose rayon. Chitosan is now being developed for slow drug-release
membranes.
Other fibers that have been developed include poly-capro-lactone (PCL) and poly-
propio-lactone (PPL), which can be mixed with cellulosic fibers to produce highly
flexible and inexpensive biodegradable nonwovens.
Melt spun fibers made from Lactic acid have similar strength and heat properties as
Nylon and are also biodegradable.
Microbiocidal compositions that inhibit the growth of micro-organisms can be applied
on to natural fibers as coating or incorporated directly into artificial fibers.
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Applications of Textiles in Medical Field
1. Repair or replacement of injured tissue
 Prostheses of bone, joint or tooth
 Artificial: heart value, blood vessel or skin
 Contact lens
2. Assist/ temporary substitution for psychological functions of a failed organ
 Artificial heart/lung/kidney/liver or pancreas
3. Disposable article in a daily medical treatment
 Tubing, syringe, suture, catheters tube inserted into a body cavity to remove
fluid etc.
4. Navel drug delivery system
 Devices for controlled release of drugs, plastic release devices
5. Clinical lab tests
 Tool with quick response, high accuracy, high sensitivity for tests
6. Separation of blood components
 Plasma separation, cell separation, removal of virus and bacteria.
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CHARACTERISTICS OF MATERIAL FOR MEDICAL USE
1. Non toxicity, non-allergic response
2. Ability to be sterilized
3. Mechanical properties – strength, elasticity, durability
4. Biocompatibility – Toxic materials which cause temperature rise, inflammation,
allergic reaction, deformity etc. are not preferred
5. Diffusion properties – drug delivery system, members in artificial kidneys
6. Optical properties – contact lens materials
7. Polyurethanes – widely used in hemodialysis sets, blood bags, heart assist devices
and pacemaker. Example – biomer: high tensile strength and artificial heart pumps.
8. Silicon rubber polymer – internal applications, thermal stability, flexibility and
elasticity, plastic and reconstructive surgery, replacement of cartilage or bone.
9. PMMA (Poly Methyl Meth Acrylate) – bone cement, dentures, repair of cranial
defects, jaw correction, spinal fixations.
10. Textile materials used – fibers, yarns (mono-filament and multi-filament), fabrics
(woven, knit, non-woven), and composites.
11. Major requirements - absorbency, tenacity, flexibility, softness, biodegradability. It
may be natural/synthetic.
12. Biodegradable/Non-biodegradable.
13. Most common natural material for Medical textiles is Cotton and Silk.
14. Artificial materials are: Carbon, glass, PTFE, polyamide, polyester, and
polypropylene.
15. Collagen fibers – speciality fiber, biodegradable material obtained from bovine skin,
used as suture, strong as silk.
16. Calcium alginates fiber – seaweed, wound healing, nontoxic, biodegradable.
17. Chitin – insect skin, fibers absorbed by the body, good healing, artificial skin.
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CONCLUSION
Textile materials are very important in all aspects of medicine and surgery
and the range and extent of applications to which these materials are used is
a reflection of their enormous versatility. Products utilized for medical or
surgical applications may at first sight seem to be either extremely simple
items. In reality, however, in-depth research is required to engineer a textile
for even the simplest cleaning wipe in order to meet the stringent
performance specifications.
New developments continue to exploit the range of fibres and fabric-
forming techniques which are available. Advances in fibre science have
resulted in a new breed of wound dressing which contribute to the healing
process. Advanced composite materials containing combinations of fibres
and fabrics have been developed for applications where biocompatibility
and strength are required. It is predicted that composite materials will
continue to have a greater impact in this sector owing to the large number
of characteristics and performance criteria required from these materials.
Non-wovens are utilised in every area of medical and surgical textiles.
Shorter production cycles, higher flexibility and versatility, and lower
production costs are some of the reasons for the popularity of nonwovens in
medical textiles.
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REFERENCE
1. Gopalakrishnan D. & Aswini R. Non-wovens for Medical Textiles. Retrieved
from : http://www.fibre2fashion.com/industry-article/pdffiles/Nonwovens-For-
Medical-Textiles.pdf
2. Ramkumar P. SITRA working to develop better Technical Textile
products. 22 January, 2016. Retrieved from :
http://timesofindia.indiatimes.com/business/india-business/SITRA-
working-with-Isro-DRDO-to-develop-better-technical-textile-
products/articleshow/50686676.cms
3. Kiron M. Introduction of Medical Textiles. Retrieved from :
http://textilelearner.blogspot.in/2012/02/introduction-of-medical-
textiles.html
4. An analysis of Medical Textiles. Retrieved from :
http://www.technicaltextile.net/articles/medical-
textiles/detail.aspx?article_id=3035
5. Annapoorani S. Recent Developments in Medical Textiles. Volume 2.
Issue 12. Page Nos. 255 to 258. December 2013. Retrieved from :
http://www.worldwidejournals.com/gra/file.php?val=December_2013_13
87276370_75066_84.pdf
6. Horrocks A. & Anand S. Handbook of Technical Textiles. Woodhead
Publishing Limited. Page Nos. 407 to 420. Retrieved from :
https://books.google.co.in/books?hl=en&lr=&id=JBGkAgAAQBAJ&oi=fnd&
pg=PR1&dq=medical+textiles&ots=v28LAQgYmP&sig=GNHx3wTieji6bkDgC
XEOnD-srD4#v=onepage&q=medical%20textiles&f=false
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Medical Textiles Project Report