AUTOMOTIVE TEXTILE
Abstract:-
Textile industry began with the need
of protecting human being from the changing climatic conditions. Man first
covered his body with leaves, plant fibers till he discovered the fabrics.
Textiles are now an essential part of every body’s life, to provide for fashion
requirement and comforts rather than just to cover the skin. Textiles are
mainly applied in three fields they are
• Apparel uses
• Home textiles and
• Technical textiles
Among which technical textiles are
an expanding area of textile industries. New yarn and fiber development is one
of the driving forces of the modern technical textile industry. The 1980s was a
particular period, which saw the commercial introduction of a wide range of new
materials, with liberalization and globalization as the slogan written on the
wall... Technical textiles are the textile applications in medical, civil
engineering and automotive fields. Technical textiles are gaining fast
recognition to be one of the most dynamic and promising areas for the future of
the textile industry in India for hi performance applications. Automotive
textiles happens to be the rewarding sector finding extensive use of technical
textiles in the product categories viz. interior trims, safety devices like
seat belts and airbags, carpets, filters, battery separators, hood liners,
hoses & belt reinforcement. The potential for the growth of automotive
textile business may be gauged from the explosive expansion projected for car
production, with Asia- Pacific as the growth
driver.
AUTOMOTIVE TEXTILE
Technical textile:
Textile materials and products
manufactured primarily for their technical performance and functional
properties rather than their aesthetic or decorative characteristics.
Automotive textile:
Textiles, which constitute
approximately 20-25 Kgs. (Approximately 80-90 square yard) in a car, are not
only used for enhanced aesthetic of automotives but also for sensual comfort
& safety. Additionally, few textile products found their applications as
design solutions to engineering problems in the form of composites, tyre
reinforcement, sound insulation & vibration control. Apart from woven &
knitted constructions, Nonwovens also find applications in transport textiles
due to certain advantages served by them.
Table 1 shows various applications
of textile fiber and their share in kgs. in average car.
|
Application area
|
% share
|
|
Carpet (
Including car mats)
|
33.3
|
|
Upholstery(seating
fabric)
|
18.0
|
|
Preassembled
interior component
|
14.0
|
|
Tire
|
12.8
|
|
Safety
belt
|
8.8
|
|
Air bag
|
3.7
|
|
Other
|
9.4
|
|
Total
|
100.0
|
The
consumers look for aesthetically pleasing interior, great comfort and fuel
economy. The textile product can satisfy both requirement and these are
constructed to light weight. Textiles offer other are significant weight
reduction which gives fuel economy. Approximately 75% of vehicles fuel
consumption is directly related to weight of vehicles and 25% related to air
drag.
Improvement in std of leaving resulting in greater demand for
personal vehicles. Ecological reforms for recycling of used cars have increased
the amount of textile in an automobile. Apart from safety & interior
textile come to engineering problems such as tire reinforcement, acoustic
protection, and gas and air filtration.
|
Use
|
Main property requirements
|
Fiber used
|
|
Seat
covers
|
Abrasion, UV resistance, Attractive
design & Texture.
|
Nylon, polyester, Wool,
polypropylene.
|
|
Seat belt
|
Tensile Strength, Extension(25%-
30%),abrasion & UV resistance
|
Polyester.
|
|
Carpet
|
Light fastness ,mould ability
|
Nylon,polyester,polypropylene
|
|
Air bag
|
Resistance to high temp inflation gases, durability to
storage over many year, tear
strength
|
Nylon6,6 and Nylon4,6
|
|
Tire cord
|
High strength, less extensibility,
compatibility with rubber
|
Viscose ,rayon,polyester,
Kevlar
|
UPHOLESTRY:-
·
Properties required:
To overcome the two major tribulations of soiling and steam
rupturing. The upholstery ones it fixed in place it must last the life time of
car without being put in a washing machine.
Wear properties-
abrasion and pilling resistance and seam strength.
Functional properties-wet ability, water repellency, oil and stain
resistance and flammability.
·
Manufacturing process:
Textile fabrics and leather have replaced PVC for car seats. However
vinyl is still used with either a polyester/cotton knit or a polyester non
woven substrate as trim on the back and in the skirt of seat. Major Upholstery
fabric structure:
·
flat woven fabric
·
pile woven fabrics
·
Warp knits
·
Circular knits
·
Double needle bar Rachel
Testing:
1)
Abrasion pilling resistance
2)
Seam strength
3)
Water repellency
4)
Oil and stain resistance
5)
Perspiration resistance.
6)
flammability
2) SEAT
BELT:-
Properties required:
Abrasion resistance, UV resistance, heat light resistance, high
tensile strength, light weight flexibility,
Extension (25%-30%) and
carry static load
of 1500 Kg
Testing
: The important testing to
performed are
|
1) Abrasion performance
2) Dynamic test
AIRBAG:
Properties required:
High material strength in warp and weft direction, High
propagation tear strength, Heat stability, good ageing characteristics , energy
absorption, coating adhesion and function at extremities, hot and cold
condition, toughness, fog resistance, package ability, High anti slip properties
of the seams, defined dimensional stability , defined air permeability 101/dm
sq/ min at 500 Pascal, product liability 15 years.
WORKING:
An airbag is an automatic safety restraint system
importance within the last decade. Airbag is built into the steering wheel and
instrument panel. they are not alternative but supplement to seat belts because
air bag provides protection only against head collisions while seat belts
provide protection regardless of crash direction.
Above figure shows, the operation sequence of an airbag. Since
almost all collision occur within
.125 second, the airbag is designed to inflate
in less than .04 second or 40 milliseconds. In
a collision, the air bag begins to fill within .03 second; the airbag is
fully inflated and cushions the occupant from impact. The airbag then deflates
.12
sec. and after absorbing the forward force. The entire event, from
initial impart to fully development, takes about 55 milliseconds-about half the
time to blink an eye.
Data shows that more than half of all serve injuries and death in
automotive accidents are the result
of frontal collisions.
TESTING:
1) Accelerated Ageing
2) Performance of airbag fabric
3) Physical properties of fabrics
4) Visual inspection and Grading
4)CARPET:-
Properties
required:
Light fastness, mouldability, and soil and abrasion resistance.
Manufacturing
process:
The carpets used in car are mainly three types
1) Tufted carpet
2) Tufted loop pile
3) Needle felt
The use of these types varies from country to country.
Testing:
1) Light fastness
2) Mouldability
3) Resistance for soil and abrasion resistance
5) TIRE:-
Properties required:
High strength, less extensibility, Capability with
rubber
Filter:-
Properties
required: to balance filtration
performance with desired cleanliness level & this level is depends on
filter efficiency of particle removal, contamination capacity or pressure drop
or resistance to flow through filter. Proper function of filter fabric is very important.
Material of filter: the
filter media ranges from mesh screen to depth side media such as threads or
chopped paper to 100% natural cellulose to 100% man made fiber or concessive
combination.
7) Head liner:-
One time the headliner was simply a covering for the metal roof
inside the car and consisted of a piece of fabric, PVC or same other material
sometimes simply slung. i.e. held in place only at a few points. Some important
requirements of headliners are light weight, thin profile but rigid without any
tendency to buckle, flex or vibrates, good dimensional stability, aesthetically
pleasing and preferably with a soft touch.
The modern headliner is a multiple laminate of up to
seven or more components all joined together. Each layer is there or a specific
purpose either for aesthetics, to provides sound insulation, vibration clamping
or to provide rigidity to the whole structure. The central layer is generally a
layer of semi- rigid
Attached to the
side facing inwards is the decorative material, a non-woven polyester scrim is
usually attached to the other side. All layers are joined together by action of
the hot-melt adhesives in a flat-bed laminator, taking care neither to damage
the aesthetics of the decorative material nor to reduce the thickness of the
centre core.
7) Noise Control:-
Sound is propagated through the air and by vibration of the car body
and there are three basic mechanisms for reducing it, by absorption, by
clamping and thirdly by isolation or insulation. In general thick piece of
material will absorb more sound than a thinner piece of the same material.
There are number of layers of material and permutations of layers of material
used in noise and vibration damping. These layers are,
1. Top decorative layer: - Tufted BCF Nylon or needle punched polyester or
polypropylene- Back, acrylic ladere.
1. Thermoforming layer: - Polyethylene powder, moldable fiber EVA or a further
thick layer of compounded SBR (styrene-butadiene rubbers) later.
2. Caustic layers: - Heavy layers of EPDM, Shoddy fibers or polyurethane
foam. These materials generally have to be fitted in small pieces, which is
time consuming and produces an insulation performance which is interior to that
of a continuous layer. In some vehicles this insulation layer is formed
directly on the back of the pre-formed carpet it self by back injection molding
using polyurethane foam.
CONCLUSION:
-
Textile materials are used in automobiles for interior
trim and for ensuring comfort (e.g. seat covers, carpets, roof liners, and door
liners) as well as for reinforcement (e.g. tire) and filters.
Textiles also
offer weight reduction which in turn results in fuel economy.
Airbags help to save lives, but at times they can also
be a source of serious injury. The search for a uniform smart airbag, which can
perceive the size of the passenger or whether the seat is empty and react in
that manner, is in progress. Such a 'smart' airbag will incorporate sensors to
judge the weight, size and location of the car passengers and hence deploy more
appropriately.
In addition, incorporated safety devices associated with
the seat belt along with other safety items, particularly for child passengers,
are under development. The trend towards uncoated fabrics is anticipated to continue
and so is the improved trend towards more airbags per car and full- size bags.
There is also a technical challenge of producing the bag by using more rational
techniques and related specifications made by the automotive industry.
Reference :-
4.
www.nptel.com
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