Textiles Applications in Automotive Industry

With the rising level of automobile production and itsincapability to be folded into small spaces and
corresponding worldwide stocks based on the rapidinclination of decay over time. Coated fab¬rics
industrialisation in Asia, Africa and Latin America plusare simple to cut and sew and the air porosity can
the rising demand in Eastern Europe, the proportionbe well managed.
of textiles in a motor car is increasing in response toThe drawbacks linked with coated airbags and their
more stringent comfort and safety needs insubsequent substitution with uncoated materials has
industrialised countries like the USA, Japan andwarranted significant developments from two sectors
Western Europe.of the industry. The uncoated airbags can be
Automobile textiles, which are non apparel textiles,recycled in a simple manner. The first development
are widely used in vehicles like cars, trains, buses,has come from the yarn and fabric producers, who
aircrafts and marine vehicles. Hence, the termhave concurrently developed the performance of the
automobile textile means all type of textilefabrics. Their gas permeability has fallen under specific
components e.g. fibers, filaments, yarns and thescrutiny since the way an uncoated fabric discharges
fabric used in automobiles.gas and establishes the capability of an airbag to
Nearly two third of the automobile textiles are forresist impact. The second development has gained
interior trim, i.e. seat cover, carpets and roof andfrom the inflator producers, who have started to
door liners. The rest is utilized to reinforce tyres,substitute the original inflators, which release air, with
hoses, safety belts, air bags, etc.devices that emit air like argon and helium. This is
It is projected that nearly 45 square meters ofgreatly helpful because these gases are equally as
textile material is utilized in a car for interior trimeffective at lower temperatures and discharge less
(seating area, headlines, side panel, carpet and trunk).hot particles.
According to a survey, the percentage of textile in aFinishing procedure of airbag fabrics
motor car amounts to 2 per cent of the overallAfter weaving, the airbag fabric is scouring to reduce
weight of a car. Apart from this, visible textilesize. To gain accurate air permeability, the airbag
components, eliminating hidden components such asfabric can be calendered. Apart from influencing the
in tyres and composites, hoses and filters; amount toair permeability by weaving and finishing, accurate
10-11 kg per vehicle in absolute terms. Industrialpermeability control can be achieved by coating.
textiles are largely utilized in vehicles and systemsWhen the airbag material has been finished, it is sewn
including cars, buses, trains, air crafts and marinetogether; the best practice is by using it with a laser.
vehicles. In automobile textile industry, four types ofAirbags are sewn with Nylon 6, 6, polyester, and
fabrics are used, namely:Kevlar aramid yarns, the sewing patterns and
. Air bag fabricsdensities being selected to maximize performance.
. Fabric used as a basis for reduction in weight ofWhen a bag is sewn it is folded inside its cover.
body partsPacking should permit for tethers connected to the
. Tyre cord fabricsbag to manage operation. Finally, a cover can be set
. Automotive upholstery and other textile fabricsup over the bag to safeguard it from abrasion.
used inside the vehicleAirbag sizes
The airbag and seat belts used as safety measuresAirbags are available in various sizes and
are one of the latest types of textiles in automobilesconfigurations depending on the type of car and
and have a potential market for technical textiles thatsteering. Moreover, the driver's side airbag is smaller
has a considerable scope for growth andthan the front passengers by about 65 liters capacity
development. Because of government legislation andupwards.
consumer interest, the applications have beenSuppliers
extremely successful over the last ten to fifteenIn airbag systems, there are mainly five suppliers of
years.the airbag module itself, representing 32 per cent of
In the last decade, airbags or inflatable restraintsthe value of the airbag system. The key airbag
have received noteworthy significance as acontrol unit has four suppliers representing 24 per
safeguard for the driver and the passengers in casecent of the value, and the seat belt portion of the
of an accident. Initially, the bags were made forsystem has two suppliers with a 31 per cent
head-on collision, but now, there are many othercontribution. Yet, the remaining part with only 13 per
safety devices like side impact bags, knee bolsters,cent of the value of the airbag system has over 40
side curtain, etc, available for safety in any type ofsuppliers.
crash. Because frontal collisions are a main reason ofTwo years back INVISTA, formerly DuPont Textiles
accidental deaths, airbags are being presented as a& Interiors, had expanded nylon 6, 6 fiber
standard product in vehicles by legislation, which hasproduction capacity, totaling 7.5 kilotons (kt.) at two
given the quick increment of airbags business in thefacilities; one in Qing Dao, China, and the second in
last decade. NHTSA and HHS report that airbagGloucester, UK.
systems have played an important role in savingA wide range of highly specialized polyamide 6.6
thousands of lives since 1985. In 2002 alone, due toairbag yarns, Enka Nylon, are made by Polymide High
the airbag system a 20 per cent reduction in fatalitiesPerformance at its Obernburg (Germany) and
resulting from fatal collisions has been observed.Scottsboro (Alabama/USA) plants.
In 1999, there were 55 million vehicles with 81 millionZapata Corporation in December, 2005 announced
airbags. In 2004, the number of frontal airbag unitsthat it completed the sale of all of its 4,162,394
was nearly 100 million and the number of side-impactshares of Safety Components International, Inc. to
airbags nearly 65 million. In the same year, nearly 23private equity investor Wilbur L. Ross, Jr. for nearly
per cent of the new vehicles in North America had$51.2 million. Zapata's stake stands for nearly 77.3 per
side airbags for chest protection and 17 per cent hadcent of Safety Components' total outstanding
side airbags for head protection. By 2005, this hascommon stock. Safety Components is an
increased to 180 million airbags and 65 million vehicles.independent producer of air bags and the company's
Fabric application demand has increased to 325 millionfabrics are largely utilized for automobile safety air
square meters in 2005, and 83 tons of fibre, mostlybags and in niche industrial and commercial
nylon has been used.applications. Safety Components headquartered in
The world airbag market is estimated to rise from 66Greenville, South Carolina, has plants situated in North
million units in 1996 to over 200 million units in 2006, aAmerica, Europe, China and South Africa.
compound annual growth rate of 12 per cent. OverTakata is a manufacturer of automotive seatbelts.
this decade, Europe will put in 60 million units,Takata started researching seatbelt technologies in
Asia-Pacific 30 million units and North America 241952. After eight years of research and development
million units.Takata became the first safety company to offer
While North American and Western Europeanseatbelts as standard equipment to the Japan market
markets are growing, considerable development isin 1960. In the early 1970's, Takata worked with
also seen in the international market. As newNHTSA to satisfy new high speed crash test
applications are developing for airbags, including rearrequirements and supplied the first energy absorbing
seat bags, inflatable seat belts and an outside airbagseat belt system to pass a 30 mph crash test. Irvin
system for pedestrians, new fabrics andAutomotive is another company within the Takata
combinations are being applied. The front andCorporation. Irvin makes armrests, cargo covers,
passenger bags have different requirements becausemolded consoles, seat covers and sun visors.
of the distance from the occupant, but they bothNarricot Industries, LP, located in Southampton,
have rapid increment and deflation in a very shortPennsylvania, is a producer of woven narrow fabrics
time span.in North America. With manufacturing facilities in
Rollover bags must remain inflated for five seconds.Boykins and South Hill, Virginia, Narricot is the number
In addition to new uses, expected trends includeone supplier of seatbelt webbing to the North
lighter fabric for use with newer "cold inflators,"American automotive industry.
blended with materials like fabric and film, newAutoliv is a manufacturer of airbag, seatbelts and
coating polymers (Silicone now dominates havingother automotive safety devices. Autoliv has nearly
replaced neoprene).80 wholly or partially owned manufacturing facilities in
Growth of safety devices in the car interior30 vehicle-producing countries. Autoliv and its joint
Increasing electronics and safety devices requireventures and licensees make over 80 million seat belt
more space in the interior together with newsystems annually.
concepts for arrangement.Toray Industries, Inc, that makes nylon 6, 6 fiber and
Worldwide market for PA airbag yarnstextile for use in automobile air bags, plans to start
The fibre manufacturer Accordis Industrial Fibres BV,manufacturing base fabric for automotive airbags at
Arnhem/ Netherlands reported that the global marketits Czech textile subsidiary in January 2006. The
for PA airbag was 84,000 tons in 2005.company plans to invest in the necessary equipment
Airbagsto its subsidiary Toray Textiles Central Europe. The
Airbags were first introduced in the late 1960s, but itproduction output is projected at 600,000 meters in
is only in the 1990s that their use increased amazingly2006 and 4 million meters in 2010. At present, Toray
and it is set to grow further. This validates themakes the fabric in Japan, Thailand and China mainly
research and development still being made on design,for airbags used in Japanese cars.
deployment and base fabric material.Performance tests and standards
The prospects for the textile and making-upMany individual tests carried out with airbag yarns and
indus¬tries are huge in the area of airbagfabrics is said to number over 50. The ASTM, the
production. This is due to its large requirementSAE and the Automotive Occupant Res¬traint
particularly in view of the legislation, which is alreadyCouncil (AORC) have established various standards
imposed by many countries.that express appropriate tests for airbags.
Around 1.42 meter2 of fabric is required to produceSeat belts
driver¬ side airbags on light trucks. ThisThe seat belt is an energy absorbing device that is
estimation gives the idea that the airbag market is ofdesigned to keep the load imposed on a victim's
great importance for the use of technical textiles.body during a crash down to survivable limits.
Airbags are normally made by coated or uncoatedBasically, it is designed to offer non recoverable
fabrics of PA 6.6 yarns with lesser air permeability.extension to decrease the deceleration forces that
A fabric cushion is included as a part of textilethe body comes across in a crash. Non recoverable
ingredient for an airbag, which is folded into theextension is significant to prevent the occupants
center of the steering wheel (for the driver) or in thefrom being restrained into their seats and sustaining
glove compartment (for the front seat passenger).whiplash injuries right away after a collision. To
Generally, the bag is woven by nylon 6, 6 filamentprevent more webbing from paying out after an
yarns, which are in demand in huge quantitiesaccident, the automatic belt has a locking device
because of their high strength-to-weight ratio,known as inertia reel. An efficient seat belt will only
favorable elongation, adequate thermal properties andpermit its wearer to move forward a maximum of
relatively low cost of production. Other propertiesabout 30 cm to avoid contact with any fixed parts
required are high tear strength, high anti-seamof the car.
slippage, controlled air permeability and be capable forIt is believed that the seat belts were invented
being folded into confined places for over ten yearsconcurrently in America as well as Sweden. The only
without deterioration.difference was that the American belt was a strap
Functionto encircle the waist and the Swedish belt was a
A triggering device sets-off explosive chemicals whendiagonal band made to defend the upper body. Now,
it senses an accident above 35 km/h is about toa blend of the two designs is a most prevalent
occur. These chemicals hold back and cushion the cararrangement and is called the 3-point belt, which is
occupant from collision with harder objects. Thesecured by two fittings on the floor and a third on
fabric from which the bag is made must bethe sidewall or pillar. Racing drivers wear other
competent for withstanding the strength of thepatterns, particularly two shoulder straps and a lap
propellant chemicals. More over, the hot gases mustbelt. The earliest automotive seat belts were set up
not penetrate the fabric and burn the skin of the carand were adjustable so that they could fit the
occupant.wearer manually. The automatic belt superseded this
For airbags to perform their protective function, eachpattern by providing the wearer more space to
function in the system must work with reliability andmove.
predictability. In frontal airbag initiation, the cushionSeat belts are available in multiple layers and are
begins to deploy within 20 ms after collision and iswoven in narrow fabrics in twill or satin fabrication
fully set up in 50 ms. Within this period of time, thefrom high tenacity polyester yarns, generally 320
bag has to spread through the plastic cover, blownends of 1100 dtex or 260 ends of 1670 dtex yarn.
up and fill the space between the dashboard andThese structures permit highest yarn packing within a
occupant.given area for highest strength and the trend is to
Material applicationsutilize coarser yarns for good abrasion resistance. For
Airbags are generally made from high tenacityease they require to be softer and more flexible
multifilament nylon 6, 6 in yarn quality fineness fromalong the length, but rigidity is needed along the
210, 420 to 840 denier, although some polyester andwidth to facilitate them to slide easily between
even some nylon 6 is utilized. As Nylon 6 is softer, itbuckles and retract smoothly into housings. Edges
is used to lessen skin abrasion. Airbag fabric is notrequire being scuff resistant, but not disagreeably
dyed, but has to be scoured to eliminate impurerigid and the fabric must be resistant to
substances, which could encourage mildew or othermicroorganisms. Nylon was utilized in some early seat
problems. Airbags are created in compact size, plainbelts, but due to of its higher UV degradation
woven fabrics.resistance; polyester is now widely used worldwide.
The amount of fabric required to make an airbagPerformance standards
depends on its location in the car and the market itNormally, the performance standards require a seat
serves. The fabrics utilized to produce a driver's andbelt to restrain a passenger weighing 90 kg involved
a passenger's airbag are quiet different. Most drivers'in a collision at 50 km/h (about 30 mph) into a fixed
side airbags are coated by using lower denier yarnsobject. Straight pull tensile strength should be at least
that give strong and light-weight fabrics. The looser30 KN/50 mm. Other tests include accelerated ageing
weave has been permitted by stronger nylon 6, 6and in the made-up form, resistance to fastening and
yarns that create fabrics with lighter weight, lessunfastening 10,000 times. The seat belt must be long
stiffness and better packagabiIity.lasting without any significant deterioration. In many
The fabric which is used to produce passengercars, after ensuring the inclusion of the airbag, efforts
airbags is generally uncoated. These kinds ofhave been made to link the function of the two
passenger bags are larger so they create lower gasdevices (seat belt and airbag).
pressures, have longer inflation times, and possessConclusion
gas which is cooler. The constituent yarns are ofNo doubt that the airbags help to save lives, but at
relatively heavy denier. Normally, airbag fabrics aretimes they can also be a source of serious injury.
made by rapier weaving machines or air jet loomsThe search for a uniform smart airbag, which can
with electronic dobbies.perceive the size of the passenger or whether the
Airbag fabrics varietiesseat is empty and react in that manner, is in
The earliest airbags were Neoprene coated andprogress. Such a 'smart' airbag will incorporate sensors
woven Nylon 6, 6, but later lighter and thinner siliconeto judge the weight, size and location of the car
coated versions followed. Afterwards, though,passengers and hence deploy more appropriately.
uncoated fabrics have emerged. The majority ofIn addition, incorporated safety devices associated
these fabrics are coated with an elastomeric materialwith the seat belt along with other safety items,
such as neoprene or silicone. The long lastingparticularly for child passengers, are under
popularity of coated materials for airbags has beendevelopment. The trend towards uncoated fabrics is
seen because of its capability to work as a heatanticipated to continue and so is the improved trend
shield and the comparative ease that designtowards more airbags per car and fuII-size bags.
engineers can expect wider performance in their use.There is also a technical challenge of producing the
Though, there are some intrinsic problems withbag by using more rational techniques and related
coated airbags, which cover their large thickness,specifications made by the automotive industry.