INTRODUCTION

 

Automotive textiles are one of the most important markets in the technical textiles sector. Many of today’s consumers regard the car as essential to their life style. A car should look good both externally and internally, and provide high performance, reliability, safety, comfort and most importantly, good fuel mileage. Textiles make a major contribution towards realizing all the expectation.

It is estimated that an average family car contains about 12-14 kg of textiles. With annual global car production now at around 38 million units, this represents total textile fiber consumption by the industry of just over 5,00,000 tones per annum. Western Europe, the largest car producing region, consumes over 1,50,000 tones per annum of automotive textiles. This represents about 10% of Western Europe’s technical textiles market. An average car usage between 40 & 45 sq. meters of fabrics to make a component where nearly 2/3rd of automotive textiles are used in internal trims i.e. seat covers, roof liners, door panels and carpets. The remainder goes to reinforce the tires, hoses, safety belts and Airbags. These can be seen in Graph No. 1.

Our project is mainly constrained to the manufacturing of Airbag fabric using NYLON 6. So it is important to know what is airbag? An Airbag is an automotive safety restraint system that has gained significant importance within the last decade. The rise in the safety consciousness in the developed nation like Australia, Europe and US has made airbag compulsory for the safety of the occupant. It is projected that by 2005 all the new automobiles will incorporate airbags.

General Motors introduced the first airbags in the early 1970s but consumer did not readily accept them. The market for airbag was assured by US when the Department Of Transportation (DOT) implemented the Federal Motor Vehicle Safety Standards (FMVSS) 208 in 1984. Because of this law, the US leads the commercialization of airbag.

In 1980 “buzzword” came on the seen fueled by a multi-media advertising blitz and a competitive urgency by the auto companies has introduce their vehicles with an airbag. The increase in the production and airbag has push material consumption of all type of material from 27.7 million linear meters in 1995 to 52.8 million linear meters by the year 2000.

Today airbag products like their predecessors, remain either coated or uncoated, these are primarily targeted for driving side, side impact, or passenger side applications, airbags fitted above gas tanks on motorcycles.

 

 

 

 

 

WORKING OF AIRBAG

 

An airbag module consists of airbag, inflator device, mounting hardware and module cover. The crash sensors and the diagnostics are the part of the system. The inflators are primarily sodium azide crystals, which upon combustion produces nitrogen gas. The Fig No.1, 2, 3 high lights the cross section of airbag assembly, sensor assembly and working of an Airbag Sensor.  

In a car fitted with an airbag a pair of sensors mounted in the front bumper evaluate the severity of the impact in the event of the crash. As per the estimate all collision occurs within 0.125 seconds hence, the airbag system is designed to inflate less then 0.04 seconds. Under normal circumstances the airbag will dipoly if the car is hit at the speed exceeding 12 miles per hour. In a collision: the airbag begins to fill within 0.03 seconds. By 0.06 second, the airbag is full inflated and cushion the occupant from impact. The operation is shown in Fig. No.4. In operation an impulse is sent to the ignitor, which releases a mixture of nitrogen and air. The gas serge’s through a filter and inflates the bag forcing it through its mounting in the center of the steering wheel or glove compartment. The time taken for the decision to deploy and fill the bag is around 35 milliseconds. After inflation the bag deflates in a controlled manner through vents and the fabric until the occupant comes to rest. The time taken from initial impact to full development is about 55 milliseconds about half the time to blink an eye. And the complete time involved for whole sequences of events is approximately 150 milliseconds.

More than half of all severe injures and deaths in automotive accidents are the result of frontal collision. The proven effectiveness to prevent deaths and decrease certain types of injures in accidents had made airbag almost a standard item in vehicles by legislative mandates. A recent study by the insurance institute showed that airbags are much more effective than seat belts alone for safety. Compared to seat belt alone airbag have reduced death by 28%, serious injury by 29% and hospitalization by 24%.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RESEARCH AND DEVELOPMENT

 

The forerunner to the modern day airbag can be traced as far back as the 1920s. However, the first patent to describe the devices was not filed until the 1950s, by The National Aeronautics and Space Administration (NASA) Organization in the US who developed the bag for air space exploration. In the intervening years until 1970s, air bag components were downsized sufficiently to be included by the General Motor in range passenger vehicles. At this time, there inclusion spurred little interest and device was dropped. It was not until the late 1980s that the automotive industry adopted the air bag as an important safety future. Now, sales of new cars are bolstered by the inclusion of an airbags, which appears to an extra value to a model.

Current research and development on the air bag is centered in making device safer. In the future, the ‘smart’ air bag will incorporate sensors to determine the weight, size and location of car passenger and hence deploy more appropriately. Another safety option would be ‘de-power’ the air bag. Which currently inflates at over 200 miles per hour with considerable force. Pressure has also being mounted the carmaker to fit on-off switch to the airbag. Already International Electronics and Engineering (IEE) based in Luxembourg with Siemens Automotive have invented and fitted the Child Seat Presence Orientation Detection (CPOD) system into 1997 versions of the Mercedes Benz Roadster. Another safety option would be to ‘de-power’ the airbag, which currently inflates at over 200 miles per hour with considerable force. Pressure has also been mounting for carmakers to fit on-off switches to the airbag.

Improvement in the airbag technology is directed towards the following:

1.      Smaller package size of the airbag module.

2.      Cost reduction thereby.

3.      Improved occupant safety. 

Moving toward development of a lightweight airbag fabric requires either finer denier yarn (as fabric density cannot be disturbed) or going away with neoprene coating. The later will help in reducing the chances of secondary injuries (like abrasion, contusion, scratches and burns), but may not ensure effective performance of airbag. Alternative to neoprene coating nowadays silicon coating has been used.

Coated inflatable fabrics, more particularly airbags to which very low add-on amounts of coating have been applied, are provided which exhibit extremely low air permeability. The inventive inflatable fabrics are primarily for use in automotive restraint cushions that require low permeability characteristics (such as side curtain airbags). Traditionally, heavy, and thus expensive, coatings of compounds such as neoprene, silicones and the like, have been utilized to provide such required low permeability. The inventive fabric utilizes an inexpensive, very thin coating to provide such necessarily low permeability levels. Thus, the

 

inventive coated inflatable airbag comprises a film laminated on at least a portion of the target fabric surface wherein the film possesses a tensile strength of at least 2,000 and an elongation at break of at least 180%. The film provides a low permeability airbag cushion exhibiting a leak-down time of at least 5 seconds as well as a very low packing volume (for more efficient use of storage space within a vehicle) for the target side curtain airbag.

 

 

FABRIC REQUIREMENTS

 

 Requirements for airbag fabrics:

 

1.      Small fabric thickness.

2.      Low specific fabric weight.

3.      High tenacity in warp and weft direction.

4.      High tenacity for furthers tearing.

5.      High elongation.

6.      Good resistance to aging.

7.      Heat resistance upto 190 0C.

8.      Good resistance to UV light.

9.      Low and very even air permeability.

10. Reduced cost.

11. Precisely controlled gas permeability.

12. Excellent seam integrity.

13. Reduced value or burn through resistance.

14. Improved pliability and pack height

 

 

 

MATERIAL USED IN AIRBAGS

 

The main requirements in airbag fiber materials are high strength, heat stability, good aging characteristics, energy absorption, coating adhesion and functionality at extreme hot and cold condition.

The most widely used yarn in the airbag market is nylon 6.6 yarn in the denier ranging from 420 to 840. Nylon 6, nylon 4.6 and polyester are also used. Nylon 6 is used in small percentage of US made airbags. Dupont, Allied Signal, Akzo and Toray are the major fiber suppliers of airbags. Table No.1 shows a typical example of nylon 6.6 fibers. Polyester which has good dimensional stability even at humid environmental condition have started been used.

 

Table No.1

Example of nylon 6.6 fibers

 

Denier

420

840

Filaments

68

140

Tenacity (g/d)

7.9

8.4

Elongation (%)

21

21

Free Shrinkage (%At 177 C)

6.1

6.5

Melting Temperature ( C)

256

256

 

Development in the US automotive industry provided for the airbag manufacture from 940 dtex yarns, the fabrics mean subsequently coated with neoprene and later on silicon. The limited availability of a space in the steering is already outline, and the ultimate disposal of coated airbags let to development in Europe of uncoated airbags utilized 470 dtex yarns. Fabrics produced from 235 dtex yarns must be coated to protect them from heat generated during development, at least until a method of deployment generating less heat is developed.

   

 

 

Table no:2

Comparison of nylon 6 with nylon 6.6

 

Properties

 
Nylon 6

Nylon 6.6

 

Tenacity            :  Dry

7.5-8.3

9.0

                          : Wet

5.4-7.1

7.7

Elongation        :  Dry

16%-19%

19%-24%

                          : Wet

19%-22%

21%-28%

Initial Modulus(gm/den)

35-40

50-60

Work of rupture(gm/den)

0.6-0.8

0.6-0.8

Thermal Property

215 C

250 C

Elasticity Recovery

100% at 8%

100% at 8%

Moisture content

4% at 65% RH

4% at 65% RH

Density

1.14 gm/cc

1.14 gm/cc

Shrinkage

9%-10%

9%-10%

 

Using nylon 6 can satisfy the required properties for airbag manufacturing.

Nylon 6 offers excellent properties like high strength-to-weight ratio, good chemical and thermal stability and durability. Textile yarn manufactured from Nylon-6 exhibits fine drape, resistance to abrasion, high flexibility, chemical and biological stability etc. Items manufactured using Nylon-6 offer excellent engineering properties even at high temperatures

 

 

AIRBAG  FABRIC  CONSTRUCTION

 

            Airbags are made of compact, plain woven fabric. Normally, nylon 6,6 filaments are used to make the fabric but nylon 6, nylon 4.6, and Polyester are also used. The amount of fabric needed to construct an airbag depends upon its position in the car and the market that it serves. The European ‘facebag’ consumes 0.6m2 whilst its American counterpart needs 1.5m2. In Europe and Japan, some 3m2 of fabric will make a passenger bag, the larger American version taking 4m2.

 The fabrics used to make a driver and passenger’s airbags are quite different. Most driver side airbags are coated, and evolution has Favored lower denier yarns that yield strong and lighter - weight fabrics. The Japanese pioneered the third generation air bag made from 420- denier fabric who is characteristically woven at 181x181 rather than 193x193 yarns per 10 cm. Stronger nylon 6.6 yarns that generate fabrics with lower weight, less stiffness, and better packagability, have permitted the looser weave.

 

Table no:3

 Typical characteristics of driver and passenger side fabrics used in air bags.

 

DRIVER SIDE

PASSENGER SIDE

 

25 X 25 plain weave

840 D nylon 6,6

Scoured, heat set, coated

 

46 X 46 plain weave

420 D nylon 6,6

scoured, heat set, coated

 

25 X 25 rip stop

840 D nylon 6,6

Scoured, heat set

 

41 X 41 plain weave

630 D nylon 6,6

Scoured, heat set

 

49 X 49 plain weave

420 D nylon 6,6

Scoured, heat set

 

            In comparison, the fabric which is used to make passenger airbag is normally uncoated. The type of fabric is suitable because passenger bags are larger so they develop lower gas pressure, have longer inflation times, and contain gas, which is cooler. The weight per unit area of uncoated fabric is greater than coated varieties; 244 or 257 g/m2 compared to 175 g/m2. The uncoated fabric is heavier in order to retain the gas during inflation. Similarly, the constituent yarns are still relatively heavy with a linear density of 840 denier. These yarns are woven to a 32 x 32 rip stop design, which is also peculiar to the passenger side bag. Generally the fabric to make a passenger bag is stiffer and thicker; the thickness can vary from 0.33mm to 0.4mm compared to 0.25mm for a driver side bag. These characteristics mean the air bags are larger, which at present is not a problem but as car interiors become more aerodynamic, space will reach a premium. In anticipation of the demand on space, more 630 denier yarns are being woven to a 41 x 41 design and a lightweight coating on a less cumbersome fabric is also being considered, which will make the bag easier to pack.

 

Table no:4

 Air Bag Fabric construction:

 

Type of Air Bag

Original Coated

Experimentation (Non-coated type)

Yarn Type

Nylon6,6

Nylon6,6

Nylon 6

Nylon 6

Yarn Denier

840

420

840

420

 

Fabric construction

(ends/dm)

25*25

50*50

30*35

55*48

Weight(gm/m2)

280

260

260

212

Thickness(mm)

0.38

0.34

0.40

0.35

 

 

 

MANUFACTURING

 

              To manufacture airbag material, the warp yarn is supplied on a beam. The American supplier, allied signal, who manufacture nylon 6,6 wind 630 denier yarns on 813 mm wide beams for their loom. A one-dip process that applies a polyacrylic coating can size the yarns. The size is adhered to the yarns by passing it in between the squeeze rollers and then series of cooling rods. Encapsulating the yarns with size mean that the ends are prevented from rolling during drying and wind-up gas fired dryer dries the size. At this stage other compound suitable for warp preparation can be added, like the grafting compound designed by Reeve’s brother. Grafting compound stops excessive fabric fraying yarn pullout, and distortion. The soft nature of the compound ensures a pliable fabric.

         Generally, airbag fabrics are woven on rapier weaving machines or air jet looms. AlliedSignal employ rapier machines that run at about 400 picks per minute and air jet looms that delivers 600 picks in the same space of time. During weaving, the rapier machines are supplied by three filling packages and the air jet looms are fed by two looms are fed by two. In the weaving shed, the machines are linked to electronic dobbies that allow loom settings to be changed almost instantaneously.

              Sulzer ruti have woven Rhone Poulene, Akzo and Japanese yarns by the same methods on their state-of-the-art looms. Sulzer Ruti claim that the stringent fabric specifications imposed up on them by the airbag industry stretch the technology to the limit. The fabric’s tensile strength and elongation are strongly influenced at weaving stage. Similarly, the weaver is responsible for engineering uniform air permeability across the whole fabric. Sulzer Ruti have proven that fabric woven on their looms meet this criteria and the air permeability across loom state and finished airbag fabrics.

 

 

 

 

EXPERIMENTATION

 

Twisting:

           

Table no:5

 

YARN

840 D

420 D

NO. OF FILAMENTS

140

68

T.P.M.

70

170

BREAKING STRENGTH (KG.)

6.35

3.25

 

Warping:

 

Sample  1:

      Warp                                       :-  840 denier( nylon 6) twisted yarn

      EPI                                          :- 28

      Reed space                          :- 50”

      Beam flange distance          :- 52”

      No. of package on creel      :- 100

      Sections                               :- 14

      No. of ends                          :- 100 x 14 = 1400

      Length of warp                    :- 80  meter for  1 beam

 

Sample 2:

      Warp                                   :- 420 denier (nylon 6) twisted yarn      

      EPI                                      :- 52

      Reed space                          :- 50”

      Beam flange distance          :- 52”

      No. of packages on creel     :- 100

      Sections                               :- 26

      No. of  ends                         :- 100 x 26 =  2600

      Length of warp                    :- 80 meter for 1 beam

 

Precautionary  measures :

 

1)     Package used in cheese form (baby package) each 250 gms. contains.

2)     Disc type tensioners with additional weights 10 gms.

3)     Ceramic guides polished and made smooth.

4)     More attention given in alignment of package at creel to avoid tension variation.

5)     Reed well polished with chalk powder yarn 1 in dent.

6)     Sectional reed well polished.

7)     While warping 840 denier weight removed to avoid the end break.

8)     For warping 420 denier extra weight where added to avoid the slack yarn between package to reduce balloon size.

9)     Antistatic oil added during beaming.

10)Paper placed between 2 layer during beaming.

 

 

Weaving:

 

Fabric construction :

                                                  

Sample 1

1)  Weave                                      :- plain

2) No. of head used                       :- 4

3)  Warp yarn                                :- 840 denier(twisted)

4) Reed space                                :-  50”

5) No. of  ends                               :-  1400

6) Denting order                            :-

            Body       - 1 in dent

            Selvedge - 2 in dent

7) Selvedge ends                           :- 2 x 20 = 40

8) EPI                                            :- 30 ( 840 denier twisted)      

9) PPI                                            :- 36 ( 840 denier twisted)

 

 

Sample 2:

1) Weave                                      :- plain

2) No. of head used                      :- 4

3) Warp yarn                                :- 420 denier(twisted)

4) Reed space                               :-  50”

5) No. of  ends                              :-  2600

6) Denting order                           :-

            Body       - 2 in dent

            Selvedge - 3 in dent

7) Selvedge ends                           :- 2 x 30 = 60

8) EPI                                            :- 54 ( 420 denier twisted)      

9) PPI                                            :- 48  ( 420 denier twisted)

 

 

Precautionary measures :

 

1)     Machine - RUTI- C

2)     Speed     - 210 rpm

3)     Center closed shedding.

Advantages:-

1)     Less strain on warp.

2)     Rising threads is particularly balanced by falling line hence speed will be high.

4)  Heald - Flat steel simplex type. To maintain the smoothness and to avoid the filamentation heald clearer with white chalk powder previously made to run on cotton sort to avoid any sharp corner.

4)     Dent spacing kept even.

5)     Rubber covered temple were used.

6)     Drop wire was not used.

7)     Emery roller covered with light weight fabric.

8)     Sley race board covered with velvet.

9)     Center weft fork motion was used.

10) Back rest lifted higher than used for cotton sorts.

11) Pirn used where smooth and serration.

12) Nylon loops are used in shuttle to maintain tension in weft.

 

 

 

TESTING

 

            One of the unique characteristics of airbag market is the potential legal liability that may lead to lawsuits for failure or injuries incurred. As a result testing requirements are very demanding: many tests are performed on airbags for physical, chemical, environmental properties and grading. Since there are only a few established industry standards, any change in manufacturing or material will require performance validation, which may exceed $50,000. Full certification by an automaker for complete airbag module may cost $100,000. Several organizations such as American Society for Testing and Material (ASTM), The Society of Automotive Engineers (SAE) and the Automotive Occupant Restraints Council (AORC) are working on standardizing the various specifications and the test methods.

           

Test results and discussion:

 

The developed airbag is tested according to the ASTM standards. Testing is conducted on three samples one with 840 denier warp/weft, second sample with 420 denier warp/weft and third sample with 420 d warp/840 d weft. Results are compared with the requirements of Mercedes-Benz and the Trial made by Sulzer-Ruti.

Breaking strength, Elongation and Tear strength are tested by INSTRON Tensile Testing Instrument. For 420 denier the Breaking Strength in warp way direction is higher than one mentioned by Mercedes-Benz. Similarly for 840 denier warp way strength is higher than trial made by Sulzer-Ruti.

Tear strength for 420 denier warp way and weft way both are higher than the requirement. Air Permeability for 420 denier is closer to the requirement of Mercedes-Benz. And for 840 denier it is less than Sulzer-Ruti. These results are shown in the table as well as in graph.

  

 

Table no:6

 

TEST RESULTS OF THE DEVELOPED AIRBAG FABRIC:

 

 

Experimentation Performed in

Project

Trials made by Sulzer-Ruti

Requirement           according to MERCEDES-BENZ

S.

N.

Specifications

840 Denier

420

 Denier

420 x

840 D

840

Denier

420

Denier

1.

Fabric Sett (per inch)

30 x 36

54 x 48

54x 36

28 x 28

57 x 53

2.

Weight (gm/sq.m)

260

212

232

198

220-260

3.

Thickness (mm)

0.44

0.36

0.41

-

0.42-0.32

4.

BreakingStrength(N)

Warp

Weft

 

3189.36

2566.12

 

3290.3

2275.9

 

3151.5

3541.4

 

2500

-

 

> 2500

> 2500

5.

Elongation  %

Warp

Weft

 

12.16

13.91

 

42.72

24.47

 

44.80

24.78

 

35

-

 

> 33

> 23

6.

Tear Strength (N)

Warp

Weft

 

421.0

397.9

 

236.59

257.42

 

262.32

448.65

 

86

-

 

> 115

> 115

7.

Air Permeability(dm/min)

At 500 pa.

 

8.71

 

10.84

 

6.60

 

10

 

< 10

8.

BurstingStrength(kg/cm2)

>60

54.8

>60

-

-

 

 

 

FINISHING PROCESS

 

After weaving, the Air Bag fabric is subjected to finishing and the first regime is scouring. To facilitate weaving, nylon fabric contains about 10% acrylate size and 1.5% mineral oil. Likewise polyester fabric is woven with approximately 30% size and 1.5% mineral oil. Air bag fabric of serviceable quality should hold 0.3% or less of these deposits.

To remove size from nylon fabric, it is impregnated with a chemical treatment of PH 10 on a saturator. The machine runs at a high liquor pick-up and low water surplus so that displaced size cannot redeposit on the fabric. Polyester size is normally removed in dispersion since it cannot be dissolved of swollen in water. The removal necessitates special washing ingredients and high liquor turbulence. Though washing the electrolyte content of the mixer is monitored to prevent the size from coagulation and re-adhering to the fabric. To remove oily preparations such as mineral and paraffin oil from polyester fabric, the fatty particles are removed at high temperature. The complete scouring operation uses 3 or 4 wash boxes that are separated by a vacuum extraction system to capture the exact size.

To achieve the precise air permeability along the full length and width of the fabric, a calendar with a deflection compensation roller is used. Here the calendar incorporates a roller with an internal pressure system that bends the roller sleeve into the deflected counter roll. The rollers are coupled with a width adjustment system. Some other important features of the  machines are the roller temperature, speed and pressure controls. If these controls are used effectively, then the permeability of the nylon and polyester fabrics can be engineered precisely.

A novel method of influencing air bag fabric permeability is by hydro-entanglement using veratec’s inter spun process. In this process, a curtain of needle-thin water jets strike the fabric and rearranges its surface fibers. This fiber entangle, making the yarn ‘bloom’ and the fabric bulk. The benefit of this process is that the fabric becomes more opaque and softer, and on the other hand pore size is altered which can increase or reduce permeability. JPS Automotive has taken a compact 630 Denier 41 X 41 nylon fabric and increase its permeability. The resulting fabric is suitable for venting hot gasses and smoke from driver and passenger air bags.

To confer dimensional stability to air bag fabric, it is heat set. If temperature sensitive fibers have been included in the material, then the heat will induce shrinkage that will principally affect the fabric’s permeability. In sophisticated finishing plant, the fabric can be inspected in close loop weft straightening. This is a computer controlled device with two cameras that lie at either end of a length of fabric and its diagnosis is used to realign the weft accordingly. It is equally pertinent to check the pick density of the fabric at the stage of production.

Silicon is being chosen to coat more air bags. Because Silicon out performs Neoprene in many areas. The typical weight of the uncoated fabric is 150 gm/m2  and the coating adds 70 - 80 gm/m2  . In processing, the Silicon elastomer is applied as a single coat by blade application. The fabric is held under tension and passed through an oven to induce polymerization.

 

Table no:7

Coated vs Uncoated fabrics:

 

Property

Coated

Uncoated

Air porosity

Precisely controlled

Variable

Pattern cutting

Easily cut

More difficult

Sewing

Easy to handle

More difficult

Packageability

Bulky

Smaller package

Stiffness

Variable

Pliable top moderate

Burn thru

Good resistance

Not good

Deployment

Excellent control

Combing effects

Cost

High

Low

Recyclability

Difficult

Easier

 

 

AIRBAG FORMATION

 

When air bag material has been finished, it is cut into panels by laser. This technique is fast and accurate, it fuses the edges of the fabric to prevent fraying and reduces cost by eliminating cutting dies. The normal design of the driver-side bag is two circular pieces of fabric sewn together. The passenger bag is tear-drop shaped, made from two vertical sections and main horizontal panel. Air bag are sewn with nylon 6,6, polyester and kevlar, aramide yarns, the sewing patterns and stitch densities being chosen carefully to maximize performance.

When this has been sewn it is folded inside its cover. Like a parachute, the fabric is folded with extreme care to ensure smooth development. A variety of folds are suitable including the accordion fold, reversed accordion fold, pleated accordion fold and overlapped. Generally the smaller airbags are preferred by the automotive industry which is the concept exemplified by a revolutionary airbag designed to fit inside a shirt pocket. It was conceived by accessing the fabric and seams of a normal airbag in a wind tunnel. The research found that the strain on a conventional airbag during deployment did not coincide with its strongest axis. Most of the strain was concentrated on its equator. The experimental results were fed into a computer and a new bag was designed to exert stress along the preferential axis. As a result less stress was exerted on the seams, so less stitching was needed and the bag could be folded into a much smaller space.

Packing should also allow for tethers joined to the bags to control its protrusion into the car during deployment. Lastly a cover can be fitted over the bag to protect it from abrasion. Dupont had made a jacket from Tyvek AC spun bonded polyethylene for this purpose. It tears to release the airbag when it inflates.

 

 

AIRBAG MARKET AND FUTURE TRENDS

 

            The market growth of airbag market chain (from fiber to module, ready to install) has been phenomenal in recent years-from $800 million in 1990 to an expected $6.6 billion by the year 2000 worldwide. The 75 million linear yards of fabric (60 inch wide) needed by the year 2000 had a market value of about $500 million. Typically, it takes about 1.7 square yards of fabric to make a driver side airbag and about 3.7 square yards to make a passenger side airbag. Almost the same amount of fabric is used for little trucks and van airbags. Chrysler, Ford and General Motors (GM) have driver side airbags on all of their domestic cares. Airbag installation is also increasing in Europe and the Far East.

Polyester fiber will most probably be used in airbag manufacturing in the future. Fabrics may have higher cover factor (low porosity) and may be calendared. Current development work is concentrated 35 x 35 plain weave made of 650 denier nylon yarns for driver side and 41 x 41 plain weave made of 440 denier polyester yarns for passenger side. Driver side bag will probably be scoured, heat set and coated while the passenger side bag may be scoured, heat set and calendared. Coating of the driver side bag may also be eliminated in the future. Lighter denier fibres may be used for fabric packages.

        Future opportunities for airbag used include side impact bags, rear seat bags, trucks, airplanes and buses.

        World wide, the number of airbag fitted included side impact cushions raised steadily until the year 2000. New positions are been found for the airbag too; in the back seat, to cushion the knees and mounted in the roof.

         A recent survey suggests that, since their introduction airbags have saved the lives of 1600 motor vehicle occupants, although approximately 35 children’s and 20 adults have been killed unnecessarily. The number of fatalities is greatest in the United States primarily due to the larger size of the bags and less stringent seat bags laws. American driver side bags have the capacity of 65 liters of gas whilst European face bags are much smaller and only hold 35 liters of gas.

 

 

 

CONCLUSION

 

From the above discussion the following facts could be highlighted:

The market for airbags has reached the maturity level in the developed nations and has also been established in the developing nations like INDIA.

            In INDIA the airbag market will receive the boost with the stringent safety regulations and increasing consciousness among the automobile users.

            The airbags has been remarkably successful over the last five years due to government legislation and consumer pressure.

            To make vehicle safer for driving, certain other prime positions like door panels, roofs (for crashing wind shield) and facing rear seats have been suggested in addition to drivers airbag and passenger side airbag.

            As per our knowledge this is the first attempt made in manufacturing airbag fabric in INDIA.

  We are successful in our project as obtained testing results are upto the standards that fulfill the requirements of the Airbag.

         As the ultimate aim of project was to weave airbag fabric with Nylon 6,still more work can be continued on finishing and developing ‘an Airbag module’.

 

 

 

 

 

 
REFERENCES

 

1.      Mukhopadhyay S.K. and Patridge J.F., Automotive Textiles, Textile Progress, The Textile Institute, 29(172), 1997.

2.      S.Adnur, Wellington Sears Handbook of Industrial Textiles.

3.      Research made by SULZER-RUTI manufacturers.

4.      Rozelle W.N., Textile World 1995.

5.      Man-Made Textiles in India March 2000.

6.      Textile Magazine Issue 3.

7.      Journal of COATED FABRICS, Jan 1995.

8.      Dorn M., Textile Month, May, 1997, 19.

9.      Textiles in Automotive Engineering.

10. R. Shruling, Textile Month, 1996, Aug, 29.

11. A. Ashton. Technical Textile Markets. Oct 1995.

12. S. Davies. Textile Horizons. Oct 1994.

13. D.Pearsons. Journal Society Of Dyers and Colourists. 1993.

14.  Airbags Sites through Internet.

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Project by

Mr. Mitesh Panchal & Mr. Avinash Dayaramani , DKTE.

"mitesh panchal" miteshpanchal2001@hotmail.com

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