Belt

AUTOMOTIVE TEXTILES- SEAT BELTSB. K. BEHERA Department of Textile Technology IIT Delhi Problem of road accident  1.2 million people die every year from road crashes  By 2020 road accident will be 3rd most important health problem worldwide next to heart disease and depression  Head injuries in crashes cause more than 50% death  Occupant restraints such as air bag & seat belt are most effective in preventing death/injury Automotive textiles Break up of textiles in a modern car (%) Carpet & mat Upholstery Pre-assembled Interior components Tyre Safety belts Air bag Others : : : : : : : 33.3 18.0 14.0 12.8 8.8 3.7 9.4 Seat belts  An energy absorbing device  Fundamentally it is desired to delivered non-recoverable extension to reduce the deceleration force by which the body encounters in a crash Role of seat belts  Prevent ejection from the vehicle in an impact . Role of seat belts  Reduce the risk of contact with the interior of the vehicle or reducing the speed of such impacts . Need for seat belt  Prevent ejection from moving car  Stop people going through wing shield  Minimise injuries due to impact with vehicles hard interior  Ensure better control of car  Hold people in position for protection due to air bag . Invention  USA-A strap to support the waist line  Sweden-To support occupant body diagonally  Present belt.Combination of both . Types of seat belts       Lap Sash Lap and Sash Three point Criss-cross Harness . Lap  Adjustable strap that goes over the waist  Used frequently in older cars. now uncommon except in some rear middle seats  Passenger aircraft seats also use lap seat belts . Sash  Adjustable strap that goes over the shoulder  Used mainly in the 1960s. but of limited benefit because it is very easy to slip out of in a collision . .Lap and Sash • Combination of the two separate belts • Mainly used in the 1960s and 1970s. Criss-cross  Experimental safety belt presented in the Volvo SCC  It forms a cross-brace across the chest . pelvis & shoulders .Three-point  One single continuous length of webbing  Help spread out the energy of the moving body in a collision with the chest. Harness  Four-point harnesses  Five-point harnesses  Six-point harnesses . Four point harnesses . Five-point harnesses  The lap portion is connected to a belt between the legs and there are two shoulder belts. making a total of five points of attachment to the seat  Typically found in child safety seats and in racing car . Six-point harnesses • Similar to a five-point harness but includes an extra belt between the legs. which is seen by some to be a weaker point than the other parts • These belts are used mainly in racing . Applications  Use of seat belts by child occupant  Use of seat belt by expecting mother  Seat belts are also used in car. racing car. buses. aircrafts and helicopters . Innovation of seat belts Seat belt cushion seat belt with mobile compartment . Innovation of seat belts Seat belt pads sheepskin cover . Innovation of seat belts Full body seat belt seat harness belt with pillow . Safety seat belt: Engineering aspects . Key components Push button mechanism . Key components Seat belt mounting Seat belt extension . Seat belt extender . Basic mechanism of seat belt 1. Retractor . Basic mechanism of seat belt 2. Locking mechanism . Pretensioner .Basic mechanism of seat belt 3. Basic mechanism of seat belt 4. Load limiters . Seat belt: Textile aspects Seat belt manufacturing . Manufacturing process Feeding of HTPY on creel weaving dyeing stretching setting quality checking winding and packing . Seat belt manufacturing     Selection of machine Selection of raw material Selection of construction details Post weaving process . grip fastness etc. . color fastness.Major machineries for the manufacture of seat belt webbings are           High speed automatic needle looms Warp yarn tension control device Tape collection machine Cone Creel of 600 ends Continuous Dying machine Steam Boiler Compressor Effluent Treatment plant Packing machine Test lab equipments for assessing breaking strength. Needle looms  Commercial loom consists of 6-8 weaving locations  Needle inserts weft from one side of warp sheet & a firm band selvedge is formed  Other side of webbing is held by an auxiliary needle which manipulates a binder and 10 cm thread. . These are combine to give a run proof selvedge  Speed as high as 1000 picks/ min. Seat belt weaving To catch cord yarn. a binder thread and a locking thread are knit at one edge portion Of webbing Pick needle insertion in shed Selvedge formation with catch cord yarns . High speed automatic needle loom . High speed automatic needle loom . High speed automatic needle loom . High speed automatic needle loom . High speed automatic needle loom . High speed automatic needle loom . Raw material  First seat belts were made from nylon  They are now almost exclusively made from polyester  Spun-dyed yarns are used but other colours are produced by pad thermosol dyeing using selected dyes . PET is preferred  PET has superior resistance to UV degradation  Low extensibility  Higher stiffness . Fabric Design criteria  To allow maximum yarn packing within a given area for maximum length & good abrasion resistance  Thicker yarn which provide even & better abrasion resistance  Seat belts should be soft & flexible in length direction and rigid in width direction To facilitate  easy sliding through buckles  retract smoothly to housing . Fabric  Narrow fabric of multiple layer woven twill or sometimes satin weave  Loom state fabric width is about 5 cm  Fabric is about 50 gm per linear metre  Bound selvedge continued . Fabric construction Typically 320 ends of 1100 dtex or 260 ends of 1670 dtex high-tenacity continuous filament polyester yarn with 550 dtex weft . )  Selvedge warp yarn: 250 D / 24 (fil.)  Locking thread: 250 D/24(fil.) .)  Weft yarn: 500D/48(fil.)  Binder thread: 100 D/18(fil.Some typical specifications  Material: PA/PET  Body warp yarn: 1260 D/108(fil. Dyeing root  Spun dyed High light & rubbing fastness  Piece dyed To provide more colour co-ordinated interiors . Dye  Pad thermosol dyeing is used  Resistance to light. wet crocking and perspiration fastness . Fabric finishing Shrinkage induced in length direction to improve the energy absorption property. so that finished fabric weight is changed to 60 gm/m from 50 gm/m . Different Routes for Finishing of Seat belt Yarn Spun-Dyed With carbon Black White Yarn Weaving Weaving Finishing Seat belts Dyeing (piece dyeing) Finishing Heat setting  Material run through an Infra-Red dryer  To impart precise extension  To suppress its recovery in the event of crash Heat setting Mechanism: By shrinking the webbing in a controlled manner which increases the weight of webbing from 50 gm/m to approx. 60 gm/m Coating Some seat belts are lightly coated to improve     Cleanablity Durability Ease of passage Impart anti static Belting fabric properties A woven fabric • Relatively stiff in filling direction and flexible in warp direction • Because weft yarn used stiffer • Filling yarn twistless multifilament polyester yarn • Filling yarn resin bonded multifilament yarn continued . Width Thickness Breaking strength and elongation for dry and wet webbing Abrasion resistance at various environmental conditions and in contact with buckles and fittings Influence of extreme environmental conditions and temperatures Rubbing fastness Microbial resistance        .Performance Tests And Standards for seat belt webbings Mechanical performance of the webbing as per BSI and the SAE. 1960 Requires a belt to restrain a passenger weighing 90.Quality standard @BS 3254.6 cm minimum for the waist strap and 3.7 kg involved in a collision at 50 km/h into an immovable object @BS 3254 Part 1 1988 • ‘Restraining devices for adults’ • Minimum belt widths 4.5 cm minimum for the shoulder strap continued . 5 cm for the smallest (9 to 18 kg) and 3.8 cm for larger children (18 to 36 kg) .Quality standard @ BS 3254 Part 2 1991 • ‘Restraining devices for children’ • Minimum belt widths for children depending on their weight. 2. 3 kN for the waist strap and 10 kN for the shoulder  Minimum of a straight pull tensile strength test result of at least 30kN/5cm .Breaking strength  BS 2576. 1986  Breaking strength and elongation-strip method for woven textiles  Minimum breaking forces for adults are 13. Properties Requirement           46 cm wide Static load bearing capacity up to 1500 kg Extensibility up to 25-30% Strength and good abrasion resistance Light weight Soft and flexible for use Properties in warp direction more critical The edges must be scuff resistant Heat and light resistance Some antistatic nature . Selvedge requirement  Bound  Smooth. no protruding thread  Abrasion resistance  Soft & comfortable to wear  Neat selvedge .  Air bag provide additional safety but not an alternative to seat belt continued . inexpensive means of protection effective.Seat belt vs Air bag  Both are occupant safety resistant device  Seats belts are easy to use. Seat belt vs Air bag  Seat belt & Air bag coexist to provide absolute safety  Air bag provide protection against head–on collision while seat belt provide protection irrespective of live of crash . Quantity 14 m length per car. of 800 gm weight . Fraying .Defect in seat belts 1. Defect in seat belts 2. UV damage . Market  Global market for seat belt  Domestic market for seat belt  Domestic Market of Webbings for Seat belt . The market of seat belt webbings accounts for 10% of the market of automotive seat belts in value terms.Domestic Market for seat belt According to Non-woven industry report. Nearly 75% of automotive textiles are used for tire cord fabric and seat belts. around 6% is generated from the sale of automotive textiles. The demand for seat belt webbings and other rigid webbings is expected to grow at 10% per annum . of the Rs 30.000 crore technical textiles Indian market projected for 2007-08. 4 billion in 2005. This is projected to grow at about 3.6% per annum during 2005 to 2010 . the market for all types of narrow fabrics is estimated at US $ 2.Global Market for seat belt According to a Market Research firm. Domestic Market of Webbings for Seat belt Particulars 2003-04 1.700 370 (%) 8 10 10 Four Wheelers in India (Million) Seat Belts (INR Million) Seat belts webbings (INR Million) .3 2.8 3.600 260 2007-08 1. The major machinery suppliers to manufacture seat belt webbings  Jacob Muller AG.. Germany  Mageba Textilmaschinen GmbH. Taiwan  Comez Spa. Italy  Metag. Germany  Kyang Yhe Delicate Machine Co. Italy  Staubly . Ltd. Japan Tokai Rika. Germany Delphi Corporation. Sweden Key Safety Systems. Australia Ribbons Limited. UK Takata. Japan Furniweb Industrial Products Berhad (FIPB). Malaysia . USA Webbing and Trimmings. USA TRW.Major global manufacturers of seat belts and webbings          Autoliv. Gurgaon  TRW Rane.The major users of seat belt webbings in India are the seat belt and webbings manufacturers  IFB Autolive. Mumbai . Chennai  Shivam Narrow Fabrics. Bangalore  Abhishek Auto Industries. Recent developments in seat belt • Smart Belt The smart belt can adapt its restraining force and hence the load on the occupant to the crash severity Trunk belt for fragile goods webbing . Recent developments in seat belt • Use of pebble weave  2-up 2-down configuration  Superior aesthetics  Less abrasion resistance  Used in replacement seat belt because standards are less demanding . Recent developments in seat belt • Inflatable belts A folded envelop of 3” is covered by 2” face fabric  warp knitted structure  yarn 3000 denier  An amalgamation of air bag and the seat belt  The belt is held by weak stitches that merit open when the belt is inflated  Under impact the belt give about 450% more surface area  Could be fitted in rear seat . combines PET with polycaprolactone or PCL. developed the fiber.Recent developments in seat belt • Developments in material Honeywell Performance Fibers of Colonial Heights. called Securus. rubbery polymer that gives it a bit of stretch. Va.. to absorb some of the crash energy . an amorphous. Conclusion  Seat belts the most important safety device in cars and trucks  About 14 meters of seat belt. are used in an vehicle  Belt strength considerably drops after two years. weighing about 800-1000 gms. Therefore it is must to change belt after every two years .