Essay: AUTOMOTIVE TEXTILES IN CARS

Humankind utilizes textile materials by eras. Many people believe that textile materials have no application other than clothing purposes. But , there are a few fields , we are utilizing the textile materials as a part of different applications , these non-clothing employments of materials are known as technical textiles. Technical textiles includes the application areas in which textile materials are used for functional purpose rather than aesthetic purpose.
Mobiltech
Automobiles , especially car turns into an essential part of a day-to- day life nowadays in all developed countries.Many sectors like Trade, Industry and Commercial activity extremely dependent on transportion. Therefore , its usage gets increased in developing countries too. Due to this enormous application, the number of researches and developments taking place in this field gets increasing tremendously. As a part of development and energy conservation, textile materials are used in the automobile manufacturing. The worldwide utilization of textile materials utilized as a part of automobile industry is assessed to be more than 4.5 lakh tons.
Automotive textiles in cars
Fig no : 1 Automotive applications and contents (Adapted from Freundenberg Vitek:2008)
The usage of textile materials in the field of manufacturing a car is in the form of all forms like fibres, filaments, fabric, composites etc., These are used both for its functional as well as aesthetic performance. Some materials can be easily identifies as they are visible to the viewer, they are known as visible components. And at the same time, some textile materials may not be visible directly to the viewers , they are mainly used for their functional purpose, they are known as concealed components. Examples of visible components are seats, seatbelts, carpets etc., examples of concealed components are airbags, tyrecord , headliner, filters etc.,
Tab no 1 : Automotive textile application categories (Adapted from Freundenberg Vitek:2008)
AUTOMOTIVE TEXTILES APPLICATION CATEGORIES
FACING STRUCTURAL FILTER ACOUSTIC / THERMAL
• Seat back / bolster
• Seating
• Headliner
• Carpet
• Trunk
• Door panel
• Package tray
• Cargo facing
• Load floor cover
• Pillar cover • Carpeting
• Carpet backing
• Headliner substrate
• Door panel
• Air bag
• Wheel house
• Trunk trim
• Tyres
• Seatbelts
• Composites
• Belts/ hoses • Engine
• Fuel
• Cabin
• Exhaustion
• Transmission
• Oil • Door panel
• Trunk
• Dash insulator
• Seat
• Anti — squeak
• Package tray
• Floor insulation
About 45 square meter of textile materials are used in the interior trims of a car , like carpets, seats, seat covers, pre-assembled interior components,side panels, trunk etc., The textile materials are selected based on its performance and its functional properties. The contribution of man made fibres are increasing nowadays due to its increased strength, high modulus, better thermal properties, high abrasion resistance, good chemical properties, better elongation. The selection of particular fiber in the area of specified application depends on the required properties to be fulfilled by the fibre, yarn structure and fabric structure.
The percentage contribution of each part of textile components is explained in the following table no 2 . The fibres which are used for the specified applications are shown in the table no 3.
Tab no 2: Textiles in average modern car – ref [2]
TEXTILE COMPONENT PERCENTAGE
Carpets (with car mats)
Upholstery
Pre- assembled interior components
Tyres
Safety belts
Airbags
Others 33
18
14
12
8
3.7
9.4
Total 100
Tab no 3: Textile fibers used in various components in an automobile — ref [3]
APPLICATION FIBERS USED
Seat belts
Airbags and headliners
Body cloth
Interior carpets
Package tray
Door trim
Trunk liners
Trunk covers
Clutch facings
Tyres Polyster
Nylon
Polyester, nylon or their blend
Nylon
PP and nylon
PP , nylon and polyester
Polyester blends
PVC coated or polymer based nylon or PET
Composites of carbon or aramid fibres
PET , glass , aramid fibres ,nylon , rayon fibres
VISIBLE COMPONENTS
Pre-Assembled Interior Components
The critical applications for pre-assembled interior segments are door kick boards, boot linings, rooftop linings, bundle racks and protection (warmth, sound, vibration and so forth.) materials. Needle-punched non-woven which are coated or laminated with required polymers , and warp knitted fabrics becomethe primary materials utilized for the pre-assembled interior segments.
Upholstery
Trim panels cover the interior parts of any car , which makes any automobile to look attractive. These cover the skeleton of the automobile to feel much better to visualize and make the journey much comfort. The vehicle interiors are made up of different type of materials depends upon the usage and the requirements. So depending on that, the fabric structure, weight per square unit will change.
Traditionally , the spun polyester yarns are used in the manufacture of fabric which is used in the upholstery application. The plain structure of this fabric was commonly made from airjet textured yarn. The textured structure is preferred due to its high abrasion resistance character. Then the required finishing like heat setting , brushing and cropping.
Nowadays the usage of weft knitted fabric gains importance in the application of upholstery. These fabrics are manufactured generally by circular knitting machine.
Carpets
A carpet is a textile floor covering whichconsists of an upper layer of pile attached to a backing. The pile fabric is made up of piles of wool or fibres such as polypropylene, nylon or polyester.It consists of twisted tufts which are often heat treated to maintain the structure.There are about 3.5 to 4.5 meter square of carpet used in each car.
The fibers and yarns used in the manufacture of automotive carpets are Nylon ,Polyester ,Polypropylene ,Wool and wool blends ,Bulked continuous filament nylon yarns.
The properties to be fulfilled by a carpet in a car are Aesthetics ,Sensual comfort ,Noise control and Vibration control.
The tufted carpets are lighter weights of approximately 12 ounces/square yard. Tufting is a process which is many times faster than weaving. Tufts can be either cut or uncut piles.The popular gauge used for cut pile and loop pile tufting is 0.1 inch. Tufting of automotive carpets is carried out on a PET spun-bonded , non-woven material weighing between 110-120 grams per meter square. Tufted carpets are used in Audi , BMW , Saap and some Rover cars. Tufted carpets have more resistant to wear and tear.
Needle punched carpets weigh about 450 grams per meter square. They have better mouldability. They have no tendency to exhibit ‘grin through’ unlike tufted carpets. It is more rapid and economical process. They have better quality compared to tufted carpets.
Both the carpets require about 70-100 grams per meter square of acrylic latex coating on the back to stabilize it and to lock in the fibres . Polyethylene powder is used on both sides of carpets to improve the thermo-mouldable properties. At temperature 110-140 degree moulding is carried out and similarly softening happens. Then it is thermomoulded to the shape of the car .
Sound absorption barrier layer of barium sulphate filled EVA polymer is laminated to the thermomouldable layer before thermoforming.It weighs about 2000-7000 grams per meter square.Certain areas of the carpets, extra heat insulation pads is added.
Seat Belts
Now a days wearing of seat belt is stricty followed to safeguard the life of drives and front seat passengers.The seat belts control the forward movement of the wearers in the controlled manner during sudden stoppage of the vehicle. About 1 Kg of textile fiber per car is used in the making of seat belts. Seat belts function as a safety device which secure the passengers in a vehicle against harmful movements during collision or similar incidents.Seat belts minimize injuries during accidents.
The surface of the seat belts has to be soft and flexible . It should have good abrasion resistance and it has to slide freely into the retractor. It should have good UV resistance to withstand the sunlight . Because of the better UV resistance property, polyester fibers are used.
Seat belts are made by shuttle less needle looms of 1000 ppm. The twill weave is the most preferred weave used in the manufacture of seatbelts, particularly 2×2 twill weave is generally used.
CONCEALED COMPONENTS
Tyres
Textile materials such as viscose, glass and steel cords are used as reinforcement materials in the tyre cord manufacturing. They provide dimensional stability as well as reinforcement. Dimensional stability is an essential requirement for tyres.There are many textile components in a tyre such as casting belt breaker fabric, bead wrapping fabric, chafer fabric, filler fabric, tyre cord fabric etc. The fibres generally used for tyre cords are high tenacity filament yarns of nylon 6, nylon 6,6, polyester and viscose. Nylon 6 is majorly used in tyre cord manufacturing.
In the olden days , plied cotton yarn was used for the manufacture as tyre cord fabric. It was preferred, as it had natural compatibility towards rubber. Kevlar glass or steel are being used in manufacturer of cords compressing the breaker or belt layer. They are preferred because of high modulus. Viscose is the commonly used fibre in radial ply tyre casing. Carbon fires are also finding application in the form of reinforcing material.
Air Bags
An airbag is an automatic safety restraint system that has gained significance within the last decade. Airbag is a supplement to seat belt. Seat belt provides a protection regardless direction of collision but air bags provide protection against head on collision.
The properties to be fulfilled by an air bag material are high strength, resistance to ageing and abrasion, compatibility with coatings and good impact absorption. Therefore nylon 6, is the mostly used material for the construction of air bags. Polyester is rarely used for this purpose and this trend seems to continue.
Preferably airbag fabrics are sufficiently flexible to be able to be folded into relatively small volumes, but also sufficiently strong to withstand the deployment at high speed, e.g. under the influence of an explosive charge, and the impact of passengers or other influences when inflated.
Ideally airbag fabrics are adequately adaptable to have the capacity to be collapsed into moderately little volumes, additionally adequately solid to withstand the organization at rapid, e.g. affected by a dangerous charge, and the effect of travelers or different impacts when expanded.
Head Liners
Headliners are used in passenger cars and multi/sports utility vehicles as non-woven light weight roofing material. In olden days , cars were fitted with knitted/woven fabric with cardboard backing. The trend has changed and increasingly non-woven headliners are being used in vehicles.
Generally the headliners are non-woven technical textiles made by polyester staple fiber (PSF) ,polypropylene or polyurethane core sprayed among two reinforced sheet. The main machinery for manufacturing headliners non-wovens is the needle loom.
Filters And Engine Compartment Items
The important components of a car engine are hoses , belts and linens. They are reinforced with textile materials. Automotive filters are largely made of textiles. Some examples of the filters are air filter and oil filter. The function of these filters is to filter the fluid before it enters the engine because of delicate machine component may be destroyed if the dust particle enters into the engine.
Paper is used in many applications such as the oil filter and carburate air filter. Nowadays non-wovens are used in some cars for the filter application. The latest advanced filters combine both mechanical filtering through polypropylene non-woven electret fabric with adsorption by activated carbon. Filter fabric is arranged in a pleated form to maximize the surface area with minimum airflow resistance.
The non-woven filter fabric must be strong. Whenit is wet, it has to be odor-free resistant to micro-organisms and resistant to extremes of temperature. Woven fabric strucyure is also used in some of the applications, but non-woven textile fabrics are the widely used textile filtration media with good filtration efficiency. It is mainly due to their complicated structures as a result of three dimensional network of fibres and considerable thickness.
Different types of finishing like calendaring , raising , chemical treatments and special surface treatments are to be given to improve the filter efficiency of the fabric .
Application
Type of filter media
Carburettor air filters wet, dry, needled or spun bonded
Engine oil filters Resin impregnated wet laid nonwoven
Fuel tank filters Activated carbon
Cabin interior filters Electrostatically charged fibre media, nonwovens, activated carbon
Diesel/soot filters Ceramic materials
ABS wheel/ brake filters Metal or fibre woven screens
Power steering filters Mainly screen fabrics
Transmission filters Woven fabrics or needle felts
Wiper washer screen filters Woven fabrics
Air conditioning
recirculation filters Nonwoven / activated carbon
Crank case breathe filters Nonwovens
The filtration efficiency of a particular filter depends upon the fibre structure, yarn structure, fabric structure, weight per unit area, porosity and the surface characteristics of the fibre. By making necessary changes in the fibre, yarn or fabric level , we can alter the filtration efficiency and the properties of the filter fabric.
s.no Application area
Main performance requirements Fibres used Fabric construction GSM required
1 Upholstery Abrasion , UV resistance, attractive design and texture Polyester , wool, nylon , acrylic Woven, knitted, non woven 150-300
2 Carpets Light fastness, mouldability, sound insulation Nylon, polyester nonwoven Around 500
3 Seatbelts Tensile strength, abrasion resistance,UV resistance HT polyester Woven-needle loom
4 Tyrecord Tensile strength , adhesion to rubber,fatigue resistance Polyester, nylon, HT rayon, steel and aramid Woven
5 Airbag Ability to withstand high temperature,inflation gases,durability to storage in compacted state over many years Nylon-6,6 , nylon-4,6 Woven, stitch bonded, needle punched non wovens
6 Rubber reinforcement(hoses, belts and air springs) Heat resistance , tensile strength, dimensional stability, adhesion to rubber, chemical resistance Nylon, polyester, polypropylene Woven — circular loom, braided
7 Headliners Good sound damping properties and good aesthetics. polyester staple fiber(PSF),polypropylene or polyurethane core sprayed among two reinforced sheet.
Knitted-tricot knit, woven, non woven backing 185-220
CONCLUSION
The technical textile market is prone to innovative new products. There is opportunity and need for functional, cost-effective materials.Great items are required and they must function admirably. It is a market that offers opportunity, additionally one that requests that much improvement and testing be done preceding receiving new items. There may be long lead times much imperviousness to things new items to advertise. The fact of the matter is we can’t manage the cost of not to have the thoughts and items.
References
[1] . Technical Textiles 2009 State of the Industry William C. (Bill) Smith Industrial Textile Associates Greer, SC 29650, USA http://www.intexa.com
[2]. Technical Textiles in Automobile: A Comprehensive Study by Joy Sarkar
[3] . A poster on “AUTOMOTIVE FILTERS” by S.Viju and A. MukopadhayayDepartment of Textile Technology, National Institute of Technology, Jalandhar-144011, India.
[4]. http://www.fibre2fashion.com/industry-article/technology-industry-article/application-of-textiles-in-automobile/application-of-textiles-in-automobile4.asp
[5]. AirQualitee Cabin Air Filters Catalog © Copyright 2004 AutoPartSources