What I intend to discuss in this paper is the use of needled nonwoven structures, what they are made from and then compare how the basic ingredients vary from country to country based on raw material availability and engineering preferences. As I hope to show, decisions about the ingredients are often made for reasons other than performance, but rather on the simple factor of raw material availability.

From the beginning it should be made clear that there is a substantial difference between the basic production methods for nonwovens that are needled and wovens which are not. When we hear about the use of textiles in automobiles, what often comes to mind is the more traditional and better known processes of woven, knit or tufted goods. These basic differences are one of the reasons that nonwovens have certain appeal, as well as practical advantages over wovens. In no way do I intend to suggest that nonwovens are in general, superior or better. Each textile process has distinct advantages over the other and the combined use of these two processes has helped to improve the vehicles we use today.

Nonwoven products are derived from random staple fibers which are formed or aligned in a consistent orientation into a continuous web and then delivered to some type of bonding process. I will speak of the mechanical bonding process that uses specially barbed felting needles to accomplish this. This process is most commonly referred to as mechanical interlocking. It differs from other bonding processes such as thermo-bonding or chemical bonding. These previously mentioned webs are delivered to a special type of loom which is filled with barbed felting needles. These are special needles which do not have a hole of any type and therefore do not carry a continuous filament or thread. Instead, they have long blades covered with very small barbs which carry the fibers from the horizontal position within the web into a vertical position at the downward stroke. This one directional needling allows the needle to exit the fibers cleanly before re-penetrating the web again. Through repeated strokes or punches onto this web, the web becomes more densified and stronger until the point that it is formed into a single structure and ready for additional processing or installation.

One of the advantages of the needled nonwoven process is that it allows for the use of very short fibers that may not have been suitable for the more traditional textile processes. Today we are seeing the use of such short fibers as wood, cotton waste, glass, and other synthetic waste fibers that may have been previously discarded. Many of the fibers in use can be little more than a fraction of an inch in length. The use of these fibers can substantially reduce the raw material costs for components within the vehicle and therefore allow a manufacturer to remain as competitive as possible. In addition to the cost savings these fibers can offer, they are performing vital functions such as filtration, sound absorption, structural rigidity, weight reduction and of course, aesthetics. It is worth noting that the needlepunched process of nonwovens grew from a waste utilization industry over 40 years ago and has grown to become a major textile process due to the development of synthetic fibers like nylon, polyester and polypropylene.

Most people will quickly recognize the needlepunched products in the car, as the interior trim fabrics and the trunkliners. The most common applications in this regard are the molded floors, formed headliners, door trims, seat backs, load floors and package trays, to name just a few. In addition to these more obvious applications, which are there primarily for their aesthetic appeal, there are the less noticeable applications such as sound barriers, filters, battery separators, structural panels, formed liners and door parts, speaker housings, headliner substrates, seat forms and even exterior body panels. There are even a number of woven products which are lightly needled to add to their dimensional stability, build body, and to provide a surface for the application of a latex type binder.

The North American automobile market and its manufacturers have been the leaders in the development of textiles in the automobile and, in particular, the development and application of needled nonwoven structures. Part of this is no doubt due to the standard of living we enjoy and therefore the level of luxury or convenience we have come to expect in our cars. It is fair to say that the European manufacturers' development and utilization of needled structures has, for the most part, paralleled the U.S. manufacturers. The Asian manufacturers have in general adopted and reproduced the technology processes developed here in North America, and to some degree Europe. But among the three geographical locations, I do not think it is unfounded to say that U.S. manufacturers of needled structures have been the leader in this technology. But this is certainly not to imply that foreign manufacturers are any less skilled at making very unique and practical needled nonwoven structures. In fact, the Europeans and the Japanese are currently developing composite structures which will soon find their way into all makes and models worldwide. These new composites will utilize such fibers as jute and mineral fibers, combined with glass and various synthetics to provide low cost, lightweight components which are at the same time easily molded, heat resistant and easily able to isolate road noise.

It is the basic differences in the selection of raw materials, processes of manufacturing and engineering policies that I would like to review here, by structure, within the car or vehicle.

MOLDED FLOORS
Please note that I have specified that these are molded to differentiate between these and the load floor type fabrics which are found in station wagons, for instance. Time and time again, the molded floor is the main area within the car which receives the most discussion as to which product is better; Needled or Tufted. It is also the area in the car where there is the most disagreement as to the fiber type which is most suitable; nylon, polypropylene or polyester. Finally, it is the area within the car where we see the most disagreement in philosophy between the U.S., European and Asian manufacturers.

The performance requirements and test standards for the floor are quite high in the U.S. Admittedly, a needled floor does not abrade as well, is more difficult to clean, has less pile crush resistance and cannot be made as plush as a tufted floor for the same raw material costs. For this reason, as well as the availability of tufted products in the U.S., we see more tufted carpets in U.S.-spec cars than in Japan-spec cars. As much as 90% of the total fiber content of a tufted carpet can be found in the surface pile. This is usually very resilient and easy to clean as they are made up of individual fibers which do not hold the debris. With needlepunched carpets it is only possible to achieve up to 65% of the total fiber content as surface pile. The balance of the fiber is part of the base material which supports the fiber tuft. Until about three years ago it was only possible to achieve about 45% face pile weight with conventional needlepunched carpet. The reason for the 20% improvement is because of the development of the DiLour process by the West German company Dilo AG. To date, this new process of structured needlepunching has not found its way into U.S. built cars, or the floor, but worldwide it continues to be among the fastest growing needled products both in volume and application. European built cars now use DiLour type carpets for the molded floors and, depending on the country of manufacture, they are either polypropylene, polyester or a blend of the two. Here in the U.S., DiLour or Super Looper structured fiber is being used in trim applications and accounts for about 5-10% of this market.

If aesthetics were the only criteria, we would see tremendous amounts of needled products on the floor because of the lower production costs and the superior moldability of needled carpets. I think you would be hard pressed to find anyone in the world who did not pick a car because it did not come with a tufted floor. In the U.S., the fiber of choice for floors is nylon and it accounts for over 90% of the fiber used by the "Big Three". However the transplants, as well as imported cars are using a great deal of polypropylene and in many cases this is needled. There is no needled nylon in use here in the U.S. for floors due in part to the limited availability of solution dyed nylon. The use of nylon for needlepunched products is only a result of designers' desire to match all the interior fiber types. It is unlikely to find nylon used in any volume in other auto producing countries. Instead, the fibers of choice are polypropylene and polyester.

In the Far East, Europe, and Latin American countries there are more needlepunched molded floors than tufted. Many of these are unique ribbed fabrics that have very good abrasion resistance. This ribbed product offers better abrasion resistance than velour.

TRUNKS
This is one area of the auto where there seems to be agreement and consistency worldwide. Nearly all trunkliners in use are made from needlepunched fabric and nearly all are made from polyester fibers. A great deal of the polyester in use is derived from bottle waste. This along with the relative low cost of polyester makes it the least expensive fiber to use. When you add the lower production costs of needlepunching, you have an unbeatable combination. It is a very inexpensive means to add a great deal of aesthetic appeal to an area of the auto usually ignored.

Polyester fabrics, when used in conjunction with substrates of fibers which melt or soften at lower temperatures like polypropylene, can be molded and formed to fit the interior dimensions of the trunk. This adds tremendous aesthetics to the area and because the substrate material is plastic, it becomes rigid and self forming when cooled and removed from the molding process. The use of any textile product certainly adds to the reduction of road noise so you have another justification for the needled structure.

In higher end cars, a waste fiber blanket or pad is also used under the molded trunk to further add to the noise reduction. This "shoddy" pad or "underfelt" as it is called in the Far East, is usually made from a blend of waste fibers which are torn and picked from woven waste products made from cotton, polyester, polypropylene, nylon, and acrylics to name a few. In some parts of the world there is still a great deal of "hard" or natural fibers used for this area. Fibers like wool, coconut, sisal, tequilla, jute, hemp, and even hair. This same type of fabric can also be found under the floor of the car and has excellent absorption of road noises. There is no question that the economic value of these fibers make them an unbeatable choice.

With the continued growth of vehicles with hatchbacks, and to further enhance the aesthetics of the rear area, we see much more use of structured nonwovens. Structured nonwovens differ from the needled structures this paper refers to. Structured nonwovens are created by replacing the felting needle with a needle which has a small fork opening at the point, hence the name "Fork" needle. These needles carry a single distinct bundle of fiber and, depending on the orientation of the needle, create a velour or a ribbed surface appearance. These ribbed and velour type fabrics will be discussed in greater detail in discussion of interior trim applications.

HEADLINERS
There is an incredible amount of textile fabric located overhead in today's automobile and this is an area where there is considerable discussion and disagreement about which type of fabric is best suited. Again, a great deal is involved in deciding which is better and once again it is more often decided on availability of raw materials and the performance standards established. In the U.S., the test standards are quite high and needled nonwovens cannot compete against knits and wovens without substantial increases in basic weight and this often prices them out of consideration. In many other markets however, it is common to find needled polyester and polypropylene nonwovens which have very good abrasion resistance and mold well with the variety of substrates commonly used. A number of the so called "transplants" are now using needled headliners and new technology in web forming. Low fiber deniers and sophisticated needle styles could easily allow needled products to be competitive within the next few model years. A number of Japanese companies are looking for sharing of technology with U.S. companies to produce these products in the U.S.

The Japanese seem to be slightly ahead in the use of the finer deniers and lighter weights needed for needled headliners to be competitive. Because they have already been developing products with very low deniers, and weights as low as 3.5 oz/yd2 for the synthetic leather and man-made leather products, it was quite easy to fill the niche created for autos. A number of European companies are also using needled headliners in their mid to low end autos.

The substrates for the headliner have long used a number of different types of needlepunched products. Glass fiber has been used for years because of its sound and thermal insulation qualities, and of course the moldability. However, recent health concerns for the workers who must frequently handle this type of fiber have prompted the use of different substrates. It would appear that the use of needled polyester that is later molded quite easily, will be one of the newer processes to be incorporated.

BODY PANELS/RIGID COMPONENTS
The U.S. has long been a user of a variety of components within the car which are made up of composites of a variety of fibers, resins and polymers. There are a number of products within the car that begin as a blend of wood fibers and a small percentage of textile fibers which are formed into needled blankets. These are then combined with a variety of resins, adhesives and binders which are molded and compressed into forms that when cooled or cured actually create lightweight, flexible and strong components. They are used around the firewall, dash, fender liners, speaker and parcel structures, engine bay enclosures, and many more. Another composite blend used in this area is glass and thermoplastic. The glass matt is formed and then needled to allow it to be handled easily. In South America they are using a variety of natural fibers as previously mentioned. The difference between these blends and the one mentioned previously for underfelts is the amount of chemicals which need to be added to ultimately form very rigid parts.

HEAT SHIELDS
Rather interesting composites are used in autos as heat insulators between "hot areas". These consist of various products which are produced from fibrous mats that include polyester, fiberglass, aramid, ceramic, shoddy, and others. Other heat shields are already being used that utilize mineral fibers because of their thermal properties and low cost. The use of this product will most certainly grow with the continued concern over handling glass fibers.

INTERIOR TRIM
This rather large category of needled fabrics could actually include both the headliner and the floor. But it is more common to refer to this type of product by the fabrics which are used primarily for their aesthetic qualities on areas other than the roof and floor, such as doors, seat backs and storage areas. Therefore this section will deal with all types except the roof and floor.

The typical interior trim fabric found on door panels, seat backs, parcel shelves, package trays, loadfloors, and rear hatches is generally a needled velour or flat needled fabric. In the U.S. the predominant fiber for this application is polypropylene because of its availability and resistance to ultraviolet rays. There is also a rather large amount of solution dyed polypropylene available in the U.S., while solution dyed nylon or polyester is not nearly as readily available. Polyester requires additional ingredients to meet the tough U.S. sunlight spec, and nylon in solution dyed colors is expensive and more difficult to needle. Here in the U.S. there are, however, a number of areas where both nylon and polyester are being used and it would appear that their usage will increase.

By contrast, the use of polyester in needled interior trim is considerably higher through all other countries of manufacture. In many countries there is considerable use of polyester even in molded floors that are needled. However, it should be said again that these types of needled fabrics are not as abrasion resistant as tufted or knit alternatives. The weight of the interior needled trim fabrics in the U.S. generally falls within a range of 9.5-16 oz/yd2 and are made of 15-18 denier fibers. However, in Japan and the Far East it is more common to find 6 denier fibers used. The abrasion resistance specifications in these markets is considerably lower than in the U.S. and this allows the weights to be lowered and it is not uncommon to find structured (velour and rib) fabrics in basis weights as low as 6 oz/yd2. This combination of lower weight and fiber denier has also meant that higher densities can be maintained to prevent adhesives and the substrate material from showing through.

VINYL SUBSTRATES
In terms of sheer yardage generated, this application of needled nonwovens is significant. A web of polyester generally 4.5-6.5 oz/yd2 is needled and then used as a substrate onto which is extruded or laminated a vinyl material for applications such as landau roof tops and seating. Because the styling trends here in the U.S. call for landau roofs, this will remain an application of considerable volume. It is not used in any significant volume in any other country and the forecast here in the U.S. calls for less and less to be used. We Americans prefer leather and cloth more and more, which reduces the consumption for seating. These are however considered upgrades and luxury items, so in other countries where function rather than fashion dictates, there will still be large volumes used in seating.

CONCLUSION
Without question my comments are only a "skimming of the surface" of the needled products used in autos today and the subject could easily fill volumes. I can tell you that there is consensus that needlepunched structures in the automobile will enjoy growth for years to come. Whether the fibers used are a single synthetic type, a natural or waste type, or some as yet unknown variation, manufacturers and designers continually finding new applications and composites are a booming area. The fibers and engineering specifications may vary from country to country, but the race is on between U.S., European and Asian manufacturers to find the lightest, most efficient and strongest composite or structure. If cost were no option, as in the case of motor racing, we would see more and more use of carbon fiber components. These fabrics and structures are often needled prior to carbonizing. Someday, we may well see the everyday commuter car comprised entirely of exotic fiber blends which started out as needled fabrics. They would easily have strength, impact resistance, anti-corrosion resistance and lightweight properties that steel or other alloys could never compete with.