Groz-Beckert KG

Newsletter 4 | 2011

"Clothes make the man" -
and nonwovens make the car

There are now more than 40 applications for nonwovens inside automobiles. That means that over 35 square metres of flat textile surfaces can be found inside one of today's cars. Visible nonwovens, however, account for only 10 percent of the entire amount, i.e. roughly 3.5 square metres. What other areas of application exist? What are the names of the technologies employed, and what criteria have to be taken into consideration? The following article answers these questions and many more.

Examples of nonwovens in a car

1)Door and side panelling  2)Underbody covers  3)Airbag covers  4)Floor and footwell covers  5)Rear of seat  6)Brake disks  7)Textile wheel-arch liners  8)Exhaust systems  9)Filters  10)Engine insulation  11)Turbocharger  12)Battery  13)Side and rear door panelling  14)Rear parcel shelf  15)Stowage compartment cover   16 A- and C-columns  17)Headliner  18)Sunshade  19)Dashboard  20)Bonnet covers  21)Floor of boot, spare wheel cover

The main reasons why more and more nonwovens are being used in cars are their low weight, their favourable cost-benefit ratio and the almost endless amount of variations, offering numerous technical solutions and design options.

Nonwovens in automobiles fulfil a large number of requirements, and are based on the most diverse production technologies. The following types of nonwoven are principally used in cars:

  • Hydroentangled nonwovens
  • Knit products
  • Multiknit products
  • Meltblown nonwovens
  • Malivlies nonwovens
  • Maliwatt nonwovens
  • Chemically entangled nonwovens
  • Needled nonwovens

Trendsetter: Finer fibres

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Generally, automobile nonwovens can be subdivided into three categories according to their application:

  • Nonwovens for sound absorption
  • Nonwovens for the creation of surfaces
  • Nonwovens as intermediate and separating layers

Colour fastness, dimensional stability, freedom from dust, flame-retardancy and non-fade properties are all important aspects here. However, strength combined with elasticity, washability, dirt repellancy and malleability are also important criteria where automotive nonwovens are concerned.

The most often used fibre type for needled automotive nonwovens is PES, alongside further types such as PP and PA. As a rule, fibre gauge lies between 1.3 and 300 dtex, whereby finer fibres are increasingly being used. Product weights used in the car amount to between 100 gsm and 1,400 gsm.

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Fork needle /crown needle with barbs at the base of the fork
Crown needle
Fork needle

In the case of visible nonwoven applications inside cars, specially structured products are often used. To achieve the required surface quality, so-called structuring needles are required. These involve two different needle types: crown needles and fork needles. They serve purely to create the surface according to customer requirements. This is why crown needles have only one barb on every edge accordingly, whereby all barbs are the same distance from the tip. Fork needles, on the other hand, have a fork-shaped opening to form the required loops. Special structuring machines known as brush conveyors are required to create the surface structure after subsequent needling of the surface. These machines have a conveyor equipped with brush segments. The fibres are pulled inside the brushes, held in place there and then transported warp-free. Very high needle densities combined with the brush treatment lead to velour that is free of any patterns or streaks.

Inside a car, the main areas of application of products structured like this range from floor coverings to rear parcel shelves, and from door and boot coverings to headliners.

Alongside conventional barb needles Groz-Beckert also supplies the structuring needles required for this special application. Depending on the product specification, crown needles or fork needles can be used for making high-quality velour products, or even a combination of both needle types. Here, crown needles provide a more even surface structure, while fork needles create grainier surfaces. The combination of both needles results in very dense velour products with constant and even surface quality. Conventional needle gauges for making structured products lie between 36 and 40 gg for crown needles and 38 and 43 gg for fork needles.

Technological specifications

Example

Headliner

Fibre gauge

3.3 - 6.7 dtex

Fibre type

PP, PES

Product weight

300 gsm

Pre-needling

15 x 18 x 36 x 3 R333 G 2017 (604051)

Penetration depth

10 mm

Penetration density

60 E/cm2 (S/cm²)

Main needling

15x 18 x 38 x 3 R222 G 3027 (609081)

Penetration depth

7 mm

Penetration density

150 E/cm2 (S/cm²)

Structuring

15x 17 x 32 x 40 x 63,5 DG 9055 (612611)
15x 18 x 38 x 2 3/5 S111 G 2017 (610881)
in combination

Penetration depth

8 mm

Penetration density

650 E/cm2 (S/cm²)

Production details

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Automotive substrates (natural fibre processing)
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Automotive velour

High abrasion resistance combined with a high-quality look

In April 2011 at the "Index" trade fair in Geneva, Switzerland, the latest generation of nonwovens for automotive carpeting was presented. The patented products with the brand names Lutraflor® by Freudenberg from Weinheim, Germany, consist of two layers. One layer is spunbond, and the other a staple fibre fleece needled into the spunbond. Both layers are made of polyester and co-polyester. The fibres consist of recycled polyester and require no chemical binding agents. According to the company, the nonwoven is especially impressive for its high abrasion resistance and high-quality look. This enables these products to be used for complete car interior carpeting, for insert mats and for interior panelling.

 (Source: Freudenberg Nonwovens, Weinheim)

If you have any questions here, do feel free to contact the Groz-Beckert experts from the Nonwovens division.