DE4403977C2 - support layer - Google Patents

Description

The invention relates to the features of the preamble of claim ches 1 a particularly for a multi-layer interior trim part for Motor vehicles certain wearing layer with a natural fibers Send core layer and with a bandage arranged on both sides thereof medium and fiber covering layers. This flat stretcher layer is intended for a multi-layer interior trim part that is designed as Carrier this base layer and a preferably soft-elastic intermediate layer and a decorative layer.

A support layer of the type mentioned is known from EP 0 411 589 A2 known. This document specifically concerns a motor vehicle Headlining made of a fibrous base layer and on both sides applied surface coatings, preferably made of polyurethane hanschaum, and a process for its preparation. The one there The core layer provided for the base layer consists, for example, of flax  fibers. Cover layers are assigned on both sides. This Ab Cover layers contain fiber reinforcement material and especially glass fibers made with the help of liquid phenolic resin are interconnected. As the core layer, apart from the flax also pre-fiber palm fibers, polystyrene fibers, glass wool and hair felt be seen. The liquid phenolic resin serving as a binder is used in a temperature of about 170 degrees Celsius and a pressure of processed about five bars, the part to be manufactured also a three can get dimensional shape. That is in the cover layers che, fiber-containing reinforcing material can according to the Aussa EP 0 411 589 A2 also contains vinyl fibers, cotton fibers, Rayon fibers, polyester fibers, polypropylene fibers and / or flax fibers or glass fibers exist. The said publication therefore mentions one Variety of very different fibers, but without one actually to disclose usable product.

Furthermore, DE 37 22 873 A1 describes a method and a device for producing a motor vehicle equipment part from a stretcher layer, a soft elastic intermediate layer and a decorative layer known that also around at least a thin-walled base layer summarizes. The base layer consists of a polypropylene-containing company servlies, which can also be recycled material. she is made up of only one layer according to this state of the art.

Another plate-shaped material, the packaging and / or pole is to serve stere purposes, is known from DE 39 36 011 A1. The parts are made of sheet material, which is made of a natural fa servlies and in particular from waste fibers mixed with binders consists. Wells are provided in the plate-shaped part to its Increase stiffness. Multi-layer webs are made according to this teaching formed by placing several single-layer plates on top of each other and be connected to each other. This prior art includes thus also a three-layer web with natural fibers in the core layer and the two cover layers and the same binder kept in all three layers.  

Another roof cladding for motor vehicles is in the German one Utility model 84 15 883 shown and described. she consists from a supporting base or a supporting part made of solidified Fa servlies and decorative material, the cross-section of the supporting part is gig. This is a layer structure made of phenolic resin strengthened, native tear cotton fiber fleece and from phenol resin compound real synthetic fiber fleece. Specifically, this means that a core layer is made of phenolic resin-bonded tearing cotton fiber fleece and on both sides thereof arranged layers of phenolic resin-bonded polyester fiber fleece are provided. The solidification takes place both in the core layer and also in the cover layers with the help of phenolic resin.

Finally, DE 39 35 689 A1 describes one method and one Device for the production of motor vehicle interior trim parts, where several, heat-stable and thin-walled layers and layers, optionally with a polyethylene portion or a polypropylene share with the help of thermoplastic plastic powder be connected by heating and pressing. The locations and Layers also form cover layers and are used in manufacturing fed as a sheet material of the device. To achieve un Different hardness of the individual layers, the amount of ver used plastic powder varies. To achieve different Ela The hardness and the other materials also become static properties of the starting material and finally the degree of ver seal changed. Above all, it is provided that the material for the Cover layers a heat-stable material made of polyester, glass fleece, Paper fleece and absorbent, heat-stable fiber material for filling fabric, textile fleece, polypropylene, polyethylene, glass fleece, paper fleece, open Foams or polyurethane can be used.

Although a very extensive literature on the use of Naturfa sern exists for automotive interior trim parts, is currently a Breakthrough in large series failed. The natural fibers change  in contrast to plastic fibers, after a relatively short time that the original material properties are lost. reason Additional natural fibers are not made with precious wood comparable, which also used as interior trim parts in Motor vehicles were used and had a longer life than the motor vehicle itself. This may be for a crowd Production of natural fibers in question - probably because of the large surface - but often so sensitive to that Presence of oxygen and especially oxygen in verbin with moisture that all considerations for this use in Ver clothing parts for motor vehicles so far, despite diverse publications solutions have barely got beyond attempts. Although the be said insights are not recent, they are but the cause of the fact that it has so far not succeeded, Naturfa Motor vehicle interior cladding parts with large series or to successfully establish in mass production.

The invention is therefore based on the objective of taking measures hen, with the help of which it is also possible to use natural fibers Motor vehicle interior trim parts from such fibers tendency support layer, a preferably soft-elastic intermediate layer and a decorative layer with the necessary durability and with constant throughout the life of a motor vehicle manufacture. The object of the invention is therefore one for this provide a suitable base layer.

This object is achieved by the support layer according to claim 1, which is provided with the features of the characterizing part that the natural fibers as filler and recyclable, thermoplastic art Material arranged as a binder for the natural fibers in the core layer are that at the same time thermoplastic as a binder for Glass fibers arranged as filler in the two cover layers is seen, and that the cover layers have a larger percentage Share in the thermoplastic serving as a binder have as the core layer with the natural fibers.  

With a base course with these characteristics, it has managed to be a force Vehicle interior trim part from this base layer, a Weichela to create an intermediate layer with a decorative layer that is not only meets the requirements and is sufficiently durable, but also has shock-absorbing properties and can be easily recycled at a later date can. All to a cost-effective motor vehicle Interior trim part requirements can therefore be met with the fulfill said features with little effort.

Both the production and can be designed particularly advantageously achieve an excellent product if in training the Erfin the ratio of thermoplastic to filler in the Cover layers is about 70:30, with polypropylene is provided as a thermoplastic.

Further features of the invention are set out in the sub-claims connection with the description and the drawing.

The invention is illustrated below using exemplary embodiments are shown in the drawing, described in more detail. Show:

Fig. 1 on a larger scale and only schematically one step through a multi-layer body with a stretcher and

Fig. 2 on a larger scale, a section as in Fig. 1 by a modified embodiment.

The multi-layer body 1 shown in FIG. 1 has an arbitrary, easily recyclable decorative layer 2 as the outer layer such. B. a fabric and a ter preferably a soft, made of plastic foam de intermediate layer 3 . A flat support layer 4 serves as a support for the decorative layer 2 and the white chelastic intermediate layer 3 .

The base layer 4 is composed of three layers. This is a natural fiber as a filler 5 and a thermoplastic 6 ent-containing core layer 7 , which is between cover layers 8 and 9 arranged on both sides. The two cover layers 8 and 9 are each also made of a thermoplastic 10 , embedded in the glass fibers 11 .

The thermoplastic 6 of the core layer 7 and the thermoplastic plastic 10 of the two cover layers 8 , 9 is preferably polypropylene, in which the natural fibers serving as filler 5, the core layer 7 and the glass fibers 11 in the cover layers 8 , 9 are melted.

Both in the core layer 7 and in the two cover layers 8 , 9 serve as polypropylene 6 and 10 at the same time as a binder or as a hot melt adhesive for the fibers and also for the layers 7 , 8 and 9 to one another.

The core layer 7 has less meltable, serve as a binder, the thermoplastic material 6 than each of its two cover layers 8 , 9th Thus, the ratio of thermoplastic material 6 or polypropylene 6 to filler 5 in the form of natural fibers in the core layer 7 is preferably about 50:50. In comparison, the cover layers 8 , 9 thermoplastic or polypropylene 10 to glass fibers 11th in a ratio of about 70:30.

The lower proportion of meltable plastic and the higher proportion of fillers in the core layer 7 compared to that in the cover layers 8 , 9 ensures that the core layer 7, in particular during the production with heat and pressure, has sufficient inherent stability and strength receives. The core layer is due to their fillers 5 in the form of natural fibers during manufacture, even at high temperatures, able to withstand the pressures due to production and the order of magnitude, with the result that they do not collapse and that the desired and for the rigidity of the finished product required material thickness arises. It is also important in this context that the fillers 5 are light and do not change at the working temperature that occurs. Natural fibers meet this requirement if they become hot due to the extensive exclusion of air, but cannot burn. During manufacture, the fillers 5 in the core layer 7 are protected from the ingress of air even at a relatively high temperature, because the thermoplastic in the cover layers 8 , 9 melts first, and air-impermeable boundary layers in the form of the cover layers 8 , 9 are formed in each case. The fillers 5 also increase the strength and rigidity of the finished product insofar as they are still present as fibers after the manufacturing process. Together, the thermoplastic 6, in particular polypropylene 6 , and filler 5 in the form of core layer 7 containing natural fibers, and the thermoplastic 10, in particular polypropylene 10 , and cover layers 8 and 9 containing glass fibers 11 , have their own stable, flat and three-dimensionally formable base layer 4 extremely favorable properties.

The production of the base layer and the multilayer body 1 from the base layer according to the invention, a preferably soft elastic interlayer and a decorative layer z. B. in a heating press under pressure at a sufficient melting temperature, whereby a one-piece composite body is formed. Its spatial physical shape is already in the production by appropriate design of the z. B. generated heating plate.

The starting material for the individual layers of the base layer 4 are each web-shaped or needled fiber material cut into pieces. This needled fiber material already consists of natural fibers and polypropylene fibers or of glass fibers and polypropylene fibers. The sheet-like or cut into pieces of suitable size is brought together in the heating press and then heated and compressed. The support layer 4 contained in this way is further brought together with the intermediate layer 3 , which is preferably already laminated with the decorative layer 2 and is made of plastic foam, the heat of the support layer 4 generally being sufficient to melt the neighboring surface of the plastic foam of the soft elastic intermediate view 3 that the necessary one-piece connection is made. The material thickness of the multi-layer body 1 and its individual layers or layers depends on the respective intended use. You can also with large parts such. B. a roof sky element for a motor vehicle in the order of less than 5 mm or little more than 5 mm.

The multilayer body 1 a, which is also shown only schematically and in section and on a larger scale in FIG. 2, is an only slightly modified multilayer body, the same parts having the same reference numbers and additionally the letter index a.

The multi-layer body 1 a consists from top to bottom of a cover film 12 a, from a multi-layer support layer 4 a, an adhesive fleece 13 a adjoining it downward, an adjoining plastic foam layer 3 a and an intermediate layer Decorative layer 2 a.

The cover sheet 12 a can be a paper fleece or a separating layer, which ensures that the support layer 4 a in the heating press can be easily detached from its heating plate or contact surface after the heating and pressing process has ended.

The support layer 4 a consists, according to the example shown in FIG. 2, also of three layers, namely a core layer 7 a and covering the top and bottom sides and integrally connected cover layers 8 a and 9 a in the finished product.

The composition of the core layer 7 a and the two cover layers 8 a and 9 a of the support layer can be as in the first described embodiment or in different orders of magnitude. For the two cover layers 8 a and 9 a, polypropylene fractions of approximately 70% and glass fiber fractions of approximately 30% therefore also preferably apply. However, the ratio of filler 5 a to thermoplastic or polypropylene 6 a in the core layer 7 a is preferably 70% to 30%. As a result, this means that the proportion of filler 5 a to thermoplastic or polypropylene 6 a in the core layer 7 a can be in the order of 50:50 to 70:30.

To 5 as a filler, a serving natural fibers include fibers from straw and / or cotton and / or flax and / or hemp and / or jute and / or sisal.

In view of the relatively high temperatures that arise during the manufacturing process in the heating press, the natural fibers must be protected to a certain extent, and this is only possible if protective layers against the contact heating plates are present. For this purpose, the cover layers 8 and 9 are used and for this reason do not contain natural fibers as fillers but glass fibers, which additionally have a stabilizing effect.

Finally, it is understood that the invention is not limited to use is limited by polypropylene as a thermoplastic. much other plastics such as polyethylene or polyurethane can do more and others are used, provided the disposal is recyclable or other usability are assured.

Claims (6)

1. Flat support layer, in particular for a one-piece and multi-layer interior trim part for motor vehicles, with a core layer comprising natural fibers and with cover layers arranged on both sides thereof, comprising a binder and fibers, characterized in that

• a) that the natural fibers as filler ( 5 , 5 a) and recyclable, thermoplastic ( 6 , 6 a) as a binding agent for the natural fibers in the core layer ( 7 , 7 a) are arranged,
• b) that at the same time thermoplastic ( 10 , 10 a) as a binder for as a filler in the two cover layers ( 8 , 8 a) and ( 9 , 9 a) arranged glass fibers is hen and vorgese
• c) that the cover layers ( 8 , 8 a and 9 , 9 a) have a larger percentage of the thermoplastic resin serving as a binder ( 6 , 6 a and 10 , 10 a) than the core layer ( 7 , 7 a ) with the natural fibers and that the core layer ( 7 , 7 a) has a larger proportion of filler ( 5 , 5 a) than the cover layers ( 8 , 8 a and 9 , 9 a).

2. base layer according to claim 1, characterized in that the core layer ( 7 , 7 a) each filler on the one hand and ther moplastic plastic ( 6 , 6 a) on the other hand in a ratio of 50% to 70% on the one hand and 50% to 30% on the other having. 3. Carrier layer according to at least one of the preceding claims che, characterized, that the ratio of thermoplastic to filler in the cover layers is approximately 70:30. 4. base layer according to at least one of the preceding Ansprü surface, characterized in that polypropylene is provided as the thermoplastic ( 6 , 6 a or 10 , 10 a). 5. base layer according to at least one of the preceding Ansprü surface, characterized in that the core layer ( 7 , 7 a) and / or the cover layers ( 8 , 8 a and 9 , 9 a) as filler ( 5 ) fibers of straw and / or from cotton and / or from flax and / or from hemp and / or from jute and / or from sisal. 6. base layer according to at least one of the preceding claims che, characterized, that as a starting material for the individual layers per web Miges, needled fiber material is provided.