DE9010276U1 - molded part - Google Patents

Description

FDNER .*E TB Oil I :rj £&EEacgr;· A«U· S FINCK PATENT ATTORNEYS EUROPEAN PATENT ATTORNEYS

MARIAHILFPLATZ 9*3. MÖNCHEN 9O POSTAL ADDRESS: PO BOX SSO16O, D-8OOO MÖNCHEN 95

1) KIHA TEXTILES GMBH DEGA-39456,9

2) NORBERT FINSEL 6 July 1990

MOLDED PART

From GM 88 07 017.4, an upholstered part for seating, reclining furniture or the like is known, which is provided as a removable cover or as a permanently integrated component with a padding containing a fleece, whereby the padding contains binding fibers made of thermofusible material, in particular so-called core-sheath fibers, and this binding fiber nonwoven is press-molded. A mixture of binding fibers and normal fibers, which are thermofusible to one another, can also be used as the nonwoven. The fibers can be polyester fibers and core-sheath fibers in a polyester core and a sheath made of copolyethers.

The object of the invention was to find several base materials with the same or at least similar properties, which are compatible with the surface materials currently predominantly and necessarily used in the vehicle industry, so that the other aims of the invention could still be met, and to provide a semi-finished product made of fibers, which by selecting these

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Basic materials, construction of the fiber structures, selection of fiber thicknesses, main layer thicknesses and staple lengths and mixing ratios, can be designed to form load-bearing molded parts without the use of any binding agents, which do not change their shape due to their own weight when installed. The parts should have a lower weight than those used for zs-it, require low energy to manufacture and, due to their material, enable production on lighter and therefore less complex, more inexpensive machines and factory doors. Particular attention is paid to the recycling of the materials used, even as laminated parts, t 3 production without waste and relief for the workplace *» .and also the later area of application with regard to "wsi ^ do: &zgr;.Zt. still required and existing volatile, partly toxic substances such as isocyanates, formaldehyde, styrene and CFCs.

Furthermore, surface finishing was to be integrated into the deformation process , whereby the aim was to create areas of high compression and areas of lower compression in a molded part using one material. The aim of these fiber structures was to meet requirements in terms of sound absorption, vibration and heat through a layered structure. It was also important to apply the surface materials currently used to the product in such a way that even where a similar surface is not possible for fashion reasons, the larger proportion of the material by volume weight can still be recycled by separating the surface from the carrier material, as well as any decorative material that may have been separated. The aim was to meet the future demands on industry in terms of disposal, which the legislator already envisages in accordance with the polluter pays principle.

This problem and the aforementioned tasks will, as

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as can be seen from the following claims.

With the materials described here, this can already be achieved today, in contrast to the molded parts previously made of different materials,

anticipation of genuine material recycling that is possible up to the point of returning to the original material, in this case a fiber, whereby energy recycling in the form of incineration with the problems or burdens on valuable landfill waste that have not yet been solved is avoided.

The fiber A) can be a solid fiber or a hollow chamber fiber. The multi-component fiber consists of a so-called multilayer fiber, e.g. side-by-side type or sheath core fiber or a fibril type, but usually as a fiber made up of a core and a sheath, whereby the melting point of the core material is usually above the melting point of the sheath material.

The characteristic feature of the fiber body according to the invention is that it is composed of fibers of the same chemical type, i.e. of simple polyester fibers, and then up to the multi-component fiber, e.g. of a polyester fiber, consisting of a polyester sheath and a polyester core.

For example, Trevira staple fiber UCCK 035/X can be used as polyester fiber A), and multi-component polyester fiber, e.g. Trevira Type 252. Polyamide fibers A) can be used, e.g. PA 6 Grilon, and multi-component polyamide fibers B) can be used, e.g. PA 6.6 Dipolyn.

Possible polyolefin fibers A) include fibers made of HDPE and LDPE and PP, e.g. Danaklon EA or Danaklon Soft, Danaklon ES types as multi-component fibers B).

As hollow fiber, for example, Dypont Polyester Fiberfill Type

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D202 can be used.

The single fibers A) have a thickness of 1.7 to 1000 dtex/ preferably 3 to 170, in particular 3 to 30 dtex. They also have a staple fiber length of 20 to 150 nm, preferably 30 to 80 nm, in particular 40 to 65 nm.

The multicomponent fiber B) has a thickness of 17 to 1000 dtex, preferably 3 to 170 dtex, in particular 3 to 30 dtex, and a staple fiber length of 20 to 150 mm, preferably 30 to 80 mm, in particular 40 to 65 mm.

Continuous fibers have a thickness of 1.7 to 1000 dtex, preferably 3 to 170 dtex, in particular 4 to 30 dtex.

As an alternative to the multi-component fiber used, which has the task of fusing the fibers and providing rigidity, a polymer powder with a chemically identical structure can also be mixed into the fiber structure.

The polymer powder is added in an amount of 10 to 60 wt.%, preferably 20 to 50, in particular 30 to 40 wt.%.

The fiber structure according to the invention can only comprise a single main layer, but in order to better represent sound, vibration, thermal insulation and different densities, it should also have two or more main fiber layers that are homogeneous in terms of the fiber mixtures. The mixing ratios in the main layers can also be different. This means, however, that the main layers are always made of the same material, i.e. either polyester or polyamide or polyolefin.

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For example, a thermally strengthened fiber body is preferred for insulation, the upper main layer of which contains 0 to 40% multi-component fibers, residual fiber A), e.g. type filler fiber, and the lower layer contains 20 to 50% multi-component fibers, residual fiber A), whereby the fiber mixtures are homogeneously mixed within the corresponding main layer. The fiber lengths here are in the lower range. In addition, the mat is mechanically strengthened on one side. The thicknesses of the main layers are not critical, they are selected according to requirements.

The fiber structures according to the invention can be used in a variety of ways and are processed into molded parts. By choosing the fiber mixtures and limiting them to one material, including the surface materials currently used predominantly made of polyester, polyamide and polypropylene, it is now possible for the first time to reprocess the molded parts using a recycling process. In addition, and this is also remarkable, no vapors or gases that pollute the environment are produced during the processing of the fiber bodies according to the invention or the molded parts, since no solvent-containing binding agents have been used.

Through the fiber structure and also through the use of only force and energy (mainly heat), the fiber structure receives its final form, whereby areas with very different densities can be created in one work step. The molded body will not change its shape due to its own weight in the installed position, even as a load-bearing part, unless this is required by the use of the molded part. Through the proportion and positioning of the multi-component fiber and its staple length, taking into account the force applied and compression, thus in one work step, important functions for sound insulation, vibration insulation, as well as heat insulation, such as layered

differently compacted structure with increasing proportions of fiber crossing points.

The use of a thermoplastic adhesive layer also ensures that foreign decorative layers, which prevent recycling, can be removed by heat activation alone, so that both parts can then

can be recycled by separation and, if necessary, disposed of!

By using continuous fibers, the tear resistance, impact strength and cold resistance can be significantly increased in order to cope with more extreme loads.

By using hollow chamber fibers, the elasticity and permanent resilience can be significantly increased.

j The different densification makes it possible to produce shapes in one operation which previously required a second material (here mainly foam), which made recycling impossible.

The fiber structures according to the invention can be processed into molded parts in the following way:

a. The processed fibers are mixed homogeneously and deposited aerodynamically on deformed, perforated, sieve-like tools using air or other fluids as a transport medium. The upper half of the tool is also permeable to air. The fiber mat is then heat-treated (e.g. hot air), pressed, cooled using cold air, for example, and then sent for further surface treatment.

b. The fibre structure is first produced as a semi-finished product in the form of a mat. This mat can then be additionally

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are mechanically pre-strengthened on both sides and pass through a heating oven. Here, hot gases, mainly air, are blown or sucked through the fiber structure and then pre-compacted over several calender rolls. The product obtained can then be placed in a hot tool, pressed and shaped in the process, then put into a mold .

&pgr;&kgr;»&eegr; and, if necessary, further processed.

c. The process is carried out as described under b, except that after pre-compaction, perforated, sieve-like tool halves are used again through which, for example, hot air is sucked, /then it is cooled with, for example, cold air and the end product is removed.

d. The process is as described under b, except that after the pre-compaction, a further curving takes place and the semi-finished product is stacked. This mat can now be processed in a further operation in a circulating air area.

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or contact heat and place between cooled tools. The molded part is then pressed, the dimensionally stable molded part is then removed and further processed if necessary.

The molded parts according to the invention can be used in particular in the motor vehicle, aircraft and rail vehicle industries for the production of any type of vehicle lining. They are also suitable, for example, for the production of car door side panels, sun visors, engine compartment and trunk insulation, armrests and insulating parts behind molded carpets.

As already mentioned above, the molded parts according to the invention can be reprocessed after wear, in the case of faulty production, stamping waste, or during dismantling of automotive parts, namely by crushing. In this case, the crushed material can be melted into

a granulate can be obtained. This granulate can be extruded from a thermoplastic state in a melt to form a film, a plate, a molded part, or if absolutely chemically identical material existed in the molded part, a fiber with the same chemical structure can be recovered. The same procedure can be used if dissimilar surfaces have been used and these can be removed by heat activation of the thermoplastic adhesive layer. The type and degree of disposal of the surface materials depends on their material composition.

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Example 1 (method a)

A molded part for the armrest in a car is to be produced. The ?fsr6 is not subject to change, but is to have high permanent restoring forces and. Strengths, as in PÜR-Schauis in a room. of

50 kg/cm ^3. The base fibre is a hollow polyester tartan of the type Dacron Fiberfill 13 dtex, 63 % rayon length and the melt fibre is a Trevira type 4.4 dtex

51 mm homogeneously mixed. The mixing ratio is 50/50%. This mixture is deposited from a type of silo via air flow onto a perforated lower tool and when the desired high surface weight is reached, the upper tool, which is also perforated, is closed, whereby the part is compacted as a whole. This tool is then exposed to a hot air flow, whereby the temperature, air flow strength and flow duration depend on the volume of the molded part. The molded part is then cooled with a density of approx. 30 kg/cm ³ using cold air, which fixes the fibers. The part is then removed from the tool and processed for further use.

Example 2 (method b)

In this example, a so-called C-pillar (molded part between the rear window and rear door in a car) is to be manufactured using polyamide fibers type PA 6 Grilon 7 dtex and a fiber length of 60 mm and a sheath core fiber type PA 6.6 Dipol.yn 4.4 dtex and a fiber length of 50 mm. The mat is laminated with a polyamide knit 170 g/m ² , 1 mm thick. This knit is previously coated on the back with a copolyamide Schenzel adhesive film with 50 g/m ^3. The activation temperatures are between 120 and 13O ⁰ C, the softening temperature is 100 ⁰ C. The mat comes out of the pre-compaction with a body heat of 80 ° C and is placed in a hot pre-forming tool. Here the part receives its required body heat of approx. 16O ⁰ C and is then placed from this tool into a cooling tool.

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Here the knitted fabric is now fed as a continuous web between the tool halves, finally pressed with the fiber body and laminated. The body heat of approx. 130 to 140 ⁰ C in combination with the pressure is sufficient to activate the copolyamide film and produce a bond. A dimensionally stable, surface-stable fora part can be removed from the cooling tool for further processing.

-ä (Verfi ^n c)

A mat made of PP fiber 17 dtex 80 mm and a bicomponent fiber ES 3.3 a_:ax 60 mejogim is mixed. The proportion of multicomponent fiber:single fiber is 30:70 in the upper main layer with a thickness of 25 mm and 15*85% in the other, also 25 mm thick. It is pre-compacted to form a mat weighing 1000 g and 50 mm thick and stored temporarily. This mat is then passed between two perforated tool halves and exposed to a hot air flow, whereby the material is deformed and pressed into areas with very different densities in order to correspond to the deformations of the body. The temperature, flow speed and duration are again dependent on the desired surface appearance of the molded part. The formed mat is then pressed directly onto a formed carpet with an EPDM heavy layer film. (A composite of PP fiber structure, EPDM heavy layer and PP fiber carpet can be recycled as a polyolefin composite). Therefore, the cooling phase is kept short and the residual heat of the molded part is used to bond the fiber structure to the carpet molded part.

Example 4 (method d)

The aim is to produce a hat shelf for motor vehicles, with a needle-punched nonwoven fabric of 340 g/m ² as the upper fabric and a needle-punched nonwoven fabric of 100 g/m ² as the lower fabric, both made of polyester.

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Ratio of polyester fiber to multi-component fiber

The polyester fiber has a thickness of 12 dtex and a staple fiber length of 50 mm _, the multi-component fiber , type sheath fiber, has a thickness of 4.4 dtex and a staple fiber length of 50 mu. A fiber body in the form of a fiber mat with a density of 1000 g/m ² is made from these two fiber components and heat treated. The mat, which is originally several times thicker , is pre-compressed to 40 mm. The semi-finished product is then fed into a type of heat chamber and ^heated to 180 ⁰ C with hot air. It is important that this heat is achieved throughout the fiber body. The flow speed , strength and duration are again dependent on the shape. The pre-treated mat is then transported to the forming tool and laid down. The copolyester melt powder used was sintered onto the two fleece materials beforehand, 50 g for the upper fabric and 30 g for the lower fabric. The decorative material to be laminated, polyester fleece with a surface weight of 340 g/m ² and a thickness of 4 mm, is previously guided as a final web between the upper and lower tools, as is the 100 g lower fabric, whereby both materials were preheated to approx. ^{90 °} C using radiant heat; the upper and lower tools are cooled. When pressed and shaped, the fiber mat transfers its own heat to the thermoplastic adhesive layer and forms a firm bond. The fibers are fixed and frozen by shock freezing, so that the molded part can be punched immediately, removed from the tool and sent for further processing.

Claims (2)

Protection claims 1. Molded part containing one or more fiber structures based on polyester, polyamide or polyolefin fibers, characterized in that the fiber structure A) essentially contains polyester, polyamide or polyolefin fibers with 1.7 to 1000 dtex and a staple fiber length of 20 to 150 mm and B) multi-component fibers of the same composition as fiber A), i.e. polyester, polyamide or polyolefin, with 1.7 to 1000 dtex and 20 to 150 mm staple fiber length, deformed exclusively from force and energy and can consist of areas with different densities, which do not change their shape in the installed position due to their own weight. 2. Moulded part according to claim 1, characterized in that it has a thermoplastic adhesive layer made of the same material on one or more surfaces. 3, molded part according to claim 1 or 2, characterized in that it additionally contains one or more decorative layers made of the same material.