MXPA01010157A

MXPA01010157A - Moldable composite article and method of manufacture.

Info

Publication number: MXPA01010157A
Application number: MXPA01010157A
Authority: MX
Inventors: Stephen D Copperwheat
Original assignee: Knowlton Nonwovens Inc
Priority date: 1999-04-06
Filing date: 2000-02-29
Publication date: 2003-07-14
Also published as: CN1346308A; EP1171291A4; BR0009554A; TW500665B; EP1171291A1; CN1159150C; KR20010108459A; WO2000059716A1; JP2002540981A; CA2368738A1

Abstract

An article that includes a layer of fabric that can be formed of the type that when subjected to molding under heat and / or pressure has a high degree of hardness. A layer of variable compression fabric is able to take variable thicknesses when subjected to molding under heat and / or pressure are attached to the surface of the variable compression fabric, with layers that are made of the same polymeric chemical substance thermoformab

Description

MOLDEABLE COMPOSITE ARTICLE AND MANUFACTURING METHOD DESCRIPTION OF THE INVENTION This is a continuation request in part of the U.S. Serial No. 08 / 839,016, filed on April 23, 1997, which is incorporated herein in its entirety for reference. The present invention is generally related to a composite article and more specifically to a nonwoven fibrous composite mouldable article. In the manufacture of articles containing polymeric materials having a hardness and strength sufficient to function as a car trunk lining, it is known that they take sheets of a thermoformable material having different properties, they are placed in layers, and then they are compressed under heat and pressure in a mold. At least one layer is used that imparts hardness and strength and another layer that produces a sufficient volume for the molding. US Patent No. 5,298,319 discloses automotive trunk liners manufactured from a fibrous composite having outer layers composed of nonwoven fabric consisting essentially of a polypropylene raw material fiber and an intermediate layer composed of extruded polypropylene. Such fibrous composites of the prior art are assembled simultaneously with the extrusion of an intermediate polypropylene layer. The inner surfaces of the two outer non-woven fabric layers adhere to the surfaces of the extruded polypropylene by the heat generated in the extrusion process and the consequent molten state of the adjacent surfaces that melt during the process. With all three layers containing the same polymer, mainly polypropylene, the eventual recycling of the articles is facilitated. Several disadvantages are inherent in this prior art process. Because the intermediate layer imparting the volume necessary for molding is extruded, the articles molded therefrom will necessarily have a uniform thickness. Another disadvantage is that the fibrous composite must be assembled simultaneously with the extrusion of an intermediate layer. It is therefore an object of the present invention to provide an improved moldable fibrous composite that can be used to manufacture molded articles of varying thicknesses and densities. It is another object of the present invention to provide an improved moldable fibrous composite made of layers that can be assembled successively. It is another object of the present invention to provide an improved moldable fibrous composite made of compatible materials that can be easily recycled.

It is yet another object of the present invention to provide a nonwoven fibrous composite that can be molded in a one-step molding process. It is yet another object of the present invention to provide a nonwoven fibrous composite that can be used to mold articles having a high thickness to weight ratio. It is yet another object of the present invention to provide an improved moldable fibrous composite which, when subjected to molding under heat and pressure, easily takes the shape of the mold without breaking or tearing. It is still another object of the present invention to provide an improved moldable fibrous compound that can be used for thermoforming articles without the need for injected resins. To achieve the above objects and other objects and to solve the problems of the prior art described above, the present invention as exemplified and broadly described herein provides a non-woven fibrous composite material and a manufacturing method. The nonwoven fibrous composite according to the present invention possesses at least two functional layers, which are made of the same non-woven thermoformable polymeric chemical material or chemical. Suitable polymeric materials include polypropylene, polyvinyl chloride, polyvinyl acetate, polyamide, polyvinyl alcohol, polyethylene, polyurethane and polyester. In a preferred embodiment, the layers are made of a polyester. These compounds can typically be used without being limited to the manufacture of automotive linings, trunk liners, passenger compartment components, luggage, furniture, sports products and filtration products. The selected polymeric chemical is manufactured in two different fabrics having different mechanical properties and / or other physical properties. At least one fabric is a fabric that can be formed, which upon finally being molded under heat and or pressure, possesses a relatively high degree of hardness and strength. The other fabric is a variable compression fabric (also described as a fabric of variable thickness) that is capable of taking various thicknesses and densities when subjected to molding under heat and / or pressure. In certain applications where the final article requires a uniform density and thickness, the variable compression fabric can also be used. Such a variable compression fabric is the subject of US Patent No. 5,532,050 which is incorporated herein by reference. In an alternative embodiment, another layer constituting a coating fabric can be applied to the outer surface of any of the layers for the purpose of improving the appearance of the molded articles from the composite. The functional layers and the coating fabric layer can be assembled into a composite capable of being transported to finished shaped article manufacturers. The composite can be assembled by stacking the layers one on top of the other and combining them. The term "compound", as used herein, includes any stack of successive layers whether or not the cohesion between the layers has been improved by a chemical and / or physical means. The cohesion of adjacent layers of the composite can be improved by such techniques as spray-powder binding, the use of liquid dispersion / solutions, stitch bonding, flame lamination, use of an intermediate adhesive fabric between functional layers, and perforation with mechanical needles. , all of which are well known to those skilled in the art. Also included in this concept is an alternative embodiment in which mixtures of selected fibers having predetermined melting temperature ranges are contained within either or both layers that effect adhesion between the layers of the composite and the hardness of the final molded article. The adhesion mechanism that is carried out can be described as "thermoplastic bonding" and is better described in U.S. Patent 5, 456, 976; cabbage. 3, lines 36-50 which is incorporated herein by reference. A composite sheet is then placed in a mold, formed with heat and / or pressure to take the shape of the mold cavity, and thereby forming the final article shape. BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the nature and objects of the invention, reference should be made to the following detailed description of a preferred mode for practicing the invention, read together with the accompanying drawings, in which: Figure 1 is an isometric view of the mouldable fibrous composite according to one embodiment of the present invention showing its layered configuration. Figure 2 is a schematic representation of a system for producing molded articles according to another embodiment of the present invention. The present invention will now be described in detail with reference to the specific embodiments and drawings. According to the present invention, the articles are molded from separate rolls or sheets of variable compression and fabric layers that can be formed, respectively. As illustrated in Figure 2, the fabric (25 and 26) that can be formed is dispensed from rolls (29 and 32, respectively), a variable compression fabric (28) is dispensed from the roll (31) and, optionally, the roll covering fabric (27) (30). These fabric layers are simultaneously fed from those respective rolls in a molding medium having upper (33) and bottom (34) portions, as shown in Figure 2. The automotive linings are formed by passing the separate layers of variable compression. and fabric that can be formed, containing binder fibers, through a compression mold having a cavity whose configuration is the shape of the liner as the roll of the composite material unwinds. To effect molding, the composite material is subjected to a high temperature for a predetermined time and then cooled in the mold. The binder fibers of the separated layers are softened and / or melted and mixed under heat and / or pressure and upon release of the mold, the fibers will cool and harden and bond the layers. According to another embodiment, layers of variable compression fabric that can be formed and, optionally, a coating fabric layer, are formed in a composite prior to the manufacture of an article. Reference is made to Figure 1, which illustrates the different layers comprising a composite article according to the present invention. For ease of illustration, the thickness of the different layers has not been drawn to scale.

In Figure 1 a composite article (1) comprises a layer of variable compression fabric (2) that is sandwiched between the fabric layer (5) that can be formed having an upper surface (6) and a lower surface (7) , and a layer (8) of fabric that can be formed, having an upper surface (9) and a lower surface (10), the upper (14) and lower (11) adhesive layers is interposed between the layer (2) of variable compression fabric and the layers (5) and (8) of fabric that can be formed, respectively, so that the upper surface (3) of the variable compression layer (2) butts the lower surface (16) of the adhesive layer (14) and the upper surface (15) of the adhesive layer (14) butts the lower surface (7) of the fabric layer (5) that can be formed and the upper surface (12) of the layer (11) ) adhesive splices the lower surface (4) of the variable compression layer (2) and the lower surface (13) of the adhesive layer (11) butts the surface ( 9) upper of the fabric (8) of fabric that can be formed, thereby improving the contact and cohesion between the layers (5) and (8) of fabric that can be formed and the layer (2) of variable compression. The above embodiment can be modified by applying the lower surface (19) of the coating fabric layer (17) on the upper surface (6) of the fabric layer (5) that can be formed by means of an adhesive layer (20). so that the lower surface (19) of the covering fabric (17) butts the upper surface (21) of the adhesive layer (20) and the lower surface (22) of the adhesive layer (20) butts the surface (6). ) of the fabric layer (5) that can be formed, thereby improving the appearance of the outer surface of the composite material and of the articles molded therefrom. The car liners or trunk liners can then be formed by passing the composite material through compression molding means, subjecting the composite material at elevated temperatures and / or pressure for a sufficient time for the composite to take the shape of the cavity printed. For use in the present invention, it has been found that the basis weight for the hardening fabric or that can be formed should be from about 4 to 18 oz / yd2. A preferred range is approximately 6 to 12 oz / yd2. These ranges provide an optimum combination of manufacturing handling capacity, hardness control properties of the final molded articles, and economy in the manufacture of the final product. In another embodiment of the invention, a polyester sheet of variable compression fabric is sandwiched between two polyester sheets which can be formed in the form of a needle-punched plush, thereby forming a composite article. Needle-punched plush is produced by Knowlton Nonwovens, Inc. of Utica, New York. The cohesion between the adjacent sheets is improved by a mechanical needling. The composite material is then rolled up into storage rolls. A decorative fabric layer, such as HOF AHMV8 printed bonding polyester or Foss needle-punched polyester can be applied to an outer surface of one of the layers of the polyester fabric that can be formed. An article, such as a car trunk liner or liner, is formed in the mold under heat and / or pressure. The molded article is then allowed to cool to room temperature. U.S. Patent 5,298,319, mentioned above, teaches the basic molding apparatus and methods for making articles of the type contemplated by the present invention and are incorporated herein by reference. It should be understood that different means for improving cohesion can be employed between different fabric layers of the same composite material. For example, the improved cohesion between the coating fabric layer and a fabric layer that can be formed can be effected by interposing between them an adhesive layer, while the improved cohesion between a layer of fabric that can be formed and the fabric layer of varying thickness can be made by needle-piercing.

Alternatively, the suitable composite material for molding can be manufactured from a single layer of fabric that can be formed and a layer of variable compression fabric. A coating fabric layer can be applied to the outer surface of any layer of fabric that can be formed or the layer of variable compression fabric. The cohesion between the functional fabric layers can be improved by such mechanical means as needle-piercing and / or by adhesive means such as spray-powder binding, the use of liquid dispersion / solutions. Flame lamination, and / or the interposition of a layer of adhesive and combinations thereof. The following examples illustrate various structural embodiments of the present invention and how the physical properties of the structures of the present invention are controlled by varying certain process parameters. In the following Example, the first and second hardening layers are produced by the needle-piercing process first by mixing the selected fibers in a standard textile mixing equipment followed by the carding of the fibers into a nonwoven web that then overlaps to build a high-flux multi-layered cotton glue which is subsequently pierced with needles with needle penetrations of approximately 1,000 pin.

A composite structure that can be molded in which a layer of variable compression fabric is sandwiched between two layers or sheets of a (hardening) fabric that can be formed is made by the following technique. The layers of the three materials are as follows: First Layer 50% Fiber Innovation Technologies 3.5 denier X 2 inches Binder hardener bicomponent crystalline polyester 50% Kosa 15 denier X 3 inches polyester type 295 base weight 6 oz yd2 needle punched construction (hardener fabric) Second Layer Same fibers, mix and construction as the previous base weight Hardener - 9 oz / yd2 Compression Layer 50% Fiber Innovation Technologies with 3.5 denier X 2 inches Variable bicomponent binder fiber 25% crystalline polyester 6.7 dtex polyester 25% 17.0 dtex polyester basis weight - 20 oz / yd2 thickness - 20 mm vertical overlap construction (variable compression fabric) There is no adhesive layer between each of these materials. The variable compression fabric of vertical overlap product is produced in a Strudo machine produced by: I.N.T., s.r.o. 460 05 Liberec, Karla Capka 302/22 Czech Republic To produce the variable compression layer, the three polyester fibers, including the binder fiber, are mixed in a standard textile fiber mixing equipment and carded to form a non-woven web. The carded web is fed to the vertical overlapped Strudo machine to fold back on itself or to fold to produce a vertically folded product of a given thickness. The coarse product is passed through a furnace that heats the product to about 150 ° C which softens or melts the binder fiber to allow it to thermally bond to the other fibers in the blend, thereby producing a coarse, fluffy three-dimensional product. To produce the molded article defined above, the process includes layered fabrics within a composite, preheating the composite to approximately 204,444 ° C (400 ° F) for about 8 minutes, placing the compound in a mold, closing the mold in a space of 16 will go for about 4 minutes, and open and remove the molded article. For hot mold samples, the mold (hot tool) preheated to approximately 148,889 ° C (300 ° F).

Samples of three composite layers, in which the variable compression layer is sandwiched between the first and second hardening layers, are made both in the machine direction and in that of the cross machine. Additional samples which have the same are made both in the direction of the machine and in that of the cross machine using an unheated mold (cold tool) at room temperature. Four samples made in accordance with the above method were tested under Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials (Methods of Testing for Flexural Properties of Reinforced and Non-Reinforced Electrical and Plastic Insulation Materials) using the Method of Test IA of three-point loading system using a central load on a simple support beam, ASTM Designation D790-92. The results of the test are tabulated in the Table 1 next: TABLE 1 FLEXION TEST RESULTS DESCRIPTION THICKNESS LOAD OF PRODUCTION PROLOGUE TO 1"SAMPLE SLOPE * (mm) DES DUCTION (N) (%) (N / mm) CENTERED (N) Tool at 16.50 20.9 21.2 101 5.72 cold SSL VCL FSL (machine address) Tool in 17.50 21.5 22.5 105 5.65 hot SSL VCL FSL (machine address) Tool in 17.50 24.5 29 118 6.46 cold SSL VCL FSL (cross machine address) Tool on 17.75 22.4 28.5 127 5.90 hot SSL VCL FSL (cross machine direction) * SSL = Second Layer Hardener VCL = Variable Compression Layer FSL = First Hardener Layer The operating range that provides adequate hardness for the molded compound of the present invention is approximately 13 to 26 Newtons for the Load of Decentralized Production. The 1"Production Load for the present invention ranges from about 90 to 140%, and the Slope should be in the range of about 2.5 to 7.0 N / mm.The product of the present invention in a preferred embodiment requires a high degree of hardness to be suitable for use as a car liner, with the term "high hardness" being defined by the results of the bending test described in Table 1 and discussed above.A molded liner requires a high degree of of hardness to be able to support its own weight on its extension, which can be up to 8 feet in a minivan, and the additional weight of the interior dome lights and sun visors without bending or cracking over a wide range of temperatures - 40 ° to 85 ° C (-40 ° to 185 ° F) when exposed for up to 3 days as evaluated in the standard environmental resistance test for linings The product should not be flexed or bent to a point of failure where It will suck the lining, making it unable to support the weight of the lining components added. Also, a fissure failure in the lining will be shown through the decorative fabric layer in the lining, giving it an aesthetically unacceptable appearance for installation in a car. When tensioned beyond its limit, the product of the present invention will bend and then crack to failure, rendering it unsuitable for use as an automobile liner for the aforementioned reasons. The "low modulus" products do not crack to failure, and do not exhibit the hardness required to support the weight of the added components while in use, particularly in the environmental strength test described above. Therefore, low modulus products are inherently unsuitable for use as automotive liners. Although several embodiments of the present invention have been described, they are for the purpose of explaining and illustrating the invention, and it should be understood that they are not limiting the scope of the invention. Various modifications, which will be apparent to those skilled in the art, are within the scope of the present invention and are included in the following claims. While the present invention has been shown and described in particular with reference to the preferred modes as illustrated in the drawings, it should be understood by those skilled in the art that various changes can be made in detail without departing from the spirit and scope. of the invention as defined by the claims.

Claims

CLAIMS 1. A suitable article that is used to mold automotive linings, characterized in that it comprises a layer of non-woven fabric that when subjected to molding under heat and / or pressure and possesses a high degree of hardness, so that its fabric does not woven that can be formed has an off-center production load of about 3 to 26 Ne tons, a production load in one inch of about 90 to 140%, and a slope in the range of about 2.5 to 7.0 N / mm all under the Test Method I ASTM D-790-92, the layer of the fabric that can be formed has a top and bottom surface, and a non-woven layer of variable compression is able to take the variable thickness when subjected to low molding heat and / or pressure, the variable compression fabric has an upper and lower surface, the lower surface of the fabric that can be formed joins the upper surface of the variable compression fabric, and wherein the layers are made of the same thermoformable polymer chemical. 2. The article in accordance with the claim 1, characterized in that the fabric that can be formed and the variable compression fabric consist essentially of a polyester. 3. The article according to claim 2, characterized in that the union between the layer of fabric that can be formed and the layer of variable compression fabric are improved by mechanical means. . The article according to claim 3, characterized in that the mechanical means for improving the cohesion between the layers is perforated with needles. The article according to claim 2, characterized in that the connection between the layer of fabric that can be formed and the layer of variable compression fabric are improved by adhesive means. 6. The article in accordance with the claim 2, characterized in that a coating fabric layer having an upper surface and a lower surface is applied to the fabric layer that can be formed so that the lower surface of the coating fabric is adjacent to the upper surface of the fabric being applied. can form The article according to claim 2, characterized in that the coating fabric layer having an upper surface and a lower surface is applied to the variable compression fabric layer so that the lower surface of the coating fabric is adjacent to the fabric. the lower surface of the variable compression fabric. 8. An article suitable for use in the molding of automobile liners, comprising a layer of variable compression nonwoven fabric capable of taking variable thicknesses when subjected to a molding under heat and / or pressure and two layers of nonwoven fabric that it can be formed that when subjected to molding under heat and / or pressure they possess a high degree of hardness so that the non-woven fabric layers that can be formed have an off-center production load of about 13 to 26 Newtons, a load of production in an inch of approximately 90 to 140%, and a slope in the range of approximately 2.5 to 7.0 N / mm all under Test Method I ASTM D790-92, the fabric layers that can be formed each have a upper and lower surface, the layer of variable compression fabric is sandwiched between the upper surface of a layer of fabric that can be formed and the lower surface of the other layer of fabric that can be formed where the layers are of the same thermoformable polymeric chemical substance. 9. The article in accordance with the claim 8, characterized in that the fabric that can be formed and the variable compression fabric consists essentially of a polyester. 10. The article according to claim 9, characterized in that the union between the layers of the fabric that can be formed and the variable compression fabric is improved by mechanical means. 11. The article according to claim 9, characterized in that the bond between the layers of the fabric that can be formed and the variable compression fabric is improved by adhesive means. 12. The article according to claim 9, characterized in that a coating fabric layer having a top surface and a bottom surface is applied to a layer of. fabric that can be formed so that the top surface of a layer of fabric that can be formed is adjacent to the bottom surface of the coating fabric layer. The article according to claim 8, characterized in that a coating fabric layer having an upper and a lower surface is applied to a layer of variable compression fabric so that the upper surface of a compression fabric layer variable is adjacent to the lower surface of the coating fabric layer. 14. A suitable article for use in the molding of automotive liners, comprising two layers of variable compression nonwoven fabric capable of taking variable thicknesses when subjected to molding under heat and / or pressure and a layer of nonwoven fabric that it can be formed which when subjected to molding under heat and / or pressure possesses a high degree of hardness so that the non-woven fabric layer that can be formed has an off-center production load of about 13 to 26 Newtons, a load production in one inch of approximately 90 to 140%, and a slope in the range of approximately 2.5 to 7.0 N / mm all under Test Method I ASTM D790-92, the layers of variable compression fabric each have a surface upper and lower, the layer of fabric that can be formed is sandwiched between the upper and the surface of a layer of variable compression fabric and the lower surface of the other layer of variable compression fabric, where the layers They are made of the same thermoformable polymeric chemical substance. 15. An article with variable thickness in the form of a non-woven fibrous composite suitable for use as automotive lining, the fibrous composite is characterized in that it comprises a plurality of layers that includes a layer of non-woven fabric that can be formed which when is subjected to molding under heat and / or pressure imparts a high degree of hardness so that such a layer of non-woven fabric that can be formed has an off-center production load of about 13 to 26 Newtons, a production load in one inch of approximately 90 to 140%, and a slope in the range of approximately 2.5 to 7.0 N / mm all under Test Method I ASTM D790-92 in the article, and a variable compression nonwoven fabric layer capable of taking variable thicknesses , and where the layers are made of the same thermoformable polymeric chemical substance. 16. The article of variable thickness according to claim 15, characterized in that the fabric layer of variable thickness is sandwiched between the two layers of fabric that can be formed. 17. The article of variable thickness according to claim 15, characterized in that the layer of fabric that can be formed is sandwiched between the two layers of variable compression fabric. 18. The article according to claim 15, characterized in that the fabric that can be formed and the variable compression fabric both consist essentially of a polyester. 19. The article according to claim 15, characterized in that it has the shape of a car trunk lining. 20. The article according to claim 15, characterized in that it has the shape of a car lining.