COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR SHOES AND MANUFACTURING PROCEDURE OF COEXTRUDED MATERIAL

Abstract: This invention refers to an innovating structural material for footwear, thermoplastic and coextruded with thermoadhesives, comprising a multilayer material. The invention also refers to a manufacturing procedure of said structural material for shoes. The structural material proposed may consist of: only a sheet of thermoplastic resins; one sheet of thermoplastic resins coupled to a substratum of woven or non-woven material on only one side; a sheet of thermoplastic resins coupled to two similar or different of woven or non-woven substrates on the two sides (right and reverse). The substrate may use, among others, the following materials: nonwoven polyester, nonwoven polypropylene, polyester web, cotton web, PVC sheet, cotton flake, jersey, mesh, etc. Its thickness may vary according to the material to be laminated. The thermoplastic sheet consists of the following layers: external layers A and C formed by thermo-reactivatable adhesives such as EVA (ethyl-vinyl-acetate), taquifying esters and auxiliary additive substances of flow, such as amides. These layers may present a different formulation among them, according to the use to be given to the structural material. Intermediate layer B formed by polyolefinic resins such as polypropylene, polyethylene or ethylene copolymers of ethylene.

Description: "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR SHOES AND MANUFACTURING PROCEDURE OF COEXTRUDED MATERIAL" This invention refers to an innovating structural thermoplastic and coextruded material with thermoadhesive substances for shoes, constituting a multilayer material The invention also refers to a manufactuπng procedure of said structural material for shoes In the shoemaking industry are nowadays largely used structural mateπals produced from thermoplastics, such as counters and cuirasses, with the purpose of strengthening and preserving the form of shoes The strengthening mateπals most commonlv used are the following 1 - Leather reconstituted with resm of elastomeπc latex, such as SBR (Styrene- butadiene), covered with therm oadhesives, gums or synthetic cements The moist procedure such as for paper forming is used, but by using leather fibres Latex in aqueous state is used as an agglutmant of fibres Afterwards synthetical adhesives or hot melts are put on so that this mateπalmay be glued to the leather of the shoes 2 - Chemically or by immersion - This composes a woven or not woven fabπc spunbonded on basis of polyester or polypropylene impregnated with an aqueous emulsion of polyestyrene, dried in a Rama type stove at the temperature of 140° C, being afterwards reactivated by the shoe manufacturer by means of thinners Immersion of the product is necessary so that same is entirely reactivated 3 - Thermically - woven or not woven fabric spunbonded on basis of polyester impregnated with aqueous emulsions of SBR (Styrene-butadiene), reϋculated by temperatures of 150° in a Rama type stove, coated with hot melt resms on the basis of EVA (ethyl-vinyl-acetate) 4 - Polycaprolactama/PVC - this type of strengthening material is described in Patents PI 8506015. of December 02, 1985 and PI 8601338. of March 25, 1986. granted to Giu ni Chemie GmbH It consists of a mixture in form of plastic powder (agglutmant) of polycaprolactama and of a filling mateπal such as PVC, PET, ABS or EVA This powder is distributed on a substratum of woven or not woven fabric warmed up in order to mollify it to be passed through a rolling machine It can also be manufactured bv extrusion of agglutmant and the filling material 5 - Extruded Plates - This consists of the extrusion of plates with polymeric resins. basically polyolefines, through one sole mold with a simple nozzle, by means of which it can only be manufactured in a sole layer. On this material are afterwards placed hot melts adhesives with a spatula. The purpose of this invention is an innovating material, to be used mainly as counters and cuirasses for shoes, obtained from thermoplastic resins coextruded with thermoadhesives, forming multilayers. The proposed structural material may consist of: - only one sheet of thermoplastic resins; - one sheet of thermoplastic resins coupled to a substratum of woven or not-woven fabric at one side only; - by a sheet of thermoplastic resins coupled to two equal or different substrates of woven or not-woven fabric on two sides (right and reverse). The substratum of woven or not-woven fabric, mesh or canvas coupled to a thermoplastic sheet, is to give a finishing touch and to improve resistance to pull and to give flexibility to the final product, minding esthetic, physical and chemical features. This substratum may be laminated on the rolling machine receiving the thermoplastic sheet. For this substratum may be employed, among others, the following materials: polyester not-woven, polypropylene not-woven, polyester fabric, cotton fabric, PVC sheet, cotton flake, jersey, mesh, etc. Its thickness may vary according to material to be laminated. The thermoplastic sheet consists of the layers described as follows: - External layer A - formed by thermo-activatable adhesives such as EVA (ethyl- vinyl -acetate) taquifiable esters and flow aiding additives such as amides. These adhesives present a very low melting and reactivation temperature, starting from 60° C, and also presenting a low viscosity, i.e., a high melting index, (over 20g/10 min, according to ASTM 1238), to penetrate profoundly into the substratum of shoe leather or another desired substratum . These mentioned adhesives have the capacity of presenting a good anchorage for the middle layer, so that the two layers do not separate easily. The ideal thickness of this layer is situated between 0,01 and 0,5 mm. Intermediate layer B - formed by polyoleflnic resins such as polypropylene, polyethylene or copolymers of ethylene. This internal layer provides the capacity to copy perfectly the shape of the shoe with low reactivation temperatures, situated between 60 and 100° C It also provides the feature of resiliency above 80%, that is. the capacity of deforming and returning to its original shape, when the load ceases, as measured by Tests SATRA PM 61/1989, SATRA PM 82 1990 and SATRA PM 83 1990 The function of copolymer of ethylene and of metacryhc acid neutralized with sodium or zinc ions is the reticulation of polymeric chains, so that the thermoplastic sheet behaves like a thermofixed plastic, and when heated at low temperatures (approximately 60° C), it behaves as a thermoplastic moulding in the desired shape These metallic ions also form a very good anchorage for external layers On the thermoplastic sheet proposed by the invention does not occur an aggregating phase and another filling phase , since there is formation of one sole phase and the dispersion of casual loads in this phase, according to Omyalene et alii Now in the other thermic strengthening mateπals known, both phases are plastic, but with different melting points, that is. with different melting temperatures With the proposed sheet there is no separate phase This fact results m higher resistence features to tear, since there are no separate points The ideal thickness of this is situated between 0,1 and 5,00 mm - External layer C - formed by thermo-reactivatable adhesives, such as specified in layer A This layer may present a separate formulation from external layer A, according to the use to be made of the strengthening mateπal Following drawings elucidate the possible arrangements of layers to be adopted by the strengthening material proposed in the invention - Figure 1 - Enlarged transversal cut of strengthening mateπal, compπsing external substrates of woven or non-woven material (TN), which cover the thermoplastic sheet on both sides and which consists of external layers (A and C) and intermediate layer (B), - Figures 2 and 3 - these differ from the strengthening material of the previous Figure by possessing the substrate (TN) at only one of its faces, which may be adhered to external layer A or C, - Figures 4 and 5 - these strengthening materials compπse a substrate of woven or non- woven mateπal (TN), which covers the thermoplastic layer at only one side, and which consists of an external layer (A or C) and an intermediate layer (B), - Figure 6 - strengthening mateπal formed by a substrate of woven or non-woven mateπal (TN), which covers the thermoplastic sheet at only one side, and which consists of only an intermediate layer (B), - Figure 7 - strengthening material formed by external substrates of woven or non- woven mateπal (TN), covering both sides of the thermoplastic sheet, consisting of only one external layer (A) and the intermediate layer (B), - Figure 8 - strengthening material formed by substrates of woven or non-woven mateπal (TN), coveπng the thermoplastic sheet on both sides, consisting of only one intermediate layer (B), - Figure 9 - strengthening mateπal only formed by the thermoplastic sheet, consisting of external layers (A and C) and the intermediate layer (B), - Figures 10 and 1 1 - strengthening materials formed only by the thermoplastic sheet, consisting of only one external layer (A or C) and the intermediate layer (B); - Figure 12 - strengthening material formed only by the thermoplastic sheet, formed only by the intermediate layer (B) , Each layer forming the thermoplastic sheet presents a specific composition Composition of external layers A and C is the following - 0 to 100% of copolymer of ethylene with polyfunctional carboxyhc radicals - 0 to 100%) of EVA (ethyl-vinyl-acetate) 0 to 40% of steaπc taquifier 0 to 10% of amide compound to help the flow EVA employed on external layers A and C should possess preferably at least 28%o of acetate and the minimum fluidity index of 5 g/10 mm according to ASTM 1238 External layers A and C may be formulated with different quantities of their contituent parts between them Composition of intermediate layer B of the thermoplastic sheet is the following 0 to 100% of copolymer of ethylene and methacrylic acid neutralized with sodium or 0 to 100% of EVA ( ethyl-vmyl-acetate) Still within the extent of this invention it may be considered advantageous to adopt the following alternative compositions for the intermediate layer B of the thermoplastic sheet Alternative 1 - 10 to 80%o of polyethylene of high or low density or lineal 20 to 90% of EVA Alternative 2 - 50 to 80%> of copolymer of ethylene and methacrylic acid, neutralized with sodium and zinc ions 1 to 40%) of calcium carbonate 1 to 40%o of SBR resin (Styrene-butadiene) Alternative 3 - 100% of copolymer of ethylene and methacryl acid neutralized with sodium or zinc ions, Alternative 4 - 100% of EVA Alternative 5 - 100% of polyethylene Alternative 6 - 100%o of polypropylene Alternative 7 0,1 to 100% of copolymer of ethylene and methacrylic acid neutralized with sodium and zinc ions 0,1 to 100%. of SBR resin (Styrene-butadiene) Alternative 8 0,1 to 100% of copolymer of ethylene and methacrylic acid neutralized with sodium and zinc ions 0,1 to 100%) alpha-olefϊne, that is, polyethylene, polypropylene or the copolymers thereof Preferably EVA employed on intermediate layer B must have at least 9% acetate and a minimum fluidity index of 5g/10 mm according to ASTM 1238 The structural material produced according to the invention presents as main features comfort and resistance, since when used as counter or as cuirass it provides - good feeling of the shoe, as it does not need to be hard to maintain the foot in a suitable position within it, avoiding any kind of lesion or injury to the user ' s foot, - it maintains the original shape of the shoe, resisting to permanent use without deforming the leather and without breaking the structural mateπal, resulting in greater duration of the shoe structure, - it possesses memory , that is, resiliency, which is the capacity of returning to its original shape after a deformation, resisting to repeated inflection, - it possesses excellent operational performance with easy moulding, because the mollification point of resin is situated at about 63° C, improving the productivity of the shoe industry Extremely important is the fact that the structural material does not include PVC, which in some cases may generate highly poisonous and mutagenic dioxides, duπng its production and discard All materials employed are susceptible of recicling, with important ecological advantages The invention also refers to an innovated procedure for manufacturing structural mateπal for shoes, whose main features is of being moulded in one sole equipment sequence, sparing any supplementary operation The operations comprising the manufacturing procedure of the structural mateπal may be identified on the table of Figure 13, which is detailed as follows 1 - mixture of compounds - with the use of mills or silos for mixture of granulated mateπals in order to obtain homogemzation of resins, 2 - Dispensing of formulations - which uses screw dispensers or electronic balances (gravimetric dispensing) for measuring the percentages of each component, there are electronic controls for automation of dispensing , 3 - Feeding of extruders - by means of pneumatic feed devices with air pumps, in order to suck the particles contained in the boxes, drums or mixing silos into the dispensers or the feed hoppers of the extruders, 4 - pπmary extrusion - employing a conventional extruder, consisting of a metallic screw, which conveys the material through a jacket warmed by resistances, being activated by an electπc motor and a gear reducer 5 - coextrusion of external layers - up to two coextruders may be employed, in accordance with an arrangement to be given to the structural mateπal, 6 - monitoring of coextrusion - a distribution case is used comprising a manifold and valves, which control the flow of molten resins corresponding to layers of the thermoplastic sheet, 7 - extrusion mould - the labial mould possesses screws which control the hoπzontal distribution of the outflow of molten resins which comprise the structural mateπal, opening of the nozzle is adjustable, determining the thickness of the thermoplastic sheet, the main features of the procedure is that the outflows are entirely independent and there is no previous mixture up to the nozzle, 8 - Passing through rolling machine of structural mateπal - it employs a rolling machine with fr e cylinders, the first one receives the melted thermoplastic sheet from the nozzle, final thickness being controlled by the distance from second cylinder On this second cylinder is made the lamination of the TN layer formed by a woven or non-woven mateπal The third cylinder, which is a finishing device, helps in defining the final thickness of the strengthening material The last two cylinders are cooled by water and serve to stabilize the material The cylinders have temperature and speed electronically controlled 9 - Cooling and dimensional adjustment - structural mateπal passes over a sufficiently long area, consisting of several rollers, where it receives stability, receives lateral cuttings and the identification pπnt of the material being manufactured, such as lot, name of product and reference 10 - Traction - This takes place in a foulard type rolling machine, equipped with rubber rollers, which pull the structural mateπal from the rolling machine Its speed is electronically controlled, to avoid that the matenal remains stretched for too much time, which could cause an undesirable direction and should be practically bi- directed, 11 - Cutting off a puller disposed in front of a guillotine, which cuts off the structural mateπal into sheets is used, 12 - Recicling - trimmings from the sides which are cut off m the cooling area, are led to a mill which pulverizes and returns the material in form of grains, which are introduced again into the mills or feeding silos, 13 - Rolling up in bobbins - the structural material may be traded in form of bobbins, for which reason in the installation is foreseen a rolling up device of the material, situated after the guillotine, with suitable electronic controls for synchronism with the traction machines The primordial features of the procedure proposed by the invention, in face of those which employ pohcaprolactama/PVC integrating the technical status, are the following - use of grains instead of powder, which is manufactured by a cryogenic procedure, with adoption of low temperatures, thus makes the procedure expensive, - existence of independent flows up to the distribution case and the mould nozzle, which permits formation of layers with different compositions, while in other procedures employing the extrusion technique occur the mixture of adhesive with the filling up mateπal, thus not forming different layers, - the use of rolling machines with speed and temperature control permits a better dimensional control, standardizing the thickness at 0.05 mm, while in other procedures, such as powder deposition, the thickness differences supersede largely these differences, - new work does not occur, because the product is ready when it leaves the plant, without the need of returning to previous stages of procedure, - the coextrusion adopted in the procedure grants the independent forming of layers and avoids dispersion of adhesive in the stuffing layer, which is a waste, since there the adhesive does not fulfil its function of glueing the structural material to the shoe upper In face of other known procedures, the invention presents the following differential features - the existence of independent flows up to the distribution case and the nozzle of the mould, thus granting formation of layers with different compositions, while in other procedures employing the extrusion technique there is the mixture of adhesive with filling material, and no different layers are formed, - the adopted coextrusion in the procedure grants the independent formation of layers, thus avoiding the dispersion of adhesive in the filling layer, which is a waste, since there the adhesive does not fulfil its function of glueing the structural mateπal to shoe upper, new work does not occur , since the product is ready when it leaves the installation and there is no need to return to previous stages of procedure, while in conventional techniques it is necessary to spread the adhesive over the sheet

Claims: CLAIMS 1 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTOWEAR", characteπzed in that it is obtained from thermoplastic res s coextruded with thermal adhesives to fonn multiple layers, consisting of a sheet of thermoplastic resins which can receive a substrate woven or non-woven on one side or on both sides 2 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to Claim 1, characteπzied in that the substrate is of a woven, knitted, mesh, or non-wooven, which can be laminated on the calender machine and receives the thermoplastic sheet 3 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 2, characteπzed in that the substrate employs preferably following materials non-woven polyester, non-woven polypropylene, polyester mesh, cotton mesh, PVC laminatge. cotton flock, jersey fabric or knitted fabric 4 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTOWEAR", according to Claim 1 , characteπzed in that the thermoplastic sheet compπses the following layers - external layers A and C formed by heat reactivatable adhesives, - an intermediate layer B formed by polyolefin resins 5 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to Claim 4, characteπzed in that the heat reactivatable adhesives of external layers A and C are preferably formed by EVA (ethyl-vinyl- acetate), taquifying esters and flow aiding additives such as amides 6 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 4, characteπzed in that the intermediate layer (B) is formed by polyolefin resins, and preferably polypropylene, polyethylene or copolymer of ethylene and metacryhc acid 7 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 6, characteπzed in that the copolymer of ethylene and metacryhc acid neutralized by sodium or zinc ions has the function of crosshnking the polymer chains, and conferπng on the thermoplastic sheet behavioural properties analogous to those of a thermoset plastic 8 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR" according to claim 1, characteπzed in that it includes arrangements in which outer woven or non-woven substrates (TN), cover both sides of a thermoplastic sheet which compπses external layers (A and C) and an intermediate layer (B), 9 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR" according to claim 1, characteπzed in that it includes arrangements in which an outer woven or non-woven substrate (TN), covers only one of the surfaces of a thermoplastic sheet, which comprises external layers A and C, united to an intermediate layer (B) 10 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 1, characteπzed in that it includes arrangements in which an outer woven or non-woven substrate (TN), covers only one surface of a thermoplastic sheet, which compπses a single external layer A or C and an intermediate layer (B) 11 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR" according to claim 1 , characteπzed in that it includes arrangements in which an outer woven or non-woven substrate (TN), covers a single side of a thermoplastic sheet, formed only by an intermediate layer (B) 12 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR" according to claim 1, characteπzed in that it includes arrangements in which outer woven or non-woven substrates (TN), ocover both sides of a thermoplastic sheet, compπsing only one external layer (A or B) andan intermediate layer (B), 13 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR" according to claim 1 characteπzed in that it includes arrangements in which woven or non-woven substrates (TN). cover both sides of a thermoplastic sheet, formed only by an intermediate layer (B) 14 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR" according to claim 1. characteπzed in that it is formed only by a thermoplastic sheet, comprising external layers (A and C) and an intermediate layer (B) 15 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 1 , characteπzed in that it is formed only by a thermoplastic sheet composed of only one external layer (A or C) and an intermediate layer (B) 16 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 1 , characteπzed in that it is formed only by a thermoplastic sheet composed of an intermediate layer (B), 17 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 4, characteπzed in that the external layers A and C of the thermoplastic sheet have the composition 0 to 100%o of copolymer of ethylene with polyfunctional carboxyl radicals 0 to 100%) of EVA (ethyl-vmyl-acetate) 0 to 40%o of a steaπc taquifier and 0 to 10%) of na amide composition in order to aid flow 18 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 17, characteπzed in that the EVA employed in the outer layers A and C preferably has at least 28%> acetate and a fluidity index of at least 5g/10 minutes b\ ASTM 1238 19 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 4, characteπzed in that the intermediate layer B of the thermoplastic sheet has the composition 0 to 100%) of a copolymer of ethylene and metacryhc acid neutralized with sodium or 0 to 100% EVA (ethyl-vinyl-acetate) 20 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 4, characteπzed in that the intermediate layer B of the thermoplastic sheet has the alternative composition 10 to 80%o of high or low-density or linear polyethylene 20 to 90% of EVA 21 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 4 , characteπzed m that the intermediate layer B of the thermoplastic sheet has the alternative composition 50 to 80%) of a copolymer of ethylene and metacryhc acid neutralized with sodium and l to 40% of calcium carbonate 1 to 40% of SBR Resm (Styrene-butadiene) 22 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 4, characteπzed in that the intermediate layer B of the thermoplastic sheet has the alternative composition 100%) of a copolymer of ethylene and methacrylic acid neutralized with sodium or zinc ions 23 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 4, characteπzed in that the intermediate layer B of the thermoplastic sheet has the alternative composition 0,1 to 100%) of a copolymer of ethylene and methacrylic acid neutralized by sodium or 0, 1 to 100% of SBR resin ( Styrene-butadiene) 24 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 4, characteπzed in that the intermediate layer B of the thermoplastic sheet has the alternative composition 0,1 to 100%) of a copolymer of ethylene and methacrylic acid neutralized with sodium 0,1 to 100%) of high olefin, I e , polyethylene, polypropylene or copolymers thereof 25 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 4, characteπzed in that the intermediate layer B of the thermoplastic sheet has the alternative composition 100% EVA 26 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to any of claims 19, 20 or 23. characteπzed in that the EVA employed in the intermediate layer B of the thermoplastic sheet preferably has at least 9% 0 acetate and a fluidity index of at least 5 g/10 mm 27 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 4, characteπzed in that the intermediate layer B of the thermoplastic sheet has the alternative composition 100%) polyethylene 28 - "COEXTRUDED THERMOPLASTIC STRUCTURAL MATERIAL FOR FOOTWEAR", according to claim 4, characterized in that the intermediate layer B of the thermoplastic sheet has the alternative composition 100% polypropylene. 29 - "PROCESS FOR PRODUCING COEXTRUDED MATERIAL", characterized in that it includes the following operations: 1 - mixing the components by means of mills or silos for mixing granular materials; 2 - dispensing the formulations using screw dispensers or an electronic balance (gravimetric dispensing ) for measuring the percentages of each component; 3 - feeding the extruders by means of pneumatic feed devices, using air pumps in order to suck the particles from boxes, drums or mixing silos into the dispensers or feed hoppers of the extruders; 4 - primary extrusion of the intermediate layer of the thermoplastic sheet; 5 - coextrusion of the external layers, employing up to two coextruders; 6 - monitoring of coextrusion using a distribution box comprising a manifold and valves, which controls the flow distribution of the molten resins of the layers of the thermoplastic sheet; 7 - an extrusion mould which regulates the horizontal distribution of the flow of the molten resins composing the structural material; 8 - calendering of the structural material; 9 - cooling of the structural material which passes through a zone comprising various rollers, where the material is stabilized, with simultaneous dimensional adjustment of the width of the structural material, by cutting the excess at the sides ; 10 - pulling the structural material by means of a foulard calender machine provided with rubberized rolls, which pull the materials from the calender machine. 30 - "PROCESS FOR PRODUCING COEXTRUDED MATERIAL", according to claim 29, characterized in that the calender machine has five cylinders, the first of which takes up the mould of the molten thermoplastic sheet, with the final thickness of the strengthening material therein being controlled by the clearance to the second cylinder; on this second cylinder can be laminated a layer TN of woven or non- woven material; the third cylinder is for finishing and for helping to define the final thickness of the strengthening material and the final two cylinders are water cooled and stabilize the material. 31 - "PROCESS FOR PRODUCING COEXTRUDED MATERIAL", according to claim 29, characterized in that it optionally includes a cutting operation (1 1 ) which employs a pulling device ,arranged in front of a guillotine, which cuts the structural material into pieces. 32 - "PROCESS FOR PRODUCING COEXTRUDED MATERIAL", according to claim 29, characterized in that it optionally includes an operation of recicling (12) the off-cuts from the sides, which are conveyed to a mill, which grinds the material once again into particles, which are then put into the mills or feed silos. 33 - "PROCESS FOR PRODUCING COEXTRUDED MATERIAL", according to claim 29, characterized in that it optionally includes an operation of winding the structural material onto bobbins (13), by means of a winding device placed after the guillotine, with electronic control devices synchronized with the pulling mechanism.

Inventors: FLECK MARTINHO, FLECK, MARTINHO
Applicants: BOXFLEX COMPONENTS PARA CALCAD, FLECK MARTINHO, BOXFLEX COMPONENTS PARA CALCADOS LTDA, FLECK, MARTINHO
Application year: 1999
Main classification: A43B13
IPC codes: A43B1, B29B15, B29C47, B29C70, B29D31, B32B27, B32B37