A PROCESS FOR MANUFACTURING PRODUCTS IN WHICH RIGID AND SOFT PARTS ARE COMBINED

Abstract: The process of the invention involves a combination of more rigid parts with less rigid parts, and includes a hot-coupling of at least one polyester-based polyurethane elastomer sheet (3) between at least a portion of a resin-impregnated first material (1) which, after treatment, constituting a more rigid part, and at least a portion of a second material (2), which constitutes a less rigid part.

Description: Description A Process for Manufacturing Products in which Rigid and Soft parts are Combined. Technical Field The invention relates to a process for manufacturing products in which there are combinations of rigid and soft parts. Background Art The invention has many possible applications. In particular, though not exclusively, it can be used in the production of clothing and footwear and accessories. In the case, for example, of special shoes or boots for motorcyclists, the prior art includes the application of "hard" inserts, i.e. especially resistant, which stiffen the shoe structure; these inserts are usually made of leather. The application of such inserts, which have a protective function, is laborious because it requires constant use of manual labour. Furthermore, manufacturing realities dictate that it is not always possible to make the shapes and combinations of inserts which would be most suitable for optimum finished product performance. The main aim of the present invention is to obviate the limitations and drawbacks in the prior art. An advantage of the invention is its substantial simplicity of application. Disclosure of Invention These aims and advantages and more besides are all attained by the present invention, as it is characterised in the appended claims. Further characteristics and advantages of the invention will better emerge from the detailed description that follows of some preferred but non-exclusive embodiments, illustrated purely by way of non-limiting example in the accompanying figures of the drawings, in which: figure 1 schematically shows, in section, the arrangement of the various parts which make up the coupling of the invention, in a first embodiment thereof; figure 2 schematically shows, in section, the arrangement of the various parts which make up the coupling of the invention, in a further embodiment thereof; figures 3 and 4 schematically shows, in section, the arrangement of the various parts which make up the coupling of the invention, in a further embodiment thereof, actuated in two stages; figure 5 schematically shows a boot made according to the invention. With reference to the figures of the drawings, the process for manufacturing products which involves a combination of rigid, semi-rigid and soft parts comprises a hot-coupling of at least one layer or sheet 3 of a polyester-based polyurethane elastomer between at least a portion of a first, resin-impregnated material 1, destined, after treatment, to constitute the more rigid part, and at least a portion of a second material 2, destined to constitute the less rigid or soft part. The first material 1 is made of fibres impregnated with resins, which after special treatment give a stable shape and good mechanical characteristics to the whole. The fibres of both the above-mentioned materials 1 and 2 can be carbon-fibres, kevlar, glass, aramide, and the like. In a first embodiment of the invention the hot-coupling is done in a single stage at the same time as the treatment bv which the first material 1 reaches its final stiffness by action of the resins, usually epoxy, which are impregnated in the material 1 itself. In order for the first material 1 to reach its final shape during this single-stage operation, the side of the first material 1 which is opposite the side in contact with at least a portion of the second material 2 (the contact being achieved by means of the sheet of polyester-based polyurethane elastomer) is placed and held in contact with the surface of a die 4. In a variation of the process, at least a layer or sheet of the polyester-based polyurethane elastomer 3 is placed on the side of the first material 1 which is opposite the side thereof in contact with the second material 2 (and, as mentioned above, contacting the second material 2 by means of a sheet of polyester-based polyurethane elastomer 3). In this case too, the permanent shape is achieved by arranging and clamping an external surface of the sheet of polyester-based polyurethane elastomer 3 arranged on a side of the first material 1 opposite the side of the first material 1 at which the first material 1 is placed in contact through a sheet of polyester-based polyurethane elastomer 3 with at least a portion of a second material 2, against a surface of a die 4. In a further embodiment of the invention, illustrated in figures 3 and 4, the hot- coupling is realised in at least two stages: a first stage in which, on at least one side of the first material 1 at least one sheet of polyester-based polyurethane elastomer 3 is heat-applied simultaneously with the effecting of the treatment giving the first material 1 its final rigidity; and a second stage in which at least a portion of the second material 2 is heat-coupled on at least a portion of the side of the first material 1 which the polyester-based polyurethane elastomer 3 has previously been applied on. In all of the illustrated embodiments the portions of the second material 2 not coupled with portions of the first material 1 can be solidly coupled with a sheet of the polyester-based polyurethane elastomer 3 in order to conserve their characteristic of softness. The products obtained are characterised by being thin in consideration of their other dimensions, while guaranteeing very considerable resistance qualities. The invention enables variously-structured materials to be achieved (with reinforced high-resistance stiffer or softer parts) as well as articles of clothing of various types (including shoes and boots) of great and versatile functionality. In particular, the invention can be usefully employed for manufacturing clothes and footwear for sporting use. Figure 5 shows a boot made according to the invention in which 5 denotes the soft part made using the second material 2, possibly coupled with a sheet of elastomer 3, while 6 indicates two stiffer parts (in the illustrated example, heel and toe), made by using portions of the first material 1 coupled with a sheet of elastomer 3 as illustrated in figures 1,2 or 4. It should be noted that whatever the adopted design, the sheet of elastomer 3 must be arranged such as to keep the first material 1 and the second material 2 completely separate one from the other, especially during the process itself.

Claims: Claims. 1). A process for manufacturing products in which more rigid parts of the products are alternated with less rigid parts thereof, comprising a hot-coupling of at least one sheet of a polyester-based polyurethane elastomer sheet (3) between at least one portion of a resin-impregnated first material (1), destined, subsequent to a treatment, to constitute a more rigid part of the product, and at least a portion of a second material (2), destined to constitute a less rigid part of the product 2). The process of claim 1, wherein the hot-coupling is done in a single stage. 3). The process of claim 2, wherein in the single stage, during the hot-coupling a treatment of the first material (1) is carried out, by means of which treatment the first material (1) acquires a final rigidity. 4). The process of claim 3, wherein in the single stage during which the hot- coupling and the treatment are simultaneously carried out, a side of the first material (1) which is opposite a side at which the first material (1) is placed in contact, through the polyester-based polyurethane elastomer sheet (3), with at least a portion of the second material (2), is arranged in contact with a surface of a die (4). 5). The process of claim 3, wherein on a side of the first material (1) which is opposite to a side thereof which is in contact through the polyester-based polyurethane sheet (3), with at least a portion of a second material (2), at least a sheet of the polyester-based polyurethane sheet (3) is contactingly arranged. 6). The process of claim 5, wherein during the single stage, in which the hot- coupling and the treatment are simultaneously carried out, an external side of the at least one polyester-based polyurethane elastomer sheet (3) arranged on a side of the first material (1) which is opposite the side of the sheet (3) in contact with the first material (1), through a polyester-based polyurethane elastomer sheet (3), with at least a portion of a second material (2), is arranged contactingly with a surface of a die (4). 7). The process of claim 1, wherein the hot-coupling is carried out in at least two stages: a first stage in which on at least one side of the first material (1) at least one polyester-based polyurethane elastomer sheet (3) is hot-applied, simultaneously with a treatment in which the first material (1) acquires final rigidity characteristics; and a second stage in which at least a portion of the second material (2) is hot-coupled to at least one portion of a side of the first material (1), on which a polyester-based polyurethane elastomer sheet (3) has previously been applied. 8). The process of any one of the preceding claims, wherein the first material (1) is constituted by fibres impregnated with resins, which resins, when subjected to a correct treatment, give a stable shape and high mechanical characteristics to the first material (1).

Inventors: MESTDAGH ALAIN, MESTDAGH, ALAIN
Applicants: MESTDAGH ALAIN, MESTDAGH, ALAIN
Application year: 2000
Main classification: B29C70
IPC codes: A43B23, B29C70, B29D31