METHOD FOR MANUFACTURING THREE-DIMENSIONAL ITEMS WITH FLEXIBLE WALLS

Abstract

A method for manufacturing three-dimensional items with flexible walls is provided, by method of a mold and counter mold between which a volume corresponding to that of the item to be obtained is delimited. The item is made up of laminar parts which are mounted on a template that is fixed to the inner surface of the mold. The laminar parts are joined to one another by means of a material which is injected in molten state through a network of conduits delimited between the counter mold, template and the facing edges of adjacent laminar parts. The template is made of an elastically deformable material and has a three-dimensional configuration.

Claims

1. A method for manufacturing three-dimensional items with flexible walls, by means of a mold and a counter mold between which a volume corresponding to that of the item to be obtained is delimited, the item of which is made up of flexible laminar parts that are mounted on a template that is fixed to the inner surface of the mold, the laminar parts thereby being joined by means of an adhesive material that is injected in a fluid state through a network of conduits limited between the counter mold, template and facing edges of the laminar parts, the template being an elastically deformable material, of a greater thickness than the distance D between the mold and the flexible laminar parts, at least along the part of the areas that limit the channels that separate the facing edges of the adjacent laminar parts, to compress the edges of said parts against the counter mold, said template having a three-dimensional configuration and reproducing, at least on the surface on which the laminar parts are arranged, the shape of the item to be manufactured, wherein the template, on the surface intended to receive the laminar parts, has ribs that limit the channels defined between the facing edges of the adjacent laminar parts.

2. The method according to claim 1, wherein the template has grooves that run in coincidence with the channels limited between the facing edges of the adjacent laminar parts, the grooves of which are wider than said channels.

3. The method according to claim 1, wherein the facing edges of the adjacent laminar parts are recessed and are occluded in the material injected through the conduits defined between said edges and the surface of the template and the counter mold.

4. The method according to claim 2, wherein the grooves of the template are limited by ribs along said grooves.

5. The method according to claim 1, wherein the template is made of silicone.

6. The method according to claim 1, wherein at least part of the surface of the counter mold a template made from elastically deformable material is arranged.

7. The method according to claim 1, wherein the template has holes coinciding with a network of small channels of the mold, through which said holes are connected to a vacuum source.

8. The method according to claim 1, wherein the laminar parts, close to the edges thereof, have holes that communicate with the conduits through which the adhesive material is injected.

9. The method according to claim 1, wherein the facing edges of the adjacent laminar parts bend according to strips that are attached and housed in grooves formed in the counter mold.

10. The method according to claim 9, wherein the counter mold is made up of a rigid or semi-rigid cover, in which the grooves are formed.

11. The method according to claim 7, wherein the template, around the mouth of the holes, has a peripheral hollow in which a microfibre part is placed.

12. The method according to claim 10, wherein, in a position coinciding with the separation between the edges of the laminar parts, the counter mold forms a channel that is filled with injected adhesive material and, when said material solidifies, it forms reinforcement cords.

13. The method according to claim 1, wherein, the adhesive material is injected and cured, the counter mold is substituted by a second counter mold, which, with the laminar parts, delimits a chamber in which the material, which when solidified will form a shock-absorbing layer, is injected.

14. The method according to claim 13, wherein the counter mold, on the surface facing the laminar parts, has needles that rest against said laminar parts and, by said counter mold being separated, form ventilation perforations in the injected material.

15. The method according to claim 13, wherein the back side of the laminar parts a repellent product is applied to the material injected in the chamber.

16. The method according to claim 1, wherein the laminar parts on the back side hold a moisture insulating membrane.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] An exemplary embodiment is shown in the attached drawings, wherein:

[0033] FIG. 1 shows a perspective view of a laminar template made according to the invention for obtaining a shoe.

[0034] FIG. 2 shows a longitudinal cross-sectional view of the laminar template of FIG. 1 coupled to the mould for obtaining a shoe.

[0035] FIG. 3 corresponds to detail A of FIG. 2 on a larger scale.

[0036] FIGS. 4 to 7 are similar views to that of FIG. 3, showing possible variant embodiments.

[0037] FIGS. 8 to 11 show cross sections of possible constructive details.

[0038] FIGS. 12 to 15 show plan and cross-sectional views of other possible variant embodiments.

[0039] FIG. 16 is a similar view to that of FIG. 2, showing another variant embodiment.

[0040] FIG. 17 shows a cross section of the mould of the shoe, obtained through the method of the invention.

[0041] FIG. 18 is a similar view to that of FIG. 16, showing another variant embodiment.

[0042] FIG. 19 corresponds to detail A of FIG. 18 on a larger scale.

[0043] FIG. 20 shows a cross section of a variant embodiment of the vacuum fastening system of laminar parts.

[0044] FIGS. 21 to 24 show another set of exemplary embodiments.

[0045] FIG. 25 shows a cross-sectional view of a possible variant embodiment.

[0046] FIGS. 26 to 29 show successive steps in the manufacturing of a seat by means of the method of the invention.

DETAILED DESCRIPTION OF AN EMBODIMENT

[0047] FIG. 1 shows a three-dimensional template (1) for manufacturing a shoe by means of a mould and counter-mould between which a volume corresponding to that of the item to be obtained is delimited. The present case deals with obtaining a shoe.

[0048] As shown in FIG. 2, the template (1) is applied on the concave surface of the mould (2), and once arranged on the same, on the inner surface thereof, the laminar parts (3) will make up the cut of the shoe, parts that are separated from one another to delimit channels (4) between the facing edges thereof. The template (1) will reproduce, at least on the surface on which the laminar parts (3) are applied, the shape of the item to be obtained.

[0049] The template (1) is made up of an elastically deformable material and can be obtained by means of a mould made of silicone, for example.

[0050] Once the template (1) with the shape of the item to be manufactured is obtained, the laminar parts (3) that will form the cut of the shoe are cut, which are placed on the inner surface of the template (1) with the edges of the adjacent parts facing each other and separated to delimit channels (4) between the same. The template (1) is then coupled to the laminar parts (3) in the mould (2), which can be made up of one, two or more parts. Lastly, the counter-mould, not shown, is coupled in the template (1) on the laminar parts (3). In the present case, the counter-mould will adopt the shape of a last and will close the mould.

[0051] The last or counter-mould can also hold the silicone template, at least in specific areas, in which it is necessary or convenient for the surface of the laminar parts aimed at the counter-mould to efficiently seal said counter-mould. On the other hand, the arrangement of the elastically deformable template on the mould and counter-mould eliminate the risk of contamination or penetration of the fluid injected in the parts that will make up the item to be obtained, especially when said parts are permeable to the injected fluid.

[0052] The channels (4) are closed on the outside by the template (1) and on the inside by means of the counter-mould (5), FIG. 3, forming a network of conduits (6) through which an adhesive product is injected in a fluid state which, by solidifying, serves as a means for joining the facing edges of the adjacent laminar parts (3).

[0053] According to the invention, the template (1) is obtained from an elastically deformable material, such as silicone, and will have a greater thickness than the distance D between the mould (2), FIG. 3, and the laminar parts (3), at least at the edges of said laminar parts, such that said edges are compressed against the counter-mould (5), thereby ensuring the seal of the conduits (6) throughout the same. This feature can be achieved by increasing the thickness of the template only in the areas that limit the conduits (6). For example, by means of ribs (7), FIG. 4, that run on one side and on the other side of said conduits and which by being pressed against the laminar parts (3), by the template compressing due to the tightness between the mould (2) and counter-mould (5), provide the longitudinal seal to the conduits (6).

[0054] As can be seen in FIG. 5, the template (1) can have grooves (8) that run in coincidence with the channels (4), limited between the facing edges of the adjacent laminar parts (3), said grooves (8) having a greater thickness than the channels (4), thereby increasing the cross section of the joining cord (9), formed by the adhesive material injected through the conduits (6) once it is solidified. Furthermore, the facing edges (10) of the adjacent laminar parts (2) can be recessed to be occluded in the cord (9), which will conform the injected material, which will increase the adhesive surface and hide said edges. In this case, the recessed edges will be pressed against the template (1), the vacuum fastening system of the laminar parts (2) being important at that moment, at least in the areas near these recessed edges, or by means of the temporary fastening with adhesive, all with the aim of maintaining the connection of the laminar parts with the template during the injection process.

[0055] As can be seen in FIG. 6, the groove (8) of the template (1) can be limited by ribs (7) with a similar function to that of the previously described ribs (7).

[0056] In the embodiment of FIG. 7, the laminar parts (3) are situated between the three-dimensional template (1), made of elastically deformable material, and the counter-mould (5) formed, for example, by a sheet made of plastic material. This counter-mould, in a position coinciding with the separation between the facing edges (10) of the laminar parts (3), forms a channel (8). In turn, the three-dimensional template (1) has ribs (7) near the edges (10). With this constitution, by treating or solidifying the injected adhesive material, joining cords (9) with a large cross section and strong resistance are obtained, which will project through the back of the wall of the item obtained. At the same time, by closing the mould and counter-mould, the ribs (7) compress the edges of the laminar parts (3) against the counter-mould (5), providing a secure closure between these components, preventing the injected material in a molten state from flowing between the same.

[0057] On the surface of the laminar parts (3), decorative cords (8) can be applied, FIG. 8, made from the same adhesive material that will be injected through the grooves (8), FIG. 5, made in the template (1).

[0058] The joining of the facing edges of the adjacent laminar parts (3) can be reinforced, for example by means of the arrangement of an auxiliary sheet (11), FIG. 9, in coincidence with the conduits (6), by the hidden surface of the product to be obtained. This auxiliary sheet can only run in coincidence with the conduits (6) or cover the entirety of the surface of the parts (2), such as a lining (12), FIG. 10, said lining able to have a recess (13) in coincidence with the aforementioned conduits.

[0059] Also, as shown in FIG. 11, on the laminar parts (3), in coincidence with the edges thereof, a fabric sheet (12) can be applied, which in the areas (13) adjacent to the conduits (6) will be impregnated with the adhesive product injected through said channels, to serve as a joining means between the fabric sheets (12).

[0060] As shown in FIGS. 12 and 13, the laminar parts (3) can have holes (3) close to the edges (10) thereof, which are in communication with the grooves (8), coinciding with the channels (4). This way, the injected adhesive material that will form the cords (9) will fill the holes (3) and by solidifying will act as rivets that serve as mechanical joining means between the laminar parts (1).

[0061] As a variant, FIGS. 14 and 15, the edges (10) of the laminar parts (1) can have facing slits (10) that increase the length of the facing edges to be joined of the adjacent laminar parts (1).

[0062] The method of the invention is applicable to obtaining three-dimensional items that can be made up of a flexible outer layer or wall and a rigid or semi-rigid inner layer or filler, and which can consist of a piece of furniture, a dashboard of a vehicle or similar.

[0063] To this end, as shown in FIG. 16, on the inner surface of the mould (2) the template (1) made of elastically deformable material is applied, which will hold the laminar parts (3) that will make up the outer wall of the item to be obtained and which are separated by separations lines (4). The counter-mould (5) is applied to the mould (2), and between the same and the laminar parts (3) is a chamber (14) in which a material in a fluid state is injected, which once solidified will make up a support (14) that joins the laminar parts (3) that make up the outer wall of the item, made up of laminar parts (3). The counter-mould (5) could even form part of the final item obtained. With this system for joining the laminar parts (3), the item obtained will lack protrusions or outer ribs, as well as separations between said laminar parts.

[0064] The mould (2) could form a chamber (15), the inner wall of which, as well as the template (1), could have coinciding holes (16) through which, and by means of a vacuum created through the nozzle (17), the parts (3) will be fixed to the template (1).

[0065] The template (1) can have a different design on the inner and outer surfaces thereof and is deformable, all of which facilitates both the mounting and dismounting of the mould, as well as the mounting of the counter-mould, all without the need to have to break the template.

[0066] In the manufacturing of certain types of items, for example footwear, parts of different material can be placed. FIG. 17 shows the neck (18) of a shoe formed by the same material as the laminar parts that form the cut, which encases the foam part (19) and which, in turn, remains inside the template (1), which has ribs (20) that limit a hole (21) in which the adhesive that closes the neck (18) will be injected, preventing the contact thereof with the foam (19).

[0067] Lastly, it must be mentioned that on at least part of the surface of the counter-mould, regardless of the item to be obtained, the template of elastically deformable material can be arranged.

[0068] In a similar way to that which is described in reference to FIG. 11, FIG. 18 shows a mould (2) on which the three-dimensional template (1) has been applied, made of elastically deformable material, which holds the parts (3) that form the cut.

[0069] The template (1), FIGS. 18 and 19, can be provided with holes (15) through which a vacuum can be applied that will serve as a means for fastening the parts (3). In turn, the mould (2) could have a network of small channels (16) with which the holes (15) will coincide. The small channels (16) will be in communication with a vacuum source, for example, through a chamber (18) with a connection nozzle (19). This way, the vacuum effect is applied uniformly to all of the parts (3) and with it the effect of fastening said parts to the template (1).

[0070] FIG. 20 shows a cross section of a possible variant in which in the template (1), around the mouth of the holes (15), a peripheral hollow (15) is made, in which microfibre parts (11) are placed, through which the aspiration produced by the vacuum applied through the holes (15) is carried out. This way, a greater aspiration area of the laminar parts (3) and an improved closure against the loss of air is achieved.

[0071] FIGS. 21 and 22 show the manufacturing of a briefcase (22) by means of the method of the invention. On the inner surface of the mould (2) the three-dimensional template (1) is arranged, which holds the laminar parts (3) which form the visible surface of the briefcase. On these laminar parts a reinforcement sheet (23), for example made of a plastic material, is applied, on which an inner lining (24) is arranged, supported by the counter-mould (5). In the channels (4) delimited between the consecutive laminar parts (3), the adhesive material that will form the joining cords (25) is injected. Also shown is the arrangement of a zipper (26) as a means for closing the briefcase.

[0072] In a similar way, FIGS. 23 and 24 show how an automobile dashboard (27) is obtained. On the inner surface of the mould (2) the three-dimensional template (1), for example made of silicone, is arranged, which holds the laminar parts (3) which form the visible surface of the dashboard. On these laminar parts a foam layer (28) or similar is applied, for example open-cell foam, followed by a rigid or semi-rigid support (29), which has protrusions or ribs (30) that press against the laminar part (3) and the template (1), thereby obtaining a sealing that prevents the injected material that makes up the cords (25) for joining the laminar parts (3) from contaminating both said laminar parts as well as the foam layer (28). The process is completed with the counter-mould (5).

[0073] In the embodiments described, the cords (25) can form decorative elements of the product obtained, both by the tracing and the colour of the same.

[0074] The use of templates made from an elastically deformable material allows for the inclusion of parts that will form part of the cut or visible surface of the same and that will have a greater thickness than the separation between the template and the counter-mould.

[0075] Another advantage of the use of the template of elastically deformable material, with a certain thickness, is the ease it provides when opening the mould and extracting the counter-mould and the formed object.

[0076] It is also worth pointing out that, as shown in FIG. 25, the facing edges of the adjacent laminar parts (3) can bend according to strips (31), which are attached and are inside a groove (32) formed in a cover (33), either rigid or semi-rigid, which acts as a counter-mould and covers the assembly of laminar parts. By means of these grooves (32), the adhesive material will be injected.

[0077] The grooves (32) can be longitudinally sealed, preventing the exit of the injected adhesive material, or open to allow for the exit of said material which, by solidifying, will form a layer of support for the visible layer formed by the laminar parts.

[0078] The cover (33) can be left out, the grooves thus (32) being made in the counter-mould.

[0079] In the described embodiment, the template (1) can also be left out, the laminar parts (3) being directly supported by the mould (2).

[0080] The method of the invention can be applied to the manufacturing of cushioned seats, for example seats for vehicles, as shown in FIGS. 26 to 29. In a first step, FIGS. 26 and 27, the laminar parts (3) are arranged on the three-dimensional template (1) and said template is mounted on the inner surface of the mould (2). The edges of the laminar parts (3) will preferably be recessed and housed in channels (4) formed in the counter-mould in which, in a first injection process, the adhesive product in charge of joining the facing edges of the adjacent laminar parts (3) will be injected. Once this adhesive product is cured, the counter-mould (5) is separated and a second counter-mould (5) is mounted, FIG. 28, which has needles (34) that rest against the laminar parts (3) with which they delimit a space (5), wherein, by means of a second injection process, a foam or similar product is injected, with which a shock-absorbing layer (36) will be obtained in the seat, behind the laminar parts (3), FIG. 29.

[0081] By dismounting the counter-mould (5), the foam layer (36) will have perforations (37) for ventilation, thereby avoiding a subsequent perforation process.

[0082] The laminar parts (3) can be held, on the back, by a moisture insulating membrane (3), which must be eliminated on the edges of said parts, to allow for the joining by means of the injected adhesive material. This membrane can be arranged in the areas in which one wants an insulating separation between the foam layer (36) and the laminar parts (3).

[0083] Also, on the backside of the laminar parts, a repellent product can be applied to the injected material in the second injection step (foam or similar), with which an outer skin will be obtained, separated from the shock-absorbing layer (36).