Method for producing a substructure for footwear, footwear, and machine for producing a substructure

Abstract

The invention relates to a method for producing a substructure for footwear, wherein an inner half shell is made of an intermediate layer (1) which forms the foot support and a lower adhesive layer (2) by heating a mass, pressing the heated mass together with the adhesive layer (2) in order to form the inner half shell, and cooling the inner half shell. Known methods are disadvantageous in that the production process is complex or in that the adhesive bond is not optimal. The invention improves thereon in that the process of pressing the heated mass positioned on the adhesive layer (2) together with the lower adhesive layer (2) and the process of foaming the sole region are carried out without removing the half shell from a mold part (8). In order to press the mass together with the adhesive layer (2), a press punch (7) is inserted into the mold part (8), and after the press punch is removed, a mold cavity (9) is sealingly placed on the mold part (8) such that a cavity in the shape of the sole region (3) remains between the lower adhesive layer (2) and the mold cavity (9), a plastic being injected or foamed into said cavity.

Description

[0001] Method for producing a base for footwear, footwear and machine for producing a base

[0002] The invention relates to a method for producing a base for footwear. Furthermore, the invention relates to a footwear article with such a base produced according to the new method, as well as to a machine for carrying out and implementing this method.

[0003] The previously used, known process for producing the base for footwear comprises the following process steps:

[0004] • Production of an inner half-shell of an intermediate layer forming the footrest and a lower, adhesion-promoting layer by

[0005] • Heating a mass as starting material for forming the intermediate layer,

[0006] • Pressing the heated mass positioned and distributed on the lower, adhesion-promoting layer with the lower, adhesion-promoting layer to form an inner half-shell in a mold,

[0007] • active or passive cooling of the inner half-shell,

[0008] • Production of a lower sole area by foaming or injection-molding the lower sole area onto the inner half-shell on the side of the lower, adhesion-promoting layer in a mold and

[0009] • Demoulding the substructure from the mould

[0010] Footwear within the meaning of the present application is understood to mean all forms of footwear that are suitable for carrying out the method according to the invention, i.e., that have a base that has the proper intermediate layer and a lower sole region molded onto the base from below. These are preferably, but not necessarily, women's and

[0011] REPLACEMENT SHEET (RULE 26) Men's shoes, including sports shoes, whereby the invention can also be used in conjunction with all other footwear, in particular in conjunction with sandals, slippers, or mules. All of these products are referred to in this application as footwear.

[0012] The lower sole area of ​​the footwear in question here has a half-shell that forms the inner support area for the wearer's foot. Typically, a lower sole area is injection-molded onto the underside of this half-shell from a plastic that foams in an injection mold, with the half-shell and lower sole area then forming the so-called substructure of the footwear. The lower sole area is usually made from a polyurethane (PU) that has been plasticized and mixed with a blowing agent. A foam structure is selected that is integrally compacted in the area of ​​the actual tread and the edge areas, resulting in a lightweight, elastic sole area with sufficient mechanical strength on the underside and edge areas.

[0013] In many footwear, the footbed is ergonomically shaped and adapted to the contours of the foot. This is achieved using a mass that can be molded during production and later solidifies into an elastic body. This mass is preferably made of a material that, after solidification and during wear, is breathable and moisture-permeable, as durable as possible, and elastic. Furthermore, a natural material should be used whenever possible. This layer of the substructure is referred to as the intermediate layer in the context of the present application.

[0014] A cover can be applied to the intermediate layer, which can further create a quality-enhancing impression, can have additional properties, for example, sweat-absorbing and / or springy properties, or can serve as a carrier for printed information, such as the manufacturer's name, model name, or size of the footwear. During footwear production, the substructure described above must now be permanently connected to the lower sole area. This can be done by injecting the material of the sole area onto the substructure or by gluing. A substructure for footwear as described above and a method for its production according to the above-mentioned type are generally known, for example, from the production of sports shoes or sandals.A disadvantage of simply gluing or molding the sole area to the base, however, is that it is often desired to use a material for the intermediate layer that, while very comfortable and inexpensive for the wearer due to its properties, is difficult to bond to a foamed plastic. It is particularly important to consider that during wear of the footwear, especially in the case of athletic footwear, the front area of ​​the intermediate layer and the sole area is subjected to constant, comparatively high mechanical stress, particularly bending stress and deformation stress.

[0015] The object of the invention is therefore to create a method for producing a base for a footwear item that enables easy and durable production of the base for the footwear item at the lowest possible cost. Furthermore, a further object of the invention is to create a footwear item with such a base and a machine for carrying out the method and for producing the footwear item.

[0016] The above-mentioned object regarding the method for producing the substructure is achieved according to the invention by a method according to claim 1. With regard to the substructure or the footwear, the object is achieved by a substructure according to claim 10 or a footwear according to claim 12. With regard to the machine for implementing the method and for producing the footwear, the object is achieved by a machine according to claim 13.

[0017] In one possible embodiment, the method is characterized in particular in that the steps of pressing the mass positioned and heated on the lower, adhesion-promoting layer with the lower, adhesion-promoting layer to form the inner half-shell and the foaming or injection-molding of the lower sole region can be carried out in one molded part without prior demolding of the half-shell, wherein for pressing the mass with the lower, adhesion-promoting layer, a press die is introduced into the molded part, then after removal of the press die, a mold cavity is placed sealingly onto the molded part in such a way that a cavity in the shape of the sole region remains between the lower, adhesion-promoting layer and the mold cavity, then a plastic is injected or foamed into the cavity and subsequently, after moving the molded part and mold cavity apart, the substructure is demolded.

[0018] Thanks to the improved process, previously manual processing steps can now be dispensed with. In particular, the use of a suitable adhesion-promoting layer means that the production of the base can now be carried out entirely using a newly developed machine. Therefore, the adhesion-promoting layer is preferably not an adhesive, but rather a layer made of a fibrous material, particularly a natural material, in order to meet the high ecological standards of high-quality footwear. This layer is, for example, a layer made of jute material, which is particularly preferably manufactured as a woven or knitted fabric from individual jute threads or fibers. Of course, other natural fibers or even synthetic fibers can also be used.

[0019] The intermediate layer is preferably made from a breathable, near-natural or natural material. This can be, for example, a mixture of cork and ethylene vinyl acetate (EVA). A mixture of cork and synthetic rubber or caoutchouc can also be used. Furthermore, another natural material can be used instead of the cork. This mixture is processed as a warm mass. While previously the associated mold, in which the mixture was pressed into shape, was filled manually, the method according to the invention now allows this to be done mechanically. For this purpose, an extruder is used in particular, via which the mixture can be produced on the one hand and also introduced into the molded part to produce the intermediate layer on the other.

[0020] First, however, if one is used, a cover is placed into a receiving cavity of the molded part with the later visible side facing down. The warm material from the compound to produce the intermediate layer is then applied to this cover, which can already be cut to the later size of the substructure or can overlap laterally. This material can be distributed evenly as it is introduced into the receiving cavity or in the thickness distribution required across the length and width of the intermediate layer. If the compound is to be extruded into the receiving cavity, the material can be fed into the receiving cavity via an extruder immediately after plasticizing. For this purpose, the machine can be designed in such a way that it temporarily feeds the receiving cavity and / or the extruder or its outlet nozzle towards one another.

[0021] After the warm mass has either been introduced into the receiving cavity with the desired thickness distribution or has been subsequently distributed in the receiving cavity, the lower, adhesion-promoting layer is applied. This layer structure is then pressed into the substructure using a press ram. However, this is preferably not demolded; instead, the press ram is removed and, in place of the press ram, a mold trough is positioned above the receiving cavity to form an injection mold. This mold has an internal cavity on the underside of which the newly produced substructure lies with the adhesion-promoting layer facing upwards. As a result of the manufacturing process, the adhesion-promoting layer is firmly bonded to the intermediate layer due to the penetration of the material of the intermediate layer's mass into the fibers and the structure of the layer.

[0022] After the injection mold with the inserted base has been closed as described above, the plastic of the lower sole section, loaded with blowing agent, is injected into the cavity. Cooling the side walls of the mold cavity, which in turn prevents foaming in the edge area, creates the outer, stable edge areas. At the same time, this plastic also interlocks with the adhesion-promoting layer, eliminating the need for adhesives and yet achieving a significantly more stable bond between the base and the lower sole section. After the resulting lower shoe section has cooled, it can then be demolded and joined to the upper shoe section.

[0023] Alternatively, an upper shoe part can also be connected to the substructure or the lower sole area directly during injection molding of the lower sole area, or even during the production of the substructure. For this purpose, the upper shoe part is inserted into the receiving cavity and secured either by the mass of the intermediate layer of the lower sole or by the plastic of the lower sole area.

[0024] In a further embodiment of the method according to the invention, the cover of the base is punched to the required shape before being inserted into the receiving recess. This punch can preferably also be used to simultaneously stamp information onto the cover, such as the manufacturer's name, the model of the footwear, or the size of the footwear. This eliminates the need for an additional step of printing the cover.

[0025] Finally, it may also be desired that the adhesion-promoting layer also covers the outer area of ​​the intermediate layer. In this case, the adhesion-promoting layer can first be inserted into the receiving cavity, then coated with the compound and, if necessary, the covering. To cover the edges with the adhesion-promoting layer, the latter is inserted into the mold so that it protrudes upwards laterally in the edge area. The assembled substructure is then pressed as described above. In this configuration, the adhesion-promoting layer naturally lies on the underside of the receiving cavity.

[0026] To be able to inject the plastic of the lower sole area onto the underside of the adhesion-promoting layer in this configuration, the tool can be rotated with the receiving cavity, for example, whereby part of the press ram can remain in the receiving cavity to maintain the shape of the substructure. At the same time, the original lower support of the tool is replaced with the mold cavity, creating a cavity for injecting the plastic material of the lower sole area above the adhesion-promoting layer.

[0027] Further features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the drawings.

[0028] In the drawings shows:

[0029] Fig. 1 shows schematically a structure of the inventive substructure of a footwear article in an exploded view, Fig. 2 shows the substructure from Figure 1 in the assembled state,

[0030] Fig. 3 schematically shows a machine for carrying out the method according to the invention for producing the substructure of a shoe article according to the invention and

[0031] Fig. 4 is a schematic view of a machine according to the invention for carrying out the method according to the invention.

[0032] Figure 1 shows a schematic exploded view of the structure of a base of a footwear article according to the invention. The arrows symbolize one possible order in which the individual layers are constructed. The top layer is a cover 4, for example, a cover 4 made of microfiber or another fabric material.

[0033] Below the cover 4 lies the intermediate layer 1, which is preferably made of a material blend of cork and EVA. Below this, in turn, lies the adhesion-promoting layer 2. Shown below is the lower sole area 3, which will later be injection-molded onto the underside of the adhesion-promoting layer 2 after the upper three layers—namely, cover 4, intermediate layer 1, and lower adhesion-promoting layer 2—have been joined together.

[0034] The adhesion-promoting layer 2 preferably consists of a porous, rather coarse or coarse-meshed material into which the plastic of the lower sole region 3 and the intermediate layer 1 can at least partially diffuse. Furthermore, it is additionally or alternatively formed from a woven, braided, or knitted fabric made of individual fibers, so that a mechanical encircling of regions of the lower, adhesion-promoting layer 2 by the material of the intermediate layer 1 and / or the lower sole region 3 is also possible. In this way, a firm connection of the four layers shown in Figure 1 is achieved, which is shown in Figure 2 as a combination of the substructure with the lower sole region 3.

[0035] Figure 3, in turn, schematically shows a possible machine for producing the part of the footwear shown in Figures 1 and 2. The machine has a workpiece carrier 6, on the upper side of which a molded part 8 is provided with a receiving recess into which the layers of the substructure, namely the cover 4, the mass for producing the intermediate layer 1, and the adhesion-promoting layer 2, are inserted.

[0036] After these components have been inserted, a press ram 7 is lowered into the receiving cavity and presses the components together to form the substructure. The press ram is then raised again and moved out of the area of ​​the receiving cavity of the molded part 8. The mold cavity 9 of another tool is then positioned above the molded part 8, with the mold cavity 9 being placed onto the receiving cavity of the molded part 8 in such a way that, together with the receiving cavity, it forms a closed injection mold, in the lower area of ​​which the previously produced substructure is located. The material of the lower sole region 3 can now be injected into the cavity above the substructure using an injection molding function (not shown), resulting in a lower sole region made of plastic that is integrally and firmly connected to the substructure.

[0037] Figure 4 shows a schematic view of an exemplary machine with which the method according to the invention can be implemented. The machine has several, in this case two, injection molding components 11, which are shown here as an example of a screw extruder with an external heating device. The mass of the starting material is first introduced into the molded part 8 via the first injection molding component 11 shown on the right. Here it is shown that the entire screw extruder is movable for this purpose, so that the sprue runner 10 can be moved over the molded part 8 so that the mass heated by friction and the external heating device can be extruded out into the mold. However, this is only a very simplified representation of a possible solution; the injection molding component 11 could just as easily be stationary and the sprue runner 10 movable.The only important thing is that the machine is able to heat the mass and, when the mould is open, to convey the heated mass into the moulded part 8.

[0038] After the compound has been heated, it is positioned in the inner half-shell in order to then press the lower, adhesion-promoting layer 2, which has been placed in the mold, together with the compound to form the inner half-shell. The lower sole region 3 is then foamed or injection-molded. This can also be done using an injection-molded component 11. According to the invention, the tool is changed before the inner half-shell is demolded in order to be able to produce the lower sole region 3 in the mold used without first demolding the inner half-shell. For this purpose, the inner half-shell was first produced in such a way that the later underside is on top. By changing the tool, a mold cavity 9 with a cavity open downwards is moved over the inner half-shell and lowered to create a closed cavity on the underside of which the inner half-shell lies.

[0039] After closing the mold by lowering the mold cavity 9, the lower sole region 3 is then molded directly onto the inner half-shell by injection or foaming. In the illustrated embodiment, the tools for preparing the upper half of the mold cavities are rotatably mounted on the support 5. Of course, all other tool change options are also possible, in particular transverse displacement or a solution using robot technology. The illustration shown is intended only to illustrate the change of the upper half of the tool and the positioning of the mold cavity onto the lower part of the tool, without limiting the type of positioning to the solution shown.

[0040] In the embodiment shown, a second injection-molded component 11 is provided to introduce the material of the future lower sole region 3 into the mold cavity or to apply it to the inner half-shell before the mold cavity is lowered. This technique is particularly suitable for foaming, so that the material can be applied first and foaming can take place after the mold is closed. Using appropriate connections, the mold cavity could of course also be lowered first and then the injection-molded component 11 positioned so that the sprue 10 can be connected to the cavity, which preferably occurs automatically during the movement of the injection-molded component 11.

[0041] Alternatively, the cavity can also be fed directly via a suitable line system, in particular with heated lines. For example, the injection molding component 11 shown on the right in Figure 4 could also have the mass injected through a sprue that runs through the workpiece carrier 6 into the recess for the molded part 8 located therein. The same applies to the injection molding component 11 shown on the left, which injects the material of the lower sole region 3. Since the 45° angle of rotation shown here is not necessary and the tools only need to be moved far enough to allow the other tool to be lowered onto the workpiece carrier 6, one of the two injection molding components 11 or both injection molding components 11 can be connected to the moving parts of the tool via a line system, so that the respective mass can also be injected via intake channels located therein.

[0042] Finally, the mold cavity 9 could also be arranged on the movably mounted injection-molded component 11 for injecting the material of the lower sole region 3. In this case, the injection-molded component 11 and the mold cavity 9 would move together, and the sprue 11 could permanently connect both components. In this case, the two components would then be arranged on a movable carriage, with the mold cavity 9 positioned such that, after being positioned above the workpiece carrier 6, it can be lowered by the movement of the carriage or a lowering device located on the carriage to form a closed cavity.

[0043] The machine shown here has a control system 12, via which the necessary settings can be made. This, too, is only shown schematically. Of course, decentralized control can also be used instead of a machine-level control option, although the input of user commands is usually not necessary after the machine has been set up. After the lower sole section 3 has been molded onto the inner half-shell, the mold opens again and the substructure can be removed so that it can then be further processed into a finished shoe. Connections for the upper shoe section can be integrated into the lower sole section simultaneously using the described method. List of reference symbols:

[0044] Intermediate layer

[0045] Lower, adhesion-promoting layer

[0046] Lower sole area

[0047] Relation

[0048] carrier

[0049] Workpiece carrier

[0050] Press stamp

[0051] molded part

[0052] mold cavity

[0053] runner

[0054] Injection molded component

[0055] steering

Claims

Patent claims: Method for manufacturing an underbody for footwear in the form of a shoe, a sandal or a mule comprising the following process steps: 1.1 Production of an inner half-shell of an intermediate layer (1) forming the foot pad and a lower, adhesion-promoting layer (2) by • Heating a mass as a starting material for forming the intermediate layer (1 ), • Pressing the heated mass positioned on the lower, adhesion-promoting layer (2) together with the lower, adhesion-promoting layer (2) to form the inner half-shell in a mold, • Allow the inner half-shell to cool 1.2 Production of a lower sole area (3) by foaming or injection molding the lower sole area (3) onto the inner half-shell on the side of the lower, adhesion-promoting layer (2) in a mold, 1.3 Demolding of the substructure, characterized in that the steps of pressing the heated mass positioned on the lower, adhesion-promoting layer (2) together with the lower, adhesion-promoting layer (2) to form the inner half-shell and of foaming or injection molding the lower sole area (3) are carried out in a mold part (8) without prior demolding of the half-shell, wherein a press punch (7) is inserted into the mold part (8) to press the mass together with the lower, adhesion-promoting layer (2), then, after removing the press punch, a mold cavity (9) is placed onto the mold part (8) in such a sealing manner that a cavity in the form of the sole area (3) remains between the lower, adhesion-promoting layer (2) and the mold cavity (9), then a plastic is injected or foamed into the cavity and subsequently, after separating the mold part (8) and the mold cavity (9), the substructure is demolded. A method for manufacturing an underlayer with a sole for footwear according to claim 1, characterized in that a layer of a fibrous material, in particular a jute layer, is used as the lower, adhesion-promoting layer (2), wherein the layer of fibrous material is in particular a woven or knitted fabric made of individual threads or fibers. A method for manufacturing an underlayer with a sole for footwear according to one of the two preceding claims, characterized in that, when pressing the heated mass positioned on the lower, adhesion-promoting layer (2) with the lower, adhesion-promoting layer (2), a cover (4) made of a textile, in particular a microfiber cover, smooth leather, or suede is applied to the side of the intermediate layer (1) facing away from the lower, adhesion-promoting layer (2).A method for manufacturing a lower shell with a sole for footwear according to any of the preceding claims, characterized in that the lower, adhesion-promoting layer (2) is trimmed before being placed in the mold cavity (9) and / or after demolding the lower shell. A method for manufacturing a lower shell with a sole for footwear according to any of the preceding claims, characterized in that the inner half-shell is shaped during the pressing process such that its side facing away from the lower, adhesion-promoting layer (2) has the shape of a footbed. A method for manufacturing a lower shell with a sole for footwear according to any of the preceding claims, characterized in that the mass used as the starting material for shaping the intermediate layer (1) is a mixture of a natural material, in particular cork, and a plastic, in particular ethylene vinyl acetate (EVA).Method for manufacturing an undergarment with a sole for footwear according to one of the preceding claims, characterized in that the. lower sole area (3) is made of polyurethane (PU), in particular of a reactive foaming polyurethane (PU foam). Method for producing a substructure with a sole for footwear according to one of the preceding claims, characterized in that the intermediate layer (1) and the lower sole area (3) are connected to each other without the use of a chemical adhesion promoter, exclusively via the lower, adhesion-promoting layer (2) and the interlocking of the layers of the intermediate layer (1), the lower, adhesion-promoting layer (2), and the lower sole area (3). Substructure for footwear in the form of shoes, sandals, or mules with a sole arranged under the substructure, wherein the substructure is produced according to a method according to one of claims 1 to 9 and is formed by an inner half-shell that forms an intermediate layer (1) directly or indirectly forming the foot support and a lower,comprising an adhesion-promoting layer (2) and wherein the intermediate layer (1) is produced by forming a warm mass, pressing the heated mass positioned on the lower adhesion-promoting layer (2) with the lower adhesion-promoting layer (2) to form the inner half-shell and subsequently cooling the inner half-shell, and wherein a lower sole area (3) forming the running surface is foamed or injection-molded onto the substructure, characterized in that the lower adhesion-promoting layer (2) is a layer of a fibrous material, preferably jute, and is connected to the substructure and the lower sole area (3) without additional adhesive by pressing in the heated mass during the production of the substructure and by foaming or injection-molding the lower sole area (3). Substructure for footwear according to claim 9, characterized in that on the lower,a cover (4) made of a textile, in particular a microfiber cover, smooth leather or suede, is applied to the side of the intermediate layer (1) facing away from the adhesion-promoting layer (2), which is bonded to the intermediate layer (1) without adhesive by pressing the warm mass on it during the production of the substructure. Footwear in the form of a shoe, sandal, or mule with a substructure including a sole, characterized in that it has a substructure according to one of the preceding claims. A machine for manufacturing a substructure according to one of claims 9 or 10 or footwear according to claim 11, characterized in that the machine is designed as a combination of a press and an injection molding machine, which • at least one workpiece holder in the form of a molded part (8) with a receiving recess in the form of the substructure of the footwear and at least one press ram (7) that can be inserted into the receiving recess of the molded part (8) for pressing the mass located in the receiving recess with the lower, adhesion-promoting layer (2) positioned below the mass and • has a mold cavity (9) that can be moved via the workpiece holder, wherein the mold cavity (9) can be placed onto the molded part (8) via the machine in such a way that, with the exception of one or more sprue channels (10), a closed mold with a cavity that is arranged at least partially above the substructure arranged in the molded part (8) is formed, wherein the machine has an injection molding component (11) that is capable of injecting plastic material into the cavity via one or more sprue channels (10). Machine according to claim 12, characterized in that the molded part (8) is fixedly arranged on a workpiece carrier (6), wherein the press ram (7) and the mold cavity (9) are movably mounted on the machine via a control (12) and can be successively positioned against the molded part (8) by moving the press ram (7) and the mold cavity (9) and / or the molded part (8).Machine according to claim 13, characterized in that the press punch (7) and the forming trough (9) are mounted on a movable, in particular pivotable or rotatable, support (5), wherein. • for positioning the press ram (7) the carrier (5) can be moved in such a way, that the press ram (7) is arranged above the molded part (8) and that, for pressing the substructure in the receiving recess of the molded part (8), either the carrier (5) or the press ram (7) with a pressing section is movable in the direction of the receiving recess, or the receiving recess arranged on a movable component of the machine is adjustable against the press ram (7) and • To close the injection mold, the carrier (5) is displaceable such that the mold cavity (9) is arranged above the receiving cavity, and to produce the lower sole area (3) in the cavity between the receiving cavity and the mold cavity (9), either the carrier (5) or the mold cavity (9) movable on the carrier (5) is movable towards the receiving cavity, or the receiving cavity arranged on a movable area is positioned against the mold cavity (9) to close the cavity. A machine according to one of claims 12, 13, or 14, characterized in that the machine has at least one screw extruder each for conveying the heated mass for producing the substructure onto the lower, adhesion-promoting layer (2) and for injecting the plastic for producing the lower sole area (3) into the cavity.

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