Method for manufacturing footwear

Abstract

To provide footwear that can easily accommodate a foot having deformation in a toe, ankle joint, or the like, and that can be easily attached and detached, and a manufacturing method of the footwear efficiently at low cost.SOLUTION: Footwear of the present invention is footwear 1 including an upper portion 11 having a front fabric and a rear fabric, an inner sole portion 12 connected to the upper portion, and a sole portion connected to the inner sole portion. At least a part of the upper portion includes a thermoplastic resin layer 101 between the front fabric and the rear fabric of the upper portion.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to footwear that can easily accommodate and attach / detach a foot with deformed toes, ankle joints, etc., and can assist in stable walking. Manufacturing method It relates thereto.

Background Art

[0002] When toes, ankle joints, etc. are deformed due to diabetic foot lesions, rheumatoid arthritis, hallux valgus, etc., it is difficult to accommodate the deformed foot and walk stably when using commercially available footwear as it is. For example, when tactile sensation, pain sensation, and temperature sensation decrease due to diabetic sensory neuropathy, painless injuries (such as shoe abrasions and calluses) can occur, leading to deformation of toes and feet, and in some cases, foot ulcers and gangrene. Also, in the case of rheumatoid arthritis, inflammation and deformation occur in the joints, which may be extremely painful. In such cases, it is necessary to reduce the pressure on the affected area and prevent the progression of damage. Therefore, when having foot ulcers or gangrene, or when having deformations in toes and ankle joints, it is generally common to use custom-made footwear according to the condition of the foot.

[0003] However, custom-made footwear is generally expensive because all processes are handmade from a mold for each piece. Also, when expanding the upper part of the footwear according to the foot deformation, conventionally, natural leather has been used as the material for the upper part due to its ease of processing. A method has been taken in which a mold corresponding to the foot deformation is pressed against the natural leather from the inside of the upper part and fixed with the mold to physically expand the upper part. Therefore, it takes several days to obtain a stable expanded shape, and there is a problem of low production efficiency. In order to efficiently produce custom-made footwear and reduce the manufacturing cost, it is effective to mass-produce intermediate-form footwear that can be commonly used, and to perform custom-made processing according to the condition of each wearer's foot at the time of use on the supplied intermediate-form footwear to obtain the final-form footwear.

[0004] Japanese Patent Application Laid-Open No. 11-178606 (Patent Document 1) discloses a sole made of silicone rubber for preventing diabetic foot lesions. Further, Utility Model Registration No. 3222296 (Patent Document 2) discloses a medical short shoe in which a processable first insole and a second insole are laminated and disposed on the inner bottom surface of the shoe, and a cup insole in which a heel region and a stepping portion region are molded to have the same thickness is disposed on the second insole. However, the sole described in Patent Document 1 is intended to disperse the load by making the sole of silicone rubber and prevent diabetic foot lesions. The medical short shoe described in Patent Document 2 is intended to prevent the worsening of symptoms such as calluses and ulcers by molding the entire surface from the heel to the toe of the inner bottom surface of the shoe to be flat so that uniform pressure is applied to the entire sole. These documents do not disclose at all a footwear that can easily accommodate and attach / detach a deformed foot, and a method for manufacturing the same efficiently at low cost.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Therefore, an object of the present invention is to provide a footwear that can easily accommodate and attach / detach a foot with deformed toes, ankle joints, etc. of and a method for manufacturing the same efficiently at low cost. In particular, a footwear useful for preventing the progression of diabetic foot lesions of and a method for manufacturing the same efficiently at low cost.

Means for Solving the Problems

[0007] As a result of intensive studies, the present inventors have found that by providing a footwear having a layer of thermoplastic resin disposed between the outer and inner fabrics of the upper part as an intermediate form of made-to-order footwear, and by subjecting the upper part of the footwear in this intermediate form to a heat expansion treatment, the layer of thermoplastic resin disposed between the outer and inner fabrics of the upper part can be thermally deformed along with the deformation of the foot, and a made-to-order footwear with an expanded upper part can be efficiently manufactured as a final form, thereby significantly reducing the manufacturing cost, and completed the present invention.

[0008] That is, the footwear of the present invention Footwear to be worn on a foot with deformed toes or ankle joints, has an upper part having an outer fabric and an inner fabric, and an insole part connected to the upper part 、 and a sole part connected to the insole part and a layer of thermoplastic resin and wherein the layer is disposed between the front and back fabrics of the upper part corresponding to the deformed toes or ankle joint of the foot, and the part of the upper part corresponding to the deformed toes or ankle joint of the foot is expanded by the thermal deformation of the layer .

[0009] In one form, the footwear of the present invention has a midsole in the sole part. The footwear of the present invention may have only a midsole, or both a midsole and an outsole, as an intermediate form of made-to-order footwear.

[0010] In the stage (final form) of wearing the footwear of the present invention, the portion of the upper part corresponding to the deformation of the wearer's foot is expanded by the thermal deformation of the layer of the thermoplastic resin. When the sole part has a midsole, the midsole may have a processed shape for assisting the wearer's walking. When the sole part has a midsole, an outsole is provided on the midsole as a final form.

[0011] The thermal deformation temperature of the thermoplastic resin is 25°C to 120°C, or 30°C to 100°C, or 30°C to 80°C, or 30°C to 60°C (load 1.82 MPa) when measured in accordance with ASTM D648. The thermoplastic resin is preferably low-density polyethylene or ethylene-vinyl acetate resin. The layer of thermoplastic resin disposed between the outer and inner fabrics of the upper part preferably has a thickness of 0.5 mm to 2.5 mm, for example 1 mm to 2 mm, or 2.5 mm to 6 mm, for example 3 mm to 5 mm.

[0012] In one form, the upper part has a strap with a hook-and-loop fastener. Also, in another form, the heel part of the upper part has a crescent-shaped core. Further, in yet another form, the footwear of the present invention has an insole inserted therein.

[0013] The method for manufacturing the footwear of the present invention is Footwear to be worn on a foot with deformed toes or ankle joints, an upper part having a surface material and a lining material, a midsole connected to the upper part 、 a sole connected to the midsole and disposed between the front and back fabrics of the part of the upper part corresponding to the deformed toes or ankle joint of the foot having a layer of thermoplastic resin A manufacturing method of the footwear, from the lining side of the upper part at the part of the upper part corresponding to the deformed toes or ankle joint of the foot of the wearer deformed foot pressing a mold corresponding thereto, heating the upper part at the portion where the mold is pressed, and thermally deforming the layer along the mold, after that, cool thereby of the layer fixing the shape and thereby expanding the upper part of the part corresponding to the deformed toes or ankle joint of the foot including.

[0014] When the sole has a midsole, it may further include processing the shape of the midsole so as to assist the wearer's walking.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0016] The footwear of the present invention has an upper part having a surface material and a lining, a midsole connected to the upper part, and a sole bottom connected to the midsole. The footwear of the present invention may be provided as an intermediate form of made-to-order footwear. By performing a heat expansion treatment on the provided intermediate form in accordance with the deformation of the feet of individual wearers, a final form of footwear in which the upper part is expanded in accordance with the deformation of the feet can be obtained. Further, the sole bottom may have a midsole, and further processing may be applied to the midsole of the sole bottom to assist the walking of the wearer. In such a case, the footwear of the present invention is provided with the sole bottom in the form of only a midsole, the midsole is processed according to the foot condition of an individual wearer at the made-to-order stage, and then an outsole is provided on the midsole. When the midsole is not processed, the footwear of the present invention may be provided in a form in which the sole bottom has a midsole and an outsole.

[0017] The upper part has a surface material and a lining, and a layer of thermoplastic resin is disposed between the surface material and the lining. The layer of thermoplastic resin undergoes thermal deformation by performing a heat expansion treatment in accordance with the deformation of the feet of the wearer, whereby the upper part is expanded along the deformed feet. The thermoplastic resin may be any material that can be easily thermally deformed by the heat expansion treatment and is not particularly limited. The thermoplastic resin used in the present invention has a heat distortion temperature (load 1.82 MPa) measured in accordance with ASTM D648, preferably 25°C or higher, or 30°C or higher, or 40°C or higher, and 120°C or lower, or 100°C or lower, or 80°C or lower, or 60°C or lower. For example, the heat distortion temperature of the thermoplastic resin is 25°C to 120°C, or 30°C to 100°C, or 30°C to 80°C, or 30°C to 60°C. If the heat distortion temperature of the thermoplastic resin is too low, it becomes difficult to maintain the shape deformed by the heat expansion treatment, and if the heat distortion temperature is too high, there is a risk of damaging the material of the upper part by the heat expansion treatment.

[0018] The thermoplastic resin may be a homopolymer or a copolymer. Examples of the thermoplastic resin include polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene-acrylonitrile resin, styrene-butadiene-acrylonitrile resin, high-density polyethylene, medium-density polyethylene, low-density polyethylene, ethylene-vinyl acetate resin, polypropylene, polymethyl methacrylate, methacryl-styrene resin, polyamide resins (such as nylon 6, nylon 66, nylon 12, etc.), polyvinylidene fluoride, polyethylene terephthalate, polybutylene terephthalate, cellulose acetate, nitrocellulose, ethyl cellulose, cellulose propionate, etc. However, the thermoplastic resin used in the present invention is not limited to these. Among the above resins, low-density polyethylene and ethylene-vinyl acetate resin, which have a relatively low heat shrinkage rate and are excellent in impact absorbency and flexibility, are particularly preferred.

[0019] The materials for the upper part are not particularly limited for both the outer and inner layers, and materials generally used for the upper part of footwear can be used. For example, natural leather (such as cowhide, horsehide, pigskin, sheepskin, goatskin, kangaroo leather, etc.), synthetic leather (materials obtained by coating fibers with synthetic resins such as polyurethane and nylon), artificial leather (artificial materials made by coating a fabric with synthetic resins such as polyurethane and nylon to resemble natural leather), natural fibers (fibers made from natural plants and animal hairs, etc.), synthetic fibers (chemical fibers such as nylon, acrylic, and polyester). The layer of the thermoplastic resin is disposed between the outer and inner layers of the upper part. The layer of the thermoplastic resin may be, for example, a sheet made of the thermoplastic resin or a coating film of the thermoplastic resin applied to the back of the outer or inner layer.

[0020] The layer of thermoplastic resin is arranged so as to be able to cover the deformed part of the wearer's foot. In order to widely provide the footwear of the present invention as footwear in an intermediate form, the layer of thermoplastic resin may be arranged over a wide range so as to be able to cope with various foot deformations. For example, even when providing for a wearer having a deformation in the toes, the layer of thermoplastic resin may be arranged not only in a range that can cover the toes of the upper part, but also over the entire forefoot part or the entire upper part of the upper part. The thickness of the layer of thermoplastic resin disposed between the outer and inner fabrics of the upper part may be any thickness that can expand the upper part by heat expansion treatment. The thickness of the layer of thermoplastic resin is preferably 0.5 mm to 2.5 mm, for example 1 mm to 2 mm, or 2.5 mm to 6 mm, for example 3 mm to 5 mm. The footwear of the present invention provides footwear in a certain intermediate form, and by subjecting it to heat expansion treatment, it is possible to widely cope with variously deformed feet.

[0021] In the footwear of the present invention, the upper part is connected to the midsole part, and the midsole part is connected to the sole part. The midsole part is a member of the part where the sole of the foot touches when wearing the footwear. The material of the midsole part is not particularly limited, and materials generally used as the midsole part can be used. For example, tannin-tanned leather, leather board, pulp board, non-woven fabric, etc. can be mentioned. The material of the sole part is also not particularly limited, and materials generally used as the sole part can be used. For example, natural leather, natural rubber, synthetic rubber [SBR (styrene-butadiene rubber), NBR (nitrile-butadiene rubber), etc.], elastomer (styrene-based elastomer, olefin-based elastomer, polyester-based elastomer, urethane-based elastomer, etc.), PVC (polyvinyl chloride), EVOH (ethylene-vinyl alcohol resin), PU (polyurethane), etc. can be mentioned.

[0022] In order to disperse the pressure applied to the affected part of the sole of the foot and prevent the aggravation of symptoms due to friction, an insole may be further inserted on the midsole part in the footwear of the present invention. The insole may be made to order according to the symptoms of individual wearers. The thickness of the insole is not particularly limited, but is generally about 3 mm to 10 mm.

[0023] The footwear of the present invention may have a midsole on the sole. The midsole is located between the mid-bottom and the outsole (the part in contact with the ground) of the sole, and is mainly used to absorb and disperse the impact when landing. The material of the midsole is not particularly limited, and materials generally used as midsoles can be used. For example, synthetic resins such as polyurethane and ethylene-vinyl acetate resin, and rubber sponges obtained by foaming rubber can be mentioned. The midsole may have a shape processed for the purpose of assisting walking according to the state of the feet of individual wearers. For example, the midsole may be processed into a rocker bottom shape (rocker bottom) to promote the movement of the center of gravity when walking.

[0024] The footwear of the present invention may have fixing means to prevent the feet from slipping off during walking. The fixing means includes means that can be operated with one hand, such as a surface fastener, a strap equipped with a snap button, or a wire fastener, but it may also be of the type tied with a string. The surface fastener is particularly preferable because the fixing position can be easily adjusted. The toe box (the space on the toe side of the footwear) of the upper part preferably has a height from the mid-bottom that is high enough to accommodate the deformed toes. For example, the height of the toe box is 3 cm to 5 cm from the mid-bottom. Also, for the purpose of supporting the wearer's feet during walking and stabilizing walking, a counter may be provided at the heel part of the upper part. The counter is made of a plate such as synthetic resin or rubber, and is disposed between the front and back fabrics of the upper part, on the back surface of the front fabric, etc.

[0025] One form of the footwear of the present invention is that a layer of thermoplastic resin is disposed between the front and back fabrics of the upper part corresponding to the toes or the base of the toes, and a counter is disposed between the front and back fabrics of the upper part corresponding to the heel and its surroundings. In the final form of the footwear of the present invention, the upper part of the portion where the layer of thermoplastic resin is disposed is heat-expanded according to the deformation of the feet of individual wearers.

[0026] The footwear of the present invention preferably has an opening at the entrance that is widely opened so as to accommodate a deformed foot. Further, it preferably has a deep-bottom structure into which a made-to-order insole can be inserted. The deep-bottom structure preferably has a depth capable of accommodating an insole having a thickness of about 3 mm to 10 mm. The lining of the upper part is preferably made of a material having a buffering function (for example, a thermoplastic resin such as polyester or nylon or its fiber) from the viewpoint of preventing friction against the skin, and preferably has no seams.

[0027] The footwear of the present invention can be manufactured by a general method. The connection between the upper part and the mid-sole, and the connection between the mid-sole and the out-sole can be carried out by generally used methods, for example, sewing, adhesion, vulcanization pressure bonding, etc. As a method of disposing a layer of thermoplastic resin between the outer material and the lining of the upper part, for example, a thermoplastic resin sheet may be sandwiched between the outer material and the lining of the upper part to form a laminate of the outer material, the thermoplastic resin sheet, and the lining. At that time, in order to dispose the layer of thermoplastic resin at a predetermined position of the upper part, the thermoplastic resin sheet may be adhered to the back of the outer material or the lining of the upper part. Further, molten thermoplastic resin may be applied to at least one of the outer material and the lining of the upper part, the outer material and the lining may be bonded together, and the thermoplastic resin may be cooled and solidified to form a coating layer of thermoplastic resin between the outer material and the lining.

[0028] When making a made-to-order process on the mid-sole of the out-sole, footwear having an out-sole made of a mid-sole may be provided as an intermediate form. When no made-to-order process is applied to the mid-sole, footwear with an out-sole further bonded on the mid-sole may be provided as an intermediate form.

[0029] In order for the footwear in an intermediate form to accommodate a deformed foot, custom processing is performed by a prosthetist or the like according to the deformation of the foot of each individual wearer. Specifically, a mold corresponding to the deformation of the wearer's foot is pressed against the lining side of the upper part, and the portion where the mold is pressed is heated to perform a heat expansion treatment on the upper part. The heat expansion treatment is performed at a temperature equal to or higher than the heat distortion temperature of the thermoplastic resin, for example, about 80 to 150°C, preferably about 100 to 120°C. The heating method is not particularly limited. For example, it is performed by applying hot air or a heating tool within the above temperature range to the upper part having the thermoplastic resin. By thermally deforming the layer of the thermoplastic resin along the mold and cooling the thermally deformed layer of the thermoplastic resin, the shape of the deformed thermoplastic resin is fixed, and the upper part can expand according to the deformation of the wearer's foot. The method of cooling the heated layer of the thermoplastic resin is not particularly limited, but it is usually performed by allowing it to cool naturally.

[0030] When the shoe sole has a midsole and the midsole is processed to assist the wearer's walking (for example, processed into a hull shape), at the custom-made stage, the upper part is subjected to a heat expansion treatment and the shape of the midsole is processed, and an outsole is provided on the processed midsole to obtain the final form.

[0031] The footwear of the present invention is useful as medical footwear for protecting a deformed foot from the progression of damage. The footwear of the present invention may be, for example, shoes (ankle boots, boots, safety shoes, sneakers, nurse shoes, etc.), sandals, slippers, and the like.

[0032] When a thermoplastic resin such as a polyolefin resin is sandwiched between the outer and inner fabrics of the upper part, wrinkles are likely to form in the inner fabric when the upper part is suspended in a shoe shape. Therefore, it has not been generally practiced to sandwich a thermoplastic resin between the outer and inner fabrics of the upper part. The present invention is based on the finding that a layer of a thermoplastic resin is disposed between the outer and inner fabrics of the upper part, and the upper part can be easily expanded into a desired shape by thermally deforming the layer of the thermoplastic resin. According to the present invention, footwear having a layer of a thermoplastic resin disposed between the outer and inner fabrics of the upper part can be mass-produced in an intermediate form and subjected to made-to-order processing. Also, in made-to-order processing, since the upper part is expanded by a heat expansion treatment, it can be processed efficiently in a short time as compared with the conventional method of physically expanding the upper part by fixing it with a wooden mold. Therefore, the manufacturing cost of footwear that requires made-to-order processing can be significantly reduced. Further, conventionally, natural leather has been exclusively used as the material for the upper part because of its ease of processing. However, according to the method of the present invention, since the thermoplastic resin is thermally deformed, the material of the upper part is not limited to natural leather. Therefore, it can also be applied to sneakers and the like.

[0033] The footwear of the present invention will be described in more detail below with reference to embodiments. The shoe 1 shown in FIGS. 1 and 2 has an upper part 11, a midsole part 12, a shoe sole part 13, a strap 14, and a vamp 15. The upper part 11 is adhered to the midsole part 12, and the midsole part 12 is adhered to a midsole 13a. The upper part 11 is composed of an outer fabric 11a made of natural leather and an inner fabric 11b made of polyester, and the inner fabric 11b has no seams to prevent friction. A sheet 101 of a thermoplastic resin (ethylene-vinyl acetate resin or low-density polyethylene) is disposed between the outer fabric 11a and the inner fabric 11b of the upper part 11 on both the left and right sides corresponding to the base part of the toes.

[0034] The shoe sole part 13 is only the midsole 13a when made-to-order processing is to be applied to the midsole 13a later. When made-to-order processing is not applied to the midsole 13a, an outsole 13b is attached on the midsole 13a.

[0035] One end of the strap 14 is fixed to the upper part 11, and a hook-and-loop fastener 104 is provided at the other end. The wearer can operate the strap 14 with one hand to engage the hook-and-loop fastener 104. An order-made insole (not shown) can be inserted into the shoe 1. The shoe 1 has a deep-bottom structure capable of accommodating an insole having a thickness of about 3 mm to 10 mm.

[0036] A crescent core 102 made of a synthetic resin (polyethylene) plate is disposed between the front and back fabrics of the heel part of the upper part to stabilize the wearer's walking. The toe box of the front foot part has a height (about 4.5 cm) from the midsole sufficient to accommodate the deformed toes. Also, the vamp 15 uses polyurethane for the back fabric to provide a cushioning function.

Explanation of Reference Numerals

[0037] 1 ··· Shoe 11 ··· Upper part 11a ··· Front fabric 11b ··· Back fabric 12 ··· Midsole 13 ··· Shoe sole 13a ··· Midsole 13b ··· Outsole 14 ··· Strap 15 ··· Vamp 101 ··· Layer of thermoplastic resin 102 ··· Crescent core 104 ··· Hook-and-loop fastener

Claims

1. A method for manufacturing footwear to be worn by a foot having a deformed toe or ankle, the footwear comprising an upper part having an outer material and an inner material, a midsole part connected to the upper part, a sole part connected to the midsole part, and a thermoplastic resin layer disposed between the outer material and the inner material in a portion of the upper part corresponding to the deformed toe or ankle of the foot, the method comprising the steps of: A method for manufacturing footwear, comprising: pressing a mold corresponding to the wearer's deformed foot against a portion of the upper part corresponding to the deformed toe or ankle of the foot from the lining side of the upper part; heating the upper part at the portion where the mold is pressed; thermally deforming the layer to conform to the mold; and then cooling to fix the shape of the layer, thereby expanding the portion of the upper part corresponding to the deformed toe or ankle of the foot.

2. 10. The method of claim 1, wherein the sole portion has a midsole, further comprising modifying the shape of the midsole to assist the wearer in walking.

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