RU2750365C2 - Footwear from thermoplastic polymer materials and method for manufacture thereof - Google Patents

Abstract

FIELD: footwear.

SUBSTANCE: proposed invention relates to the footwear industry, namely to manufacture of waterproof footwear containing rubber parts. The footwear is made of thermoplastic polymer blends and textile materials using an injection moulding machine with two independently operating injectors, is manufactured using a press mould by high pressure injection thereof, and consists of a sole and an top moulded thereto which can be made in different colors and materials with different properties. The top therein in shape constitutes a galosh with stripes injected to the bootleg made of polymeric or textile materials so that said stripes cover the seams thereon.

EFFECT: ensured possibility of manufacturing highly sealed waterproof footwear, prevented asymmetry in a footwear pair.

1 cl, 3 dwg

Description

The technical field to which the invention relates

The claimed invention relates to the shoe industry, namely to the production of waterproof shoes containing rubber (polymer) parts.

State of the art

Currently, the following methods are used to obtain rubber (polymer) footwear: glue method, stamping, molding, and injection molding.

The glue method is used to produce solid rubber and rubber-textile shoes, which are assembled (glued) on a block from separate parts. The parts are joined with rubber glue. The collected shoes are varnished and vulcanized. In glued footwear, the sole and lining rubber have different thicknesses, the joints of the parts are clearly visible. The bonding method is used in the production of all types of rubber footwear, but in recent years it has been supplanted by others due to its considerable labor intensity.

Solid rubber galoshes are produced by the stamping method. The outer parts and sole of the shoe are molded from a rubber compound. Finished shoes are varnished and vulcanized. Stamped overshoes have thick lining rubber walls, making them rough and heavy, but highly durable. The external distinguishing feature of stamped shoes is the presence of mold marks.

Solid rubber boots and galoshes are made by molding. In the production of molded shoes, rigid or elastic cores are used, on which the lining is put on. The lined cores are overlaid with uncured rubber and placed in a mold, where the shoe is finished and vulcanized. Molded shoes are produced unvarnished and are used for heavy-duty wear. The molding method is also used to attach the sole in rubber-textile shoes.

The liquid molding method is used in the production of shoes with uppers from fabrics, knitwear, leather, artificial shoe materials with a sole and a polyurethane vamp.

The injection method is used in the production of footwear from PVC or thermoplastic elastomer (boots, galoshes).

Closest to the claimed invention is Canadian patent No. 2755330 "IMPROVED METHOD FOR MANUFACTURING WATERPROOF SHOES WITH COMPRESSIBLE LINING AND DEVICE FOR ITS IMPLEMENTATION" (priority date October 19, 2011).

The essence of this solution lies in the fact that in the manufacture of waterproof footwear, a mold in the form of a galoshes is used. In this case, casting is limited precisely by galoshes, and the shape of the entire product is maintained due to the selection of material for the top of the boot, as well as the construction of the boot top. The disadvantage of this method is that the material for making the top of the boot in this way is selected dense, since it is necessary that it keep its shape, which leads to additional costs due to the fact that such materials are sold at a high cost. The use of more affordable and cheaper thin materials in this case is not possible, since such materials do not hold their shape. The material of the top of the boot is partly glued to the kalosh, partly sewn on. In this regard, there is a need for additional protection in order to ensure the tightness of the product, since punctures are formed during sewing, where moisture can enter. In addition, sewing is expensive, which increases the cost of the product. Also, when implementing this method, there is a possibility that in one pair one shoe may differ from the other in geometry due to the use of manual labor when sewing, which, in turn, may cause dissatisfaction of consumers.

The technical problem to be solved by the claimed invention is the need for gluing or stitching when using several types of material in one product, which leads to a decrease in tightness and quality, an increase in time and material costs. The footwear filed for registration and the method for its manufacture can eliminate the above disadvantages.

The technical result is to ensure the possibility of producing waterproof footwear with a high degree of tightness, avoiding asymmetry in a pair of shoes, as well as minimizing time and money.

Disclosure of the essence of the invention

The inventive footwear is a product made from thermoplastic polymer mixtures and textile materials using an injection molding machine with two independently operating injectors, created using a mold by casting it under high pressure and consisting of a sole and an upper molded to it, which can be made in different colors and materials with different properties.

Shoes can be made in several versions, the type depends on which mold is used in the manufacture. The mold consists of several parts (more than one), inside there are cavities into which the molten mixture enters. The main types of products are boots, in the manufacture of which a bootleg is additionally added to the kalosh.

Multilayer casting consists of alternately injecting at least two polymer melts from at least two injection molding devices into an injection mold. In the cylinder of the injection molding machine, the rubber mixture is plasticized, heated and, after entering a viscous-flow state under pressure, is injected into a closed heated mold, which moves in a circle and automatically opens after the end of the cycle.

The fundamental difference between the process of manufacturing footwear from thermoplastic rubber compounds by injection molding is the minimum cutting-stocking and preparatory production. When implementing the injection molding process, there is no need for the manufacture and assembly of rubber parts, since the rubber mixture in the form of a blank of a simple configuration is automatically fed into the injection unit.

The footwear, produced by injection molding from thermoplastic rubber compounds, consists of an inner textile frame and an outer rubber compound layer. But since the requirements for the upper of the shoe and the sole are different, materials of various characteristics and different brands are used for their manufacture, usually used in the manufacture of shoes, which are subject to requirements for waterproofness and tightness.

Filling is done using an injection molding machine. The collection of material into the injector barrel is made from a hopper with material granules. Plastic material in the form of granules (polyvinyl chloride, thermoplastic elastomer or other materials suitable for high pressure casting) is poured into the hopper. In this case, two independently working injectors are used, with the possibility of using materials of different colors and different properties in each of them. Heating is carried out to the required temperature, first of all, the lower part of the shoe is poured - the soles, in the second place, the upper part is poured - the top of the overshoe with the bootleg.

Both parts are poured in one complete revolution of the turntable on which the molds are fixed. The filling time of both injectors is automatically adjusted, the pressure and injection speed can also be changed depending on the material used.

The boot shaft can be made of both polymeric materials and textile materials with the required properties. In this case, if necessary, an image can be applied to the bootleg by any of the methods that make it possible to apply the specified image to the material from which the bootleg is made. At the same time, strips of polymer materials are poured from the galoshes up the shaft. The stripes are arranged in such a way that they cover the seams on the shaft. Also, these strips of polymeric materials can be embedded in other parts of the boot, if necessary, for example, along the perimeter of the top of the bootleg.

The strips extending from the overshoes and the closing seams, thus, ensure the fixation of the shape of the product and protection from moisture penetration into the holes formed during sewing. The number of stripes may vary depending on the number of seams on the shaft and the material used.

After the end of the pouring, the lining stocking is put on on the last (a stocking is used as a lining, sewn either from a knitted plush weave tube, or from a cut of a knitted two-elastic technical fabric), extraction of material from the sprue holes for the possibility of repeated casting and visual check of the product quality, and also the removal of possible surplus material. A warmed insole is put into suitable products, after which the boots are matched up in pairs.

In contrast to monolithic rubber boots, the proposed technology makes it possible to use different materials for the sole, the top of the galoshes and the tops of the boots, depending on the required characteristics. Due to the possibility of using textile materials for the bootleg, the product allows air to pass through and does not allow water to pass through, that is, the leg in the boot will not melt.

This method of manufacturing footwear ensures the tightness of the product, since there is no danger of moisture getting into the holes formed during sewing. In addition, the absence of the need to carry out work on sealing the seams reduces the cost of finished products. The special threads used to seal the seams are expensive. The invention proposed for registration allows the use of ordinary threads.

Also, the use of the claimed invention eliminates the risk of making a mistake during sewing, which can lead to asymmetry and deformation of the product. Polymer strips cover possible unevenness of the seam, and therefore the number of products to be rejected is reduced. Due to the uniform shape of the used molds, the risk of producing asymmetric paired products is eliminated.

One of the variants of execution of the footwear made in the framework of the implementation of the present invention is shown in the accompanying drawings.

Description of drawings

FIG. 1 is a side view of the boot.

FIG. 2 is a front view of the boot.

FIG. 3 is a rear view of the boot.

Claims (1)

Shoes made from thermoplastic polymer blends and textile materials using an injection molding machine with two independently operating injectors, created using a high pressure injection mold and consisting of a sole, an upper and a shaft, characterized in that the upper is adhered to the sole, while the shape of the upper is a galoshe with stripes molded to the shaft made of polymer or textile materials in such a way that the said stripes cover the seams on the latter.

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