Method for producing especially soles in mechanical shoes-production

Abstract

Rubber compound is introduced into a tool(2) with a die(5) and side parts(7) at just below the vulcanizing temperature. A punch(6) closes the tool and compresses and prevulcanizes the rubber. Both tool sides are opened and partial vulcanization occurs. After punch removal the rubber layer is cooled and degassed. Controlled under-vulcanization occurs in both latter stages. A molding cavity is then formed between a tool-closing shoe last(8), the tool sides and the rubber layer. Reactive polyurethane(PU) injected into the cavity cures and exothermic heat completes vulcanization of the rubber layer and bonds both layers together. The bonding surface of the rubber layer is increased by impressing. The resulting profile corresponds to that of the sole tread profile so that uniform thickness occurs over the entire sole. The punch(6) is heated to 140-220degreesC, the die(5) to 90-150degreesC and the tool sides to 40-80degreesC. During the degassing stage the partially vulcanized rubber surface is heat activated and degassed with radiant heaters.

Description

technical field [0001] The invention relates to a method for the manufacture of shoe soles in mechanical shoemaking, wherein the shoe sole consists of at least one outer and one intermediate layer, one of which is made of rubber and the other of which is made of polyurethane The two layers are produced in the same mold consisting of a bottom mould, a mold frame of at least two parts and a displacer or last, wherein first the rubber sole is formed, on which the The polyurethane is reacted to form the midsole. Background technique [0002] The known methods used today are all flawed. The vulcanization of the rubber sole forms an outer skin layer, the so-called vulcanized skin, which almost always prevents bonding to the polyurethane. If rubber / polyurethane soles or the like are now manufactured, the process is characterized by a multitude of steps and is laborious. Production is expensive, expensive, and unsafe, in addition to being a burden on the environment. Manufacture...

AI Technical Summary

Problems solved by technology

[0007] According to the invention, the solution to this task is that, for the manufacture of rubber soles, the bottom mold is first driven together with the mold frame parts into a cavity open at the top, into which a plastic rubber substance is injected at a temperature slightly lower than that of vulcanization temperature, after placing an extruder, the rubber mass is extruded and prevulcanized in a first stage t1 in the thus completely closed mold and then in a second stage t2 with the mold frame open Partial vulcanization takes place, the displacer is then removed and the surface of the rubber layer passes through a cooling stage t3, wherein a controlled undervulcanization takes place in a second stage t2 and cooling stage t3, the displacer is then removed by a last or by Another ejector is replaced in such a way that between the last / extruder and the free surface of the rubber sole remains a mold cavity for the intermediate sole to be formed, into which the polyurethane substance is injected after the mold frame is also closed , the polyurethane substance reacts on the rubber sole in the closed mold with excess heat of reaction being directed outwards, wherein the re-vulcanization stage t4 of the rubber sole and the bonding of the rubber layer to the Tight bonding between polyurethane layers

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