Method for manufacturing footwear from recycled waste PVB film and products manufactured by the method

Abstract

The subject of the application is a method for manufacturing footwear from processed waste PVB foil, characterized in that it starts on the shredding line with the operation of sorting waste in terms of physical and mechanical properties through initial separation during loading onto a transport feeder, then the material is subjected to a three-stage fragmentation process, in the first stage it is shredded on a slow-speed mill, using sieves enabling obtaining fractions of the order of 50 - 100 mm, then the fraction thus obtained, after sorting using a metal separator, is shredded in the second stage using a high-speed mill, using sieves shredding the fraction to the size of pieces of the order of 10 - 15 mm, and in the third stage of fragmentation, the material, after sorting on the metal separator, is shredded using a high-speed mill, on sieves with holes of a diameter of 3 mm, a fraction of the order of 2 - 3 mm is obtained,The obtained and crushed material is then sorted in a metal separator and subjected to a pulverization process in a cryogenic pulverizing mill, dosing mineral filler during the pulverization stage. The pulverized material is then granulated on a granulation line, beginning with cross-linking the components according to the recipe in a warm mixer and then in a cold mixer. Following the initial base injection of polyvinyl chloride with the cross-linking assembly along with the pulverized secondary material, the ecoPVB material obtained in a twin-screw extruder is extruded into a strand. After cooling to ambient temperature, the strand is cut into fine granules using a cutting knife assembly. The resulting ecoPVB granules are injected into shoe molds using a two-color injection molding machine. The subject of the application also includes footwear produced using the above method.