A method for producing a molded part, in particular a component of a sporting good, includes providing a mixture of a polymer melt and a foaming agent and injecting the mixture into a mold. The method includes solidifying at least a first portion of the molded part without foaming and at least a second portion of the molded part after foaming inside the mold, wherein the mixture includes a polymer having an average molecular mass corresponding to a viscosity number 130 ml/g, preferably 170 ml/g, more preferably 190 ml/g and most preferably 225 ml/g, wherein the viscosity number is determined via solution viscometry according to the ISO 307 standard.

A process of manufacturing a foam molded article includes opening an open-closed molding system; applying a release agent into a female cavity section of the molding system; injecting PU into the female cavity section; closing the molding system; placing the closed molding system in a foaming device; activating the foaming device to heat the PU; forming a plurality of interconnecting first air pockets in an air permeable foam core of a foam molded article to be formed; forming a plurality of interconnecting second air pockets in each of a top surface and a bottom surface of the foam molded article respectively by involving a chemical reaction with the release agent wherein the second air pockets are in air communication with the first air pockets; opening the molding system; and removing the finished foam molded article from the molding system.

In methods and apparatuses for producing auxetic foam from conventional foam, conventional foam is compressed into a mold before thermal, chemical or thermo-chemical treatment processes are performed. A segmented mold is accommodated in a compressing apparatus. After compressing the foam between the mold segments, the mold is fastened shut and removed from the compressing apparatus. The forces applied to any given volume of foam and the amounts by which the foam is compressed while being processed are controlled to impart desired mechanical properties to the produced foam. Poisson's ratio and density of discrete portions of finished foam shapes are reliably predicted and controlled to achieve uniform and non-uniform mechanical properties within a single continuous quantity of foam.

A continuous process for preparing a sheet article includes preparing a wet pre-mixture comprising a water-soluble polymer and a surfactant and having a viscosity of from 1,000 cps to 25,000 cps measured at 40 C. and 1 s.sup.1; aerating said wet pre-mixture to form an aerated wet pre-mixture having a density of from 0.05 to 0.5 g/ml; forming said aerated wet pre-mixture into a sheet having a top side and a bottom side; and drying said formed sheet of aerated wet pre-mixture on a conveying belt with the bottom side of said formed sheet contacting said conveying belt.

A method for producing a molded part, in particular a component of a sporting good, includes providing a mixture of a polymer melt and a foaming agent and injecting the mixture into a mold. The method includes solidifying at least a first portion of the molded part without foaming and at least a second portion of the molded part after foaming inside the mold, wherein the mixture includes a polymer having an average molecular mass corresponding to a viscosity number 130 ml/g, preferably 170 ml/g, more preferably 190 ml/g and most preferably 225 ml/g, wherein the viscosity number is determined via solution viscometry according to the ISO 307 standard.