摘要 |
Sheet material is deformed, for example crimped or bulked by feeding it to the surface of a rotating roll having a multiplicity of depressions in its surface and pressing the material against the roll surface, the material being fed to the roll at a rate exceeding the linear peripheral speed of the roll. Examples of materials which may be so deformed are filaments consisting of or containing thermoplastic polymers, woven and non-woven fabrics, thermoplastic sheets, paper and metal foils. Preferably, the roll surface consists of sintered particulate material, the depressions being the voids between adjacent particles. |