Method of producing a seam-like connection between two or more layers of porous material

摘要

956,305. Seaming sheet materials. GES. FUR INDUSTRIELL TECHNIK. Dec. 15, 1961, No. 45020/61. Heading B5K. Two or more layers of porous material are given a seam-like connection by the application to an outer surface of the layers of a unit comprising a reinforcing element combined with a thermoplastic material followed by heating so that the thermoplastic material is melted in and between the layers, after which the reinforcing element is pulled away. The seaming unit may be in the form of a string, tape or strip and may consist of a core of thread with a thermoplastic sheath or the thread may be impregnated with thermoplastic material or twisted with it. If the thermoplastic material is in the form of a tape or strip, a thread or an element of synthetic material may constitute the reinforcing element, the synthetic material having a higher melting point than the thermoplastic seaming material. In the method of connecting layers illustrated, a thermoplastic strip is placed on layers 1, 2 resting on a base 10 and a heated press ram 5 is lowered on to the layers until the thermoplastic material has penetrated the layers.