Verfahren zur Bildung einer Seitenlängsnaht an heissverschweissbarem Bahnmaterial, das zu einem rohrförmigen Körper mit einander überlappenden Längsrändern geformt ist

摘要

1,220,100. Seaming non-metallic sheet material. AMERICAN CAN CO. 5 Nov., 1968 [27 March, 1968], No. 20702/69. Divided out of 1,220,099. Heading B5K. The subject matter is identical to that disclosed in Specification 1,220,099 but the claims relate to a method of forming a longitudinal side seam in a tubular body of thermoplastic material with the longitudinal side edges overlapping, comprising heating the overlapped margins to soften the thermoplastic material and applying non-uniform pressure transversely thereof with lesser pressure adjacent the underlapped side edge to cause flow of thermoplastic material theretoward.