Patent ID: 6217689
Filing Date: 2001-04-17
Classification: B29C,B29L,Y10T

Abstract:
A method of manufacturing packing material from a web material with an apparatus including a lateral sealing assembly having a pair of sealing rollers including staged heat-sealing surfaces and a longitudinal sealing assembly having first, second and third pairs of rollers in respective rolling engagement with each other, the method comprising:(a) folding the web material into a folded web such that longitudinal ends of the web material are oriented facing each other at one end of the folded web and a fold is oriented at another end of the folded web;(b) sealing the longitudinal ends of the web material forming a continuous tube of the web material by (b1) pre-forming the web material for sealing with the first pair of rollers, (b2) heat sealing the longitudinal ends of the web material with the second pair of rollers, and (b3) setting the seal with the third pair of rollers; and(c) disposing the sealing rollers of the lateral sealing assembly in constant rolling engagement with each other and rotating the sealing rollers to contact the staged heat-sealing surfaces and thereby effect heated staged lateral sealing of the continuous tube of the web material.