Viscous material strip-parting method - by subjecting strip briefly to load exceeding its mechanical strength causing crack propagation

摘要

Lengths are parted off from a strip of highly viscous material by exerting a force at right angles to it. At the parting point, the material is briefly and rapidly subjected to a load exceeding its mechanical strength. This causes independent crack propogation and complete parting. The time from load application to when cracking starts can be less than the relaxation time of the material, load being typically applied as a blow. The load can be such that no additional fractures take place, and a notch can be formed to initiate the parting operation. ADVANTAGE - Accuracy without edge distortion. Used for caramel in the confectionery industry, or molten silicate glass or high polymer.