Patent ID: 6592703
Filing Date: 2003-07-15
Classification: C03B,Y02P,Y10T

Abstract:
A method of cutting a laminate to form a cut piece of the laminate, said laminate consisting of a brittle material, a plastic layer extending over one side of the brittle material and, optionally, an adhesive layer bonding the plastic layer to the brittle material, said method comprising the steps of:a) engaging a cutting tool on the plastic layer on said one side; b) during the engaging of step a), heating the cutting tool bearing on the plastic layer so that a viscosity of the plastic layer in the vicinity of the cutting tool is lowered sufficiently so that a loading pressure of the cutting tool on the plastic layer that is required to sever the plastic layer is reduced; c) adjusting the loading pressure of the cutting tool engaged on the plastic layer to a predetermined loading pressure value below that for severing the plastic layer without heating the plastic layer, but which is sufficient for severing the plastic layer heated during the heating of step b) and which is sufficient for scoring the brittle material; d) during the engaging of the cutting tool on the plastic layer of step a), during the heating of the cutting tool of step b), moving the cutting tool along a predetermined cutting line on the plastic layer on said one side while the cutting tool bears on the plastic layer with said predetermined loading pressure value, whereby the plastic layer is severed along the predetermined cutting line with said cutting tool and the brittle material is scored on said one side with said cutting tool at the same time as the plastic layer is severed, thereby inducing a mechanical stress in the brittle material along the predetermined cutting line; and e) additionally, if appropriate, increasing mechanical stress in the brittle material along the predetermined cutting line to exceed a rupture strength of the brittle material; whereby the cut piece of the laminate is formed without uncontrolled rupture of the brittle material.