Patent TW-336191-B (TW)
Title: Injection-compression molding process, improved-cleanliness molding process and apparatus the invention relates to an injection-compression molding process, improved-cleanliness molding process and apparatus
Inventor: GRORGE JOSEPH GALIC
IPC: B29D11/00
Filed: 1995-12-18
Granted: 1998-07-11
Abstract: An injection-compression molding process for forming of thermal plastic lenses by reducing overflow in sub mold, by installing the mold in an injection forming machine for operation, having the injection forming machine programmable controller, for application of holding force and opening force onto the mold dividing line between molds A, B, having the injection forming machine a programmable controller, that moves a retreat assembly inside side B of the mold; by means of at least one lateral grouting variable mold hole in the mold, having A embodiment and side B embodiment in opposite by the mold division line a forming surface, having at least one elastic of variable length to be stretched or compressed to determine the mold hole height in the existing range of the machine, having the elastomer an operation assembly of the following elements; (I) steel-made coil spring, of which the first holding position provides a medium elastic force of a longer distance, and (ii) Belleville steel-made spring washer, providing short-distance hard elastic force in the second holding position, being the elastomer disposed between side B mold division line mold and side B panel of the mold, application of synthetic elastic force to have side B mold division line panel press against the mold division line, making the holding force applied by the injection forming machine be less than the first elastic force, which equals the steel-made coil mod elastic force from side B mold division line mold against the mold division line, legnth of the elastomer in the first holder shall be the maximum in the mechanical limit, and when the holding force is over the first elastic force of the steel-made coil mold spring when pressed against the mold division line, yet less than the second elastic force of the steel-made spring washer equalling the steel-made coil mold, with the side B mold division line panel against the mold division line, the length of the elastomer shall be the middle value of the second holder of the mold, and when the holding force exceeds the second elastic force of the steel-made coil mold spring and the steel-made spring washer, side B mold division panel is pushed against the mold division line, length of the elastomer in the third holding position shall be the minimum as programmed in the mechanical limit, having the method the following steps: a) pre expansion of the mold hole at the mold division line by means of the circumference of the closing mold, to keep molten fluid from overflowing and, in the first place in the mold, before injection, determination of the first mold height be the desired compression plus the mold final thickness; b) after injection, and by gradual decreasing the mold hole height to the second position and partial filling the mold hole, the second position shall be over the first elastic force while less than the second elastic force by means of the holding force applied; c) full stuffing the hold hole by means of further decreasing the mold hole height to achieve the third position, which is formed by determining the holding force over the second elastic force; d) cooling the formed piece in the mold hole by maintaining the height of the mold hole at the third position, until the thermal plastic lens is stable; e) releasing the holding force and opening the mold along the line to retreat the molded piece.