METHOD FOR INJECTION MOLDING AT LOW, SUBSTANTIALLY CONSTANT PRESSURE

• Main Authors: SCHILLER, GARY FRANCIS, SCHARRENBERG, RAINER, BERG, CHARLES JOHN, JR, NEUFARTH, RALPH EDWARD, ALTONEN, GENE MICHAEL, LAYMAN, JOHN MONCRIEF
• Format: Patent
• Language: English; French
• Published: 29.11.2012
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

Disclosed herein is a method of injection molding at low, substantially constant melt pressures. Embodiments of the disclosed method now make possible a method of injection molding that is more energy-and cost-effective than conventional high-velocity injection molding processes. Embodiments of the disclosed method surprisingly allow for the filling of a mold cavity at low melt pressure without undesirable premature hardening of the thermoplastic material in the mold cavity and without the need for maintaining a constant temperature or heated mold cavity. Heretofore, it would not have been expected that a constant pressure method could be performed at low pressure without such premature hardening of the thermoplastic material when using an unheated mold cavity or cooled mold cavity.