INJECTION MOLDING METHOD AND APPARATUS, AND MOLDED PRODUCT OBTAINED FROM THE METHOD

• Main Author: TSUTOMU NAGAOKA
• Format: Patent
• Language: English
• Published: 30.03.2007
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, ORYARNS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; MECHANICAL FINISHING OF YARNS OR ROPES; MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OFARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES ORRIBBONS; NATURAL OR ARTIFICIAL THREADS OR FIBRES; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; SPINNING; 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; TEXTILES; TRANSPORTING; WARPING OR BEAMING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; YARNS; YARNS OR THREADS

A MOLDED PRODUCT CONSISTING OF A SKIN LAYER AND A CORE LAYER IS OBTAINED BY INJECTING A SKIN LAYER RESIN AND A CORE LAYER RESIN FROM A SKIN INJECTION UNIT (13) AND A CORE INJECTION UNIT (12) INTO METAL MOLDS (8, 9), RESPECTIVELY. THE SKIN LAYER RESIN INJECTION PRESSURE BY THE SKIN INJECTION UNIT (13) AND THE CORE LAYER RESIN INJECTION PRESSURE BY THE CORE INJECTION UNIT (12) ARE CONTROLLED IN SUCH MANNER THAT A VOLUMETRICALLY REDUCED QUANTITY AT THE TIME OF COOLING AND SOLIDIFYING THE SKIN LAYER RESIN IS COMPENSATED SO AS NOT TO GENERATE DEFECTS SUCH AS HOLLOWS AND THE LIKE IN THE MOLDED PRODUCT. IT IS CHARACTERIZED IN THAT THE STATE THE CORE DWELLING PRESSURE IS HIGHER THAN THE SKIN DWELLING PRESSURE OVER A PREDETERMINED LENGTH OF TIME.(FIG 2)