Method of forming hollow foam moldings

• Main Authors: NAITO MASATO, IMANARI DIASUKE, OKUDA MASAYASU, TAKASE KENICHI
• Format: Patent
• Language: English
• Published: 17.09.2013
• 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; INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULARARTICLES; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; PERFORMING OPERATIONS; PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCESIN A PLASTIC STATE; 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

A method for producing a hollow foam molding having a thin and uniform wall thickness, including extruding a foamable melt containing a polypropylene resin having an equilibrium compliance Jeo of 0.5×10-3 to 1.8×10-3 Pa-1 and a swell ratio Sw of 2.5 or less and a physical blowing agent through a die to obtain a parison having a softened polypropylene resin foam layer, placing the parison in a mold, and blowing a gas into the parison to obtain a hollow foam molding having a hardened polypropylene resin foam layer with an apparent density of 0.35 to 0.65 g/cm3.