The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 16, 1989
Filed:
Sep. 15, 1987
Hirofumi Maeda, Takatsuki, JP;
Kanegafuchi Kagaku Kogyo Kabushiki Kaisha, Osaka, JP;
Abstract
The present invention provides that, in a process for production of foamed articles of a polyproplene resin which comprises compressing pre-expanded beads of propylene resins under a gaseous pressure, filling a mold capable of closing but incapable of sealing with the compressed beads, then venting from the mold and heating and fusing with steam thereby to produce the molded article in the shape of the mold, the improvement wherein the pre-expanded beads of the polypropylene resins having two melting points when measured by differential scanning calorimetry and having a quantity of the peak fusion heat QH based on a melting point at a high temperature peak of the two melting points being 0.3 to 3.5 cal/g are introduced compressively into the mold so that a compressive rate is 10 to 60%. According to the present invention, the foamed articles of polypropylene having a minimized dimensional shrinkage rate (good dimensional accuracy) and excellent fusion rate and surface appearance can be produced in high productivity.