Patent ID: 8518504
Filing Date: 2013-08-27
Classification: B29B,B29C,B29K,B29L,B65D,Y10T

Abstract:
1. In a successive injection process in which multiple resins including at least one colored resin are successively injected into a cavity of a mold by way of a gate located at a position opposed to a center of a bottom of a preform to be molded, a process for injection molding a preform comprises: initially injecting a short shot of a colored resin into the cavity of the mold; after the initial injecting, injecting a second resin and letting the second resin wedge its way through a central part of the initially injected colored resin to form laminated layers; and forming a double cylindrical color-gradated portion wherein a thickness of a colored resin layer made of the colored resin is gradually reduced toward the bottom, wherein the colored resin layer made of the colored resin reaches the bottom.