| 摘要 |
PURPOSE:To obtain a molded item excellent in solid state properties such as surface gloss, by carrying out the blow molding of a crystalline thermoplastic that is melted in such a manner that said thermoplastic is injected into a mold having a particular surface temperature. CONSTITUTION:A crystalline thermoplastic (e.g. a crystalline polyolefin resin) is injected into the mold having a surface temperature in the range represented by the formula II : Tc-T1-DELTAT< mold surface temperature <Tc+T2(I) wherein Tc denotes the crystallizing temperature of the resin, T1 is 30 deg.C, T2 is 10 deg.C, and DELTAT is a value represented by the formula (II): DELTAT=-12.7 log 10 -15.2+25t (II) wherein lambda is the value of the heat conductivity of the heat insulating layer in cal.cm<-1>.sec<-1>. deg.C<-1>, and it is the thickness of the heat insulating layer in cm, and is subjected to the blow molding. |
