| 摘要 |
PURPOSE:To contrive to save energy for molding styrene resin molded product by reducing heating temperature and time through such an arrangement wherein only the surfaces of foaming particles are made to become such condition wherein they tend to easily fuse and adhere by covering them with a mixture of a solvent and a nonsolvent of styrene resin immediately before foam molding is carried out, and then in a metal mold, those foaming particles are caused to foam and to fuse and adhere to each other. CONSTITUTION:A solvent of styrene resin shall be such that when resin foaming particles are immersed in it for 30min at 60 deg.C, foaming particles dissolve or inflate and change their shape, and a representative solvent of this type is n-heptane. A nonsolvent of styrene resin shall be such that when foaming particles are processed under the same condition, they don't change their shape at all, and a representative substance is fluidic paraffin. It is required that a solent and a nonsolvent, when they are mixed at 80 deg.C, dissolve each other and form a uniform phase. The rate of mixing is within the range of 99-0.01 of a nonsolvent for 1 part of a solvent. If the amount of a mixture is larger than 0.5-0.1pt.wt. for 100pts.wt. of foaming particles, foaming particles tend to adhere to each other and form lumps. If it is less than 0.1pt.wt., foaming particles are not uniformly covered. In a container wherein prefoaming is carried out, it is preferable that prefoaming is carried out simultaneously when foaming particles are covered by the mixture. |
