| 摘要 |
PURPOSE:To facilitate the control of an expansion ratio and prevent the danger of an expanding agent catching fire or exploding from developing by a method wherein resin particles containing the expanding agent and resin particles containing no expanding agent, which are manufactured independently, are fed to the extruder screw of an extruder through separate courses. CONSTITUTION:Firstly, two kinds of resin particles or resin particles B containing expanding agent and resin particles A containing no expanding agent are independently manufactured and fed to the extruder screw 2 of an extrusion equipment so as to melt and knead and at the same time uniformly mix both resin particles A and B with each other. Accordingly, because no mixing equipment to mix the resin particles A and B is necessary, neither the lowering of blowing power due to the escaping of blowing gas during mixing operation nor the danger of blowing gas catching fire or exploding develop and safety operation is realized. In addition, the feeding of the resin particles at constant mixing ratio to the extruder screw 2 at all times is done by setting the ratio of the supplies of expansion ratio is easily done by controlling either one of the resin particles A or B. |
