| 摘要 |
The present invention provides a process for production of foamed articles of a polypropylene resin which comprises compressing pre-expanded beads of the propylene resin under a gaseous pressure, filling a mold which can be closed but cannot be sealed with the compressed beads, then venting the mold and heating and fusing the beads with steam thereby producing the molded article in the shape of the mold. The process is characterized in that pre-expanded beads of a polypropylene resin having two melting points when measured by differential scanning calorimetry and having a quantity of the peak fusion heat QH based on the melting point at the high temperature peak of the two melting points of 0.3 to 3.5 cal/g are introduced into the mold at a compression rate is 10 to 60%. According to the present invention, 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. |
