The present invention provides a process for production of expansion-molded articles of a linear low density polyethylene resin in a mold which comprises compressing pre-expanded linear low density polyethylene resin beads having two melting points (measured by differential scanning calorimetry) and having a ratio: 5%/= AH /AL x 100% /=80% using a pressurized gas, filling a mold capable of closing but incapable of sealing with said compressed beads, then venting said mold and heating and fusing the beads with steam, wherein the compression rate of the pre-expanded beads immediately before said heating with steam to the original pre-expanded beads is maintained at 5 to 60% (AL being the peak fusion area at the melting point at the low temperature side (TML) and AH being the peak fusion area at the melting point at the high temperature side (TMH)). According to the present invention, molded articles of linear low density polyethylene having a minimized dimensional shrinkage rate (good dimensional accuracy) and excellent fusion rate and surface appearance can be produced in high productivity.
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机译:本发明提供一种在模具中生产线性低密度聚乙烯树脂的膨胀模塑制品的方法,该方法包括压缩具有两个熔点(通过差示扫描量热法测量)且具有一定比例的预膨胀线性低密度聚乙烯树脂珠粒。 :使用加压气体将5% = AH / AL x 100% = 80%填充到能够关闭但无法用所述压缩珠密封的模具中,然后排气并加热模具并使之与蒸汽熔合,其中紧接在用蒸汽加热到原始预发泡珠之前的预发泡珠的压缩率保持在5%到60%(AL是在低温侧(TML)的熔点处的峰值熔合面积和AH是在高温侧(TMH)的熔点处的峰融合面积。根据本发明,可以以高生产率生产尺寸收缩率(尺寸精度)最小,熔融率和表面外观优异的线性低密度聚乙烯成型体。
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