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同向锥形双螺杆混合挤出性能的比较

DOI: doi:10.3969/j.issn.1006-7043.2011.10.018

Keywords: 数值模拟, 粒子示踪法, 同向锥形双螺杆, 混合挤出

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Abstract:

为了给同向锥形双螺杆的设计和实际加工提供理论依据和技术支持,在螺杆转速为25r/min,进出口压差为零的条件下,使用POLYFLOW软件,数值模拟了同向和异向旋转锥形双螺杆、平行同向双螺杆混合挤出RPVC的过程,计算了3种双螺杆计量段流道内熔体的三维等温流场,用粒子示踪法统计分析了3种双螺杆的混合挤出性能,将同向锥形双螺杆的混合挤出性能与异向锥形双螺杆和平行双螺杆的混合挤出性能比较.统计分析结果表明,同向锥形双螺杆分散性混合能力最大,分布性混合能力比异向锥形的大,比平行双螺杆的小.同向锥形双螺杆既保存了异向锥形双螺杆有利于物料的压缩的优点,又克服了异向锥形双螺杆剪切能力小的缺点.锥形双螺杆计量段流道内熔体的压力波动最小,有利于挤出制品的稳定性.用实验和数值计算2种方法研究了HT??30平行双螺杆挤出RPVC的停留时间,验证了所采用的数值计算方法的可靠性.

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