高收缩率干法腈纶毛条的生产工艺

探讨了用干法腈纶长丝开发生产高收缩率膨体毛条的生产工艺 ,结果表明 ,合理选择长丝束的内在质量、拉断热板温度、热牵伸倍数及冷却效果等工艺参数 ,可成功开发出汽蒸后缩率值达 2

细特FDY高沸水收缩率控制因素探讨

文章介绍了FDY的生产设备,原料,工艺参数,着重讨论了牵伸温度,牵伸倍数,定型温度等牵伸工艺对FDY高沸水收缩率的影响。

涤纶高收缩FDY33dtex/12f丝的生产技术分析

北京中丽设备生产涤纶高收缩FDY33dtex/12f丝,使用改性涤纶切片,经过干燥、纺丝、牵伸定型等工艺过程,得到沸水收缩率20%~50%的高收缩FDY丝。控制好干燥、纺丝、牵伸定型等工艺条件,可以得到适当要求的高品质丝。

Climate change and glacier area variations in China during the past half century

Glacier variations in the Tibetan Plateau and surrounding mountain ranges in China affect the livelihood of over one billion people who depend on water from the Yellow, Yangtze, Brahmaputra, Ganges and Indus rivers originating in these areas. Based on the results of the present study and published literature, we found that the glaciers shrank ：5.7% in area from 1963 to 20：0 with an annual area change of -0.33%. The shrinkage generally decreased from peripheral mountain ranges to the interior of Tibet. The linear trends of annual air temperature and precipitation at 147 stations were 0.36℃（10a）^-1 and 8.96 mm （10a）^-1 respectively from 1961 to 2010. The shrinkage of glaciers was well correlated with the rising temperature and the spatial patterns of the shrinkage were influenced by other factors superimposed on the rising temperature such as glacier size, type, elevation, debris cover and precipitation.

大长宽比注塑支架灯采用PP材料的研究

一般灯具的注塑结构件都采用低收缩率的塑料,如PC(聚碳酸酯),PA(聚酰胺)等,但这些材料成本较高。PP(聚丙烯)材料价格低,韧性好,但收缩率大,高收缩率对产品结构设计带来了相当大的挑战,尤其是大长宽比的产品,除不同结构件之间尺寸的匹配度外,结构件还会出现翘曲现象,因此需要对各处零件尺寸进行更加精确的设计。本文采用PP材料设计了一款大长宽比的注塑支架灯,通过对灯罩和底座采用不同的收缩率,合理的结构设计及模具工艺设计,最终零部件匹配良好,产品质量合格,论证了大长宽比结构件采用PP材料的可行性。