Local thermo‐oxidative degradation in injection molding
Local thermo‐oxidative degradation in injection molding
复制标题
注射成型中的局部热氧化降解
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
E. Schmachtenberg
中科院分区：
文献类型：
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作者：
D. Schmiederer;A. Gardocki;I. Kühnert;E. Schmachtenberg
热塑性材料加工过程中的热、机械和热氧化应力会导致部件性能和使用寿命的损失。与工艺相关的热应力和机械应力是不可避免的。然而，在排除氧气的情况下加工可以减少热氧化应激。较低的热氧化应力可以产生较高的光学部件透明度，例如在微注射成型中平均分子量减少较少，以及由于加工过程中稳定剂消耗较少而具有较长的使用寿命。对于具有成本效益的温和工艺，重要的是要知道聚合物在加工的哪个步骤暴露于热氧化降解以及氧来自何处导致降解。为了研究局部热氧化应力，将注塑机封装并在局部排除氧气的情况下运行。如本文所述，由于周围空气中的氧气和溶解在聚合物树脂中的氧气，在塑化装置中发生热氧化降解。Polym.工程科学，2008.© 2008年塑料工程师协会
A loss in part properties and service life is caused by thermal, mechanical, and thermo-oxidative stress during processing of thermoplastic materials. Process related thermal and mechanical stresses are inevitable. However, processing under exclusion of oxygen can reduce the thermo-oxidative stress. A lower thermo-oxidative stress can yield a higher transparency of optical parts, less reduction of average molecular weight for example in microinjection molding, and a longer service life due to less consumption of stabilizers during processing. For a cost-effective and gentle process it is important to know at which step of processing the polymer is exposed to thermo-oxidative degradation and where the oxygen comes from causing degradation. To study the local thermo-oxidative stress, an injection molding machine was encapsulated and run under local exclusion of oxygen. As reported in this article, thermo-oxidative degradation occurs in the plasticating unit due to oxygen from the surrounding air and oxygen dissolved in the polymer resin. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers