Rheology of glass-filled polypropylene plastics during injection molding

注塑是通过将熔融材料(主要是塑料)**注入工具(模具)**来生产零件的制造工艺。从优化的注塑(IM)过程中获得无缺陷的零件需要**充分了解和控制熔体的流动、材料和工具之间的热传递以及**材料的固化。材料流控制归档时间和完全填充工具的材料能力。热传递速度影响材料的流动性及其凝固速度。一方面，在注模过程的充模阶段使用较高的工具**温度可以获得质量较好的零件，但由于需要较长的冷却时间，因此延长了**循环时间。另一方面，在**灌装过程中使用较低的工具温度将缩短循环时间，但这将极大地影响**所生产零件的视觉质量和物理性能。目前的注射成型实践采用恒定的工具温度，通常**通过对所处理的每种熔体材料和零件几何形状进行试验来确定，这使得整个注射成型过程**不是最优的。**本研究项目与开发一种创新的、更高效的注射成型工艺有关。**该项目将与温莎模具集团(WMG)合作实施，后者是一家加拿大**注射成型公司，位于安大略省温莎市。申请者**和WMG已经制定了一项长期计划，以彻底改变IM过程。该计划的主要目标是通过**使用双温度工具(DTT-IM)来优化IM流程。DTT-IM概念包括在充填阶段和冷却阶段分别对**工具进行快速加热和快速冷却。建议的DTT-IM工艺将带来**更好的零件质量、更少的缺陷、更短的周期时间和更高的生产率。这一长期计划的第一阶段**是本申请中建议的研究，重点是研究熔融**聚合物(塑料)在流动条件下的流变性(流动性)以及拟议的DTT-IM计划的温度范围。

Injection Molding is a manufacturing process for producing parts by injecting molten material (mostly plastics)**into a tool (a mold). Obtaining a defect-free part from an optimized injection molding (IM) process requires a**full understanding and control of the molten material flow, heat transfer between the material and the tool, and**material solidification. Material flow controls filing time and material ability to completely fill the tool. The**rate of heat transfer affects material flowability and its rate of solidification. On one hand, using a high tool**temperature during the tool filling stage of the IM process results in a better quality part, however it extends the**cycle time because longer cooling time will be required. On the other hand, using a low tool temperature during**filling would reduce the cycle time, but it would drastically affect the visual quality and physical properties of**the produced part. The current practice in IM employs a constant tool temperature that is usually determined**through trials for each molten material processed and part geometry, which renders the whole IM process**non-optimal.**This research project is related to the development of an innovative more efficient injection molding process.**The project will be carried out in collaboration with Windsor Mold Group (WMG), which is a Canadian**injection molding company located in Windsor, Ontario. A long-term plan has been developed by the applicant**and WMG to revolutionize the IM process. The main objective of this plan is to optimize the IM process by**using a dual-temperature tool (DTT-IM). The DTT-IM concept involves rapid heating and rapid cooling of the**tool during the filling stage and the cooling stage, respectively. The proposed DTT-IM process will result in**better part quality, less defects, lower cycle time, and higher productivity. The first phase of this long-term plan**is the research proposed in this application which focuses on studying rheology (flowability) of molten**polymers (plastics) at flow conditions and range of temperatures intended for the proposed DTT-IM.