Rheology of glass-filled polypropylene plastics during injection molding

注射成型是通过将熔融材料（主要是塑料）**注入工具（模具）来生产零件的制造过程。从优化的注射成型（IM）工艺中获得无缺陷的零件需要充分了解和控制熔融材料流动，材料和工具之间的热传递以及材料凝固。物料流控制归档时间和物料完全填充工具的能力。传热速率影响材料的流动性和凝固速率。一方面，在IM工艺的刀具填充阶段使用较高的刀具温度可以得到质量更好的零件，但是它延长了周期时间，因为需要更长的冷却时间。另一方面，在**填充过程中使用较低的工具温度可以减少周期时间，但会严重影响**生产零件的视觉质量和物理性能。当前的IM实践采用恒定的刀具温度，通常是通过对每一种被加工的熔融材料和零件几何形状的试验来确定的，这使得整个IM过程**不理想。**该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）合作进行，这是一家位于安大略省温莎的加拿大注塑公司。申请人**和WMG制定了一项长期计划，以彻底改变IM流程。本计划的主要目标是通过使用双温工具（DTT-IM）来优化IM过程。DTT-IM概念涉及在填充阶段和冷却阶段分别对**工具进行快速加热和快速冷却。提出的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。该长期计划**的第一阶段是本应用程序中提出的研究，重点研究熔融聚合物（塑料）在流动条件和拟议DTT-IM的温度范围下的流变性（流动性）。

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.