中文摘要：

为实现注射成型制品的微观结构调控,在气体辅助注射成型等方法的基础上,设计并实现了高分子材料多熔体多次注射成型的新型加工技术,即对两种聚合物组分,其中一种欠料注射进入模具型腔后,另一种熔体对基体聚合物熔体快速穿透,并推动外层熔体充填满整个型腔。初步探索了多熔体多次注射成型的剪切场分布与结晶性高分子制品的多层次晶体形态。研究发现：与传统注射成型过程不同,多熔体多次注射成型过程由于引入了二次熔体穿透的过程,流场特性情况比传统注射成型更为复杂,剪切速率沿制品厚度方向的分布表现出双峰分布特征。聚合物在多熔体多次注射成型过程中,受到刚性模壁和柔性熔体的双重界面约束,导致制品的形态结构的形成与演变更为复杂。在多熔体多次注射成型制品的次表层和芯层区域有柱晶结构形成,其制品表现出特殊的双＂皮-芯＂结构。

英文摘要：

Multi-melt and multi-injection molding（ MMMIM） was designed and applied as a new processing technology for polymer materials to control the microstructures of the products,based on methods such as gas-assisted injection molding（ GAIM）. Its main feature was that the mold cavity was partially filled with the polymer melt that was used as the first fluid,and then the second fluid penetrated the first one and drive it to fill out the entire cavity. The shear field distribution and multi-layered crystalline morphologies of crystalline polymer parts by MMMIM were explored. Different from the conventional injection molding（ CIM）,the flow field characteristics of MMMIM process was more complicated due to the introduction of secondary melt penetration process,and the shear rate showed a bimodal distribution in the normal direction of the parts. The formation and evolution of morphological structure were more complex due to the dual interface constraints of rigid mold wall and flexible melt. Cylindritic structures were formed in the sub-skin and core layer of MMMIM parts which also showed a special double ＂skin-core＂structure.