化工学报 ›› 2017, Vol. 68 ›› Issue (11): 4359-4366.DOI: 10.11949/j.issn.0438-1157.20170552

• 材料化学工程与纳米技术 • 上一篇    下一篇

注射成型中聚合物剪切诱导结晶行为的三维模拟

赵朋1, 赵耀1, 严波2, 汪晓蔓1, 卢圣坤1, 傅建中1   

  1. 1 浙江大学机械工程学院, 浙江省三维打印工艺与装备重点实验室, 浙江 杭州 310027;
    2 上海交通大学材料科学与工程学院, 上海 200030
  • 收稿日期:2017-05-04 修回日期:2017-07-20 出版日期:2017-11-05 发布日期:2017-11-05
  • 通讯作者: 严波
  • 基金资助:

    国家自然科学基金面上项目(51475420);国家自然科学基金重点项目(51635006);中央高校基本科研业务费专项资金资助项目(2017QNA4003)。

Three-dimensional simulation of shear-induced crystallization for polymers during injection molding process

ZHAO Peng1, ZHAO Yao1, YAN Bo2, WANG Xiaoman1, LU Shengkun1, FU Jianzhong1   

  1. 1 Key Laboratory of 3 D Printing Process and Equipment of Zhejiang Province, College of Mechanical Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China;
    2 School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
  • Received:2017-05-04 Revised:2017-07-20 Online:2017-11-05 Published:2017-11-05
  • Supported by:

    supported by the National Natural Science Foundation of China (51475420, 51635006) and the Fundamental Research Funds for the Central Universities (2017QNA4003).

摘要:

在考虑剪切导致分子链取向并升高其平衡熔点的基础上,建立了基于Nakamura方程的剪切诱导结晶动力学模型。在WLF-Cross黏度模型中引入结晶对黏度系数的影响,构建了考虑结晶的注射成型过程模型。采用改进的有限体积法对聚合物剪切诱导结晶行为进行了三维数值模拟,模拟中耦合了流动场、熔体压力、温度、诱导时间与结晶度。结果表明,本方法可清晰模拟出注射成型过程中聚合物的三维“喷泉”流动行为以及3层“皮-芯”结晶结构,同时,诱导结晶时间指数与相对结晶度的模拟结果与理论及实验结果吻合。

关键词: 注射成型, 流动, 结晶, 计算机模拟, 有限体积法

Abstract:

Based on shear induces polymer orientation and increases its equilibrium melting temperature, a Nakamura equation based shear-induced crystallization kinetics model was presented. A model for injection molding simulation was also established, in which the influence of crystallization was considered into WLF-Cross viscosity coefficient. Three-dimensional shear-induced crystallization behavior was simulated by an improved finite volume method, which coupled flow field, melt pressure, temperature, induction time index and crystallinity. Experimental results show that the proposed method can clearly simulate the three-dimensional “fountain” flow behavior and the three-layer “skin-core” crystallization structure during injection molding process. The simulated shear-induction time index results and crystallinity results agree well with the theoretical and experimental results.

Key words: injection molding, flow, crystallization, computer simulation, finite volume method

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