标题: 多层膜共挤出制程的模内材料变形与流动行为探讨
Investigation of the Mold Flow Phenomena in the Co-Extrusion Process of Multi-Layer Film
作者: 陈仁浩
CHEN REN HAW
国立交通大学机械工程学系(所)
公开日期: 2011
摘要: 多层膜共挤出制程是制作各种高品质的功能性塑胶膜的重要方法。本计画拟针对多层膜共挤出制程中材料在模具内的变形与流动行为进行探讨,以了解层间材料性质差异、成形条件、模具设计等对于多层膜制品品质的影响,并提供做为多层膜的膜层设计、各层材料的选择与性质调整、模具设计、以及成形条件的决定等的参考依据。计画分两年来进行,兹分述如下。
第一年:首先进行由两种材料构成的三层膜的共挤出实验,观察、量测合流后的材料变形流动行为。其次利用有限元素软体POLYFLOW,并选用Bird-Carreau纯黏性非牛顿模型,进行衣架形流路、合流部、以及合流部下游至模唇的三维流动分析。最后进行实验结果与数值模拟结果的相互比较与检证,期能了解各层材料的黏度与流速、合流角度、合流部间隙等因子对于合流后的材料变形流动的影响,并掌握材料在模具各阶段流路内的变形与流动特性。
第二年:改为使用三种素材以进行材质非对称的三层膜共挤出实验,并增加对合流部下游的宽度面进行高速摄影,以观察层间界面不稳定现象的发生过程。数值模拟的部分,改用White-Metzner黏弹性模型进行三维流动分析,并分别与实验结果、第一年的纯黏性数值模拟结果做比较,以进一步了解材料的黏弹特性对共挤出的变形流动的影响,以及对模内各阶段流路使用黏弹性模型模拟的必要性。
The co-extrusion process of multi-layer film is an important approach to functional polymer films of high quality. This project will investigate the mold flow phenomena in the multi-layer co-extrusion process to understand the effects of material property differences between two contiguous layers, process conditions, and mold design, on the quality of produced multi-layer films. The results of this project will be useful for layer design of multi-layer film, mold design, and decision making for co-extrusion conditions. The project will be carried out for two years.
In the first year, we will conduct co-extrusion experiments of two-kind-polymer three-layer film. The side view of the flow phenomena at the confluence will be recorded using a high speed camera. We will also perform three-dimensional analysis of the flow inside the coat hanger manifold, the confluence, and the downstream from the confluence to the die lip. This work will employ POLYFLOW, a finite element analysis software, and will select the Bird-Carreau model, a non-Newtonian viscous model, to use in numerical simulation. According to these results, we can figure out the effects of viscosity and velocity of each polymer layer, the converge angle, and confluence clearance on the flow phenomena at the confluence. Moreover, we can know the flow phenomena inside each section of the channel in the mold.
In the second year, we will conduct co-extrusion experiments of three-kind-polymer three-layer film instead of two-kind-polymer three-layer film. In addition to the side view of the flow at confluence, the front view (film width plane) of the polymer flow at the downstream from confluence will be photographed using a high speed camera, so we can analyze the process of the unstable polymer interface. We will use the viscoelastic White-Metzner model to conduct three-dimensional numerical simulation of the mold flow. The results of viscoelastic numerical simulation will be compared to the experiment results, and the results of non-Newtonian viscous numerical simulation, respectively, to further understand the effect of the polymer viscoelastic property on the co-extrusion flow. The study will discuss the necessity of using a viscoelastic model in the numerical simulation of polymer flow inside each section of the channel in the mold.
官方说明文件#: NSC99-2221-E009-022-MY2
URI: http://hdl.handle.net/11536/98925
https://www.grb.gov.tw/search/planDetail?id=2218837&docId=355488
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