多層膜共擠出製程的層厚均勻性改善及奈米多層膜的開發

Abstract

多層膜各層的厚度均勻性是多層膜共擠出製程的重要加工特性之一，其對於多層膜產品的性能 和品質有重要的影響。本計畫擬探討多層膜各層的厚度均勻性對於共擠出製程參數、模具條件以及 熔膠性質等的關聯度和依存特性，以發展能改善層厚均勻性的技術措施，並且藉由開發奈米多層膜 來做為技術提升的載具和驗證指標。計畫時程共兩年，茲分年敘述如下。

第一年：首先進行PC/PMMA/PC三層膜共擠出實驗，利用高速相機攝錄熔膠在模具內合流後的 層間界面位置和平穩性的變化，並與模口流出並冷卻後的多層膜之各層厚度分布進行比較分析。其 次利用有限元素軟體POLYFLOW，並選用黏彈性模型的White-Metzner模型，進行合流部以及合流 部下游至模唇的非等溫三維流動分析。最後進行實驗結果與數值模擬結果的綜合比較和檢討，以了 解共擠出多層膜的各層厚度分布對於諸影響因子的依存特性，並研擬改善層厚均勻性的策略。

第二年：首先依據第一年度研究所擬定的策略，實施必要的模具修正和材料性質調整，並以類 似第一年度的手法進行新階段的共擠出實驗和數值模擬分析，以發展改善層厚均勻性的軟硬體技 術。其次應用前階段所得的知識技術，配合使用多重的模流分割再疊合的方法，進行奈米多層膜的 開發，以驗證本計畫所發展的技術之有效性和品質。

The uniformity of layer thickness in multilayered films is one of the important processing characteristics of the multilayer film co-extrusion process and an important property and quality factor of multilayered film products. This study examines the correlation and dependence of the uniformity of layer thickness in multilayered films regarding the co-extrusion process parameters, die conditions, and properties of polymer melts to develop technical measures to improve the uniformity of layer thickness. This study develops nano-multilayer films as a vehicle for technology improvements and a verification indicator. This study is set to be conducted over two years; the detailed study schedule is provided below.

During the first year: First, the co-extrusion experiment of the PC/PMMA/PC three-layer film will be performed. The layered interface location of the polymer melts in the die at the confluence and the change of stability will be recorded using a high-speed camera, and then compared to the distribution of layer thickness of the multilayer films that are released from the die outlet and cooled. Additionally, the finite element analysis software POLYFLOW with the viscoelastic White-Metzner model will be employed to analyze the non-isothermal three-dimensional flow of confluence and downstream confluence to the die lip. Finally, the results of the experiment and numerical simulation will be compared and analyzed to understand the dependent properties of the distribution of layer thickness in co-extrusion multilayer films regarding different influential factors, and strategies for improving the uniformity of layer thickness will be developed.

During the second year: First, the strategies developed during the first year will be used in to adjust the die and material properties. Using a similar approach to the one employed in the first year, the co-extrusion experiment and numerical analysis will be performed to develop software/hardware technology to improve the uniformity of layer thickness. Additionally, by combining the knowledge obtained during this study and the developed method of dividing and superimposing multiple material flow to develop nano-multilayer films, we can validate the effectiveness and quality of the technology developed during this study.