Films of ethylene–vinyl acetate (EVA) copolymer with different vinyl acetate (VA) contents were adopted as flexible substrates for fabrication of micropyramid arrays by roll‐to‐roll (R2R) hot embossing at roller temperatures 40–80 °C. An empirical relationship between rheological behavior of EVA in rubbery state and demolding performance of the films was explored. Dependence of average forming height of micropyramid arrays on VA content and roller temperatures was investigated. Our study showed that both viscosity and relaxation behavior of EVA can be related to the ultimate forming height of micropyramids. The relationships can provide references for experimental research and industrial manufacture on R2R hot embossing. Retroreflection of micropyramid arrays was observed and transmittances of the two sides of embossed films were studied. Transmittances of the VA28 film embossed at 60 °C were 97.9% (the embossed side) and 41.8% (the smooth side), which showed potential applications in reflective film and antireflective film fields. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45228.

中文翻译：

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乙烯-乙酸乙烯酯共聚物的流变行为和薄膜上卷对卷热压花制备微金字塔阵列

采用具有不同乙酸乙烯酯（VA）含量的乙烯-乙酸乙烯酯（EVA）共聚物薄膜作为柔性基材，以辊对辊（R2R）在40–80°C的辊温进行热压花来制造微金字塔阵列。探索了EVA在橡胶态下的流变行为与薄膜脱模性能之间的经验关系。研究了微金字塔阵列的平均成型高度对VA含量和辊温度的依赖性。我们的研究表明，EVA的粘度和松弛行为均与微金字塔的最终形成高度有关。这些关系可以为R2R热压花的实验研究和工业生产提供参考。观察到了微金字塔阵列的逆向反射，并研究了压纹薄膜两侧的透射率。在60°C下压花的VA28薄膜的透光率分别为97.9％（压花面）和41.8％（光滑面），显示出在反射膜和减反射膜领域的潜在应用。©2017 Wiley Periodicals，Inc. J. Appl。Polym。科学2017年，134，45228。