Recycling of cliche waste from flexography printing for production of composites with applications for acoustic and thermal insulation

ABSTRACT Flexography is a widely used method in flexible packaging printing, where the cliche is a resilient photopolymerized printing plate. Cliches are difficultly recycled, because they acquire a crosslinked molecular structure. This also generates serious environmental problems in the final discard, as soon as, it has an indeterminate period of decomposition. Companies need grounding the cliches after their lifetime. Currently, there are no products or methods for recycling of this material. Therefore, the aim of this work is the recycle of cliche waste for the production of plates for thermal and acoustic insulation. A method of comminution of the material with suitable particle size was developed. Composites produced with cliche and PET by means of press molding at 350°C, obtained high flexibility and elongation of 22% until rupture. Up to 90% of the cliche can be useful in the compositions studied. Thermal insulation of the composite was 18% lower than of a laminated wood plate with similarly thick. For other hand, acoustic insulation has increased by 30% with the composite plates, especially in the frequency range above 2 kHz, showing to a potential insulation application.

摘要 柔性版印刷（Flexography）是柔性包装印刷领域应用广泛的工艺，其所用印版（cliche）为弹性感光树脂印刷版。由于该印版形成了交联分子结构，难以回收利用，最终废弃时会引发严重的环境问题——其降解周期难以确定。印版在达到使用寿命后，企业需对其进行报废处置。目前尚无针对该类材料的回收工艺或产品。为此，本研究旨在回收利用印版废料，制备用于热与声学隔热的板材。本研究开发了一种可获得合适粒径的材料粉碎工艺。以印版废料与PET为原料，在350℃下通过压制成型制备的复合材料，展现出优异的柔韧性，断裂伸长率可达22%。在所研究的配方体系中，印版废料的掺加比例最高可达90%。该复合材料的隔热性能比同厚度的层压木板低18%。另一方面，复合板材的隔声性能提升了30%，尤其在2kHz以上的频率区间表现突出，展现出良好的隔热隔声应用潜力。