权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Welding of amorphous and semicrystalline PLA Bead Foams (EPLA)

无定形和半结晶 PLA 珠状泡沫 (EPLA) 的焊接

基本信息

批准号：
392851979
负责人：
Professor Dr.-Ing. Volker Altstädt
金额：
--
依托单位：
Institut für Kunststofftechnik (IKT)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2018
资助国家：
德国
起止时间：
2017-12-31 至 2021-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/392851979?language=en
关键词：
Welding amorphous semicrystalline PLA Bead

项目摘要

The welding of bead foams is usually done with hot steam in a so called steam chest mold. Depending on the thermal properties of the polymer of the bead foam (amorphous/semi crystalline) different mechanisms occur during the welding with hot steam in a volume around the bead interfaces (the later weld line). In EPS (expanded polystyrene) as an example for amorphous polymers only interdiffusion and entanglements of polymer chains can be observed while in semi-crystalline EPP (expanded polypropylene) different crystal structures show an influence. Furthermore, the properties of the welded parts strongly depend from the welding quality. Here the weldability is influenced by softening/melting behavior of the single beads and the processing parameters of the steam chest mold (steam temperature, -pressure, -time).Aim of the project is the systematic investigation of PLA bead foams as a model substance to uncover relationships of the thermal properties of the used polymers, the morphology in the welded parts and in the weld line with the mechanical properties of the welded parts.Due to process conditions and/or modifications PLA bead foams can be amorphous or semi-crystalline which is unique compared to other polymers that are used for bead foams (e. g. PP and PS) which makes it interesting for fundamental research focusing on correlations of thermal behavior, welding mechanisms and mechanical performance.Additionally, PLA owes a high potential to be an environmental friendly pendant to EPS because of its similar property profile. Thus, EPS will be the benchmark system in this project. Although, in the past 10 years some patents in the field of EPLA were done it is yet not well established. With this project a scientifically contribution regarding welding mechanisms in bead foams will be made.

泡沫珠的焊接通常是在所谓的蒸汽箱模具中用热蒸汽完成的。根据胎圈泡沫聚合物(非晶态/半晶态)的热性能不同，在焊道界面(后一条熔接线)周围的体积内使用热蒸汽进行焊接时，会出现不同的机理。在以无定形聚合物为例的EPS(发泡聚苯乙烯)中，只能观察到高分子链的相互扩散和缠结，而在半结晶EPP(发泡聚丙烯)中，不同的晶体结构表现出一定的影响。此外，焊接质量对焊接件的性能有很大的影响。在这里，焊接性受单个微珠的软化/熔化行为和蒸汽箱模具的工艺参数(蒸汽温度、-压力、-时间)的影响。本项目的目的是系统地研究以聚乳酸微珠泡沫塑料为模型物质，以揭示所用聚合物的热性能的关系，由于工艺条件和/或修改，聚乳酸胎圈泡沫可以是无定形或半结晶的，这与用于胎圈泡沫的其他聚合物(例如PP和PS)相比是独一无二的，这使得它对于专注于热行为、焊接机制和机械性能之间的相关性的基础研究很有兴趣。此外，由于聚乳酸具有相似的性能轮廓，因此它具有很大的潜力成为一种环保的挂件。因此，EPS将成为该项目的基准系统。虽然，在过去的10年里，在聚乳酸领域已经取得了一些专利，但还没有得到很好的确立。该项目将对焊道泡沫的焊接机理做出科学的贡献。