Analysis of the bubble building in with blowing agent loaded polymer melts

负载发泡剂的聚合物熔体中气泡形成的分析

• 批准号: 426052763
• 负责人: Professor Dr.-Ing. Christian Bonten
• 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: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/426052763?language=en
• 关键词: Analysis; bubble; building; blowing; agent

Foam structure in extrusion foam experiments is analyzed dependent on physical foam agents, on chemical formulation of the modified strain hardening polymer melts and on the process parameters of the extrusion. The correlation of the extensional properties of the polymer melt can be effected with the bubble and structure building only insufficiently, pure qualitatively, because no realible informations exist about the extensional rates in gas bubbles. No selective modification of the polymers can be taken for foam buildings in order to their extensional viscosity and strain hardening for a controlled bubble building process.Based on these rheological and process specific deficits in order to describe the foam processes is necessary the development or a physical and especially rheological based simulation model for a better prediction of the bubble building in for foaming modified polymers. An experimentally verified bubble building model and a rheological constitutive equation, its parameters can be identified on for foaming modified polymer melts using suitable rheometrical measuring systems, shall be taken. The chemically modified PLA-type shall be characterized rheologically by using rotational, capillary and extensional rheometer systems. Extensional viscosity at extensional rates shall be determined, which are relevant for at the bubble rand equibiaxially stretched polymer melt and a diffusion model shall be developed and applied in order to describe the bubble building process during extrusion foaming.Existing models for the bubble building in with blowing agent loaded polymer melts must be enhanced with a time and strain dependent extensional viscosity function and the relation of the extensional viscosity and the strain hardening with the bubble growth shall be taken into account. For this reason the molecular stress function (MSF) model can be applied and its parameters can be determined from uniaxial extensional experiments. The equibiaxial extensional flow in real bubble building process then can be described correctly with this model.

分析挤出泡沫实验中的泡沫结构取决于物理泡沫剂，根据改性应变硬化聚合物熔体的化学制定以及挤出的过程参数。聚合物熔体的伸展性能的相关性只能通过质量纯化的气泡和结构构建来实现，因为没有关于气泡的扩展速率的可实现信息。为了使这些流行病和过程特定的缺陷对泡沫的延伸粘度和应变硬化，不可能对聚合物进行选择性修饰，以使其具有液体和过程的特定缺陷，以描述泡沫过程是必要的，或者是物理和尤其是基于流感学的模拟模型，以便在foble buildions for Polimers buildified Prolimers buildified Prolimers buildifiend forified Poligriged Polymers forififiend fo a。通过实验验证的气泡构建模型和一个流变构成方程，可以使用合适的流感图表测量系统来确定其参数以用于泡沫修饰的聚合物熔体。化学修饰的PLA型应通过使用旋转，毛细管和延伸的流变仪系统来表征流变学。应确定以扩展速率下的延伸粘度，这与在气泡兰特等于等轴旁拉伸的聚合物熔体相关，并应开发和应用一个扩散模型，以描述挤出泡沫期间的气泡构建过程。在挤出泡沫中的气泡建立过程。在挤压模型中，与吹式聚合物融合的相关型均应依赖于吹式聚合物的功能，并具有相关性的访问性，并且相关的聚合物融合均应依赖于时光趋势，并且具有较量的探测性，并具有较量的探视性，并具有较高的效率范围。并且应考虑带有气泡生长的应变硬化。因此，可以应用分子应力函数（MSF）模型，并且可以通过单轴伸展实验确定其参数。然后，可以使用该模型正确描述真实气泡构建过程中的近端延伸流。