Using Ultra Violet Light to Produce Layered Fiber Reinforced Materials Derived from Biological Sources

该项目的目标是研究紫外线(UV)处理作为一种可行的方法，以实现从生物来源提取的结构应用的层状纤维增强材料的可持续方法。这些生物基复合材料加工中的一个关键挑战是不能采用传统的热固化方法，因为主要由纤维素和半纤维素组成的天然纤维随着长期暴露在高温下开始降解。紫外光固化是一种快速、低温的光聚合过程，它比热固化消耗的能量要少得多。如果成功，这项研究将使制造高强度厚层压板的成本效益和更环保的工艺成为可能，这种厚层压板对轻量化汽车和航空航天结构非常关键。轻量化与提高燃油效率和减少污染息息相关。PIS将让研究生和本科生参与这一跨学科研究项目，并培训他们理解过程建模、实验、优化和控制在先进可持续制造中的整体作用。PIS还将利用与工业合作伙伴的合作和互动来广泛影响加工生物基复合材料的工业实践。该项目的具体技术目标是，首先提取用于生物基复合材料UV加工的物理激励和实验验证的工艺模型，然后将它们应用于新的分层、放大优化和工艺控制方案，以使用这些材料制造厚结构部件。模型和实验工作要描述的基本现象包括：1)紫外光强度通过生物基树脂和纤维系统时的衰减性质，以及2)空间分布的固化和温度状态的耦合演化的性质。该项目还将研究逐步并行固化和分层方案的潜力，该方案将利用这些材料中的固化动力学、热演变和紫外线衰减的知识。该项目将应用一种新的混合建模观点，将层的添加视为固化过程中涉及的其他连续物理过程的离散事件。这一观点将有助于推广该方案的放大优化，目标是以最少的时间/能量需求制造出更厚、固化质量最高的部件。该项目还将通过扩大优化中的不确定性处理以及在线反馈补偿来解决工艺稳健性方面的考虑。

The goal of this project is to study ultra violet (UV) processing as a viable pathway towards a sustainable method of manufacturing layered fiber reinforced materials derived from biological sources for structural applications. A key challenge in the processing of these biobased composite materials is that traditional thermal curing approaches cannot be employed since the constituent natural fibers, which are primarily made of cellulose and hemicellulose, start to degrade with prolonged exposure to high temperatures. UV curing is a fast, low temperature photopolymerization process that uses significantly less energy than thermal curing. If successful, the study will enable a cost-effective and greener process for making high-strength thick laminates that are highly critical for lightweighting automotive and aerospace structures. Lightweighting is tied to achieving improvements in fuel-efficiency and reducing pollution. The PIs will engage graduate and undergraduate students in this interdisciplinary research project and train them in understanding the integral role of process modeling, experimentation, optimization, and control in advanced sustainable manufacturing. The PIs will also leverage collaborations and interactions with industrial partners to broadly influence industrial practices for processing biobased composites.The specific technical objectives of the project are to, first, extract physically motivated and experimentally verified process models for UV processing of biobased composites, and then apply them in new layering, scale-up optimization and process control schemes for building thick structural parts with these materials. The basic phenomena to be characterized by the modeling and experimental efforts include: 1) the nature of the attenuation of UV intensity as it passes through the biobased resin and fiber systems, and 2) the nature of the coupled evolution of the spatially distributed cure and temperature state. The project will also investigate the potential of a stepped-concurrent curing and layering scheme that will exploit knowledge of the cure kinetics, thermal evolution and UV attenuation in these materials. The project will apply a new hybrid modeling perspective that treats the addition of layers as discrete events on the otherwise continuous physical processes involved in curing. This perspective will help generalize the scale-up optimization of the scheme with the goal of building ever-thicker parts of highest cure quality with minimal time/energy needs. The project will also address process robustness considerations via uncertainty handling in the scale-up optimization as well as with online feedback compensation.