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

Clemson University, Clemson SC

Investigators

Abstract

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.