Polymer Engineering Center > Research > Processing of Reinforced Thermosetting Polymer Parts

Fiber reinforced thermosetting materials are often used to manufacture automotive body panels as well as for under-the-hood automotive applications, household goods, breaker switch boxes in the electrical industry, etc. These materials are chosen because of their high strength, light-weight, heat resistance and electric properties. There are various projects we are currently working on which deal with these types of materials. Currently, of interest to us are fiber matrix separation during processing and the curing of thick thermosetting parts.

During processing of fiber reinforced polymer parts a main assumption has always been that there is a constant fiber density throughout the part. However, burn-out tests on various parts have revealed that there is a fiber density distribution throughout the part. In fact, some regions contain half the fibers as other regions in the same part. This is especially true for parts that are ribbed, or have regions that are difficult to access by the reinforcing fibers. A varying fiber density distribution throughout the part not only leads to anisotropies but also to surface waviness in large thin parts such as automotive body panels. Within this research project we are studying the causes of fiber matrix separation through modeling and experimental work. The ultimate goal of this project is to predict and control fiber density distributions throughout a part.

For many thermosetting articles the thickness can be large enough that the curing process during manufacturing takes place in a non-uniform fashion, leading to severe residual stresses and in many cases under-cured regions in the final parts. This portion of the project addresses four major issues:

• Material characterization using differential scanning calorimetry tests
  

• Cure kinetic model development and fitting using the experimental DSC data
  
• Implementation of the curing models into our own 3D finite element heat transfer programs
  
• Couple 3D heat transfer curing program with a stress-strain FEM program, to predict residual stresses and properties within the finished product.