Modeling and simulation of the vacuum forming of wood fiber-filled thermoplastic composites

Vacuum forming of wood fiber-filled thermoplastic composite sheets has become an important process in the industry because of their low cost, good formability, and high strength to weight. Nonuniform thickness distribution of a vacuum formed part caused by inappropriate mold design and processing condition is one of the problems that confound the overall success of this technique. A novel viscoelastic model of two-dimensional finite element scheme, with eight noded overlay isoparametric elements was developed to numerically simulate the vacuum forming of wood fiber filled isotactic polypropylene. Computed results are in agreement with literature experimental data. Numerical simulation of a vacuum forming process can be used to optimize the molds and the forming parameters to achieve a product with ideal thickness distribution. Copyright © 1997 Society of Plastics Engineers.