Moldflow fiber orientation

The modeling of fiber-reinforced thermoplastics (composites) is more complex than in other applications, since the parts are usually thin and shorter fibers are often used.Other aspects, such as the 3-dimensional orientation of the fibers and the significant orientation variations across the part also contribute to the complexity of the problem.

Gate position and fiber orientation

Fiber orientation on Peek + Glassfiber part

Fiber orientation - IXEF + 50% Glassfiber

Affecting fiber alignment (orientation)

In injection-molded composites, the fiber alignment (or orientation) distributions show a layered nature, and are affected by:

  • filling speed
  • processing conditions
  • material behavior
  • fiber aspect ratio (ratio of the length of the fiber to the diameter)
  • fiber concentration (weight percentage)

Without proper consideration of the fiber behavior, there is a tendency to significantly overestimate the orientation levels. The results from a fiber orientation analysis can be used as input for a warpage analysis, providing more detailed elemental results, and considerably enhanced analysis accuracy.