Application Guide: Thermoplastic Polymers
and Compounding
BACKGROUND
Thermoplastic polymers are characterized primarily by their molecular structure. They soften
when heated and re-harden on cooling. Plastic resins are typically customized to meet
specific customer applications by adding reinforcements, flame retardants, processing aids,
and colorants. Reinforcements are used to enhance mechanical properties, such as flexural
modulus, tensile strength and thermal properties such as heat deflection temperature.
Note: Loading is primarily dictated by resin selection. For best shrinkage and warpage
results, try a blend of mica with either milled glass fiber or wollastonite. Other mechanical
properties may also be improved by blending reinforcements.
EXPECTED OBSERVATIONS
Overall increase in mechanical properties.
Median particle size can significantly affect tensile strength and flexural modulus. Particle
size can be a determining factor in deciding importance of elongation versus tensile
strength.
Platy minerals, such as mica, are very useful in providing uniform shrinkage. The aspect
ratio of platy products can play a significant role in increasing flexural modulus.
Mixing methods and speeds influence flexural modulus and flexural strength.
COMMENTARY
Applications and resins can vary. It is crucial to match reinforcements, reinforcement blends,
and concentrations to optimize properties. Contact Fibertec for discussions on specific
product grades and surface treatments to achieve desired end results.