The role and effect of fiberglass in plastic modification
1. Significant Improvements:
Tensile strength, flexural strength, and flexural modulus: Improvements can reach several times or even more than ten times that of the base resin. Rigidity is particularly significantly improved.
Heat Deflection Temperature: Significantly improves the plastic's heat resistance, enabling use at higher temperatures.
Dimensional Stability: Reduces shrinkage, minimizes warpage, and improves dimensional accuracy.
Creep Resistance: Significantly reduces deformation under long-term loads.
Abrasion Resistance: Generally improved.
Some Flame Retardancy: Glass fiber itself is non-flammable and can form a "wick effect" skeleton, sometimes assisting the flame retardant system.
2. Potentially Reduced or Affected:
Impact Toughness: Notched impact strength, in particular, is generally reduced (increased brittleness). However, long-fiber reinforced pellets can better retain impact toughness.
Elongation at Break: Significantly reduced (material becomes more brittle).
Density: Increased (glass fiber density is approximately 2.5-2.6 g/cm³).
Flowability: Increased melt viscosity, resulting in poor flowability (process adjustments are required). Surface gloss: Typically reduced, and "floating fibers" (exposed glass fibers) may appear.
Equipment wear: Increased wear on the screw, barrel, and mold (wear-resistant materials are required).