INJECTION MOULDING THERMOPLASTIC COMPOSITES

Injection molding process is well known for producing complex shape plastic
components, manufacturing close dimensional tolerance and automatic production.
In the reports, the process was used for producing short glass fiber reinforced
thermoplastic composites. A range of composites formulation was injection molded to
optimize fiber contents. One of formulations was the result of the experimental work. The
others were the discussion ofthe result obtained.
Molded specimens were tested mechanically and it was found that elongation, tensile
strength and modulus were dependent on fiber weight fraction in the composite. An
increase of fiber content in samples willincreased the tensile strength and modulus of the
samples. However, increasing fiber content will decrease the elongation value of the
samples.
An impact test was done as well and it was found that the impact energy was dependent
on fiber content and notching condition. For notchedcondition, it was found that increase
fiber content in the samples will increase theimpact energy for the samples.
Molding defects of the samples were identified using x-ray radiography and microscopy.
For x-ray radiography, results show no evidence of micro voids and surface defects. But,
for microscopy test, it was found that the surface of the molded specimens contain
surface flaws. Furthermore, it was initiated that from microscopy test held, there were
dimples and voids in the internal specimens.