6 popular Injection Molding Materials of Plastic Enclosure


We would like to organize 6 popular injection molding materials, which often used for electronic product enclosure, and plastic cases. The information would be a good reference for product designers or mechanical engineers, when they’re going to develop a new product.The materials we are going to discuss are:  PP, HIPS, ABS, PC, ABS+PC, and ASA.

At the beginning, we would like to list the cost comparison of the 6 materials. 
It can help us having a quick guide line when preparing a project schedule at early stage.
What we would like to mention about here is that, HIPS is often used as an alternative of ABS. While at rapid tooling, we prefer using ABS, as their unit prices are pretty close, and no much cost difference at low volume production. But HIPS is not as bright as ABS, not as tough as ABS either.

Besides the material cost, what we concern about at enclosures, would be the strength, cosmetic, applications at different environments. For a quick understanding, we listed their most famous property here:

  • PP is very famous for its folding property, often using at case with integral hinge. For example galsses case.
  • PC is very good at strength and its clear, and also bad flowing. A very important component of bullet-proof glass material.
  • ABS, is the most widely used one at product enclosure and cases.
  • PC+ABS, a compromising choice between PC and ABS, because of their strength and flowing ability.
  • ASA is very famous for its out-door usage, because of its weather resistance.
  • HIPS, often used as ABS alternative, at high volume production, for cost saving.

In general, we also put their advantages, disadvantages and general applications in  a same form:

Full Name Advantages Disadvantage Application Examples
PP Polypropylene Low cost, good at toughness,
very good for hinge
Not strong as other materials,
high shrinkage.
Trash Bins, Glasses Cases,
Covers with hinge
HIPS High-Impact
Alternative of ABS,
for cost saving.
No as bright,
as tough as ABS.
Trash Bins, cases, covers and etc.
ABS Acrylonitrile Butadiene Styrene Very good general mechanical property.
Most widely used.
n/a Bins, Most Cases, Cover,
most frequent used engineering resin.
PC Polycarbonate Best strength in 6 materials,
High clear
High cost, bad flowing,
not tough as ABS
Defensing Covers, Clear Windows
PC+ABS Polycarbonate +
Acrylonitrile Butadiene Styrene
Strength between ABS and PC.
A choice for higher strength but with material flow concern.
High cost Most covers, chassis, cases,
a comprising choice between strength and toughness.
ASA Acrylonitrile Styrene Acrylate Weather resistant,
High cost,
not bright as ABS
Bicycle Light, Mountaineering products, Forest Monitors.



Lastly a general property comparison in density and shrinkage.
Most of the materials are non-crystalline ones, except PP, which is crystalline material.
The other 5 materials have a very closing material shrinkage, around 1.005. It is ideal for product development. If multi material trials needed, for cost saving, strength testing, weather-resistant testing and etc., the materials can share one proto mold. Their dimensions will be almost the same and should not affect general assembly.

Full Name Density Shrinkage Remark
PP Polypropylene 0.91 1.018 Crystalline resin
HIPS High Impact Polystyrene 1.1 1.005 Non-crystalline resin,
closing shrinkage,
good for material trials
ABS Acrylonitrile Butadiene Styrene Plastic 1.07 1.005
PC Polycarbonate 1.15 1.005
PC+ABS Polycarbonate + Acrylonitrile Butadiene Styrene 1.25 1.005
ASA Acrylonitrile Styrene Acrylate 1.07 1.005

Just be noted that the information here is for general grades. There would be slight variance in different brands. The materials also can be in special usages after adding special additives, for example additive of fire retardant, UV resistance, glass fiber and etc.

Dank Mold will keep sharing more tooling and injection molding knowledge at our website www.dankemold.com, in a more and more organizing and easy-understanding manner. Should you be developing a consumer product enclosures/cases, or any material enquiries of injection molding, just email us via info@dankemold.com. We will response in 12 hours.