Materials
Polyethylene (PE) moulding: lightweight, moisture-resistant components
We injection-mould polyethylene components to customer drawings, in low, medium or high density: a lightweight thermoplastic that does not absorb water and resists chemicals.
What is polyethylene (PE)?
Polyethylene is the simplest of polymers: a chain of ethylene units. Its character changes with density: low-density polyethylene (LDPE) is soft and flexible, high-density polyethylene (HDPE) is rigid and stronger, and MDPE sits in between.
It does not absorb water, resists many acids, bases and solvents and stays tough at low temperatures. Its moulding shrinkage is high, which the mould design has to allow for, and it is difficult to bond and paint.
Properties of polyethylene
- Low density (LDPE), medium density (MDPE), high density (HDPE)
- Moisture-resistant
- Good chemical resistance
- Flexible (LDPE), rigid (HDPE)
Indicative continuous service temperatures for the most common grades: the exact value depends on the grade and formulation and should be checked on the data sheet of the chosen material.
What is polyethylene (PE) used for?
- Caps and closures
- Lids and containers
- Protective caps for threads and pipes
- Flexible snap-fit components
- Parts in contact with water and chemicals
How we mould polyethylene (PE)
Polyethylene needs no drying. To limit shrinkage and warpage, walls should be as uniform as possible and mould cooling well controlled.
PE or another material?
The material is chosen according to the conditions of use of the component. The closest alternatives:
-
PP Polypropylene
Polypropylene is stiffer and withstands higher temperatures; polyethylene stays tougher in the cold.
-
SBS / SEBS Styrenic thermoplastic elastomers (TPS)
If the part has to be truly elastic, a thermoplastic elastomer such as SEBS is the next step.
Do you have a component to make in PE?
Send us your drawing or a sample: the contact form opens with the material already selected. If the material is still open, we will choose it together.
Materials
Other materials
- PSPolystyrene
- ABSAcrylonitrile butadiene styrene
- PPPolypropylene
- PCPolycarbonate
- PVCPhthalate-free polyvinyl chloride
- TPUThermoplastic polyurethane
- SBS / SEBSStyrenic thermoplastic elastomers (TPS)
- POMPolyoxymethylene
- PA 6 / PA 66Polyamide
- PEIPolyetherimide (e.g. ULTEM™)
- NRNatural rubber
- EPDMEthylene propylene diene rubber
- NBRNitrile rubber (acrylonitrile butadiene)
- VMQSilicone