The ‘workhorse’ of the plastics industry, polypropylene is one of the high-volume “commodity” thermoplastics. It has low density, is fairly rigid, has a high heat distortion temperature of up to 95°C (making it suitable for “hot-fill” packaging applications), and excellent chemical resistance and electrical properties.
COPP: Co-polymer Polypropylene
This is a specially modified highly transparent polypropylene random copolymer with medium melt flow, intended for injection moulding and injection stretch blow moulding. In addition to these properties, COPP is the best material for active hinges.
A thermoplastic material composed of polymers of ethylene. Polyethylene is the most widely produced polymer available in various densities.
HDPE: High Density Polyethylene
Its comparatively high density gives HDPE high stiffness, good temperature resistance and very good water vapour barrier properties.
LDPE: Low Density Polyethylene
Commonly used for reducer plugs in packaging, or can be blended with HDPE to adjust overall density.
LLDPE: Linear Low Density Polyethylene
Typically used for tubes, LLDPE is a material that is slightly stiffer and more stable than LDPE. It is also less prone to warpage and distortion on thin section mouldings.
PET: Polyethylene Terephthalate
PET plastics are clear in appearance and are available in a range of colours. Although lightweight, PET is tough and a good defence to gases and liquids. It is also highly resistant to dilute acids, oils and alcohols.
PETG: Glycol – Modified Polyethylene Terephthalate
This is a durable material with an excellent gloss, clarity and sparkle that makes for very clear bottles. PETG can be processed via conventional extrusion blow-moulding methods, generally on machines designed to process PVC. It is popularly used for shampoos, soaps, and detergents. The chemical resistance of PETG is fair, but compatibility testing is recommended, especially with products that contain alcohol.