Polyolefins is the collective term for the kinds of plastics that include polyethylene, namely low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), polypropylene (PP) and multi-layer (other).
What are Polyolefins?
The word polyolefin means ‘oil-like’– It comes from the oily or waxy texture of plastics types that include polyethylene. Polyco facilitates the recycling of all the different types of polyolefins used in packaging, including :
How are polyolefins made?
Polyolefins are produced from substances that are rich in carbon: coal, oil or natural gas. In South Africa, this means mainly coal. Polyethylene (the substance common to all polyolefins), is made up of many molecules of ethylenes linked together to become one molecule, called a polymer.
Thus ‘poly’ (many) + ethylenes = the polymer called polyethylene (or also commonly called polythene).
Most polyolefin packaging materials are made through film extrusion or moulding :
Did you know?
Recycling codes 2, 4 and 5
They are used extensively in packaging and are recyclable as per the table BELOW :
|Polymer Identification Code|
|Polyolefin Name||High-density polyethylene (HDPE)||Low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE)||Polypropylene (PP)|
|Definition||Packaging made from HDPE has very good chemical resistance, and can therefore be used for bottles and drums for a wide range of chemicals. HDPE can also be made into opaque (not clear) film for packaging.||Film made from low-density polyethylene (PE-LD) and linear low-density polyethylene (PE LLD) is strong and tough and is used for general packaging and wrapping of consumer goods.||The inherent stiffness of polypropylene (PP) makes it ideal for thin-walled packaging items. Various kinds of film from polypropylene are used for different applications. They are different in the way they look and behave. Film-extruded clear PP films are very strong, the biaxially orientated PP (BOPP) films are shiny, clear and crackle when handled. It is therefore ideally suited for integral lid closures and containers like tablet vials. The bulk of bottle caps and closures are made of PP.|
|Identification||Translucent and identified by a crackling sound when handled.||Translucent or foamed.||Translucent and very (glass-like) clear.|
|Examples||Crates and boxes, bottles (for food products, detergents, cosmetics), food containers, industrial wrapping, carrier bags and drums for food, drinks and chemicals.||PE-LD: shrink film, carrier bags, and heavy duty refuse bags.
PE-LLD: stretch film, industrial packaging film, thin walled containers, and heavy-duty, medium- and small bags.
|Food packaging, including yoghurt and margarine tubs. Buckets made of PP packaging are used for detergents, peanut butter, paint and animal feed. Stationery items, confectionery and even clothing. PP film is also used to manufacture tapes for woven tape applications as cement, bulk and feedbags. Non-woven textile applications for PP include personal hygiene products.