| Ethylene polymers are thermoplastic polymers | | | | moderate barrier properties but is not suitable for |
| which are used in the production of various | | | | use at high temperatures. It is widely blow molded |
| packaging materials. These polymers (especially | | | | to form soft bottle-containers, e.g. to store milk, |
| the ones mentioned below) generally have good | | | | detergents, etc. It is a low cost and easily |
| resistance to alcohols, oils grease and dilute acids | | | | produced material. |
| and alkalis. One of the most important features of | | | | Low Density Polyethylene / Linear Low Density |
| this type of material in the context of packaging | | | | Polyethylene (LDPE -LLDPE) |
| is that it has moderate to good barrier properties | | | | LDPE is a thermoplastic made from oil. It is |
| to oxygen and carbon dioxide which makes is | | | | extremely tough but flexible, waxy, moisture/ |
| suitable for food packaging. | | | | weather-proof, has good low temperature |
| Below is a description of some of the common | | | | toughness and is easy to process by most |
| ethylene polymers used in various forms, | | | | methods at low cost and has good overall |
| especially for the packaging of perishable | | | | resistance and moderate barrier properties. It is |
| consumer items (foodstuff and pharmaceuticals). | | | | widely used for its heat sealing properties in a |
| Ethylene Vinyl Acetate (EVA) | | | | laminated material. It is not suitable for use at |
| This is known as foam rubber. Amongst its | | | | temperatures above 100° C and is recyclable. |
| properties: Flexible, elastic, transparent, good low | | | | It is also corrosion-resistant. These properties |
| temp flexibility and it has a high friction | | | | make it appropriate for the production of general |
| co-efficient. | | | | purpose containers for foodstuff (jars etc) and |
| EVA is used primarily as a padding material in | | | | laboratory use and is also used to coat/ laminate |
| packaging cartons e.g. for electronics etc. | | | | cartons and make six-pack-soda-holder rings. |
| Ethylene Vinyl Alcohol Copolymer (EVOH) | | | | Polyethylene Terephthalate (PET or PETE) |
| This is a formal copolymer of ethylene and vinyl | | | | PET is a thermoplastic polymer resin of and is |
| alcohol. It is used as a high barrier material to | | | | used in synthetic fibers. It is rigid, extremely tough |
| gases (O2 and CO2) but is a low moisture vapor | | | | and impact-resistant, has good creep and fatigue |
| barrier material. These properties diminish in a | | | | resistance, wide range temperature resistance |
| humid environment. . This is expensive packaging | | | | (-40 to 220° C) and does not flow on |
| material. Widely used as the barrier film in a | | | | heating. This material is usually oriented to |
| laminate. EVOH is used primarily for food | | | | improve its barrier properties to gasses and |
| packaging and usually as a thin layer within | | | | water vapor. It has excellent clarity and is often |
| cardboard or foil, to improve the shelf life of food. | | | | used as a glass replacement. C-PET is widely used |
| High Density Polyethylene (HDPE) | | | | to produce containers for carbonated beverages |
| HDPE is a polyethylene thermoplastic made from | | | | and solvents due to its good resistance and |
| petroleum. It is Semi-rigid, translucent, very tough, | | | | barrier properties and is extremely easy to |
| and also has low water absorption. HDPE has | | | | recycle, which makes it very environment friendly. |