Material Fact Sheets

Plastics Resin Identification Code

Many kinds of plastic look exactly the same to the human eye – this is why the plastics identification code was developed – so people could quickly work out what kind of plastic a product is. The Plastics Resin Identification Code is a voluntary measure introduced to New Zealand some years ago by Plastics New Zealand – the Trade Organisation representing NZ Plastic Manufacturers. The majority of Plastics Manufacturers in New Zealand now use these codes on their products. The Code serves to assist in identifying which resin a particular product has been made from. It is not a recycling code and it is not intended to imply that the product will be recycled. Most, but not all plastic items, have a Plastics Resin Identification Code stamped on them.

Fact Sheets - Basic Resin Types

Polyethylene Terephthalate
Resin Code: 1
Abbreviation: PET
Characteristics:

• clear, tough glossy, heat resistant
• can exist in sheet — film and fibre -as a fibre called polyester
• as a thin rigid plastic as in bottles
• solvent resistant
• acts as a barrier and is almost impervious to CO2
• is a thermoplastic

Applications:

• major use as carbonated drink bottles, eg Coke bottles
• also used for some edible oil bottles, peanut butter jars and liquor bottles
• fibres are spun from PET for use in domestic and industrial fabrics including insulation in clothing and as carpet. These can be mixed with organic fibres such as wool or other synthetics such as lycra.
• pillows and sleeping bag filling
• audio and video tapes are made from PET film
• some fishing nets & sailcloths are woven from PET fibres

Recycling:

• PET from post consumer bottle use can be recycled into polyester fibres for carpets, pillow stuffing etc
• PET can be recycled back into non food grade bottles
• In the United States PET is depolymerised back into its raw constituents
• the major drink manufactures are using PET bottles that have a layer of recycled PET sandwiched between two virgin layers

High Density Polyethylene

Resin Code: 2
Abbreviation: HDPE
Characteristics:

• hard to semi flexible, has a waxy surface appearance
• there are almost 1000 different grades with varying melting temperature, densities. & molecular weights
• generally stiff and very resistant to breakage
• resists a wide temperature range, down to -75°C without becoming brittle
• moisture proof, but allows the passage of oxygen
• highly resistant to chemicals and is unaffected by food acids & household solvents
• is available in clear, translucent or opaque form
• is a thermoplastic

Applications:

• used in critical applications where improved stiffness is required eg tote boxes & automotive parts
• used for milk and cream bottles
• used for detergent, shampoo, bleach bottles, and paint pails
• used for corrugated pipe for farm drainage
• used for high pressure piping of water
• for insulation around electric wires and cables in situations where added stiffness and increased water resist-ance is required
• food packaging film
• supermarket bags
• natural gas subtransmission piping
• powdered HDPE is used for rotationally moulded products

Recycling:

• HDPE is recycled into plastic bags, compost bins, crates, bottles and pipes
• HDPE is one of the most recycled plastics

Polyvinyl Chloride

Resin Code: 3
Abbreviation: PVC
Characteristics:

• is a thermoplastic
• all variants are tough and strong
• unaffected by prolonged contact with water, oils, foods, common chemicals
• is attacked by chlorinated solvents, nail polish & nail polish remover
• has a very slow rate of water absorption
• good resistance to temperature variation, 55°C to -20°C
• comes in a wide colour range; clear, coloured, translucent & opaque
• comes in two forms; plasticised (flexible) or unplasticised (rigid)
• inexpensive to make, uses less crude oil than other plastic
• self extinguishing

Applications:
A. plasticised

• shower curtains
• shrink wrap
• garden hose
• coating for paper etc
• wire & cable insulation
• shoe soles

B. unplasticised

• pipe & pipe fittings
• conduit
• extruded profiles
• guttering & down pipes
• bottles for foods and cleaning materials

Recycling:
PVC is recycled into a range of products such as

• floor mats
• hoses and pipes
• cleaning material containers

Low Density Polyethylene

Resin Code: 4
Abbreviation: LDPE
Characteristics:

• is a thermoplastic
• soft, flexible & waxy surface, translucent & scratches easily
• inexpensive to make
• resists water and chemicals and has good impact strength
• easily heat sealed
• maintains strength and flexibility at sub-zero temperatures
• excellent electrical insulator

Applications:

• shrink film
• food storage film
• shopping & garbage bags
• pipe for agricultural and industrial use
• LDPE film is applied to other materials such as paper, aluminum, cardboard (for milk & fruit juice cartons) etc
• flexible sqeeze bottles
• insulation for electric wires
• housewares & toys

Recycling:
is recycled into rubbish bags, compost bins, crates etc

Polypropylene

Resin Code: 5
Abbreviation: PP
Characteristics:

• is a thermoplastic
• has very low density with good heat resistance and machanical properties (rigidity & immunity to flex fatigue
• can be bent indefinitely)
• resists acidic, alkaline and saline solutions
• hard but still flexible and has a waxy surface
• excellent resistance to gas and water vapour
• a very versatile plastic
• can be spun into a fibre

Applications:

• kitchen bowls
• plastic hinges (ie hinged lunchbox lids) and where repeated flexing is occurring
• medical and other hygienic situations where extreme sterilisation is required
• clothes pegs and buckets
• crates for soft drink, beer and milk
• food containers for icecream, mayonnaise, syrups, pickles, cheese spreads etc
• garden furniture
• bags for fertilizers, stockfoods, chemicals etc
• films for wrapping bread, vegetables and potato chips
• components for home appliances
• washing machine agitators
• stereo & TV cabinets
• automotive parts
• moulded doors panels and fascia
• battery cases
• toys
• drinking straws
• syringes
• ropes (polypropylene ropes do not absorb water — and thus float on the surface)
• thermal undergarments
• carpet backing
• artificial grass
• bristles for brooms/brushes
• strapping for pallets
• microwave safe dishes

Recycling:
Polypropylene is readily recycled into

• floor mats,
• compost bins,
• plant pots etc

Polystyrene

Resin Code: 6
Abbreviation: PS = polystyrene
EPS = expanded polystyrene (foam)
Characteristics:

• a thermoplastic
• polystyrene
• clear hard rigid and brittle - often has a glassy appearance
• tasteless & odourless
• resistant to most common foods, drinks, acids, oils, alcohol & vinegar but is attacked by cleaning fluids, petrol, turpentine, nail polish and nail polish remover
• expanded polystyrene
• extremely low density
• impact resistant and energy (dynamic) absorbing
• excellent thermal insulator

Applications:
Polystyrene (PS)

• plastic cutlery
• imitation crystal glassware
• video cassette cases
• low cost toys
• plastic Petrie dishes
• disposable packaging
• light diffusers for ceiling lights

Expanded Polystyrene (EPS)

• chillybin liners
• buoyancy aids
• crash helmet linings (cycle helmet liners)
• bean bag filling
• building insulation
• protective packaging for fragile items

Recycling:

• expanded polystyrene can be reused as an aggregate replacement in potting mix
• foam can be recycled into insulation and industrial packaging

NB: The following are examples of polymers found in resin code 7. This category includes all other resins and multi materials (e.g. laminates not identified in 1-6 above).

Polyurethane

Resin Code: 7
Abbreviation: PU
Characteristics:

• is a thermoset plastic (there are also some thermoplastic types) S
• tough and shock resistant
• has outstanding abrasion and tear resistance
• liquid polyurethane has strong adhesive qualities (one of the few adhesives which will bond to EPS without damaging it)
• resistant to most chemicals including organic solvents & petroleum products

Applications:

• a foam for upholstery, cushioning, beds etc
• is used in foam form as a thermal insulator
• as a surface coating in industrial & marine environments as well as the home
• as an alternative to plaster casts for broken limbs

Recycling:
Not generally applicable but chipped polyurethane foam is used in carpet underlay.

Polyesters

Resin Code: 7
Abbreviation:
Characteristics:

• a thermoset plastic (also a thermoplastic as in PET — resin code 1)
• often used in conjunction with a reinforcing fibre such as fibre glass
• can be produced as a liquid, a powder, or as premoulded sheets, rods & tubes
• in its thermoplastic form it can be spun into a fibre for textile use
• highly resistant to most solvents, acids & bases
• have a low water absorption rate

Applications:

• used with fibreglass to form glass reinforced plastic (grp) to make
• boat hulls
• corrugated roof sheeting
• car bodies
• utility canopies
• transportation tanks
• fishing rods
• polyester is used on its own to encapsulate electronic components and botanical & zoological specimens

Applications:

• combs, toothbrush bristles
• fishing line
• gears and bearings

Recycling:
Not applicable

Polytetrafluoroethylene

Trade Name: Teflon
Resin Code: 7
Abbreviation: PTFE
Characteristics:

• extremely low coefficient of friction
• high anti-stick properties
• low water absorption
• extremely high temperature resistance, capable of continuous service @ 500°C

Applications:

• used in space exploration (developed for this purpose)
• non stick cookware
• many specialized engineering applications including self lubricating bearings
• chemical processing structures
• pipe thread tape

Recycling:
Not applicable