Plastic Types & the Identification Codes

The Resin (Plastic) Identification Code was created in 1988 by the Society of the Plastics Industry (an American trade association). The international code was developed as a uniform system for the identification of different polymer types and helps recycling companies to separate different plastics for reprocessing.

The plastic coding system identifies the six most common plastics, grade or type 1 to 6, and has an “other” category, the number 7, for all other resins. “Other” includes combinations of resins, multi materials (e.g. laminates) and degradable plastics.

In the early 1990s Plastics New Zealand introduced the Plastic Identification Code to New Zealand. Members of the Plastics NZ (Which we are) voluntarily label their plastic products so they can be easily identified for reuse and recycling. The Plastic Identification Code does not equal recyclability. The code was not intended to be - nor was it ever promoted as - a guarantee that a given item will be accepted for recycling.

PET - Polyethylene Terephthalate (Plastic)

Properties	Clear, tough solvent resistant, barrier to gas and moisture, softens at 80°C.
Common Uses	Soft drink and water bottles, salad domes, biscuit trays, salad dressing and peanut butter containers.
Temperature Range	-30ºC to +60ºC.
Moulding Methods	Injection, Blow.
Structural Strength	Good.
Impact Resistance	Excellent.
Repair Options	None.

HDPE - High Density Polyethylene (Plastic)

Properties	Hard to semi-flexible, resistant to chemicals and moisture, waxy surface, opaque, softens at 75°C, easily coloured, processed and formed.
Common Uses	Crinkly shopping bags, freezer bags, milk bottles, ice cream containers, juice bottles, shampoo, chemical and detergent bottles, buckets, rigid agricultural pipe, milk crates.
Temperature Range	0ºC to 105ºC.
Moulding Methods	Injection, Blow, Extrusion, Rotary.
Structural Strength	Excellent when injection moulded. Poor when extruded in sheet form.
Impact Resistance	Good.
Repair Options	Plastic Welding.

SFHDPE - Structural Foam High Density Polyethylene (Plastic)

Structural foam is not a material, but actually a method that is employed to process thermoplastic resins. Best thought of as a subset of the injection molding process, structural foam molding is a low pressure method of processing thermoplastics, with the most commonly used resin being HDPE (High Density Polyethylene).

Products with structural foam exhibit thicker walls with an excellent strength-to-weight ratio & improved thermal and acoustic insulation properties.

PVC - Polyvinyl Chloride (Plastic)

Properties (Unplasticised PVC-U)	Strong, tough, can be clear, can be solvent welded, softens at 80°C
Properties (Plasticised PCV-P)	Flexible, clear, elastic, can be solvent welded
Common Uses	Cosmetic containers, electrical conduit, plumbing pipes and fittings, blister packs, wall cladding, roof sheeting, bottles, garden hose, shoe soles, cable sheathing, blood bags and tubing, watch straps.
Temperature Range	0ºC to 60ºC though varies with resin type.
Moulding Methods	Injection, Blow, Vacuum, Extrusion.
Structural Strength	Very Good.
Impact Resistance	Varies with resin.
Repair Options	Plastic Welding, Gluing with methylene chloride as solvent.

LDPE - Low Density Polyethylene (Plastic)

Properties	Soft, flexible, waxy surface, translucent, softens at 70°C, scratches easily.
Common Uses	Plastic Food wrap, garbage bags, squeeze bottles, black irrigation tube, garbage bins.
Temperature Range	-40ºC to +60ºC.
Moulding Methods	Injection, Blow, Vacuum, Extrusion, Rotary.
Structural Strength	Good.
Impact Resistance	Excellent.
Repair Options	Plastic Welding.

PP - Polypropylene (Plastic)

Properties	Hard but still flexible, waxy surface, softens at 140°C, translucent, withstands solvents, versatile.
Common Uses	Dip bottles and ice cream tubs, potato chip bags, straws, microwave dishes, kettles, garden furniture, lunch boxes, blue packing tape.
Temperature Range	0ºC to 105ºC.
Moulding Methods	Injection, Blow, Extrusion, Rotary.
Structural Strength	Excellent when injection moulded. Poor when extruded in sheet form.
Impact Resistance	Good.
Repair Options	Plastic Welding.

EPS - Expanded Polystyrene (Plastic)

Properties	Foamed, light weight, energy absorbing, heat insulating.
Common Uses	Foamed polystyrene hot drink cups, hamburger takeaway clamshells, foamed meat trays, protective packaging for fragile items.
Temperature Range	-40ºC to +70ºC.
Moulding Methods	Injection.
Structural Strength	Good.
Impact Resistance	Poor.
Repair Options	Gluing.

HIPS - High Impact Polystyrene (Plastic)

Properties	Clear, glassy, rigid, brittle, opaque, semi-tough, softens at 95°C. Affected by fats and solvents.
Common Uses	CD cases, plastic cutlery, imitation 'crystal glassware', low cost brittle toys, video cases.
Temperature Range	0ºC + 60ºC.
Moulding Methods	Injection, Extrusion, Vacuum.
Structural Strength	Excellent.
Impact Resistance	Varies between Poor to Good.
Repair Options	Plastic Welding, Gluing.

Other (Plastic)

Other relates to all other resins and multi materials (e.g. laminates) & the properties depend on plastic or combination of plastics. Examples of resins categorised as 'Other' include acrylic, acrylonitrile butadiene styrene, fiberglass, nylon, polycarbonate and polylactic acid.

Regrind (Plastic)

Regrind plastic is comprised of non-contaminated rejected parts that are produced in-house by the manufactuer or in the initial molding processes. These rejected parts are crushed to smaller size and recycled with virgin materials.

Products manufactured are used for cost saving and environmental consideration.