Plastic Container Recycling

Plastic Container Recycling

This is what typically happens to plastics collected for recycling in NZ.

Recycling plastic makes good environmental sense as most plastics originate from oil-based compounds that are not sustainable. It is increasingly important to use resources efficiently. Recovery of waste plastic for reuse into new products conserves non-renewable raw materials, uses less energy than that used to produce virgin plastic and creates employment and businesses opportunities.

Recycling solutions should be designed and made to suit individual user's needs. Factors taken into consideration include size of organisation, working space, plastic volumes, plastic types and site access.

The most popular plastics recycled in NZ are:

Plastic Film (large sheets of film and shrink wrap from manufacturers and distributors - not as waste packaging from the general public)
HDPE (white milk, drinks and janitorial containers - ideally not as a mixed plastic that uses various colours of plastic)
PET (clear soft drinks bottles and other containers)
Plastic Strapping (industrial strapping)

Types of Plastics



There are many different types of plastic, but they all fall into one of two basic groups, Thermoset or Thermoplastic.

Thermoset plastics are the very rigid "set" plastics used for toys and electronic appliances (usually as casing). These plastics are cured and will only char and break down. Thermoset molecules are formed by cross-linked chains of molecules further strengthened by chemical bonds. A thermoset is essentially one large molecule, without a crystalline structure. Thermoset resins generally come in liquid form, and when mixed with a catalyst, a chemical reaction occurs forming a solid. Thermoset molecules crosslink with each other during curing, thus once cured, they cannot change. These do not have a plastic resin code on the product and tend not to be recycled.

Thermoplastics are permanently fusible and can always be melted down and recycled. The reason why thermoplastics melt down so easily is because the molecules have a relatively weak attraction between the chains of molecules. Thermoplastic resins have molecules that are generally not cross-linked, meaning, the resin can be repeatedly melted and reused. Usually, no chemical change occurs when thermoplastic is cured. Thermoplastic resin usually starts out in solid pellet form, and changes shape with the addition of heat and pressure. Thermoplastic polymers are more widely used because of their flexibility, so there are, therefore, more of them. Most thermoplastics are identified by a plastic resin code on the product. This code has numbers from 1 to 7. To identify the type of waste plastic you have for recycling refer to the plastic identification code.

Not all plastics are recycled. Some types (1,2 and 4) are easier to recycle than others. Some get contaminated with food waste and cost more to be recycled (take-away food and drink containers). Some plastic types (3,5,6 and 7) are simply not worth recycling. There is low value in the recovered plastics because they are harder to recycle and/or manufacturers struggle to make any profit from them.

Numerical Code - Plastic Composition - Properties - Typical Applications - Products Made with Recycled Content:

Numerical Code - 1 (22% of all recovered plastics in 2004)
Plastic Composition - Polyethylene Terephthalate (PET)
Properties - Clear and optically smooth, resists water, oxygen and CO2, resists high impacts, resists most solvents, can be filled with hot liquids.
Typical Applications - Soft Drinks Bottles, Sports Bottles, Condiment/Food Jars, Food Trays.
Products Made with Recycled Content - New Containers, Strapping, Carpet Fibres, Cushion/Jacket Filling.

Numerical Code - 2 (26% of all recovered plastics in 2004)
Plastic Composition - High-Density Polyethylene (HDPE)
Properties - Resists most solvents, high strength characteristics, stiff material.
Typical Applications - Water Bottles, Milk Bottles, Cleaning Products, Personal Cosmetics.
Products Made with Recycled Content - New Containers, Piping, Edging, Bins.

Numerical Code - 3 (6% of all recovered plastics in 2004)
Plastic Composition - Poly Vinyl Chloride (PVC)
Properties - High impact and strength, resists grease and chemicals.
Typical Applications - Packaging/Wraps, Plumbing Pipes, Flexible Packaging/Bags.
Products Made with Recycled Content - New Piping, Carpet Backing, Packaging, Traffic Cones.

Numerical Code - 4 (36% of all recovered plastics in 2004)
Plastic Composition - Low-Density Polyethylene (LDPE)
Properties - Resists acids and oils, tough, flexible and transparency is good.
Typical Applications - Film and Stretch Wrap.
Products Made with Recycled Content - Rubbish Bin Liners, Floor Tiles, Compost Bins, Outdoor Furniture.

Numerical Code - 5 (4% of all recovered plastics in 2004)
Plastic Composition - Polypropylene (PP)
Properties - Great optical clarity, low moisture vapor penetration, inert towards acids, alkalis and most solvents.
Typical Applications - Hard Containers, Medicine Bottles, Takeaway Containers, Bottle Caps, Refrigerated Food Containers.
Products Made with Recycled Content - Automotive Products, Household Tools/Utensils, Outdoor Tools, Trays.

Numerical Code - 6 PS (1% of all recovered plastics in 2004)
Plastic Composition - Polystyrene (PS)
Properties - Great short shelf life moisture barrier, high optical clarity, good rigid structure, light yet stiff, low thermal conductivity.
Typical Applications - Plastic Plates/Cutlery, Food Containers, CD Cases, Small Hard-wearing Bottles, Cable Spools, Toys.
Products Made with Recycled Content - Light Switches, Plastic Mouldings, Packaging, Desk Trays.

Numerical Code - 6 EPS (0.5% of all recovered plastics in 2004)
Plastic Composition - Expanded Polystyrene (EPS)
Properties - Great short shelf life moisture barrier, low thermal conductivity, can absorb knocks.
Typical Applications - Styrofoam Cups, Food Trays, Protective Foam Packaging.
Products Made with Recycled Content - Light Switches, Plastic Mouldings, Packaging, Desk Trays.

Numerical Code - 7 Composite (4.5% of all recovered plastics in 2004)
Plastic Composition - Composite (other)
Properties - Dependent on resins and combination of resins.
Typical Applications - Milk/Fruit Juice Cartons, Oven Bags.
Products Made with Recycled Content - Low Grade Bottles and Outdoor Goods.

 

Videos

From Plastic Bottle to Polyester Fabric

From Plastic Bottle to Polyester Fabric

An amazing video showing you how plastic drinks bottles are converted into polyester fabric for clothing manufacture.
 
How Plastic Bottles are Made

How Plastic Bottles are Made

See how recycled plastic shavings are transformed back into new plastic drinks bottles.
 
TetraPak Recycling at Work

TetraPak Recycling at Work

TetraPak drinks cartons are prevalent in NZ, we struggle to cope with the recycling of the materials (card, aluminium and polythene), however this video demonstrates how easy it is to recycle and convert into useful by-products.
 
 
 

Before & After

 

Frequently Asked Questions



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