2013 Archive

What Do Recycling Symbols NO.1 on Plastics Mean?

Full Name: Polyethylene Terehthalate

Other abbreviations: PETE, PETP (obsolete)

Type: Amorphous or Semicrystalline Thermopolymer (depending on processing)

Patented: 1941

Family: Polyester (linear)

Plastics have common abbreviations. Can you imagine asking “can this polyethylene terephthalate container go in the recycling bin?”. Never mind writing the plastic name on the bottom of a product, small recyclable plastic parts would be nothing but words. And the recycling symbol, number and optional letters need to be machined into the mold, so full worlds would require additional cost. This is why plastics have pet names, in polyethylene terephthalate’s case, it’s coincidentally PET (or PETE).

PET is part of our daily life. It contains our beverages, our foods, and our cleaning chemicals. We find it in our clothing and other fibers in our surroundings. It’s a common material because it has great properties for the price and is actually used in recycled/down-cycled applications

Properties

Good strength

Impact resistance

Lightweight

Inexpensive

Can be processed using many methods

Good barrier properties (limits exchange of gases and fluids through material maintaining integrity of material content)

Does not affect taste of product

Can be processed to be crystal clear

Applications of PET

Originally used as a fiber

Cloths, rope, belts, cord etc.

Filaments for brushes, carpets, sports equipment

Beverage containers (water, cola, juice etc) because of excellent barrier

properties, almost monopoly the market

Transparent cleaning product containers

Semi-Crystalline PET can be used in frozen dinner trays

Thermoformed sheets

Photographic films

Sheets for food packages

Recycled applications

The availability of PET allows it to be a commonly down-cycled material. It is often converted into fiber for use in “polar fleece”, pillow filling and carpet materials. It can be recycled into bottles for non-food contact applications.

Other facts:

-PET crystallizes slowly so quickly cooling a part from melt temperature to below glass transition temperature allows the PET to solidify as an amorphous material, allowing for excellent transparency.

-PET is an excellent candidate for incineration as it’s structure is mostly carbon, hydrogen and oxygen with very minimal catalyst elements.