Since they were discovered in 1941, the properties of polyester polymers have become well established in the fibre, packaging and structural plastic industries, thanks to their high performance. PET is manufactured from high-specification crystallisable thermoplastic polymers. The polymer has a large number of properties suited to the production of quickly mouldable, heat-resistant high-precision components and high-quality commercial products. PET is available in transparent and coloured grades.
Among the technical advantages of PET, mention can be made of excellent impact tolerance and stiffness. Very fast mould cycle time and good deep-drawing characteristics with even wall thickness. No drying of plate before moulding. Wide range of use (-40° to +65°). Can be cold-formed by bending. Very good resistance to chemicals, solvents, cleaning agents, oils and fats etc. High resistance to stress cracking and crazing. PET has a number of commercial advantages. Short cycle time ensures high productivity in moulding operations. Aesthetically attractive: high gloss, high transparency or evenness of colour and can easily be printed or decorated without pre-treatment. Versatile technical performance and fully recyclable.
Uses Since it was introduced onto the market, PET has been successfully evaluated in such varied applications as sanitary ware (bathtubs, shower cubicles), the retail trade, vehicles (also caravans), telephone kiosks, bus shelters etc. PET is suitable for food and medical applications and for gamma-radiation sterilisation.
There are two main types of PET: Amorphous PET (APET) and crystalline PET (CPET), the most important difference being that CPET is partially crystallised, while APET is amorphous. Thanks to its partially crystalline structure CPET is opaque, while APET has an amorphous structure, giving it a transparent quality.
Partially crystalline thermoplastics are characterised by the chain molecules of which they are made up being arranged in partially densified structures on cooling from molten and liquid state.
Amorphous thermoplastics are characterised by firstly being repeatedly meltable and secondly having a chemical structure such that they are transparent in their basic state.
APET is a transparent material, but can also be coloured. APET is very suitable for foods where maximum exposure of the product is desirable.
APET is suitable for use between -40C and +70C. APET is a very tough material with good impact resistance and has an extremely effective barrier against oxygen, water, carbon dioxide and nitrogen, and is therefore compatible with MAP (modified atmosphere packaging*)
CPET is very suitable as packaging for ready meals, and can be taken straight from the freezer to either an ordinary oven or a microwave oven due to its high temperature stability.
Because of the very precise control of the material’s crystallinity, CPET is suitable for use between -40C and +220C. CPET provides an extremely good barrier to oxygen, water, carbon dioxide and nitrogen, and is therefore compatible with MAP (modified atmosphere packaging*).
r-PET – 100% recycled material
r-PET plastic is produced from 100% recycled material that meets the requirements of EFSA. It’s produced mainly from PET beverage packaging collected and recycled from the market. r-PET is usually produced in transparent and black but is available in other colors.
*Modified atmosphere is various mixtures of oxygen, nitrogen and carbon dioxide added to the packaging to prolong the shelf life of the food.