Polymers Flashcards
Main advantages of thermoplastics in commercial packaging:
-Lightweight and versatile -strong, tough, rigid, durable, and impact and water resistant -easily formed and moulded -easily printed on -inexpensive -recyclable
Thermoplastics once heated ….?
Can be formed into a variety of interesting shapes using different forming techniques such as blow moulding
PET stands for?
Polyethylene terephthalate
HDPE stands for?
High density polyethylene
PVC stands for?
Polyvinyl chloride
LDPE stands for?
Low density polyethylene
PP stands for?
Polypropylene
PS stands for?
Polystyrene
PET properties
Excellent barrier against atmospheric gases - prevents gas from escaping packaging - doesn’t flavour contents - sparkling ‘crystal clear’ appearance - very tough - lightweight, low density
HDPE properties
Highly resistant to chemicals - good barrier to water - tough and hard wearing - decorative when coloured - light weight and floats on Water - rigid
PVC properties
Weather resistant (doesn’t rot) - chemical resistant (doesn’t corrode) - protects products from moisture and gases while holding-in preserving gases. - strong, good abrasive resistance and tough - can be manufactured either rigid or flexible
LDPE properties
-good resistance to chemicals -good barrier to water, but not gases - tough and hard wearing - decorative when coloured - very light and floats on water - very flexible
PP properties
-lightweight -rigid -excellent chemical resistance -versatile, can be stiffer than polyethylene or very flexible -low moisture absorption -good impact resistance
Two types of polystyrene
Rigid and expanded
Rigid polystyrene properties
-transparent -rigid -lightweight -low wager absorption
Expanded polystyrene properties
-excellent impact resistance -very food head insulation -durable -lightweight -low water absorption
PET applications
Carbonated (fizzy drinks) bottles. Packaging for highly flavoured food. Microwaveable food trays.
HDPE applications
Unbreakable bottles (for washing up liquids,detergents,cosmetics,toiletries etc.) vey think packaging sheets.
PVC applications
Packaging for toiletries, pharmaceutical products, food and confectionery, water and fruit juices.
LDPE applications
Stretch wrapping (cling film), milk carton coatings.
PP applications
Food packaging - yoghurt and margarine pots, sweet and snack wrappers, uses for laminating paper and board
PS applications
Rigid: food packaging eg. Yoghurt pots, cd jewel cases, audio cassette cases. Expanded: egg cartons, fruit, vegetable and meat trays, cups etc. packing for electrical and fragile products
