Plastics Flashcards
What is the difference between thermoplastics and thermo setting plastics?
Thermoplastics:
-Reheated and reshaped
-become mouldable after reheating- don’t undergo significant chemical change
-bond between molecules is weak- become weaker when reheated- allows reshaping
-Composed of ‘long chain monomers’
-recyclable
EXAMPLES: acrylic, ABS, PVC, HIPS, PET and extended polystyrene
THERMOSETTING PLASTICS
-ONCE ‘set’, cannot be reheated to soften, shape or mould.
-bond between molecules is very strong
-cannot be recycled
EXAMPLES- Melamine Formaldehyde, epoxy resin
HIGH- DENSITY POLYETHYLENE (HDPE)
THERMOPLASTIC
-Large strength to density
-recycled
-more durable and safe
-used in food and drink packaging
-harder than LDPE
-waxy to touch
-flexible
USES:
-food and beverage containers
-cleaning product bottles
-cutting boards
LOW DENSITY POLYETHYLENE (LDPE)
-LIGHTWEIGHT
-flexible
-Most food safe plastic
-Flexible
-recyclable
-soft
-available in range of colours
POLYETHYLENE TEREPHTHALATE (PET) THERMOPLASTIC
-commonly recycled
-rigid
-lightweight
-can be made clear
-shatterproof
USES:
-used to manufacture blow moulded bottles- soft drinks
POLYSTYRENE PS HIPS
-light
-hard
-stiff
-lightweight
-good sound + heat insulator
-colourless
-transparent
-hygienic with food
USES:
-disposable plates/cups
-fridge linings
-packaging
POLYVINYL CHLORIDE PVC
-range of colours
-soft
-weather resistant
-stiff
-tough
-lightweight
-flexible
USES:
-pipes
-guttering
-bottles
-shoe soles
-window frames
ACRYLIC.
POLYMETHYL METHACRYLATE
-polishes well, range of colours
-can be made to look like glass
-versatile
-hard but scratches easily
-brittle and not hard wearing
-good weather resistance
USES:
-signs
-car light covers
-wash basins baths
NYLON
POLYAMIDE
-creamy colour
-clear
-very durable
-tough
-fairly hard
-resists wear
-resistant to high temps
USES:
-hinges for cupboards
-curtain rail fittings
-washers
ACRYLONITRILE BUTADIENE STYRENE
ABS
-high quality surface finish
-high impact strength
-tough
-scratch resistant
-lightweight
USES:
-car components
-kitchenware
-lego
MELAMINE FORMALDEHYDE
-resists scratches, marks and stains
-wide range of colours
-hard and shiny
-good surface finish
-non toxic- imparts no smell onto food
-heat resistant
USES:
-plastic laminates of kitchen surfaces
-electrical insulation
-tableware
EPOXY RESIN
-rigid finish
-hard
-brittle
-strong adhesive (sticking together- covering surfaces)
-good electrical insulator
-resists chemicals well
USES:
-jewellery/beads
-interior of pocket calculator
