Learning Intention Know different types of plastics Be aware of the different characteristics of different plastics Be able to identify a number of types of plastics

Sources of plastics. Although the main source of plastic is crude oil.

…there are other sources of plastic plants - from which cellulose can be extracted

trees - from which latex, amber and resin can be extracted

insects - from which shellac (used to make polish) is obtained

Plastics Plastics Thermo plastics Thermo-setting plastics

Thermo Plastics Can be reshaped when reheated Properties are often changed by addition of additives - such as anti-static agents, flame retardants, plasticisers Temperature changes can alter properties Most common group of plastics

Thermo-setting plastics The chemical polymers bond permanently when heated and set hard when cool Used because of their hardness and resistance to chemicals, oils and solvents. Tend to be more expensive Usually formed into products by heating powder in moulds

Common Name Working NamePropertiesCommon Uses PETPoly ethylene terephthalate Moderate chemical resistance – excellent transparent qualities ? HDPEHigh density poly ethylene Strong & stiff with excellent chemical resistance. Easily coloured. Excellent finish ? PVCPoly vinyl chlorideGood chemical and weather resistance uPVC – tough, stiff, lightweight, can be coloured Plasticised PVC - flexible ? Common thermo-plastics

Common Name Working NamePropertiesCommon Uses LDPELow density poly ethylene Tough and flexible with good chemical resistance. Very popular. Easily coloured and very smooth finish ? PPPoly propyleneLightweight, food safe with excellent chemical resistance. Easily coloured. Excellent finish, tough, resists work fatigue, withstands high temperatures ? PSPolystyreneExpanded – very lightweight Conventional – light, hard, food safe and cheap, good for vacuum forming ? Common thermo-plastics

Common Name Working NamePropertiesCommon Uses HIPSHigh impact polystyrene Good stiffness and impact resistance, lightweight ? PMMAAcrylicStiff, hard but scratches easily, durable, brittle in small sections, good weathering – doesn’t yellow, machines and polishes well. Glass-like qualities ? NylonPolyamideTough, fairly hard, resists wear, self-lubricating, good resistance to chemicals and machines ? Common thermo-plastics

Common Name Working NamePropertiesCommon Uses ABSAcrylonitrile butadiene styrene High impact strength, lightweight, durable, scratch resistant ? Common thermo-plastics

Examiner’s Tip You should be able to name a number of individual plastics explaining what properties they have and how this influences their use You should be able to identify individual plastics from looking at a range of plastic products Examiner’s Tip You should be able to name a number of individual plastics explaining what properties they have and how this influences their use You should be able to identify individual plastics from looking at a range of plastic products

Match these ranges of products with the correct plastic – think about the properties of the plastic and the properties needed

Match these products with the correct plastic – think about the properties of the plastic and the properties needed

Common Name PropertiesCommon Uses Epoxy ResinsGood chemical and wear resistance. Adhesive to many surfaces Common thermosetting-plastics

Common Name PropertiesCommon Uses Melamine Formaldehyde Rigid, good strength and hardness. Tough Resists stains Scratch resistant Can be coloured Common thermosetting-plastics

Common Name PropertiesCommon Uses Phenol formaldehyde Very good heat resistance But very dark Hard and quite brittle Common thermosetting-plastics

Common Name PropertiesCommon Uses Polyester Resins Good heat and chemical resistance Brittle Rigid Embedding objectsUsed with glass reinforcing (GRP) Common thermosetting-plastics

Common NamePropertiesCommon Uses Urea formaldehyde Rigid Brittle Good strength Heat resistant Good electrical insulator Common thermosetting-plastics

Check your understanding – which thermosetting plastic?

Check your understanding – which thermoplastic?

heck your understanding – which thermoplastic?

Check your understanding – which thermoplastic?

Match these products with the correct plastic – think about the properties of the plastic and the properties needed

Check your understanding – which thermoplastic?