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HIGH DENSITY POLYETHYLENE (HDPE)
V. Ryan © 2009
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Polyethylene (HDPE). HDPE is used to make bottles for fruit juice, milk,
water, kitchen cleansing products and even dust bins including recycling
bins. It has been used in recent years for garden furniture and recycling
bins as it resists the weather and can be cleaned very easily. It is
lightweight which means bins made from this material can be handled and
transported very easily. It is an ideal material for the injection
moulding process making it suitable for batch and continuous production.
It has the following properties:
Stiffness, strength, toughness, resistance to chemicals and moisture, permeability to gas, ease of processing, and ease of forming.
LIGHTWEIGHT - RECYCLABLE - CHEAP - PIGMENTED - TOUGH - STRONG - RESISTANT
|Look at the HDPE recycling bin seen on the previous page. Why is High Density Polyethylene suitable for the manufacture of outdoor recycling bins? Write a couple of sentences on HDPE using each of the keywords listed above.|
|A common steel used
widely in school workshops and in the construction and manufacturing
industries. Relatively easy to form and shape. Tends to rust if not
galvanised or coated with paint.
Smaller sections can be shaped by hand tools and formed by ‘hand’ pressure. Larger sections require machines such as centre lathes and milling machines for shaping and heating to red heat when forming into shapes and forging.
RUST - RECYCLABLE - CHEAP - GREY - TOUGH - STRONG - RESISTANT
- HARD WARING
|Look at the mild steel mechanism seen on the previous page. Why is mild steel suitable for the manufacture of this mechanism ? Write a couple of sentences on mild steel using each of the keywords listed above.|
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