DT Paper 3 Flashcards
Air seasoning
Planks are stacked on top of each other to allow the air to circulate between them so that they can dry out
Kiln seasoning
Planks are stacked on top of each other to allow the heated air to circulated by the fans to dry the timber at a faster speed than air seasoning.
Warping
Bending and twisting of timber, should be avoided
Advantages of manufactured boards
Environmentally friendly
Do not split
Less costly
Wider variety of lengths
Steam bending
Deforming process
Thin layers of timber are placed into a steam chamber where steam enters and travels through the chamber, heating up the veneer and absorbing the timber. This makes the timber malleable and flexible as the veneers are removed, which makes it possible to bend the timber into different shapes and then left to cool.
Laminating
this process involves no heat as it used thin laminates of timber and bonds them to each other over a former. PVA adhesive is used as it is cheap, non toxic and easy to work with.
This process is used in furniture making.
Ferrous metals
Are alloys that contain iron
High melting and boiling points
Can rust as they react with oxygen
Ferrous metals:
Cast iron
Stainless steel
HSS - high speed stainless steel
Mild steel
High carbon steel
Non-ferrous metals
alloys that don’t contain iron
Lead
Tin
Zinc
Duraluminium
Aluminum
Brass
Bronze
Copper
Changing structure of metals
Work hardening
Annealing
Case hardening of mild steel
Faster process which usually only hardens the outer 0.05 mm of the metal unless the process is repeated to increase the depth.
Metal more malleable and flexible as the core isn’t hardened.
Joining acrylic with other plastics
Acrylic cement
Joining polystyrene and fabrics
Contact adhesive
Joining metals to plastic
Epoxy resin (it’s waterproof)
Joining timber
PVA - polyvinyl acetate
Synthetic resin
