Rotational moulding. A measured amount of polymer powder is placed
in a mould. The mould is then rotated in a complex motion in an furnace or oven until the polymer
lines the mould cavity. Polymer home heating tanks are made by this method.
4. Heat forming, (Vacuum Forming).
This uses sheets of polymer,
which are clamped and heated. The heat is then removed and the mould is forced
up through the polymer sheet, a vacuum is applied which pulls the polymer
against the mould. The polymer is allowed to cool and the polymer sheet then
removed.
5. Foaming.
Polymers, which are
converted into sponge like materials, are formed or expanded. A foaming agent is mixed with the resin. The
combination is heated during moulding. The products, which are produced, have a
very low density. Both rigid and flexible foams can be produced.
6. Lamination.
Impregnating sheets of paper
or cloth with a resin can produce high strength polymers. Layers of this
material are bonded, by allowing the resin to set into a solid structure. Heat
and pressure are often used in this process.
7. Machining.
Polymers supplied in rods,
tube or sheet can be machined into their final shape. These materials can be
machined by both hand tools and machines but can require different cutting
speeds.
8. Welding.
Polymers are used to make
variety of components for example in cars the bumpers, grill etc. But these can
crack due to light impact, using a hot air welding tool can repair these
cracks. The welding tool provides heat to make the polymer molten. A filler rod
of the same polymer is fed in through a special nozzle.
No comments:
Post a Comment