Manufacturing with Polymers 2.

Question 1

Vacuum forming process.

Answer 1

1. The mould is placed on the bed of the machine called the platen which is lowered all the way down.
2. A polymer is clamped over the mould and heated.
3. When the sheet is softened the plated is raised up into it and the heat is removed.
4. The vacuum pump is switched on, which sucks the polymer pulling it up against the mould as it takes it’s shape.
5. When the polymer is cooled, the platen is lowered and vacuum is switched off.
   * the excess polymer is trimmed.

Question 2

The purpose of vacuum forming.

Answer 2

To give sheets of polymer depth and shape.

Question 3

Extrusion process.

Answer 3

1. Polymer grains are poured into the hopper.
2. The Archimedian screw pulls the granules past the heaters as it becomes molten.
3. When sufficient polymer has melted the hydraulic ram pushes the archimedian screw forcing the polymer through a steel die. The steel fiesta determines the shape of the extrusion.
4. The extruded plastic may be supported by rollers as it is cooled by water or air.
5. The extrusion is cut to the desired length.

Question 4

What is the purpose of extrusion?

Answer 4

To produce solid objects with same cross sectional area throughout.