Material Processes

Question 1

Process of Injection moulding

Answer 1

1. Plastic granules are fed into the hopper.
2. The screw in the chamber below the hopper sends the granules forward.
3. Heated jackets around the screw mel the polymer.
4. The screw winds back and the hydraulic ram
5. The mould is closed and sealed as the ra, forces the melted plastic into the mould.
6. The plastic is allowed to cool and the halves of the mould release.
7. The screw is released off.

Question 2

Process of Vaccum Forming

Answer 2

1. The mould is placed into the former.
2. A sheet of thermoplastic such as HIPS is clamped over the mould.
3. The plastic is slowly heated to become soft.
4. The former is raised as air is sucked out, drawing the plastic over the former to take its shape.
5. The edges must be trimmed and finished.

Question 3

What process will blow moulding contain

Answer 3

Water bottles (unrecyclable ones you get from Tesco)

Question 4

What polymer process uses line bending

Answer 4

Anything that is formed into a shape.

Question 5

What polymer process contains extrusion

Answer 5

Something that is long (pause)

Question 6

What are the commercial processes for timbers

Answer 6

• Routing: use a router

- Turning: using a lathe

Question 7

Routing process

Answer 7

• The cutting blade on a router will spin at a high speed.
• Material is removed as the user moves the router over or through the timber, which is held securely
• A centre lathe on the other hand, holds the timber securely and spins this at high speed
• The cutting tool is controlled by the user and is moved into the timber to remove material

Question 8

Turning process

Answer 8

• A lathe works by spinning a piece of timber at speed.
• While the timber is turning, a wood-turning tool is pushed into the timber to change its shape.
• Some timber can be held in place by compressing it from end to end.
• This would allow a spindle or cylinder to be shaped.
• Another way to hold the timber is to screw it to a faceolate - the timber spins on the lathe, and this would allow a bowl to be turned.

Question 9

Three main methods of shaping metal

Answer 9

• Turning
• Milling
• Casting

Question 10

Process of turning

Answer 10

• Metal can be turned in a lathe, which can be hand operated or controlled via a computer on a CNC lathe.
• A lathe spins the work at high speed as a cutting tool is introduced to the metal to produce round and cylindrical shapes.
• Round pieces of metal are held in a lathe using a three-jaw chuck, and metal that is not round is held by a four-jaw chuck

Question 11

Process of milling

Answer 11

• Metal can be shaped using a milling machine - a tool to smooth surfaces or edges and for cutting grooves and profiles.
• Milling machines can work either horizontally or vertically - both machines can perform the same tasks; the main difference is the direction the cutting tool is held.

Question 12

Process of sand casting

Answer 12

1. Former is made, usually by hand and is placed in the ‘green’ sand which is packed tightly around the former before it is removed
2. Repeated on the other part of the mould
3. Two holes are made in the sand, one for molten metal to be poured and the other for metal to come up and out the other side
4. Once they are both ready, parting powder is applied to the sand and the two moulds are placed together, one on top of the other
5. The molten metal is poured into the runner until it comes up to the riser when the cavity sand is full of metal.

Question 13

Extrusion process

Answer 13

1. Granular plastic is held in a hopper
2. It is moved by Archimedean screw along a heated tube, called the heating chamber
3. Once the poly,er has been melted it is pushed through a die mould, which will form the shape of extrusion
4. Because there is no hydraulic rammin the process, molten plastic can be fed through the die continuously