Page 122 - Module DMV20173

6.0 POLYMER PROCESSING

.3.3 PROCESS SEQUENCE

1. Blow molding a shape is a common industrial process.
2. The example shown below is of the production of a plastic bottle (Figure 6.8).

3. The plastics normally used in this process are; polythene, PVC and polypropylene.

Figure 6.8 Extrusion process to produce plastic bottle

1. The process is similar to injection molding and extrusion.
2. The plastic is fed in granular form into a 'hopper' that stores it.

3. A large thread is turned by a motor, which feeds the granules through a heated section.
4. In this heated section the granules melt and become a liquid and the liquid is fed into a
mold. Air is forced into the mold, which forces the plastic to the sides, giving the shape
of the bottle.
5. The mold is then cooled and is removed.

BPLK 154 DME 1083