Blow moulding

Question 1

Blow moulding process

Answer 1

1. Plastic granules are heated
2. A tube of soft plastic is extruded
3. A steel mould is clamped around the tube
4. Air is forced into the tube to expand it to the shape of the mould

Question 2

Characteristics of extrusion blow moulding

Answer 2

• A line is visible on the bottom of the container where the extruded tube has been welded together as the two parts of the mould close
• Screw threads are visible on the inside of the bottle.