PLASTIC PROCESSING TECHNIQUE
Plastic processing can be defined as the process of converting the plastics raw
material into semi-finished products.
Ex: Buckets, Automobile Parts, Crates, Tanks, Pipes, Bottles, Carry bags, Ropes,
Profiles etc.
Classification of processing methods
1. Primary Processing Methods: Injection, Extrusion, Blow, Compression and
transfer moulding.
2. Secondary Processing Methods: Roto, Thermoforming, Coating, Casting,
Fabrication and Calendaring etc.
3. Tertiary Processing Methods: Cutting, Drilling, Welding and Bending etc.
Fundamentals of Processing
Processability:
Processability is generally the ease or difficulty with which a plastic can be handled
during its fabrication into film, moulded products, pipe, profile etc.
A plastic with good processability possesses the properties necessary to make it
easy to process the plastics into desired shapes. The main characteristics or the
properties which determine a plastic’s processability are molecular weight,
uniformity, additive type, content and plastic feed rates.
Primary Processing Technology Types:
1. Injection Moulding: Thermoplastic or Thermoset plasticated at control
temperature inside the screw pump (a combination of screw & barrel), then
forced under pressure through a nozzle into sprue, runners, gates and
cavities of mould.
Types of products: Spools, bobbin, bottle caps, automotive parts, gem clips,
crates, buckets etc.
Types of Injection moulding machine:
Performance Requirements
Engineering Approach
Practical Approach
Material Selection
Cost/Performanc
e
Process
Properties
Ideal Choice
