Comparison Between Injection Moulding And Extrusion Moulding -->

Comparison Between Injection Moulding And Extrusion Moulding

Injection moulding and extrusion moulding

Injection moulding and extrusion moulding are popular plastic manufacturing processes. At an initial glance, it may appear to be similar. Both injection moulding and extrusion have their own purpose and advantages.


🔗What is injection moulding?


Injection moulding is similar to die casting. Here plastic pellet is first melted and injected to mould cavities of the required shape with some types of injectors. Then it is allowed to solidify in the die. The final product is then ejected from die ejectors. Example chair, basket, casing, toys


Extrusion is the process of making continuous linear or two-dimensional shapes. In the extrusion process, the material is first melted and then forced through a metal plate (die cavity), having shaped cut and creating a continuous form. Then it is cooled to set. This continuous shape can be cut to length into parts once it is set as per demand. Example: rails, pipes, tubes.


Difference between injection moulding and extrusion moulding

Injection moulding

Extrusion moulding

Higher initial design cost

The initial cost is low


Making a three-dimensional shape. Its cross-section does not need to remain in a parallel line.


Continuous one or two-dimensional product

Molten material pushed to desired mould cavity then allow solidifies there.

Molten material forced out through die having desired cross-section profile.


It is a cyclic process

It is a continuous process


The product is in the final dimension.

It is ideal when a different length of the same profile shape is required. It is cut to length as per demand.


Parts with excellent tolerance can be produced.

The surface of extruded material is so smooth. Do not require post-production surface finishing.


It offers good strength to the product

Comparatively weaker product.


Expansion of material is constrained.

Free expansion is possible.


Load comments