blow extrusion

materials technology

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Last updated

June 22, 2026

Quick Summary

Blow extrusion is a method used in the plastics industry to create continuous shapes with a constant cross-section. In this process, a melted polymer is forced through a die. For products like plastic bags, a tube is extruded and then expanded by air into a bubble before cooling. This expansion, known as blow extrusion, can create biaxially oriented structures, which often have superior mechanical properties compared to unoriented materials. This technique is also used to create multilayer films by extruding multiple materials simultaneously, allowing for specialized properties like strength and moisture resistance.1

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plastic
Extrusion
In the blow extrusion process, polymer molecules are oriented around the circumference of the bag as well as along its length, resulting in a biaxially oriented structure that often has superior mechanical properties over the unoriented material.
Read More
In the blow extrusion process, polymer molecules are oriented around the circumference of the bag as well as along its length, resulting in a biaxially oriented structure that often has superior mechanical properties over the unoriented material.
Read More