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Common problems with a non-return valve

Process improvement by understanding how a non-return valve works

Video shows how to improve your injection molding processes

This video will go into common problems that occur with a non-return valve in the injection molding process.

The key to trouble-free injection molding of thermoplastic materials with less downtime and improved quality begins before production ever starts. Choosing the appropriate equipment components, then setting up the ideal machine and process conditions, can make or break your bottom line. In the end, it's imperative for the quality of the molded part. This video will dive deep into the common challenges of a non-return valve and provide guidance on how to avoid and solve them.

What does a non-return valve do?

During the start of the injection phase of the cycle, the non-return valve (NRV) prevents the back flow of material. Because the material can only flow in one direction, the movement and pressure of the injection unit can now be transferred into the material and then into the mold. When the screw is in the plasticizing phase of the cycle, the NRV allows the movement of material to the front screw.

The video covers the following topics:
  • How a non-return valve works

  • What are the causes of the NRV not closing

  • How to tell if the non-return valve is leaking during production/when press is not in production

  • Factors that affect the closing behavior or NRV

  • Some things to try to get the non-return valve to close more repeatably

Image shows how to change a mold

How to change a mold

Tutorial for quick mold installation

Image shows causes and solutions for common injection molding defects

Causes and solutions for common injection molding defects

Short shots

Image shows quick mold changes

Quick mold changes

A cost-efficient solution also for small machines

Markus Lettau

Molding Industry Business Advisor

+1 (717) 767 2016

Write us

The ENGEL team is happy to support you with extensive knowledge in the field of injection molding.