The injection moulding industry is full best practice beliefs and guidelines that most in the industry follow quite diligently but did you know that some of these tips and tricks are more myth than anything else?

When it comes to optimising your injection moulding process there are a number of myths that are accepted as truth and in this two-part post we’ll debunk six of the most common.

Any part with a lower weight than the maximum shot weight of the machine can be moulded

This is false. To mould the biggest possible part of the highest flow ratio requires a higher injection rate for a given size screw. This means that bigger moulding (within the maximum shot weight) is possible with the machine having a larger injection rate.

Quality problems can only be corrected by machine parameters

Part design and mould design have the most impact on the quality of parts and should take care of moulding process constraints like sink marks, warpage, dimensional inaccuracy etc.  Machine parameters should be set in the middle of possible parameter range to leave room for any minor swings on side of the set value.

Injection speed profile and pressure profile improves quality

To achieve uniform surface quality of a moulded part the skin development while spreading melt in the mould needs to be consistent. This is possible when melt moves with uniform velocity in the complex shape of the part. This makes the object of injection profile setting to set the scene for this requirement, therefor it has more of an indirect impact on quality.

Plastic and Chemical Trading are the leaders in injection moulding in Southern Africa. If you’re looking for a world-class injection moulding solution you can trust, contact us today.

Myths sourced from A guide to Injection Moulding of Plastics 3rd edition