If you are looking for a little more sophistication in your product, then this might be the time to think about using a side-action mould, instead of a standard straight-pull mould. Here, we will discuss the pros and cons of both manufacturing processes and assess how and when each process should be used.

Straight-pull moulds are very efficient at the job they are designed to do – that is, to produce simple, one piece parts. Nothing wrong with that! However, there are other aspects of a design that may require something a little more complicated and this is where side-action moulds can come in useful. Side-actions incorporate moving parts into the mould, by way of a cam mechanism, as the mould itself opens and closes at the relevant stage of each production process. There can be more than one of these side-actions in the mould at the same time, although it is important to take into account the space that this would take up with respect to the design of the part.

In order to create a perfect part, there are certain aspects that need to be considered when designing and manufacturing side-action parts and these are:

• Space for the side-action cam to operate engineered into the design.
• Ensuring that the action of the cam is exactly horizontal or vertical.
• Ensuring that the draft is of the correct angle so as to allow small withdrawal of the side-action part without causing any warping, distortion or other unwanted factors to interfere with the end design.

Side-actions are very useful in being able to create parts with a flat finish, as it is not required to incorporate a draft on two opposing faces. This can provide a useful option for external faces, as they can have differing textures depending on the design requirements.

However, what happens when side-actions are not enough and you have complicated parts to produce? "Shutoffs", which use the normal opening and closing action of the mould to produce openings in the wall of the part, are often used as an alternative to a side action. "Bumpoffs" create added resistance, which makes the part more difficult to eject, causing the part to shrink onto the face that is recessed, which results in more drag when ejecting the part. This allows a bump or lip to protrude from the outside of the part, which remains even after the part has been ejected from the mould.

We are experts at both straight-pull and side-action injection moulding – please do not hesitate to contact us when thinking about you next moulding project!