Our third blog on demystifying plastic injection moulding terminology focusses on some more obvious terms. Here, however, we will explain why it is important to consider them early on in the design stage to ensure your finished part has the desired functionality and aesthetic you are hoping for. These are:
1. Texture
Texture can be included in the design of plastic injection moulded parts for a number of reasons including aesthetics and to provide grip. Approximately 70% of the parts that OGM moulds have some form of texture, generally with a different texture on the outside of the part compared to the inside. Heavily textured surfaces may require extra draft to aid removal of the mould without causing drag marks.
Different textures on the same surface may also be needed, for example if you have a recess that you want to maintain a smooth finish on, so that you can easily attach logos or name plates that will adhere better to a smooth surface.
In contrast, highly polished or mirror finishes may be required for clear parts that need to have light transmitted through them such as light guides or for high-end consumer electronics. Plastic injection moulding offers solutions for each end of the scale when it comes to texture so it is worth speaking with an expert to find out what options there are for your design.
2. Lettering
Lettering is required on most plastic components whether it is for traceability, quality and branding purposes or to provide instructions and information to the end user such as recycling symbols and safety warnings. Some things to consider are:
- The position of the text on the part so that it doesn’t impede ejection from the mould tool
- The size of your part and therefore quantity of text in your design so that it remains legible
- The size of the text to ensure your material choice is able to fill the lettering once it enters the mould in its molten form
- The font style for legibility
3. Living hinges
A living hinge is a small section of plastic that acts as a hinge to hold two parts together. Some common examples can be found on caps, such as shampoo bottles or pill boxes, or on larger items such as plastic cases.
One of the main considerations at the injection moulding design stage is material choice as living hinges need a highly flexible plastic to function correctly. There are other ways of achieving the same, or sometimes a better, result so it’s worth speaking to your plastic injection moulder for advice.
Contact one of our experts to find out how we can help you with your next project.
You can read part one and two of our demystifying blog series here: