All for the Aesthetics.

Welcome to the Moulding Matters by MGS newsletter, where you can find insights into the plastic industry. Perfect for if you are new to plastics or want to learn something new.

You may want your product to look a certain way to appeal to your customers or may require a certain aesthetic for its use. There are a few areas for you to consider in the early stages of your project, so what are they?

The first is the surface finish, and this has to be considered before and when designing the tool. The surface finish can be for both aesthetic and functional reasons, for example appealing to the end user, scratch resistance or grip.

Paint also adheres to a textured finish better.

The surface finish can range from a super glossy to a dull matt or textured finish. The different standards are SPI, VDI or Mold-Tech, and depending on your location one can be a more popular standard to use.

SPI, which is the American standard but is also used in the UK and worldwide, has 4 categories (A, B, C and D) - from High-Gloss to Textured finishes.

VDI is categorised by numbers from 0 to 45, and similar to SPI going from a High-Gloss to Textured finishes.

Mold-Tech also has 4 categories like SPI (A, B, C and D). Mold Tech covers textured finishes different to the other standards, such as sand, wood, polka dots and checks.

This video is a great overview of the three standards with examples of the finishes.

Colours can help to appeal to a customer, differentiate between different versions of a similar product, or be your company's colours. There are many reasons to use colour in your component.

There are a few different ways to get colour into your plastic component. The polymer can originally be the colour you want, such as black or transparent; a colour masterbatch can be added beforehand to production to make it your desired colour or tint; or the colour can be compounded into your material so no mixing is required before production.

Material selection can also be a factor in how a part looks. Polymers, such as Nylon (PA6, PA66, PA12), can be glass-filled and the glass fibres can be seen after moulding.

This is a great guide that goes into more detail on how Masterbatch works and how your ideal colour is developed.

For masterbatches, there are universal colours that can be used with any polymer but can look different depending on the material or specific polymer masterbatches, such as for PC, PP or ABS.

Masterbatches can be used with recycled material, however, the colour cannot be guaranteed as the source of the recycled material will not always be the same. This is the same for any mechanical properties of polymer.

We also shared a video in our previous newsletter about colours in different lights and how they change.

Your moulded component or set of mouldings may be part of a larger Assembly, that includes other items such as springs and inserts.

Parts can be designed to assemble together or to have added bought-out parts, such as springs and inserts.

Parts can also be ultrasonically welded - a process where ultrasonic vibrations are locally applied to work components together under pressure to create a weld between them.

Assembly can also be completed at the machine or separately in an assembly department. Jigs can be manufactured at a cost to assemble clips and inserts at the same time and remove labour previously needed in the assembly process.

An after-moulding process that can be considered to add logos or additional details is pad printing (also known as Tampo Printing) or hot foiling.

Pad printing is a process using a silicone pad that takes a 2D image coated in ink from a laser-engraved printing plate and transfers that onto a plastic component.

Inks can be matched to Pantone colours, so the colour design is more flexible. The design can have multiple colours, but each colour requires a separate printing plate.

Hot foiling is a similar process but a silicone pad is engraved with the design, and this is used to transfer the foil onto the plastic. The foil however cannot be Pantone matched, and the design has to be fairly simple.

Another option for adding an all-over colour is paint or chroming (Chrome Electroplating), both can be planned for during the design-for-manufacture phase and when your tooling is being manufactured.

Certain textures, tool steel and part design need to be considered to provide the best finish for the painting and chroming process.

The Material also needs to be considered. For painting, ABS and PC/ABS is the best material for the process. Other materials, such as PP, requires a two-layer paint system, including a primer to adhere the paint to the plastic.

Chroming is similar, however, instead of paint, metal is applied to the component.

The most suited material for this process is PC. Other materials that are suitable for the chrome process are ABS, PC/ABS and PMMA.

Don’t miss this:

1. We spoke about surface finishes above, but if you fancy reading more, we wrote a handy guide about the different surface standards.
2. Designing for Injection moulding is different to designing for 3D printing. There are design elements that you need to be aware of, such as draft angles, to make a successful injection moulded part. This video about designing a plastic moulding for manufacturing can show you an insight into what goes into design.

If you've got this far, find out how else we can help you:

• We have more insights on our website, where you can learn more about MGS.
• MGS is exhibiting at Southern Manufacturing & Electronics on Stand L260 in February, are you visiting? Register for the exhibition to meet us face-to-face.
• Want to work with us? It's easy to contact us, email [email protected] with your project details.