When manufacturing plastic products, there are multiple plastic finishes to consider. Each finish will impact production, the finished look, and the feel of the item. Four plastic finish types to consider include:
- Shiny
- Semi-Gloss
- Matte
- Dull
When a company designs a product that will be made of plastic, they often outsource the item’s production process. The contract manufacturer will ask the company which grade of plastic finish they desire for their product. The finished grade is determined by the Society of the Plastics Industry (SPI). The following will take a more in-depth look at each of the four finishes listed above.
Shiny Plastic Finish
Shiny plastic finishes are those in the A-1, A-2, and A-3 SPI categories. These finishes are smooth to the touch and very shiny. A-1 is so shiny that many manufacturers consider this a mirror finish.
How do manufacturers produce a shiny plastic finish? To get the shiny plastic finish, manufacturers use an oil solution and a diamond powder. This finish is very popular with mirrors and optical parts.
Semi-Gloss Plastic Finish
Plastics that are B-1, B-2, and B-3 SPI grades are considered semi-gloss. They have a polish that is rated medium to medium-low. Semi-gloss is a popular choice for plastic pieces that will be used on the exterior of the product. Additionally, this level of polish is known for its durability, making it a robust option for parts that need to withstand environmental exposure and regular handling.
How is semi-gloss finished? Manufacturers use grit papers and memory cloths during production. Even though grit paper is used, semi-gloss is still considered smooth. A benefit of this type of finish is that it is great at hiding tooling, molding, and machining marks. Also, since this finish is commonly used for exterior parts, manufacturers often add barytes to enhance the hardness and durability of these plastics. This addition makes the finish more resistant to wear and tear, ensuring that the product remains in good condition even with regular use.
Matte Plastic Finish
Plastic finishes that fall into the C-1, C-2, and C-3 SPI categories are considered matte. Matte finishes are produced by using fine stone polish powders. What are matte plastic finishes used for? Many manufacturers use matte in products that are either diecast or thermoset.
Dull Plastic Finish
The fourth plastic finish to be considered is a dull plastic finish. Dull finishes are popular with pieces that won’t be seen or touched by the customer, such as internal parts. How is this finish produced? A dull finish is typically sandblasted into the product.
The SPI grade for a dull plastic finish can fall into the categories of D-1, D-2, and D-3. D-1 is considered a textured dull satin finish. D-2 is a dull finish without the satin. D-3 is a rough textured plastic finish.
What is the benefit of choosing a dull finish? This type of finish is famous for hiding product blemishes. Product blemishes that a dull finish can hide can include deformations, marks, and smudges. This type of finish can even mask fingerprints.
How Should the Product Look and Feel?
The four above finishes are very popular with companies selling and producing items made of plastic. When a company is trying to choose which plastic to use for their product, they need to consider the look and the feel desired for the finished product. The right finish can help pull the item’s look together and make it more desirable to consumers.
The finish chosen will also help determine the production cost of the project. Some finishes cost more than others. For example, a product with a high SPI trade made of shiny plastic will cost more than an item made of dull plastic.