Hey there! As a Plastic CNC Machining supplier, I often get asked about the different surface finishes available for plastic CNC machined parts. In this blog, I'll walk you through the most common surface finishes, their pros and cons, and when to use them.
1. As - Machined Finish
The as - machined finish is the most basic surface finish you can get for plastic CNC machined parts. When we machine plastic parts using CNC (Computer Numerical Control) technology, the part comes out with the texture and appearance directly from the machining process.
The good thing about the as - machined finish is that it's fast and cost - effective. There's no need for any additional post - processing steps, which saves both time and money. It's great for parts where the surface finish isn't a critical factor, like internal components in a machine or parts that will be hidden from view.
However, the as - machined finish may have visible tool marks, which can be a bit rough. If the part needs to be aesthetically pleasing or if it will come into contact with other sensitive surfaces, this finish might not be the best choice.
2. Sanding
Sanding is a popular way to improve the surface finish of plastic CNC machined parts. We use sandpaper of different grits to smooth out the surface. Starting with a coarse - grit sandpaper to remove any large tool marks and then moving on to finer - grit sandpapers for a smoother finish.
One of the advantages of sanding is that it can significantly reduce the roughness of the surface. It can make the part look more professional and can also improve its feel. Sanded parts are often used in consumer products where the appearance matters, like the casings of electronic devices.
But sanding has its limitations. It can be a time - consuming process, especially if you want a very smooth finish. Also, if not done carefully, sanding can cause scratches or uneven surfaces.
3. Polishing
Polishing takes the surface finish to the next level. After sanding, we use polishing compounds and buffing wheels to create a shiny, mirror - like finish on the plastic part.
Polished plastic parts look really great. They have a high - end, professional appearance and can enhance the overall look of a product. This finish is commonly used in products like jewelry boxes, display cases, or high - end consumer electronics.
However, polishing is an expensive and time - consuming process. It requires specialized equipment and skilled operators. And not all plastics are suitable for polishing. Some plastics may melt or deform under the heat generated during the polishing process.
4. Painting
Painting is another option for plastic CNC machined parts. We can apply a coat of paint to change the color of the part, protect it from environmental factors, or add a decorative touch.
There are different types of paints available for plastics, such as acrylic paints and urethane paints. Acrylic paints are easy to apply and dry quickly, while urethane paints offer better durability and chemical resistance.
The benefit of painting is that it gives you a lot of flexibility in terms of color and appearance. You can match the part to the overall design of the product. It can also provide some protection against scratches and UV rays.
On the downside, painting requires proper surface preparation to ensure good adhesion. If the paint doesn't adhere well, it can peel or chip off over time. And the painting process can add some cost to the production.
5. Plating
Plating involves depositing a thin layer of metal on the surface of the plastic part. Common metals used for plating include chrome, nickel, and copper.
Plated plastic parts have a metallic look and feel, which can give them a high - end appearance. They also have improved electrical conductivity and corrosion resistance. Plated parts are often used in automotive components, like trim pieces, and in some high - tech applications.
But plating is a complex and expensive process. It requires a series of chemical treatments and specialized equipment. There are also environmental concerns associated with some plating processes, as they may involve the use of toxic chemicals.
6. Texturing
Texturing is used to create a specific pattern or texture on the surface of the plastic part. We can use different methods to create textures, such as engraving, embossing, or using textured molds during the machining process.
Textured surfaces can serve different purposes. They can improve the grip of a part, like the handles of tools. They can also add a decorative element to the product. Textured parts are commonly used in products like automotive interiors, where a non - slip surface is needed.
The drawback of texturing is that it may require additional tooling or processes, which can increase the cost. And if the texture is too deep or complex, it can be difficult to clean the part.
When to Choose Each Finish
- As - Machined: When cost and speed are the main concerns and the surface finish isn't critical. For example, internal brackets in a machine.
- Sanding: When you want to improve the appearance and feel of the part without going overboard on cost. Consumer product casings are a good example.
- Polishing: For high - end products where a mirror - like finish is required, like luxury item display cases.
- Painting: When you need to change the color or add a protective layer. This is common in consumer electronics and toys.
- Plating: For parts that need a metallic appearance, improved conductivity, or corrosion resistance, such as automotive trim.
- Texturing: When you need a non - slip surface or a decorative pattern. Automotive interiors and tool handles are typical applications.
If you're interested in CNC Turning Stainless Steel, CNC Turning Milling Drilling Componenets, or Custom Cnc Plastic Machining, we've got you covered. We can help you choose the right surface finish for your specific needs.
If you're in the market for plastic CNC machined parts and want to discuss the best surface finish options for your project, don't hesitate to reach out. We're here to help you make the right decisions and get the high - quality parts you need.
References
- "Plastic Machining Handbook", Industry Press
- "Surface Finishing Techniques for Plastics", Plastic Technology Journal