Milling plastic: technology, materials & tips
Plastic milling
At MK Plastteknik we offer plastic milling as part of our wide range of plastic processing. We combine long experience with a modern CNC-controlled machinery to deliver dimensionally accurate plastic parts, customized to your drawings and specifications.
We can manufacture both single prototypes and series deliveries, with consistent quality and reliable delivery times.
A flexible partner for milling plastics
Milling is just one of the methods we master. We also offer help with injection molding, vacuum forming and wire EDM – all under one roof. This makes us a flexible partner who can adapt production to your needs and material choices.
Milling plastic is a suitable method when:
- There are few to medium-sized series and injection molding is not economically justifiable.
- High precision and complex geometry are required.
- Prototypes should be produced quickly without tooling costs.
- The parts are larger and not suitable for injection molding or vacuum forming
What is the difference between milling plastic and milling metal?
Plastic milling involves removing material with rotating cutting tools to shape a part. Thermoplastics and engineering plastics have completely different properties than metal: they are more heat sensitive, softer and more elastic. This means that tool selection, feed rate and cooling must be carefully adjusted.
To avoid problems such as melting, stresses and poor surface quality, it is important to balance the cutting parameters and use tools with geometries adapted for plastics.
Material selection for plastic milling
Different plastic materials behave differently during machining. We are happy to help you choose the right material for your application. Below are some of the most common materials when milling plastic:
- POM (polyacetal/Delrin): Stiff, dimensionally stable and easy to machine. Suitable for gears, bearings and sliding surfaces.
- PE (polyethylene): Durable and chemical resistant, but soft and can "fringe" with incorrect cutting parameters.
- PC (polycarbonate): Impact resistant but sensitive to heat build-up. Requires good cooling.
- PMMA (acrylic): Provides high gloss and optical clarity, but is brittle and requires sharp tools.
- PTFE (teflon): Low friction and very temperature resistant, but difficult to machine without the right settings.
Tips for milling plastic
Choose the right material
Adjust the material selection based on requirements for strength, finish, optics and chemical resistance. ABS is good for robust prototypes while PMMA is used where transparency is important.
Set the correct cutting parameters
Plastic melts at lower temperatures than metal, so you should choose a high speed combined with a fast feed to get large chips that effectively transport the heat away.
Use the right tools
The tools should be sharp, with a spiral geometry that quickly evacuates chips. Carbide tools with a coating provide longer life and reduce the risk of chips sticking.
Ensure cooling and chip evacuation
Blowing air or a small amount of cutting fluid will prevent the plastic from melting and sticking. Also, make sure that chips do not accumulate in the work area.
Plan for post-processing
The surface quality can be improved with a fine pass or by polishing, grinding or chemical treatment depending on the finish requirements.
Common challenges
Milling plastic often means that heat builds up in the part. We therefore adjust feed rate, speed and cooling to minimize the risk of melting edges and internal stresses. Burrs and chips are prevented with the right tool and correct cutting depth. Our long experience means that we can choose optimal parameters right from the start.
Contact us
We are happy to receive your drawings and help you evaluate which processing method is most cost-effective for your product. With our combination of experience, modern machinery and material knowledge, we ensure that you receive a plastic part that meets all requirements for quality and function.