Comparison of milling, laser and waterjet for clear thermoplastics

Introduction to machining processes

In the industrial production of clear thermoplastics, various machining processes are available. The choice of the right process depends on several factors, including cost, machining accuracy and throughput. This article compares milling, laser cutting and waterjet cutting in detail.

Milling of clear thermoplastics

Milling is a mechanical machining process that is typically used for producing complex shapes and structures in thermoplastics. It offers high flexibility in shaping, but tool costs can be relatively high. Milling enables precise tolerances and a high-quality edge finish, which makes it ideal for applications with tight specifications.

Advantages of milling

• High precision and good tolerances
• Versatility in shaping
• Surface quality is easy to control

Disadvantages of milling

• Higher tool costs
• Longer machining times compared with other processes

Laser cutting of clear thermoplastics

Laser cutting is known for its precision and the ability to cut complex contours without tool changes. Particularly with thinner materials, the laser shows its advantages in reproducibility and speed. However, edge quality can depend on material thickness and laser parameters.

Advantages of laser cutting

• High speed and accuracy
• No tool costs
• Well suited to thin materials

Disadvantages of laser cutting

• Limitation in material thickness
• Edge quality can vary

Waterjet machining of thermoplastics

Waterjet cutting uses a high-pressure water jet, often with abrasives, to cut materials. This process is particularly suitable for thick or temperature-sensitive plastics, as it works without heat input, which minimises thermal distortion.

Advantages of waterjet cutting

• No thermal stress on the materials
• Well suited to thicker materials
• Versatile in use with different types of material

Disadvantages of waterjet cutting

• Higher operating costs
• Longer set-up times

Comparison of the processes

The choice of the best machining process depends heavily on the specific requirements of the application. Milling offers flexibility and precision, but is cost-intensive in terms of tooling. The laser is fast and precise with thin materials, while the waterjet is versatile but more cost-intensive to operate.

Frequently asked questions

Which materials are best suited to laser cutting?

Clear, thin thermoplastics are ideally suited to laser cutting, as the laser enables precise cuts without major material loss.

How does material thickness influence the choice of cutting process?

Thinner materials often benefit from laser cutting, while waterjet cutting is better suited to thicker materials, as it works without heat.

What are the main cost factors in milling?

The main cost factors are tooling, machine running times and any post-processing that may be required for certain surface requirements.

What tolerances can be achieved with waterjet cutting?

Waterjet cutting can offer tight tolerances, especially with thicker materials, where minimal thermal influence is guaranteed.

When is milling the better choice compared with laser cutting?

Milling is advantageous when complex three-dimensional structures or a very high surface quality are required.