- Understanding your process requirements is critical to choosing the right cutting method.
- Commonly used cutting technologies include laser, plasma, EDM and water jet.
- Each process offers a range of capabilities and has various strengths and weaknesses.
No single cutting method makes sense for all applications. A variety of technologies are available, each offering a unique set of capabilities, advantages and disadvantages. To make sure that you have the right equipment for your application, it's important to carefully evaluate your process requirements, as well as your facility, workforce capabilities and budget.
Look at your processes
The first step is to establish the requirements of your application, including:
- Material to be cut
- Part specifications such as thickness, cutting accuracy and cutting width
- Desired production volume
- Edge quality
- Environmental footprint and energy source limitation
In a dynamic business environment, requirements can change quickly due to new trends or shifting customer demands. Make sure you have the right equipment to match your current and future needs.
Selecting the right cut
Commonly used cutting equipment includes laser, plasma, electrical-discharge machining (EDM) and water jet.
Lasers use focused light to make very precise cuts. Lasers can cut most metals, plastics, glass and wood. On very thin material, lasers can cut at very fast speed. On materials more than a quarter of an inch thick, however, laser cutting slows significantly. Lasers are also better at cutting high-quality material; impurities can impact cutting quality. With its high upfront costs, laser equipment is best for high production volumes.
Plasma cutting is a thermal process for cutting electrically conductive materials, such as stainless steel, aluminum and copper. The plasma arc melts the metal, while the high-velocity gas flow removes the molten material. Plasma cuts at high speeds and generates heat that leaves rough edges. Dross sometimes builds up on the bottom side of the cut. Plasma units are generally less expensive than laser equipment.
EDM machines remove material from a workpiece through a rapid series of electrical sparks between two electrodes. EDM is useful when low-residual stress is needed because it doesn't require a substantial cutting force. EDM is widely used in the tool and die industry. EDM machines can cut hard material into complex shapes. However, the EDM process is slow and power consumption is high.
Water jets spray high-speed water onto the material, cutting it using an erosion process. This method can cut a variety of thicknesses and material types and it's useful for heat-sensitive materials. Water jet units have a relatively quick set-up time, making them useful for small and medium batch runs. Also, water jets are a green technology, producing no hazardous waste and reducing waste disposal.
The following table summarizes the capabilities and additional considerations of each cutting technology:
|Method||Thickness Range (inches)||Cutting Accuracy (inches)||Width (inches)||Considerations|
|Laser||Steel 0.35 to 0.5
|+/-0.001 to +/-0.010||0.001 to 0.05||High capital cost requires high-volume production|
|Plasma||Metals up to 0.75||+/-0.030 to +/-0.060||0.10 to 0.25||Conductive metals only|
|EDM||Up to 6||+/-0.0001 to +/-0.0015||0.08 to 0.015||Slow process|
|Water Jet||Up to 10, but typically less than 4||+/-0.003 to +/-0.015||0.03 to 0.05||Metals and non-metals, fast set-up|
By carefully assessing the benefits and costs of each technology, as well as your facility and processes, you can select the right method to fit your needs and make your business more competitive.