Waterjet is one of the most sought-after industrial cutting technologies. Waterjet cutting uses the force of high-pressure stream of water to pierce the material. The cutting force is enough to cut thick materials of extreme strength. This includes the hardest metals, alloys, plastics, glass, and other materials.
Waterjet cutting is effortless to adapt in any industrial setting. However, some waterjet cutting tips and trick can help improve the results for beginners and professionals alike. This article will go through these tips for improving the pure and abrasive waterjet cutting performance.
Top Tips to Maximize Waterjet Cutting Productivity
Each of the following tips can be very useful when cutting any material with the waterjet cutting process:
1. Parameter Selection: Parameters like the cutting speed and the abrasive flow rate are based on the use cases. There is no universal ideal value. Try various settings on your application-based test cases to determine which value will give the best result for you. You can note down that value and use it for future cutting.
2. Stacking: You can place multiple sheets of material on each other to cut them simultaneously. This process is called stacking. Stacking can increase the productivity of the whole operation exponentially. However, it is only applied when multiple pieces of the same shape are required consistently.
3. Material Orientation: The orientation of the material can significantly influence the cutting quality. Cutting across the grain will produce different results than cutting against it. Try different orientations for the material being cut to determine which will create the best outcome.
4. Operator Skill: A skilled operator can get the most out of a waterjet machine’s capability. At the same time, an unskilled operator can create disastrous results even from high-end waterjet machines. It’s essential to ensure your operator is highly skilled and has the necessary training to work on the machine.
However, the importance of ongoing learning and adaptation can’t be overstated. The field of waterjet cutting is continually advancing, with new techniques and technologies emerging regularly.
Regular training programs, workshops, and industry events can be valuable resources for staying updated with the latest trends and improvements in the waterjet cutting process.
5. Piercing Point: For a high quality cut, use a pierce point inside the area that will be cut out. This helps in providing precision cutting as well. If you directly cut the material at the cut location, the initial starting point will have a higher kerf width.
6. Taper: Thick materials show the phenomenon of taper during cutting with a waterjet. This happens due to the spread of the waterjet stream as it travels vertically. Account for taper when adjusting the cutting parameters. Modern software have automated adjustments for taper deviation.
7. Material Usage: When cutting out multiple pieces from a single sheet, use the software to arrange cutouts to get most out of the material and generate minimal waste.
8. Supports: The workpiece requires proper support during the cutting process. Insufficient or loose support fixtures can cause warping and bending of the material. Lack of support or improper support can also cause vibrations, reducing precision. Supports can include jigs, fixturing, clamps, or an alignment guide.
9. Safety Process: Ensure that the operator is trained in the safety procedure for the machine. Additionally, ensure the machine has safeguards like light curtains or guard railings. Waterjet machines also require safety goggles to protect the eyes from the water splatter.
10. Selecting Material: If there is an option for choosing between different materials, choose a material that is easier to machine. Waterjet cutting can cut hard and thick materials. However, materials with good machinability can provide faster cutting speed.
11. Lead-in and Lead-out: Understand using lead-in and lead-out to optimize material usage while keeping the cut quality high. The lead-in and lead-out points should be outside the production part so as to not create any scarring on the part itself. However, the distance of these points from the part should not be excessive as it would create added material waste.
12. Choosing Lead-in and Lead-out Points: Lead-in and lead-out points should not be arbitrary. The best location for these points is on the material area that will go to waste. If these points have to come inside the production part, choose an area where the quality is unimportant, such as features that will not be visible to the eye.
13. Brittle Material: Brittle materials can have excessive chipping when the waterjet cutting starts and the machine adjusts the flow rate and water pressure. Therefore, brittle material requires additional lead-in distance. If there is insufficient lead-in, chipping will occur inside the production part area.
14. Single vs. Dual Cutting Head: Dual cutting head can create faster cuts. However, equating the water pressure between the two cutting heads can be difficult. Therefore, the cutting quality can deteriorate. It is better to choose a single cutting head, making it easier for the operator to oversee the process.
15. Maintaining Logs: When making changes to any cutting parameter like water pressure or abrasive flow rate, note down the value that you are using. This helps in later iterations to create the same result or to avoid any problems. It can also provide a reference point to understand which direction to choose for getting the desired result.
16. Air Gaps: When stacking thin materials, ensure that the parts are layered together without any gap in between. Air gaps higher than 0.020 inches can cause poor cutting on the bottom layer. This is because the water stream tends to spread out in the air gap.
17. Underwater Cutting: Cutting underwater is a great way to eliminate the noise generated in a waterjet cutting. It will also eliminate any water splatter, which is a common problem with waterjet technology. Another benefit is that underwater waterjet cutting will avoid any unwanted surface frost effects.
18. Nozzle Cleaning: The nozzle is prone to getting clogged due to debris and impurities present in the water. It is important to clean the nozzle regularly to ensure the cutting results are up to the standards.
19. Nozzle Inspection: The nozzle will wear out with the use due to the extreme pressure of the water. Inspect the nozzle regularly and change it when the wear is excessive. The manufacturer’s manual will provide detailed guidelines to change the nozzle for your particular waterjet machine.
20. Tool Path Optimisation: Use the waterjet software to optimize the tool path for the cutting process. Remove any unnecessary movement of the cutting heads. Additionally, it is better to use single-pass waterjet cutting than to use multiple passes. Extra tool movement increases abrasive usage, which builds up the operation costs of abrasive waterjet cutting. It also increases tool wear and decreases precision.
21. Test Cut: Waterjet cutting provides different results for different materials, water pressure, and various settings. Therefore, before cutting the actual part, always do a test run to find out how the machine is performing and if any variation is required.
22. HP vs. Psi: A common confusion occurs when choosing between a higher horsepower or a high pressure. A common rule of thumb is to go with a high horsepower when seeking a rapid increase in cutting speed. A high waterjet pressure will not increase cutting speed substantially, but it will increase the cutting efficiency.
23. Water Quality: Water quality can be essential in waterjet cutting. Treating the input water before feeding it into the machine is recommended. The ideal Total Dissolved Solids (TDM) of the water should be less than 100 ppm. The ideal value of silica in the water is 1 ppm. Water with poor quality will still cut the workpiece. However, it can degrade the parts of the machine at a faster rate.
24. Water Temperature: The extreme pressure used in waterjet cutting can lead to the water reaching high temperatures. This degrades the seals and other parts inside the intensifier pump. Using cool water for the cutting process can reduce this problem. The ideal temperature of water fed to the direct drive pump is 21.1° C.
If the water temperature exceeds the ideal value in a waterjet cutting system, it can have several negative impacts:
- System Damage: Higher temperatures can cause premature wear and damage to the waterjet system’s components. This is especially true for seals and other parts inside the intensifier pump, which can degrade faster under high-temperature conditions. This can lead to frequent equipment breakdowns and increased maintenance costs.
- Reduced Efficiency: The effectiveness and efficiency of the waterjet cutting process can decrease as the temperature of the water increases. High temperatures can alter the water’s properties, affecting the precision and speed of the cutting process.
- Safety Concerns: Overheating can also lead to safety issues. For instance, very high temperatures could potentially cause a fire hazard in certain situations.
25. Abrasive Flowrate: The cost of abrasive is the major operating cost in abrasive waterjet cutting. However, this does not mean you can reduce costs by lowering the abrasive flow rate. Lowering the abrasive flow rate will significantly increase other costs due to a longer cutting time. Therefore, use the best abrasive flow rate for faster and high-efficiency cutting.
26. Protection Covers: Install a protection cutter on the cutting head. A protection cutter will protect the cutting head from damaging particles in abrasive waterjet cutting. It also protects against water backsplash and debris from damaging the machine parts.
27. Cutting Laminates: Cutting of laminates always brings the risk of delamination. You can avoid this with waterjet cutting by beginning the cut from the sides instead of the middle of the workpiece.
28. Spare Parts: It is a good idea to have spare parts for various components of the waterjet cutting machine. Having spare parts will avoid any downtimes during part failure. In addition, the operator should learn the basic fixes and repairs for the machine.
29. Soundproofing: Waterjet machines can cause a lot of noise pollution. It is a good idea to use soundproofing panels on the workshop walls to avoid noise pollution in the vicinity.
30. Software Update: It is common for waterjet cutting software to get new features. You can update the software to get these features. New updates can also improve the cutting tool path movement and efficiency.
31. Correct Abrasive: Multiple abrasive size options are available in the market. A good quality abrasive will have a uniform size of the particles, resulting in a uniform cut. The smaller abrasive size will create smooth and high-quality cuts. 120 mesh abrasive can be the best fit for most requirements. However, a smaller abrasive will have a slower cutting speed.
Follow the tips above to improve the quality of your cutting operation significantly. These tips will also eliminate most problems of the waterjet machine, reducing downtime and repairs. Most of these tips are easy to incorporate into your daily waterjet cutting process.
If you have more questions or are interested in learning more about optimizing your waterjet cutting process, don’t hesitate to get in touch with our team at Techni Waterjet.
We’re always here to assist you in improving your industrial cutting operations.”