More is not always better
Have you been overfeeding your machine?
How many times have you heard the saying ‘more is better’? For some things, that can certainly be true. But when it comes to the amount of garnet abrasives used in your waterjet cutting operations, it can cause an opposite effect.
Waterjet cutting machines are sophisticated pieces of equipment where various factors interplay to deliver optimal results. Among these, the garnet feed rate plays a crucial role. Contrary to what some might assume, increasing the amount of garnet does not necessarily enhance performance.
What happens when you overfeed your waterjet machine?
So, how do you know if you are overfeeding your machine?
One example is the garnet can tend to chug or come out sporadically or intermittently. Therefore, you need to set the right amount of garnet for mixing with the high-pressure water and flow perfectly through the mixing tube onto the material that it is cutting.
The Venturi Effect: How Garnet is Delivered
The way garnet flows and is introduced into the cutting head by a vacuum-like suction, caused by the high-pressure water flow is called the “Venturi effect”. The stream of water pushes through the high-pressure tubing to the cutting head and through another tube, garnet is fed and mixed with the high-pressure water in the cutting head.
The two elements then combine to go through the nozzle or mixing tube. It is the combination of both garnet and the high-pressure water that gives it the ability to cut through hard materials such as stainless steel, carbon steel, aluminium, and other specialty metals.
However, for this process to work efficiently, the garnet feed rate must be carefully calibrated. Too much garnet can disrupt the flow, causing clogs or inconsistent delivery, while too little garnet may result in inadequate cutting power.
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Getting the feed amount right
The way to measure the amount of garnet to be fed to the cutting head is through an Abrasive Regulator (AR). This unit is typically mounted on the rail of the waterjet machine, above the cutting head. Above the AR is a mini hopper, which feeds the garnet to the AR by gravity. It will usually have several settings that determine how much garnet goes to the cutting head.
Most waterjet OEMs will have a guide for standard abrasive feed amounts. While these are suggested starting points, they are not necessarily the best or most efficient. For example, for a particular setup, it might suggest a setting of 0.54kg (1.2 lbs.) of garnet per minute. To see if that is the best setting, try reducing the amount of garnet fed via the AR. Go down to 0.49 kg (1.1 lbs.) per minute, and if you are still achieving the same cut finish and edge quality, then drop down to 0.45kg (1 lb.) per minute. Continue to adjust the settings until you see a noticeable or unacceptable difference in the cut quality that you are trying to achieve.
The Benefits of Optimization
By fine-tuning the garnet feed rate, operators can often achieve faster cutting speeds and improved efficiency, all while using less abrasive material. This not only cuts costs but also enhances overall productivity, making "less is more" a guiding principle in waterjet cutting operations.
In conclusion, while it might seem intuitive to increase garnet usage for better results, the opposite is often true. Careful adjustment and monitoring of the garnet feed rate can lead to better performance, lower costs, and higher productivity—demonstrating that when it comes to waterjet cutting, more is not always better.
Speak to an Expert
Top waterjet cutting manufacturers trust GMA Garnet™ for a reason. We combine customer focus with technical expertise, and as the only company that manages the entire supply chain—from mine to machine—you can rely on us for consistent quality.
Contact us today and discover the precision and productivity that GMA Garnet™ can bring to your operations.