There are various types of abrasives available. These include garnet, staurolite, olivine, crushed glass and copper slag. A variety of brands, grades and sizes are also available. Garnet is a common abrasive for abrasive waterjet cutter use. It stabilises the cutting speed, costs, reduces silica content and mixing tube wear.
How to Determine the Quality of an Abrasive For Your Waterjet Cutter
Two sifting processes are necessary for this particular abrasive. (1) To discard large particles. (2) To discard fine particles. This ensures the particles that remain are the size you need.
How well your abrasive particle will cut depends on the sharpness. For instance, crushed garnet is sharper than garnet from the beach. The garnet from the beach resembles worn-out round beads.
Pure abrasives are important to search for. Something labelled as garnet may in essence only be 10% garnet. So this would affect your cutting results.
How well your abrasive will cut depends on its hardness. Are you cutting aluminium or something “soft”? Select an abrasive softer and more affordable than garnet. This will lower your abrasive costs and increase the life of your mixing tube.
80-mesh abrasive can be costly. Save on costs with abrasives that are more coarse or fine. Even though these might not cut as well it still might be worthwhile.
Finer abrasives might be useful to decrease the pitting on glass edging. This will mean more taper, though. A coarser abrasive may cut better but might increase the wear and tear of the mixing tube. This will create the risk of major nozzle plugging. Using a suitable, bigger mixing tube will prevent this.
Note: Be sure to change the settings in MAKE to match the abrasive you use.
You do this by adjusting the “abrasive index” and “abrasive size” values. You will find these under Setup/Pump and Nozzle Settings. You can report the actual (measured) value of the abrasive flow rate. Incorrect values create poor cutting results. The cutting model will not be able to determine: edging quality, taper, correct cutting speed, corner pass distances, piercing, etc.
Which Abrasive Should You Choose?
Barton’s garnet for waterjet applications:
This abrasive is available in High-Performance Alluvial (HPA) or High-Performance Hard Rock (HPX). Both provide various meshes for all your waterjet requirements.
Higher-mesh HPA is applicable in waterjet cutting and lower-mesh HPA for abrasive blasting. Created from superior alluvial garnet, processed to BARTON’s high standards. HPA waterjet abrasives offer amazing results, surface finishes and are affordable.
HPX’s main application is to waterjet cutting. HPX has a certain amount of breakdown and creates sharp, angular cutting edging. These sharp, angular grains cut with speed and provide excellent edging results. To adhere to BARTON’s specifications, they mine, mill and process this garnet. Extra processing steps and intricate awareness to detail during the refining stage is necessary. So, this pure garnet may be more expensive but ensures excellent cutting.
Constant management of particle size distribution will help you make the most of your waterjet cutter.