Our tips for choosing the right abrasive media for maximum affect
Choosing the right abrasive media for your surface preparation is vital to do work more effective. With the right choice, you can significantly reduce the cost of consumption of abrasives and ensure longer life of blasting equipment. Different media types have different characteristics, and create different surface profiles. The more you know about your application, the more accurately you can determine how long you can use some abrasive.
The effect achieved on the surface is influenced by three factors:
Hardness: Determines the ability to remove the coating from the treated surface. Harder abrasives are more aggressive. Hardness of abrasive is measured using a Mohs scale.
Shape: Abrasive media with sharp edges, when applied to the machined surface, removes applied layers faster than round media.
Size: Larger particles create more impact force, which results in two different effects. Larger abrasives achieve faster removal of the applied layers and more rough surface treatment.
How to blast faster?
Choose the smallest media grain size.
How to reduce the wear of blasting equipment ?
Choose the least aggressive media, which will be suitable for your sandblasting. This will help you to lower costs of your equipment maintenance. Find the lowest blast pressure, which will offer you the benefits of energy sevings.
Recycle abrasive media in Blast cabinets for maximum efficiency
For portable sandblasting and outdoor blasting, the used media is difficult to collect and reuse, so that media generally gets disposed, but if you’re using blast cabinets recycle process can happen. Number of recycles depends on many variables factors which can extend or shorten any abrasive recycle rate:
- Hardness of the abrasive We can measure hardness by Mohs or mineral scale. Recycling rates dependes of the hardness of your apllication. Aluminum will have a higher rate of abrasive recycling, and heat treated steel will have a shorter recycling rate.
- The type of abrasive delivery used. Pressure blasting or injector blasting creates very different rates of abrasive at the same blasting pressure, which affects how many times the abrasive can be reused.
- Amount of CFM and blasting pressure used with any delivery type, cubic feet of air per minute used with the delivery type and blasting pressure will determine frictional heat that is constantly changing. Blasting pressure used is very different between direct pressure and siphon delivery. At 80 psi using siphon delivery, beads will bounce off the part. Using direct pressure delivery at 80 psi will turn the beads into dust by exceeding maximum impact velocity. Many people don’t understand pressure delivery doubles the abrasive velocity at any specific pressure.
- Starting size of the abrasive used, measured in mesh or grit size, larger abrasives recycle more times and can be used longer as they wear to a finer size.
- Efficiency of the abrasive separator reclaimer used to remove the dust and spent abrasive and return usable back to the stored abrasive volume.
- Distance of the blasting nozzle to the part, which affects the maximum impact velocity and the frictional heat created.
- The volume of abrasive being delivered in pounds per minute also effects frictional heat created, more heat can shorten the number of times abrasive can be used… this is apparent with walnut shells or plastic abrasives.
- Volume of abrasive inside the machine does not affect the actual recycles but does affect the time before you reach maximum recycles. Having a smaller gas tank does not affect mileage but does affect how many times you need to stop for gas.
Optimise flow of the media through the nozzle
Too little flow gives poor productivity, high flow can causes clogging and slower speed.
Shorten the blasting cycle
A worn blast nozzle will result in reduced media velocity, which in turn will increase cycle times. Check nozzle condition regularly and replace when the bore has increased by 20%.
Prevent sticking of the abrasive
Control the moisture and oil of the compressor from entering to the blast pipe.
For all your surface finishing solutions and selecting the best abrasive for your application, our technical engineers will help you with more information!