It is critical you maintain a balanced abrasive particle size to obtain a consistent, quality finish. When a machine is first installed it should be filled with new abrasive constituting a “working mix” of different sizes of media.
The quantity of abrasive for your machine will be advised when the machine is first installed; as with all shot blasting processes though, abrasive will wear and as a result the level in the storage hopper will drop. Where you are running an aggressive process (especially with angular or irregular abrasive) this can happen quickly and so it is vital you are constantly checking the level. Abrasive levels can also drop as a result of carrying media out on the parts being blast so regular checks are essential.
Should the level drop you will effectively ‘starve’ the blast wheels and as a consequence process times will increase, your finish quality will deteriorate and your processing costs will escalate accordingly.
Similarly be careful of the amount of media being introduced each time as it is possible to ‘flood’ the machine. An automatic replenishing system can overcome this. Correct media levels will be set when the machine is set up for the first time. This should be recorded and referred to on an ongoing basis.
For more information on Shot Blasting please visit www.rosler.com
Post written by
Shot Blasting Technical Manager