Mass finishing/vibratory machines are some of the easiest machine tools to use.
As a result sometimes operators can get in to the habit of just turning them on each day and ignoring simple operating and maintenance rules. Here are 9 mistakes people make which you can avoid to help you get the most from your equipment:
Sometimes things change … including the starting condition of your component parts to be blasted. Worn tooling, changes in materials or investment in new manufacturing methods can result in you no longer getting the result from your shot blasting machine.
A number of factors can affect blast wheel operating efficiently, some of which may not be obvious until your shot blast machine is stripped down and/or serviced. Monitoring the amps the blast wheels are pulling can allow you to see that something needs attention.
Every time you use your shot blast machine, wear will take place on anything the abrasive comes into contact with. In the blast wheel itself, over a given period this will result in changes that will affect your blast pattern (how and where the abrasive is thrown).
Wear parts in your shot blast machine are the: blades/vanes, control cage, impellor and side / top wear plates in the blast wheel(s) themselves and the wear protection plates in the blast zone (in the area calculated to have the most impact from the abrasive when it is thrown from the wheel).
The blast media in your shot blast machine is provided as a “working mix” to achieve your required process. After a period of blast time it will not perform to the required standard as it has now reduced in size. If it remains in your machine, you can expect to increase the wear and degradation of the blast wheel components together with the recovery system of your machine. It will increase production times and power consumption because of the longer blast duration required. An efficient separator will remove unwanted contaminants and undersized media without carrying out good, usable abrasive. It is vital you regularly check the efficiency of your separator and the size at which media, fines and dust are being removed.
Just as abrasive circulates in your shot blast machine so will any contaminants that aren’t removed by screens (if fitted), by the air wash separator and/or dust collector.
When larger oversized particles are allowed to remain in the machine they can cause damage to the blast wheels (giving a high risk of blast wheel part breakage) and can affect the finish produced and process times adversely.
As abrasive is recycled and re-used within your shot blast machine it is affected by impact. It will gradually reduce in size as a result of a combination of: splintering, spalling (peeling), deformation (i.e. rounding) or smoothing (i.e. grit becoming blunt).
Irrespective of the starting size of your media in your blast machine (i.e. S110, S230, etc…) within a very short time that media will reduce in size as a result of abrasion, deformation as a result of impact (i.e. rounding) and/or fracture/splintering. This will cause a drop in the abrasive level which needs to be topped up with new media (as per tip 1).
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.