HOW A SANDBLASTING MACHINE WORKS
This training document will explain how a Sandblasting machine works and advise on how to safely operate the different parts involved.
Sandblasting Engraving is achieved by propelling an abrasive medium such as aluminium oxide onto the surface of the product to be etched, under compressed air. Wherever the abrasive makes contact with a surface, it subsequently erodes that area of surface.
THE EXTRACTION SYSTEM
The extraction system is designed to extract broken down dust particles (aluminium oxide dust particles) and recycles the blasting media for reuse.
THE AIRFLOW CURTAIN
The air flow curtain provides air flow inside the sandblasting cabinet viewing glass so that the operator can see the item being blasted.
THE DOOR SEAL
The door seal is comprised of a rubber seal that ensures dust extraction is strong and also keeps the abrasive media and dust inside the cabinet.
THE BLASTING NOZZLE
Normally made from Carbide which is a very tough material, it allows the operator to control the jet of air and abrasive media when sandblasting a substrate.
Normally abrasive media is added from the top of the pressure pot whilst the pot is not pressurised. It is recommended not to top up but rather discard old oxide and empty half a bag (approx. 12kg) into the pot.
PRESSURISING THE POT
The pressure pot is pressurised by pushing the Pressure Pot Closure Lever forward (normally on the left hand side of the unit). Hold in place whilst the Air Inlet Valve is open (normally on the right hand side of the unit) -- which allows the air to come in from the compressor.
SETTING THE BLAST FLOW
For efficient blasting the air and abrasive need to be mixed at the correct ratio. Poor etching occurs with too much abrasive and not enough force (air) -- and vice versa.
Correct mix -- set Abrasive Flow Valve to 7 O’clock (45 degrees), and the Air Flow Valve to 7 O’clock (degrees).
RATTLING THE FILTER
The filter bags at the back to the unit collect the broken down blasting media. On a daily basis use the Shaker Lever to shake the filter bags, you will see the dust particles drop into the plastic bag used to collect the dust.
Not shaking the lever daily will result in inefficient functioning of the dust collection.
KEEPING THE DUST CONTAINED
For health and safety we need to contain the dust inside the cabinet. This is done in the following ways:
- After blasting is complete, leave the unit running to extract all the dust in the cabinet prior to opening the door.
- Gently tap the door prior to opening to allow blast media to fall into the hopper.
- When dusting items with an air hose, do it inside the cabinet whilst the extraction is running.
- Wherever the abrasive makes contact with a surface under pressure, it subsequently erodes the surface it comes in contact with.
- Extraction removes Dead media from circulation.
- Ensure door seals are intact to maintain clean and safe work area.
- Air flow curtain circulates air on the viewing glass to allow you to see what you are blasting.
- The Nozzle gives you control of the blasting stream.
- Pressurising -- left lever IN and hold, open air flow.
- NEVER top up oxide, always use fresh 12kg.
- Air/Oxide setting 7 and 7.
- Rattle filter daily to maintain efficiency of the unit.
- Clean it!