Every loaded blade rod is consists of 400 pieces of blades which around 25cm tall. The blasting nozzle vertical height different is just about 10 cm. The nozzle will blast the blade rod from the top till bottom in 10 seconds takt time. Then the blade rod will rotate to another blast nozzle to repeat the process. This would obtain a compromise that all blades are totally remove burrs.
Even at this stage we found that the blast blades contain a lot of abrasive material. This will affect the result of washing process. After study this incident, we had decided to add in another sequence before this sand blast end. This sequence not only won't affect the result of washing, it will also reduce the unwanted abrasives that remain on blades. We implemented air curtain compressed air blow. To build additional air compressed curtain on the both side of blast rod in a different room from blasting room.
The nozzles distance with work pieces are designed very close. It is just a 15 cm distance from the nozzles. We all know that the blast force is very powerful. To avoid a direct blast on blades, we had offset the nozzles header from direct blast toward blade tips. This is one of the risk analysis had made and quality procurement action taken.
As a result, we had overcome the unexpected problems. By implementing V shape diversified system and installing additional compressed air curtain to remove burrs and exceed abrasive on blades. We had also offset the nozzle head to avoid direct blast on product due to risk of having damage blade tips.