To inspect dies properly, especially for smaller imperfections, dies have to be cleaned after the caustic soda dip stage.
Wet blasting is more effective at cleaning extrusion dies than other surface finishing process. There are several reasons for this:
- Wet blasting is highly effective at removing all caustic trace and residual aluminium after the caustic soda dip operation because of the abrasive action of the wet blast slurry, combined with additional degreasers and inhibitors.
- Unlike dry blasting, dies do not have to be dry from the caustic soda dip before wet blasting.
- Wet blasting is sensitive enough to polish the critical bearing faces without damage and thanks to the cushioning effect of water, it does this without producing any changes to the geometry of the die profile or surface roughness.
- In the wet blasting process there is no need to worry about damaging the edges, which can happen with aggressive shot or wheel blasting.
- Wet blasting is particularly good at cleaning complex profiles right down to the baring surface thanks to the lubricating action of the abrasive flow.
- Because of the effectiveness of wet blasting some users can reduce the time needed in the caustic soda dip or the concentration of caustic soda dip itself can potentially be reduced.
Wet blasted (or vapor blasting, or vapour blasting, or aqua blasting to give it its other names) dies are left extremely clean making inspection and correction significantly quicker and more accurate. We would typically recommend an abrasive mixture of glass beads and aluminum oxide for speed and final finish. As a result, die correction is done to a much greater degree of accuracy, production runs are longer and there is less chance of failure and dies being pulled. The resulting return on investment (ROI) due to reduced inspection time and increased uptime is impressive.
