Blasting process

Blasting with metal blasting media in wheel blasting systems has been a standard process for the surface treatment of metals for around 80 years, e.g.

  • blast cleaning to prepare the surface for corrosion protection coatings
  • production of surface finishes after casting operations, heat treatment and shaping
  • surface treatment for the strain-hardening of metals

Contrary to widespread opinion, blasting is not a simple, coarse process that is only dirty.

In various production processes oils, greases, release agents, etc. are used. The spreading of these contaminants in the blasting process must be avoided.

In general, contamination of the blasting shot, i.e. the actual tool in the blasting process, by oils, greases and oily or oil-like substances must be avoided. If this prerequisite is not, or not sufficiently, observed this results in a chain reaction of damaging influences and effects on the shot peening process itself and on the results of peening. The manufacturers of blasting systems therefore make very clear that no oily or greasy workpieces (the objects subjected to blasting) may be introduced to the process. The user is fundamentally aware of this, and this is also described in the operating instructions of the blasting systems.

Metal blasting media have metal surfaces just like the workpieces to be blasted. The blasting process entails permanent contact between both of these. A very intensive exchange of embedded oils and greases is therefore possible between the objects blasted and the blasting shot. Initially, the fatal result is the homogeneous distribution of these interfering substances over the entire process, like an infection. This results in the contamination of the abrasive, the workpieces subjected to blasting, the blasting system and, not least, the filter media of the filter systems.
As a result of preceding production processes, the object subjected to blasting can become contaminated with:

  • oil used as a temporary corrosion protection > more 
  • quenching oil following heat treatment
  • oil used for cutting threads
  • grease used for bending and deep drawing  > more
  • release agent spray during welding > more
  • cooling lubricants during machining
  • mould release media from pressure die casting
  • lubricants from deburring presses
  • and much more.