Removing of glass bead residues prior to further coating
If serial parts are produced components are often glass bead blasted prior to coating in order to reach an optimal surface pretreatment with regard to adhesion and cleanliness.
Partly the glass bead residues adhere very firmly to the blasted parts and the removal is difficult. Particularly in uncovered threaded bores and undercuts glass bead residues can accumulate. If, for example, residue-covered threads are coated, the consequence is that the threads are no longer smoothrunning due to the residues trapped under the coating and therefore the parts have to be reworked or disposed as rejects.
State of technology
Up to now it is tried to remove the residues by dipping the components in a solvent-containing liquid and subsequent blowing out of the parts with compressed air which, however, succeeds only partially and thus led to relatively high rejection rates.
Advantages of the low pressure hot cleaning
- The deposits in the components can be residue-free removed by using hot water.
- Good accessibility of difficult areas using different interchangeable tools (optionally available!)
- Elimination of unhealthy solvents (cost reduction - disposal Topic)
- Compared with other methods a relatively favourable investment
- With suitable cleaning agents also usable for iron phosphating (better corrosion protection by iron Ions)
- Less use of resources compared with high-pressure cleaners
- Sewage situation is reduced as well since the water can be used several weeks in the cycle (only 90 liters per filling)
- Mobile system
- Due to cycle operation and low splash effects an „in house-cleaning“ is possible; thus saving way times and way costs
- Short lead time owing to the efficient flow heater, ready for operation after approx. 60 sec.
- Moreover, the high temperature contributes to a very fast drying of the workpieces.
Since the parts would be ready for sale after coating and some other operations were already carried out like (injection) moulding, turning, milling, thread-machining substantial losses are arising very quickly!
This is why a purchase of out technology has a very short amortization period:
- With assumed reject costs of only €50,-per piece the amortization period of a 1000 SR device is already reached after only 100 pieces of less rejects!!!