3 Fundamentals of press design

Sheet metal forming lines
Fig. 4.4.16 Destacker with magnetic belt for maximum blank dimensions of 2,100 �750mm,
suitable for coated and non-coated blanks
Washing
To ensure the maximum possible part quality, the blanks – particularly
those used to produce visible parts such as doors and roofs etc. – are
washed and cleaned prior to forming. The washing/cleaning process is
performed using cleaning emulsions or oils in conjunction with cleaning
brushes. The blanks are fed towards the washing machine through a
conveyor belt (Fig.4.4.22). The blank is mechanically washed in the
washing/cleaning machine by a pair of roller brushes. During this
process, the washing medium is continuously applied to the blank by
means of nozzles. Downstream from the pair of roller brushes is a pair of
squeezing rollers made of non-woven fabric. These reduce the cleaning
medium uniformly and assure that there is only a minimal residue. The
high throughfeed velocity based on the cycle rate is up to 150 m/min.
For less complex parts, subsequent lubrication can be eliminated if the
residue of the washing emulsion is sufficient for drawing, and the medium
used is suitable for this purpose.
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998
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