In the process of manufacturing stamping and forming parts with the corresponding presses, the disposal of the occured scrap web can often be a challenge. If the material allows to coil the scrap web, then often the easiest way to dispose the scrap web is to coil it directly after the press onto a hasp if there is enough space for such an additional device.
When coiling of the material is not possible, then a scrap shear has to cut the scrap web behind the press to avoid enormous disposal costs. Realizing a scrap shear with its own drive unit is a complex task because of very high press stroke rates and high press feed rates.
A scrap shear may not take more time for a cut than the operating time of the press durates unless it is possible to de-couple the process via a "hump-table" in front of the shear. The latter often fails because of the material thickness respectively the little elasticity of the band. Continuous stroke numbers of the shear of 250 1/min are therefore not unusual.
Another challenge is the feeding of the unstable scrap web especially at high press feeding rates. If for example the scrap web is pushed 900mm forward after every press stroke, a single cut is most likely not sufficient enough to stay in the maximum scrap dimensions. In such a case it has to be realized with a double cutting shear which is able to make two cuts in one stroke simultaneously. The problem here is not the double cut but rather the guiding through of the unstable crap web through both of the blades of the shear. It has to be prevented that the crap web is getting caught thus jamming the band in the press.