Hmm, the shear values are influenced by various factors. First, the shape of the connecting zone (groove) must be correct. In the crimping process, the quality of the knurling plays the most important role. This in turn depends on the quality of the knurling wheels and the correct setting of the knurling machine. The rolling force also has an influence. Here the ideal average values must be found. Too little rolling force may not be sufficient to close the hammer properly. Too much force can destroy the knurls and thus counteract an increase in the shear strength.
In most cases, the performance of a complete insulation system is limited by external influences. Time studies show that in particular the supply and removal of the material is often solved very unfavourably. Often, the logistics are not properly handled, so operators have to wait for material for the next job.
At the moment there is only one way to check the knurling. By using a suitable magnifying glass, you can visually check the shape and depth of the knurls.
Basically, there is no profile shape that cannot be rolled on our machines. It is only necessary to ensure that sufficient space is left outside the insulating strips within the range of the hammer to allow the roller disks to reach in. For very complex profiles, additional tools may have to be used to guide the profile properly through the machines. If it is necessary to design a profile in such a way that the entrance to the insulating strips can also be used, it is possible to change to rolling from the inside. We also offer the necessary machine in our product range; however, connecting such profiles is time-consuming.
There is no general limit to the rolling force; this depends on the profile shape and wall thickness of the profile. Too much force can irreversibly deform the profile. In addition, it can destroy the tips of the knurling and thus counteract an increase in shear strength.