An initial preload pressure of 1 MPa between the beams and the drum was achieved through a mounting interference. This interference is mainly absorbed by the elastic deformation of the polypropylene beams. Additionally, the product thickness between the beams and the drum increases the initial preload. The model predicts a quite linear correlation (R2 = 0.9887, p < 0.01) between the thickness of the product and the pressure on the drum ( Fig. 3).