Perforated sheet is used to screen something like plastic pellets, candies or almonds and remove impurities. The pattern of the sheet is blank at the periphery which helps to remove long shaped particles. Compare to wire mesh using a perforated sheet is much better in such an application because it gives longer life and accurate screening. It also used to give support of the de-blinding kit. Because of its smooth surface movement of the ball tray is very easy and gives strong support to the bottom of it.