Belt filter-automatic mesh belt screen changer/ extrusion melt filter This kind of extrusion melt filter consists of the main body of the screen changer, the heating system , the cooling system , and the electrical controlling box. and this kind of screen changer can be controlled by -timer -pressure sensor - manual 1, when the material is virgin material , and the pressure is stablitity, under this case we can control the screen changer by the timer. for example, preset the screen changer inter