The screen surface is the primary working component of a screening machine, where the screening process takes place. Proper use of the screen surface is crucial for successful screening.
Screen bar.
It consists of parallel, spaced-apart round steel bars or steel rods. The size of the screen openings is determined by the width of the gaps between the bars. The bars come in a variety of cross-sectional shapes, generally larger at the top and smaller at the bottom to prevent clogging. Screen bars are typically used on fixed gratings, which are tilted with the screen surface at a 30° to 60° angle to the horizontal. The mesh size is generally larger than 50mm. Screen bars offer high mechanical strength and are easy to maintain.
Screen plate.
Screen plates are made of punched steel plates, often with circular, square, or elongated mesh holes. To reduce clogging, the mesh holes are slightly tapered, with a taper angle of approximately 7°. Screen plates offer high mechanical strength, rigidity, and a long service life, but they have a small effective screening area and are difficult to manufacture with smaller mesh sizes. Therefore, they are generally used for secondary crushing.
Screen mesh.
This is the most widely used type of screen surface. Made of woven wire, it comes in either square or rectangular apertures, with square apertures being most common. The outstanding advantage of screen mesh is its large effective screening area, which can reach 70% to 80%. The wide range of aperture sizes, from tens of microns to tens of millimeters, makes it versatile, and it is commonly used in both fine and medium crushing operations.