Membrane screens


One of the characteristics of the polyurethane screens system is the ability of the sorting area to oscillate in a vertical direction, in dependence on the movement of the sorter. This phenomenon, characterized by the fact that the screen area has apart from a consistent movement with the whole sorter its own oscillating movement, is called the spring-board effect and is the most effective feature of membrane screens. The thin membrane is stretched into the inserted steel welded frame, cast in the hard polyurethane on the circumference and in the spots of the transversal ribs and it oscillates when sorting in a vertical direction. Thus the sorted material permanently goes up and the screen is cleaned. Because of this principle the membrane screen system is recommended for sorting extremely precisely fine powdery material, which is difficult to sort. The screen is subject to overload and therefore it is recommended that the material layer is kept to the maximum of approx. 3 sizes of gran.



Welded steel frame covered by an A-type polyurethane mixture with 85 Shore hardness and a clamped membrane with 60 - 87 Shore hardnesss. It can be also deliverred without a frame as a membrane screen with a special fixing for the screen machine BIVITEC, LIWELL, ...


Assembly instructions:

To install membrane screens manufactured in the same way as the ADAPT system, the same principles detailed in the previous chapters are valid, i. e. individual structure elements are mounted into the sorter with adaptation ledges. As for the installation of crosswise or lengthwise tensioned areas, all the principles for tensioning harp screens are valid, i. e. welts are used for tensioning. The supporting beams must be built-in with the rise of 18 mm per 1 m and must be covered in rubber sections. The screen is not punched at the place of contact with a beam. The special clamping system for membrane polyurethane screens, which is a part of the sorter construction, includes mainly HEIN, LEHMANN LIWELL and BINDER - BiVTEC sorters.


Size of mesh:

Meshes can be square, circular or oval. The usual dimensions of the mesh ranges from 2 to 40 mm. The meshes are punched into the membrane and can be made within the given range according to the sorting requirements as well as in the requested form and orientation.


Thickness of screen:

30 mm total height of modular systems, the thickness of the membrane is 3 - 5 mm



polyurethane elastomer type D 15/90



a) only 300 x 1000 mm segments are supplied as a sectional system

b) after consultation with the supplier and under certain conditions, the screen area can be supplied tensioned in a crosswise or lengthwise direction

c) independent membranes with a width of 200 - 360 mm and length of 1500 - 2500 mm are produced to the order according to the type of the sorter. The screen has mounting holes punched at the edges.