Screen changers are hydraulic devices, which ensure the effective filtration of the plastic melted in the extrusion process (e.g. PP, PS, PE, PET, ABS) before it is intended for granulation in the pelletizing systems. The important advantage of screen changers is the ease of use, which does not require any adjustment to improve tightness and thus it provides continuing of the extrusion process in extruders.
The principle of operation of the plate filter screen changers is based on the alternating, automatic or manual use of the various replaceable filter screens, fixed on specially designed sliding plates. To pass the material through the screen meshes, the screen plate is led into the filtration chamber of the device, from where it is discharged only after heavy contamination of the screen. Increasing the mass pressure inside the filtration chamber becomes a signal for manual or using a mass pressure sensor, the automatic change of the exchangeable screen. The plate screen changers are equipped with a hydraulic aggregate and a accumulator (condenser), so that moving the screen plate does not require stopping the extruder. Heaters placed in the changer body ensure constant temperature and adequate fluidity of the filtered material.
Double piston continuous screen changer consists of two drum type filters with large area for filtration, where the filter screen is wrapped on each slide bearing bars full of small holes – the same function as the breaker plates. The piston screen changer can ensure continuous production during screen changing. It is designed with pre-filling and air vent mechanism, no air bubbles in final products. This provides constancy and stability during the extrusion production process. It works well under the high pressure 400 bar (40 MPa) not impact the high performance.
Our company also manufactures simplier in design – manual screen changers, designed for lightly contaminated materials. To our Clients, we offer as well comprehensive consultancy, technical service and spare parts. We invite you to introduce yourself with our offer of the filter screen changers involving the JC and PFWS series.