Screen Changer (Hydraulic Slide Type)
What is a Screen Changer?
A screen changer is a device that melts plastic scrap and filters out contaminants with a metal mesh. This ensures that the final product, pellets, are free from contaminants, providing end users who perform molding processes with reliable raw materials.
Video explanation about Screen Changer
Structure of the Screen Changer
A metal mesh is applied to a metal plate with numerous holes, commonly referred to as a ‘honeycomb’ or breaker plate. The resin that flows through the extruder passes through this metal mesh and continues on.
However, if there are contaminants, they cannot pass through the mesh and get caught, preventing them from moving further.
Over time, more and more contaminants get caught in the mesh (mesh), and eventually it clogs, preventing the resin from passing through.
Then, the blocked resin backflows and starts to ooze out from the vent (a phenomenon called “venting up”).
The operator must replace the mesh before this happens.
You can see the process of changing a screen changer in the video below.
Here, we introduce the POLYSTAR’s standard dual piston screen changer in a 3D video. We believe you will get a clear image.
With clean scrap with few contaminants, replacements are seldom necessary.
However, post-consumer scrap that has once been in the market can sometimes be so dirty that it needs to be replaced every 10 minutes.
Of course, replacing the metal mesh increases production costs, and the replacement itself takes 5-10 minutes, so processing overly dirty scrap is often not economically viable.
Comment