Screen Changers for Polymer Melt Filtration

Screen Changers for Polymer Melt Filtration can be used for Retrofit of Existing Lines. For retrofit line projects, we can offer screen changer replacing another type of screen changer to meet the requirement of existing line.

Screen Changers for Polymer Melt Filtration:
Because the footprint of a screen changer is almost always smaller than that of any other type of screen changer that it is replacing, various factors are taken into consideration when designing the adapters required to fit the screen changer into an existing line:
Optimizing the flow channel diameter and length for minimal pressure drop
Maintaining the shortest distance between the screw tip and the breaker plate to minimize polymer inventory and stagnation
Whether or not there is an existing screw tip extension
Whether or not there is the possibility of moving existing equipment to shorten length of flow channels
In instances where the customer does not wish to move any existing equipment, the adapters are designed to compensate for the smaller footprint of the screen changer.

Advantages of a Screw Tip Extension:
Screen changers can be installed in an extrusion line with or without a screw tip extension.
The drawings below illustrate both solutions.
If there is no screw tip extension, a reduced flow canal is normally used to minimize the polymer inventory as much as possible.

Whenever possible, a screw tip extension is strongly recommended since it has the following advantages:
Polymer degradation is eliminated as a result of uniform velocity across the section of the material between the tip of the extruder screw and the filtration screen
The color change-over time period is reduced due to low polymer inventory between the tip of the extruder screw and the filtration screen.
The following drawings are representative of the most typical ways in which our Screen Changers for Polymer Melt Filtration can be retro-fitted into existing lines.