PSI-Polymer Systems

Low Delta-P Breaker Plate Options

Breaker Plate for Polymer Extrusion Screen Changer Melt Filter
Breaker Plate for Polymer Extrusion Screen Changer Melt Filter
Class 3 Breaker Plate

Get More from Your Process

Breaker plate design is a key factor for production run times between screen changes.  Every process has a high pressure limit defined either by the extruder or the yield strength of the screen pack.  Starting (clean screen) pressure drop defines the low end of the process pressure window. Since screen micron rating and related wire diameters are generally standardized, when working with a defined filtration level, the remaining variable for reducing pressure drop is the diameter of the holes in the breaker plate.

Efficient breaker plate design balances open area and yield strength to minimize pressure drop. For most polymers and adhesives processed through screen changers, the industry standard (Class 2) breaker plate hole size works well.  However, for high viscosity, fractional melt materials, the typical hole diameter generates a high pressure drop.  This reduces the pressure window and corresponding run time available for a given screen pack and results in more frequent screen changes.

To reduce pressure-drop for these materials and add run time between screen changes, PSI offers Class 3 and Class 4 breaker plates, each having successively larger holes than the standard Class 2 plate.  The Class 2 holes are ideally sized to support a 20-mesh screen.  The larger diameter of the Class 3 & 4 holes use a Super Plate or a 10 mesh support screen for the finer filter screens.

Available for:

  • CSC (continuous) and DSC (discontinuous) bolt-type screen changers
  • MSC (manual) slide plate screen changers

Example

  • Material:         HDPE
  • Melt Flow:      HLMI 5 fractional melt
  • Viscosity        2413 Pa·s @ 100 Sec-1 / 340 Pa·s @ 1000 Sec-1
  • Rate:              3,000 PPH
  • Screen size:  200mm diameter
  • Note:             Below calculations shown for delta-P across one filter only

Delta-P calculation – 200 mm breaker plate

  • Class:                        Class 2      Class 3       Class 4
  • BP only                           994          415             237
  • BP/20 Mesh                  1152          566             395
  • BP/20/60 Mesh             1508          908             752

Availability:

  • Class 2 & 3: Breaker plates up to 125 mm
  • Class 2,3 & 4: Breaker plates 148 mm and above
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