Parkinson Technologies

Why an RDW Filter is Essential to Optimizing Screen Changer Performance

Automatic, ribbon-style  continuous belt screen changers used in plastics extrusion require long filter belts that pass through the filter chamber. These belts are made up of high-tensile, stainless steel wire woven into a mesh. While it may be tempting to use lower-priced, plain-weave wire cloth filters, the reality is that these lack strength and can fail over time. The better bet? Consider using a reverse Dutch twill weave (RDW) filter belt, which is specially engineered to provide added strength and durability required for continuous belt screen changer operation.

What Exactly is RDW?

RDW is a blend of twill weaving and Dutch weaving:

  • Twill: Twill weave is created by passing the shute wire over and under the two warp wires, creating a sturdier weave. This approach allows for the use of heavier wires, resulting in an extra-strong mesh.
  • Dutch: This style of weave is produced using two different sizes of wire. Smaller wires—as small as micron size—are used in the shute direction and woven with a thicker warp wire. The smaller wires are woven tightly together, creating a very fine mesh for filtering. At the same time, the larger wire reinforces the mesh and provides added stability.
  • Dutch Twill: This is a combination of twill and Dutch style of weave. Smaller wire in the shute direction is woven over/under two thicker wire in the warp direction.
  • Reverse Dutch Twill: This style is the opposite of the Dutch twill. One thicker wire in the shute direction is woven over/under two smaller wire in the warp direction. This combination in reverse provides an extremely fine mesh with high tensile strength.

RDW technology also accommodates an ultra-fine mesh filtering cloth that’s ideal for liquid applications. RDW filter belts replace conventional extruder screen packs and can last for many months of nonstop operation, making them a reliable and cost effective choice. They’re available in roll form in custom or standard lengths—and just one belt is equivalent to several hundred screen packs.

The bottom line? The type of weave used in your filter belt matters. And the extra cost of an RDW belt is well worth the added reliability and peace of mind.

Parkinson Technologies offers a large inventory of standard meshes and sizes for high tensile RDW filter belts. Learn more.