Spiral belts are produced by using of different technology than woven belts. Two neighbouring spiral coils in belt are connected together with monofilament yarn.
Spiral belt does not need extra seam (joint) like woven belts, because spiral coils at the both ends of the spiral belt can be connected together. Spiral seam on spiral belt is stronger and lifetime of this connection is in some applications more durable that clipper seam AISI316, which is used for woven belts. Therefore spiral belt could be a solution for applications, where woven belt with clipper seam prematurely fail.
Belt edges are standardly reinforced by strip of high mechanically resistant and flexible two component glue. High quality glue increases mechanical resistance of belt edges and holds the filling yarns strongly in fabric.
Spiral filter belts are usually made of abrasive resistant polyester.
Dewatering and filtration properties of spiral belts are related with its air permeability, which can be adjusted by inserting a suitable type of filler yarns inside the spirals. We offer spiral fabrics within the range of air permeability from 350 to 1,000 CFM.
Spiral belts are especially suitable for dewatering of fibrous material (paper sludge, pulp) and sludges with a high content of inorganic particles (e.g. mining sludge, coal, sand), but they can also be used for dewatering of good quality digested municipal sludge. If the sludge has a high content of organic particles or if it is sticky and muddy, there is a risk of spiral fabric blinding.
Benefits:
- Long service life
- Suitable especially for machines where belt deformation often occurs
- Abrasion resistant design
- No problems with the seam
- Smooth adhesive treated belt edges
- Suitable for fibrous sludges
Examples of Application:
- Dewatering of pulp and paper sludge
- Dewatering of industrial and municipal sludge in belt filter presses
- Dewatering of mining and abrasive sludge
- Thickening of sludge in gravity thickeners
- Forming belt for production of MDF boards
- Conveyor belts
Fabric Designs

MicroSpiral F
MicroSpiral F
Air permeability range: 450–900 CFM
Caliper:2.1mm
Spiral yarn diameter: 0.6mm
Spiral fabric with fine spirals and a high density of spiral yarns.

Spiral F
Spiral F
Air permeability range: 400–900 CFM
Caliper:2.5mm
Spiral yarn diameter: 0.7mm
Spiral F is a widely used spiral filter fabric with flatfiller wires. It is used in a wide range of industrial applications, including the dewatering of sludge in waste water treatment plants.

HeavySpiral F
HeavySpiral F
Air permeability range: 550–900 CFM
Caliper:3.1mm
Spiral yarn diameter: 0.9mm
Heavy-duty spiral fabric with long service life for very abrasive sludge, used for dewatering of pulp and mining sludge.
For more information please contact us here.