Harp Screens and Flex Mats: Improving Throughput in Difficult to Screen Materials
At ScreenProducts, screening performance comes down to one thing: if your screens underperform, your plant underperforms. Harp screens and Flex-Mats are built to keep throughput up on materials that blind or peg conventional weaves – wet, sticky, or fine feed.
What Is a Harp Screen?
Harp weave is one of ScreenProducts’ standard woven wire weaves, alongside plain, intermediate, lock crimp, flat top and slotted. The wires run parallel under tension rather than interlocking, so each wire flexes independently – giving the screen a natural self-cleaning action. Harp weave screens are supplied in high carbon spring steel, stainless steel 304, or stainless steel 316.
Harp Screens vs Flex Mats
Both are harp weaves, but how they’re bound changes everything:
- Binding – traditional harp screens use wire (usually two or three wires); Flex-Mats use bonded 90 Shore polyurethane strips instead
- Flat surface – wire binding runs up and over the mesh, lifting it near the aperture edge; PU bands sit flush for a fully flat screening surface
- Failure mode – one broken binding wire and a traditional harp screen falls apart; a bonded PU band doesn’t fail the same way
- Open area – traditional harp binding wire pitch tops out around 150mm – 180mm; Flex-Mats can run 300mm – 350mm, for significantly more open area
- Panel joins – Flex-Mats allow a PU overlap between panels; traditional harp screens need a wire finish instead
- Compatibility – Flex-Mats work on both static and mobile screening units
- Cost – Flex-Mats cost more upfront, but a traditional harp screen may need replacing two or three times over the working life of a single Flex-Mat
Engineering the EaziFlow Panel
Flex-Mats are manufactured using high-quality 90 Shore polyurethane. Camber bar and PU band placement is what makes an EaziFlow panel perform:
- Main PU wear bands sit directly above the camber bars
- Camber bar bands are cast at 25mm, intermediate bands at 15mm
- Reinforced PU is added along the hook edge, the first point of wear
- Two weave types: Square harp (2mm aperture and above), Tri harp (1.1mm aperture and above)
Open Area Drives Throughput
Screening efficiency comes down to open area – more holes means material passes through faster, with less abrasive wear on the screen. Wire that’s too thick for the aperture extends screen life but shrinks open area, so throughput drops instead of rising. The right ratio depends on feed size and material density – ScreenProducts’ full reference table is available on request.
