Epoxy mesh specification: bare vs coated wire diameter
A buyer asks for "18 x 14 mesh, 0.25 mm wire". Is that before or after coating? The answer changes open area and pressure drop.
Why the coating changes open area
Epoxy powder adds a layer to every wire, so the coated wire is thicker than the bare wire and the openings get smaller. For a mesh with pitches p1 and p2 and wire diameter d, open area = (p1 - d)(p2 - d) / (p1 x p2).
Example: 18 x 14 mesh has pitches of 1.411 mm and 1.814 mm. With 0.25 mm bare wire the open area is about 71%. Measured over a coating at 0.30 mm, it is about 66%. On finer meshes such as 28 x 28 or 30 x 30 the difference is larger.
How to write the specification
State the mesh count, both wire diameters, the colour and the roll size, for example: 18 x 14 mesh, 0.25 mm bare / 0.30 mm coated, black, 455 mm x 234 m. If you only know one diameter, say whether it was measured before or after coating, or send an A4 sample of the mesh you use today.
Why filter makers use epoxy coated screen
- The coating bonds every crossing, so the mesh stays square through slitting and high-speed pleating and edges do not fray into the media.
- It adds stiffness to the pleat pack and keeps pleat spacing even.
- It seals the wire against moisture and oil mist inside the filter.
See the epoxy coated screen page for the 12 standard mesh counts.
Related support media
Matching an existing epoxy mesh?
Send the mesh count, wire diameters, colour and widths, or post us an A4 sample.