Globally wire mesh is specified by a mesh count (see below) x a wire dia (either imperial or metric). All of the other data are functions of these two variables.
The next time you order weavemesh, keep in mind the following terms associated with its manufacture and specification.
Mesh count: the number of holes per linear inch running across the width of the material x the number of holes per linear inch running the length of the material. For example:
A 20 x 20 mesh has 20 holes per linear inch running across the width of the material x 20 holes per linear inch running along the length of the material.
Mesh is not always square. For example, most insect screen is a 18 x 14 or 18 x 16 mesh.
Wire dia: Usually specified in inches or millimeters after the mesh count. For example, 20 x 20 mesh x .016” dia wire.
Clear Opening: The actual spacing in between consecutive wires. It is a function of mesh count and wire dia. Mathematically it is 1/mesh count – wire dia. Using our example from above 1/20 mesh - .016” dia wire = .034” clear opening.
Percent open area: The percent open area in mesh describes the amount of flow that will go through mesh. The higher the percentage of open area, the more something will flow through the mesh. Another way to think about it is if a product has 40% open area, it means that 60% of that product is metal or solid.
You can have mesh with small holes that has a larger percent open area than mesh with larger holes, e.g:
A 20 x 20 mesh x .016” dia wire has a .034” x .034” square clear opening with 46.2% open area.
A 6 x 6 mesh x .062” dia wire has a .104” x .104” square clear opening (much larger holes) with a 38.9% open area (smaller open area).
Mathematically (for square mesh) it is mesh count squared multiplied by clear opening squared multiplied by 100 e.g. the percent opening of a 20 x 20 mesh x .016” dia wire is: 20^2 x .034^2 x 100 = 46.24% open area.
Space cloth: Instead of mesh count, the actual spacing is specified. For example, a 2 x 2 mesh is the same as saying 1/2” x 1/2" centre to centre. A 1/2” space cloth has an actual 1/2” x 1/2" clear opening.
Shute: The wire running across the width of the mesh (short wire). Also called weft or fill wire.
Warp: The wire running through the loom parallel to the length of the roll (long wires).
In addition to the specifications above, crimps and weaves can be important when considering which mesh to use for a specific application. Crimps and weaves are generally only options on mesh 1/4” or coarser.
Plain weave: The wires simply run over and under each other.
Double Crimp: Each wire has a crimp in it.
Intermediate Crimp: There is an extra set of crimps in between each wire.
Flat (smooth) top: The crimps are only on one side of the mesh allowing the other side to be completely flat. Often used for sifting so that material can run smoothly over the flat side of the mesh.
Lock crimp: Both wires have a crimp in them approximately the size of the wire allowing the wire to “lock” together.
Finer filter cloth mesh can be separated into the following categories:
Market grade mesh: A family of mesh with heavier wire diameters than tensile bolting cloth for more strength and typically for industrial filtering applications.
Tensile bolting cloth (TBC): A family of woven wire mesh where the wire diameters are thinner than market grade wire diameters for larger percent open areas allowing for greater screen throughput.
Dutch weave: Strong fine filter cloth where the warp wires (long ones running parallel to the length) are thicker than the shute wires (short ones running across the width). There are fewer warp wires than shute wires.
The shute wires actually touch each other and the opening through the mesh is not straight through (like regular plain weave mesh). The openings slant diagonally and are the little triangles where the shute wires run over and under the thicker warp wires.
Twilled weave: The wires run over and under two wires at a time.
Reverse twilled dutch weave: Opposite of the dutch weave as there are more warp wires than shute wires and the warp wires are thinner than the shute wires. This results in the strongest filter weave mesh available.
For more information on our weavemesh capabilities and product range, give us a call today!