Micron Mesh Filters – Part Three: Manufacturing Filtration Wire Mesh Components for Lowest Cost of Operation
In part three we separate the possible from the practical and discuss manufacturability or forming of the wire mesh media to meet the shape of the filter design, and how it can affect the filtration properties of the wire mesh. As a recap of our series, in part 1, we discussed different mesh weaves and their roles in filter design and in part two, we looked at factors that degrade micron wire mesh performance and ways to design for filter durability.
When using wire mesh and wire cloth to design filters for manufacturability, considering the following areas is the easiest path to manufacturing functional, durable, and cost-effective products.
- Specified Tolerances
Is the Material Suitable for the Intended Processing?
Processing – that is how easy or difficult it will be to turn a roll of woven wire mesh into a filter, and how many steps that will take, is key to filter design and mesh selection. There are innumerable ways that micron wire mesh can be shaped and mounted, so there is no comprehensive list of steps or a flow chart to follow to maximize manufacturability. However, there are a few areas to consider.
- The woven mesh strength is important. A paper-thin micron mesh screen will need to be supported.
- Exclude any micron mesh that will not meet your micron retention requirements.
- Select a mesh that will hold up to whatever forming and treating processes you will use to shape the filter mesh. If you press it into a shape there will be some deformity of the open area. Is that ok? If the pleat has too sharp a crease will the mesh tear?
- How will the mesh be mounted and what edge treatments are needed in preparation for that? Epoxy, welding, over-molding, crimping?
- Will the mesh need heat treating to remove the possibility of the woven wire cold working during the forming process?
- If multiple layers of mesh are sintered, how can the mesh be formed without delaminating it?
- Who will build the filter? Will you cut, form, and assemble all components in-house, or outsource some or all of the manufacturing so you can focus on the engineering?
Is the Wire Mesh Available?
Mesh screen manufacturers publish tables of all the products they are capable of weaving. What these tables do not often indicate, however, is how common those micron meshes are.
|Example : One mesh customer picked a #43 mesh for their project. It was listed on the data table on the brochure and could be woven, but was not a stock item on the shelves in any warehouse. The customer only needed 30 square feet and the mill had a 900 square foot minimum order with a 6–8-week lead time. Would that cost and delay really be worth it or would considering a #42 or #45 mesh already in stock, without minimum order, and ready to ship that day accomplish the same task for a fraction of the cost?|
With custom weaving, sourcing nearly any mesh is possible. Collaboration with a mesh expert will help you source one that is the most practical for your application.
Is the Wire Mesh in Compliance?
Looking at any data table from a mesh supplier, there are many columns of data. Particle retention size is important to filter manufacturers, so mesh producers publish this data alongside the specifications on warp and shute diameter and spacing.
For some mesh customers purchasing for medical, military, or aerospace applications, their purchasing choices are constrained by regulations that have been determined by committees representing multiple agencies with prohibitively long approval processes.
|Same Micron rating, Same Weave Type – what can be different? PZ80, a popular Reverse Dutch 80-micron filtration mesh is produced differently by two weavers. One weaves a 128×24 mesh, while the other a 130×22 mesh. Both have the same 80-micron particle retention but got there by using different wire diameters and number of wires. While that might seem like a distinction without a difference, if the mesh count is also called out on a specification, one manufacturer may not comply.|
Deviating from these approved specifications is not an option, and close enough is not good enough for QC compliance. Another example is if the regulation requires a woven wire mesh with a wire diameter of 0.009”. A published diameter of 0.0093” might not pass quality control due to the addition of one extra significant figure.
In these cases, the obstacle to manufacturability might be that the samples from which the regulators derived their specifications were not representative of the minor variations between mesh manufacturers. This is an instance where the path of least resistance, and likely the only path, is to find the exact same mesh from the same manufacturer.
Is the Material Specified to Appropriate Tolerance?
Conversely, inexperienced engineers might specify an unnecessary or unrealistic level of precision, either in the mesh itself, or in some other part of the filter design, under the impression that the tightest tolerances possible are always best. Consider just how significant your significant figures really are. They might price you out of manufacturability not because of an arduously long review process, but simply due to the number of digits on a calculator screen.
Some mesh suppliers offer data tables that list each mesh’s absolute and nominal particle retention. An inexperienced engineer may try to get these match as closely as possible. While it is true that there are instances where this can be valuable, mesh experts often find that fixation on having them in perfect agreement can steer buyers toward higher costs and longer lead times and away from more cost effective, readily available, and functionally equivalent mesh products.
Additionally, once a mesh product has been deformed or subjected to pressure loads, the absolute measurement is likely to vary from the published data. Taking a filter from concept to production line includes a lot of decisions. The best way to be sure the mesh one chooses is a pragmatic choice and not a problematic one is to consult with a mesh expert.
Gerard Daniel’s Expertise
At Gerard Daniel, we’ve been sourcing, weaving, and distributing woven wire mesh for 70 years and stock the largest range of inventory in North America. Our application engineers use their deep expertise in woven mesh and components to develop the most effective solution, collaborating with your design, development, and production teams to ensure the lowest cost to manufacture. Please reach out if you would like to learn more about our capabilities.