Wednesday, June 23, 2010

Cutting Wire Mesh

Written By Mark Batson Baril

This brief and right to the point question came up during the Fall 2000 IADD Association meeting in Vancouver. Should Wire Mesh be die cut or laser cut into unusual shapes?

Well it just so happens that a recent job required an in-depth investigation of this very subject. The answer, as is almost always the case, lies in the details of the job at hand. The main details to consider with this type of cutting project are these:

Type of Material and the Tooling - Wire mesh or screen comes in a large variety of different material types. Everything from hard stainless steel to light duty aluminum are included in the category "wire mesh." Thicknesses can range from a micro-wire of only a few thousandths of an inch to mesh used to screen out rocks for landscaping which can be just about as thick as you can imagine.

When I think of diecutting I automatically think of steel rule dies, forged tools and matched metal tooling. During the research I found that companies are using steel rule dies and forged dies to cut wire mesh, in stainless steel, up to wire diameters of .0625" (1.6mm). This does raise some questions of die-life, or maybe we should call it die-death! Even with some sophisticated coatings, it's tough to find a rule that is much harder than a 60RC and steel rule has the problem that all of it's cutting power is concentrated in the cutting edge. The most common problem with cutting the harder and thicker meshes is not with bending or failing of the rule but is with chipping of the tip of the blade. The steel rule die is great for mesh that is softer than the rule and/or where the quantities are very small. In thicker and harder meshes, no matter the quantity, it really makes no sense at all to use the steel rule or forged die.

Laser cutting or hard tooling is the answer in these more extreme cases. Long run aluminum jobs can run well on steel rule dies but most stainless and other steels are best left for other types of dies or other types of cutting.

Matched Metal tooling is a great way to cut most types of wire mesh. Although the cutting edge of a matched metal tool can experience the same chipping a steel rule die does, there is less of this tendency and the cut edge results of the part will tend to be excellent. Depending on the type of mesh to be cut and the type of press you are cutting with, surprisingly good quality and good running speeds can be achieved with hard tooling. The one disadvantage is the high tooling cost and this may be one good reason to go with laser cutting if the quantity you need is low. If it's a long running job, and the equipment is available, using a matched metal tool will result in far fewer headaches than dealing with a steel rule die or the laser cutter. In some situations wire mesh is being used as screening for a medical device or other high end product and good edge quality far outweighs any other consideration. In this case the sky becomes the limit on the method used, no matter the quantity needed. In most of these cases, the matched metal tool will be the best method.

Quantity to be Cut and Repeat Orders - When we die cut, we are typically dealing with a substantial quantity of parts that need to be produced. The main reason this is true is SPEED. Given a diecuttable product, no other cutting method can beat diecutting for processing speed - and it doesn't matter how many head laser you have! In making the decision on laser vs. die cutting or steel rule die vs. matched metal tool, the total quantity over the course of the life of the project has one heck of a big influence. Laser cutting has the advantage when the material is too thick and/or hard to be cut with a die, and/or the quantity needed is very small - less than 1,000 parts may be a good starting point.

Combine the quantity factor with the type of material factor, and the edge quality factor, and you will be closing in on the perfect cutting method. In the case we were involved with, the parts were produced using a male/female set-up by a company that stocks thousands of different tools specifically made to cut stainless steel mesh/screen. This company also produces the mesh! Once the contact was made the choice became easy as there was no tooling charge and we were able to reach the quantity minimums with no problem even though the run was very small - only 500 parts total. The quality of the cut was perfect and the question of using an alternative method was ruled out. It won't always be so obvious, especially when the shape is a bit on the unusual side or the material is on the edge of being diecuttable. All-in-all this question is a very open ended one with lots of room for discussion of details. This makes it hard to answer with absolute definition, but will make it an interesting and fun job to tackle when it comes into your shop.

3 comments:

  1. Wire meshes are had less diameter compared to the other metal cutting by the tools. So we can use less expensive tools for cutting wire mesh.
    Wire Mesh Manufacturer

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