It is unlikely that you haven’t witnessed the art of weaving at some point in your life, as it is a process that has existed for thousands of years. From the origins of basket-weaving to the introduction of mechanical looms in the Industrial Revolution to present day high-speed weaving looms, the concept is primarily the same.
The demand for “woven wire goods” in the mining and pulp industries in the late 17th century drove the development of the modern weaving loom. Today, there is an endless list of applications for woven wire mesh. Filtration, particle analysis, plastic extrusion, aggregate screening, and architectural mesh are just a handful of examples of where we see woven wire mesh used in our everyday lives.
W.S. Tyler has been a leading supplier of woven wire mesh for over 140 years and has a team of experts that have a comprehensive understanding of the weaving process, inside and out.
This article will provide insight into what woven wire mesh is, what a weaving loom is, how to prepare a loom, what the weaving process looks like, and an understanding of the capabilities of modern weaving technology.
Woven wire mesh is best described as a pre-determined number of metal wires interlaced together to form a roll or sheet of wire cloth that upholds a specific pattern. When weaving mesh, parameters such as wire diameter, opening (aperture) size, micron rating, weave pattern, width, and length can be customized to your specific needs.
Wire mesh is generally manufactured in one of two ways. Mesh that has a larger wire diameter, or where the aspect ratio (ratio between the wire diameter and the opening size) is either too large or too small, requires a wire that is “pre-crimped”. In this process, the wire (or wires) is crimped prior to the weaving process. For finer wires and where the aspect ratio permits, the wires are crimped during the weaving process. This article will be focusing on a regular non-crimped weave.
A weaving loom is a piece of machinery used to weave individual metallic wires to form a roll of woven wire mesh. Traditionally, looms are developed to weave 48”, 60” or 72” mesh rolls but more recently 98” and even wider have become available.
Generally, a loom consists of a warp beam, a predetermined number of heddle frames, a reed, a rapier to transport the weft wire, and a front take-up mechanism.
The warp wires are the wires that run lengthwise with the cloth during the weaving process.
The weft (or shute) wires are the wires that run across the width of the cloth during the weaving process.
The warp beam is a cylindrical drum that is wound with a specific number and length of warp wires that have yet to be woven and is located in the back of the loom. The length and amount of wires are both determined prior to the winding process.
So, for example, a 48-inch loom producing a 10 mesh cloth would need a beam with 480 wires wound on it. The length of each wire would depend on the demand of that specific customer but would typically range from 300 ft to 6000 ft. It should be noted that long production runs can significantly reduce the ratio of set-up time vs. run-time and subsequently reduce the cost of the woven wire product.
A heddle frame is a medium used to separate the individual wires being fed by the warp beam. Each loom contains at least two heddle frames. In a loom that uses two heddle frames, heddle frame 1 will initially lift half of the warp wires while heddle frame 2 pulls the other half down. The heddle frames change position with each insertion of a weft wire.
A rapier band is a mechanism that, during each cycle of heddle frame motions, feeds a single wire, known as a weft or shute wire, between the two sets of warp wires.
A reed is a piece of tooling that is used to hold the warp wires in the exact spacing while beating the weft wire into place.
Lastly, the finished roll of woven wire cloth is wound onto a front take-up mechanism and, depending on the weave specifications and customer requirements, is removed in increments of 100 feet up to a maximum of 1,000 feet.
Preparing a weaving loom to produce high-quality rolls of wire mesh begins with the raw wire itself. Each wire used to produce fine wire mesh (for example 80 to 630 mesh) arrives at the weaving facility on an individual spool.
Prior to winding each wire onto a warp beam, these spools are placed onto a rack system, referred to as a creel. The creel holds each of the spools in
Once the spools are loaded onto the creel, an operator (beamer) will take a set amount of wires and, once they have arranged each wire through a set of tensioning rollers and a beaming reed, will wind a specific number of turns onto the warp beam. The wound beam is then moved to a threading station where the individual wires are threaded through the heddle frames and the reed.
In a two-frame heddle frame system, the first wire of the beam is placed in the first heddle in heddle frame #1, the second wire is placed in the first heddle in heddle frame #2, the third wire is placed in the second wire heddle in heddle frame #1, and so on. This process is repeated until each and every wire on the beam has been threaded through a heddle frame.
The next step in the threading process is to take the wires from the heddle frame and thread them through the reed. Missing just one opening or placing two wires in one opening will compromise the technical integrity of the mesh. It is not difficult to imagine the precision and patience that is required to ensure that each wire on a 630-mesh beam is placed into the exact reed opening. That’s more than 30,000 wires on a 48” beam.
The quality of the reed determines the accuracy of the opening in the weft or shute direction. Obviously, the manufacturing tolerance of each reed opening will dictate the final position of the warp wire that it is holding. It is therefore critical that this piece of tooling is sourced from a high-quality supplier.
In recent years, and with the introduction of modern technology to the weaving loom (electronics, servo-drives, load-cells, etc.), there has been significant improvements in the accuracy of the position of the weft wire. It used to be generally accepted that the warp wire spacing (as it was held by the reed) was more accurate than the shute wire spacing. This is no longer the case with the introduction of modern weaving looms and the latest technology. Subsequently, the leading weavers can now provide levels of mesh/opening accuracy that simply was not possible on looms that were manufactured 20 years ago.
Once the beam is wound, and the heddle frames and reed are threaded, the whole assembly is transported to a weaving loom. The setup of the loom is then completed by an experienced technician.
Once assembled, the weaving process is, for the most part, automatic and seamless.
As the loom begins, the warp beam unwinds in very small increments that could be missed with the blink of an eye. At the same time, the front take-up mechanism winds the woven cloth at the same small increment in the same direction. This simultaneous movement allows the loom to maintain a specified tension on the warp wires, which is absolutely critical when producing
high-quality cloth.
As soon as the two beams rotate, heddle frame 1 pulls half of the warp wires up while heddle frame 2 drives the other half down. At this time, a rapier, whether a two-part or one-part rapier, transports a shute wire between the two sets of warp wires. The shute wire is typically delivered from a spool of wire located at the side of the weaving loom.
Once the rapier has returned to its resting position, the reed pushes the shute wire into its final position and creates a perfect cross-section.
The reed then returns to its original position and, simultaneously, the warp beam and front take-up mechanism rotate at the same small increment, the heddle frames change position and the loom begins a new cycle. This process is repeated over and over until the entire mesh cloth is woven.
The length of time taken to weave a full beam can vary dramatically. While a 300 ft. beam of 10 mesh can be completed in a matter of hours, a 6,000 ft. beam of 630 mesh will run for several months.
It is not unusual to see weaving looms that are still in operation after decades of use. The old mechanical looms from the early twentieth century were a heavy-duty mechanical construction and were built to last.
As long as the user is performing general maintenance of the wear parts and not exceeding the capability of the loom, they are more than capable of producing acceptable quality industrial woven wire cloth.
There are hundreds of weavers across the globe that have the ability to produce high-quality woven wire cloth. Conversely, only a handful of weavers have the capability to produce the finest meshes, with the finest wires, to the highest accuracy level.
The weaving industry leaders have taken the responsibility to design, construct and build their own weaving looms. To this end, they have stayed at the forefront of the ever-increasing demands of their customer base, and developed looms capable of weaving cloth to a quality level never thought possible just 30 years ago.
This commitment has supported new and innovative weave types, such as three-dimensional filter cloth that provides significantly improved flow rates while maintaining the same filtration capabilities. The weaving knowledge and industry experience of these companies combined with the advancements and integration of modern technology, has resulted in the on-going development of weaving equipment that goes well beyond the capabilities of the old mechanical looms.
Woven wire mesh is an assortment of metallic wires intertwined with one another that form a specific pattern. In order to achieve the highest quality levels, industry leaders have developed equipment capable of meeting the ever-increasing demands of a broad customer base.
With that, the major components of a weaving loom are the warp beam, the heddle frames, the reed, the rapier, and the take-up mechanism. Each component and process play a significant role in the quality and integrity of the mesh.
With over 140 years of woven wire experience, W.S. Tyler takes pride in providing its customers with high-quality wire mesh solutions.
Download our woven wire, fabricated parts & customized filters brochure to learn more about the possibilities of woven wire mesh.
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