WIRE JOURNAL MAY 2018
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INTERNATIONAL www.wirenet.org
DIES
Wire Expo Update
OFFICIAL PUBLICATION OF THE WIRE ASSOCIATION INTERNATIONAL
FEATURE
Dies: an old story that still matters
Dies may have changed relatively little over the years, but that doesn’t mean that these essential industry workhorses are a given. Below, die suppliers share their thoughts on what they offer companies and the manufacturing problems they see all too often, and more.
WJI: Why should a manufacturer want to get dies from your company? The increasing demand for power, light and communication has kept high demand for wire and cable. This trend will continue as demand for reliable, efficient energy and data communications will J.S. Gupta with an assortment of dies. strengthen the wires and cables industry in the future as well. The wire and cable industry eventually needs to focus on supplying wires and cables for specific applications pertaining to the industry needs. Considering all these special requirements, the R&D team of Ajex & Turner left behind the traditional wiredrawing dies to develop its VNT Nano dies, which provide better wire surface as well as energy savings. These dies provide the best solution between economical tungsten carbide dies, which wear out quickly, and PCD dies, which last longer but are more costly. Our VNT Nano dies, which are based on high-quality carbide, have a firm coating of Nano diamond on the die surface. That enables wire plants to lower the production cost and save metal as the extremely hard diamond coating has very low friction, so the die hole sizes remain the same throughout its working life. A single VNT Nano die is equivalent to 100 carbide dies, and provides more than double the produc50 | WIRE JOURNAL INTERNATIONAL
tion of any make PCD dies for ferrous and nonferrous wires. Thus, we enable wire plants to set a high standard of wiredrawing efficiency and reductions in production costs. Our VNT Nano dies are an ideal solution for companies to achieve their goals. J.S. Gupta, CEO, Ajex & Turner.
Customers buy their dies from Esteves Group to thrive in the competitive market place by partnering with us to achieve the lowest cost to produce their wire. Our advanced engineering methods help our customers lower their cost in very big ways through optimized processes that greatly improve their throughput. Our customers value our engineered dies and die sets as a new product in the industry that has had a positive effect on their processes. Thousands of hours went into developing sophisticated software we use to design dies and die strings for any given type of wire material and drawing process. We take the wire alloy, the machine mechanics and process speeds into account to calculate precise die size sequences and die profile geometries. We’ve been proven successful where our wire dies made to these calculations result in a homogeneous material flow through the dies, minimizing wire breaks, maximizing die life, and allowing for increased process speeds. We hardly have to run trials anymore. The calculations are that good and our wire dies match those calculations that accurately. This custom engineered game changing approach is the result of Esteves Group’s long-term vision and desire to help our customers with their goals and challenges to make them thrive today and in the future. Esteves Group Sales Director Gary Kantz/Sales Director Carsten VanderPutten.
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Want to know more about die angles? Visit www.hardwired.com for a five-minute WAI educational video, “Die Angles.” Industry experts Don Young and Tom Maxwell offer tips for finding the optimal die angle for the best product quality and long die life.
Die geometry and angles: why they matter The below column is by Dr. Horace Pops, an industry consultant/guru who has made many presentations and taught numerous classes on the causes of wire breaks and surface damage. The first written documentation of a conically converging die, which was similar to the type of design currently in use throughout the wire industry, is attributed to a monk named Theophilus. It was done somewhere between 1000 to 1100 AD, but sometimes I’m wondering just how far modern wire drawing has come. Not in terms of the technology, because that has Pops made great strides, but because some people in the industry still don’t believe that the die geometry and angles really matter. That it is the stuff of eggheads. I am here to remind everyone that, yes indeed, die geometry and angles do matter. The most important feature of a proper die design is the deformation zone, which is a function of the reduction in area and the die angle. However, the die semi-angle is used in most drawing related equations instead of the total included angle, which is what many people are familiar with (typically between 6° and 15°). Those fine points aside, what matters is that wire should first make contact with the die somewhere near the middle of the reduction zone. If the approach die angle is too small or the wire is too large—i.e., a very heavy area reduction—high friction may develop and result in heating of the wire and die. Consequently, wire breaks may occur during start-up. If the approach angle is too wide, the area reduction will be too light, likely resulting in poor lubrication, excess die wear and central bursting of
the drawn wire. Definitely not good. The recommended contact point on the reduction zone is 75% to 100% of the wire diameter. Factors affecting the drawing force include the strength of the wire, resulting friction coefficient, area reduction, and die reduction angle. Although the reduction zone is the most important feature of a die, there are other important features of the die geometry. For example, the entrance bell has a flared profile and allows lubricant to enter the die with slightly increased pressure. It also compensates for slight misalignment between the wire and the die. The bearing (or land) is downstream of the drawing cone, and although it plays no part in the prior reduction in area of the wire, it does help to preserve the wire size. A bearing surface that is too large will increase the drawing stress because of friction. Finally, it is most important to have adequate blending between the aforementioned zones to reduce abrasive wear and generation of fines. Now here’s what some people just doesn’t get. Yes, a die with an entrance angle that is not optimum likely will still be able to draw wire. If you are running at a low enough speed and have optimum lubrication, the wire may not even break, but is the wire quality going to be as good as it should be? I don’t think so, and I More die content suspect customers in this issue will notice that too. The product section that follows The wire industhis feature on p. 62 includes dies try is a very comfrom companies in this section. petitive field, so That section is followed by a why anyone would technical paper, “The influence of want to cut corners the dies geometry on the drawing on the tools of the force for steel wires,” which trade, risking more starts on p. 68. problems, is a mystery to me.
MAY 2018 | 51
FEATURE
Fort Wayne Wire Die, Inc. is a third generation managed, family-owned business that just celebrated its 80th year in business, so we are not new to the die business. You could say that wire dies are in our blood and our DNA! No company is any better than the people who work for it and we have the best people in the business. We try to treat every member of our team as part of the family and that results in having people who really care about our business and our customers’ success. We have one of the lowest employee turnover rates in the industry resulting in a well experienced staff of professionals and technicians. We are proud that we currently have 85 employees that have been with us for 20 years or more!