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On Thursday, January 10, 2019
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Manufacturing embossing paper, foil, tissue, non-woven and films requires very precise machines. It also requires highly skilled machinists, pattern developers, master engravers and engineers who specialize in creating custom patterns and equipment [1, 2]. Many different metals can be embossed such as aluminum, brass, copper, zinc, cold- and hot-rolled, galvanized, high strength and low alloy steels. The tools used for carrying out the process are subjected to very high contact stresses and friction. The important parts, and very often the most expensive tools in the engraving machines, are the roll dies. Typically, rolls are made of low alloy steels for the ease of manufacturing proper engraved patterns. Durability of these components can be significantly enhanced by the plasma/ion nitriding process [3]. This is especially the case when the rolls are large in size and dimensional stability is very important.
Plasma/ion nitriding is a thermochemical surface method carried out in a vacuum chamber, and it can be applied for hardening of such roll dies. The ion nitriding process offers a clean, low temperature treatment and significant hardening, up to 65 HRc equivalent (or more) for low alloy steel engraving tools. The nitrided layer is typically 0.25-0.50 mm (0.010-0.020”) thick, depending on the type of engraving patterns. (Hundreds of engraved pattern samples are available including natural grains, geometric, metal, wood, stone/marble, fabric, and decorative patterns [4].) The rolls are processed in vertical position to avoid any unwanted distortion.
Advanced Heat Treat Corp. (AHT) can treat large rolls, up to 9 meters (about 27’) in length. The process is environmentally-friendly and results in a gray/silver appearance with high surface hardness. Additionally, there is very little, if any, need for finishing. Ion nitriding is especially recommended for roll dies used in machines producing patterns 70"+ wide.
This was written by Edward Rolinski (Sr. Scientist) and Mike Woods (President) at Advanced Heat Treat Corp. If you have any questions regarding heat treatments, please feel free to contact them at 319-232-5221.
Authors:
Dr. Edward Rolinski received his M.S. in manufacturing technology from Warsaw University of Technology, Poland, and received his Ph.D. doctorate for his research on phenomenon in the ion nitriding process. He has taught physical metallurgy and surface engineering and received his ScD (habilitation) for studying plasma nitriding of titanium. Rolinski is a senior scientist at Advanced Heat Treat Corp. in Monroe, Michigan, solving technical problems and developing technologies.
Mikel Woods is the president of Advanced Heat Treat Corp. (AHT) and has been with the company for over 13 years. Woods obtained his bachelor’s degree in accounting at the University of Iowa and received his executive masters of business administration from the University of Wisconsin. To contact Woods or learn more about Advanced Heat Treat, please visit www.ahtcorp.com.
References
1. Industrial Engraving, LLC, https://www.industrial-engraving.com/
2. Paper Converting Machine Company, https://www.pcmc.com/northern-engraving
3. Advanced Heat Treat Corp., www.ahtcorp.com
4. IR Engraving, https://irengraving.com/gallery/pattern-catalogs/