WCA September 2021

Technology news Modular mixing and dosing technology

The Plasticolor range of mixing and dosing equipment, manufactured by Woywod Kunststoff- maschinen, includes single dosing units, multiple dosing stations, colour change systems, and volumetric and gravimetric mixing stations. Gravimetric throughput measurement systems are also part of the portfolio. All of the equipment is modular and can be interchanged and upgraded. Controls and software programs are developed and manufactured in- house. Based on the experience of more than four centuries in the industry, systems to handle even extremely low mixing ratios (1:2,000) have been developed. The gravimetric “loss-in-weight” systems work with high precision to ensure that valuable material is not wasted. Woywod Kunststoffmaschinen GmbH & Co Vertriebs-KG www.woywod.de

❍ Plasticolor PC1500 with screws cylinders An examination of “cup and cone” wire breaks Due to the COVID-19 pandemic, the NF Wire Forum was held online. its inside continues to move, causing shear stresses.

Wire breaks during the drawing process are the result of unfavourable interactions of forces, tensions and other physical phenomena in the wire material that exceed its tensile strength. The consequences are increased machine down times and scrap production. One of the main types of wire break is the “cup and cone” break, so called because one end of the broken wire is deepened like a cup or a crater, and the other is cone-like. These breaks usually occur when the wire passes through a drawing die. Faulty pre-treatment of the wire, insufficient lubrication or inappropriate drawing die geometry may result in the surface of the wire being braked while

The webinar was organised by the consortium NF Wire Forum (Non- Ferrous Wire Forum), consisting of copper manufacturer Aurubis AG, drawing die producer Balloffet GmbH, lubricant manufacturer Carl Bechem GmbH, wire drawing machinery specialist Maschinenfabrik Niehoff GmbH & Co KG and the association Deutsches Kupferinstitut (German Copper Institute) DKI. The event was dedicated to an interdisciplinary examination of “cup and cone” wire breaks. Lecturers from the consortium partners shared specific aspects of this topic in short presentations.

These induce local cracks that grow with additional strain and reduce the load-bearing cross-section of the wire until the material breaks, with the tip of the cone-like wire end oriented in the drawing direction. In order to avoid such wire breaks, the interaction of the drawing machine, the wire, the drawing tools and the drawing medium must be observed. The basis for a successful drawing process is provided by the melting and manufacturing of the cast wire rod. A recording of the NF Wire Forum presentations on this subject can be found on the consortium’s homepage, with contributions from Dr Cornel Abratis (Aurubis) on refined manufacturing and testing methods; Stephan Gorgels (Niehoff) on the introduction of electronically controlled individual drives; Michael Biller (Balloffet) on monitoring during multi- wire drawing; and Christopher Folland (Bechem) on targeted maintenance and monitoring of the drawing medium. NF Wire Forum www.nf-wireforum.com

❍ The wire ends after a “cup and cone” break

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Wire & Cable ASIA – September 2021

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