Heraeus Carbon Infrared Oven Improves Powder Coating Flexibility and Quality at SFS Intec

It has allowed the Leeds-based company to change powder curing from a continuous to a batch operation, so that it can now respond more quickly to customer requirements for corrosion-resistant screws and fasteners. In addition, the new pyrometer-controlled oven delivers a more consistent coating quality, is much more energy-efficient than the previous powder coating curing installation and requires considerably less space. 

SFS Intec is part of a Swiss-owned international group, which is involved in a range of activities, from the manufacture of solar fastenings to hinge systems. The Leeds site, which has produced fasteners for over 100 years, today develops and manufactures stamped parts and supplies multifunctional thread rolling screws and sub-assemblies for use in the construction industry. It has the resource to offer architects, designers consulting engineers and contractors a proven commitment to effective technical solutions and efficient and responsive service.

Screw fasteners for the construction industry represent an important product line at SFS Intec. The heads of these screws must be coated to resist corrosion in use and the powder coating was formerly cured using an electrically-heated oven, through which the screws were passed continuously on a conveyor belt. 

However, this was very energy-intensive, as the oven had first to be heated up to temperature and then held at that curing temperature for some time. More importantly, this continuous operation lacked flexibility as it could not respond quickly to changes in color or to customer demands for fast delivery of limited numbers of screws, as often happens in the construction sector, especially in the closing stages of a construction contract.

To solve both of these problems, SFS Intec contacted Heraeus, who designed, manufactured and installed a carbon infrared medium wave curing system. This is a three-zone oven with seven 4kW medium wave infrared emitters in each zone. Medium wave radiation is readily absorbed by powder coatings and allows rapid and efficient curing.

In operation, trays of coated screws are now manually loaded into a selected zone and the emitters are switched on. The curing temperature of 180°C, monitored by an integral pyrometer, is achieved in a matter of seconds, rather than the 30 minutes or so required by the previous system, and a digital timer is then set to determine the time that the screws need to be held at the curing temperature. All three zones are individually loaded and controlled so that three different batches of screws can be cured simultaneously, if required.

“We very much pride ourselves on the quality of our customer service,” says Bob Mrozik, the technical services manager at SFS, “and the new batch processing with the infrared oven now means we have improved this service by being able to respond more quickly to last minute customer requests – and often provide a next-day service. In addition, we have found that the pyrometer control of the product surface temperature, as opposed to merely controlling the oven air temperature, as was previously the case, has given a much more consistent quality cure.”

The Hanau-based precious metal and technology group Heraeus is a globally active family-run enterprise with a history of more than 160 years. We provide high-end solutions to our customers to lastingly strengthen their competitive position. Our areas of competence include precious metals, materials and technologies, sensors, biomaterials and medical devices, quartz glass and specialty light sources. In the financial year 2013, Heraeus achieved a revenue from the sale of products of €3.6 bn, while the revenue from precious metal trading was €13.5 bn. With about 12,500 employees in more than 110 companies world-wide, Heraeus is in a leading position on its global sales markets.

Heraeus Noblelight GmbH with its headquarters in Hanau and with subsidiaries in the USA, Great Britain, France, China and Australia, is one of the technology- and market-leaders in the production of specialist light sources and systems. In 2013, Heraeus Noblelight had an annual turnover of 138 Million € and employed 875 people worldwide. The organization develops, manufactures and markets infrared and ultraviolet emitters, systems and solutions for applications in industrial manufacture, environmental protection, medicine and cosmetics, research, development and analytical measurement techniques.

For further information, please contact:

Technical:         Heraeus Noblelight GmbH

                        Reinhard-Heraeus-Ring 7

                        D-63801 Kleinostheim

                        Tel +49 6181/35-8545, Fax +49 6181/35-16 8545

                        E-Mail hng-infrared@heraeus.com

Press:               Dr. Marie-Luise Bopp

                        Heraeus Noblelight GmbH,

                        Abteilung Marketing/Werbung

                        Tel +49 6181/35-8547, Fax +49 6181/35-16 8547

                        E-Mail marie-luise.bopp@heraeus.com

                        www.heraeus-noblelight.com/infrared