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Products and solutions, 2000-03-20, 01:00 AM

Steel segment: Thyssen Krupp Stahl AG expands coating competence and capacity

Coated sheet is a key focus of the presentation being staged by Krupp Stahl AG (TKS) at the 2000 Hanover Fair. With examples from the domestic appliance, electrical equipment and consumer electronics sectors, the company will be showing that today's video recorders, refrigerators and washing machines owe their good looks to the competence of material suppliers. The equipment housings are made of cold-rolled strip ? supplied in up-to-the-minute colors by Thyssen Krupp Stahl AG.

Alongside manufacturers of domestic appliances and electrical equipment, the building sector and automobile industry are the most important customers for pre-finished sheet from Thyssen Krupp Stahl AG. As well as painting ? known in the trade as "organic coating" ? key coating processes include electrolytic and hot-dip galvanizing, hot-dip coating, and polymer film coating. In addition, TKS supplies composite materials with a sound-insulating plastic core. The aim of all coating processes is to supply customers with starting material which already features as many of the desired end-product properties as possible, such as corrosion resistance, scratch resistance, sound insulation or color design.

Customers benefit in several ways: without having to invest in their own painting and coating facilities, they can reduce their own production costs and at the same time enhance the quality of their finished products. Two examples: by opting for pre-painted blanks from TKS in a plant producing washing machines and dryers, a German domestic appliance manufacturer was saved the 30 to 40 million marks investment in a new painting facility. The fact that rust penetration in cars is virtually unheard of these days is down to the increased use of hot-dip and electrolytically galvanized sheet. It also explains why the automobile industry is one of TKS's major customers for coated sheet.

The latest market figures also show above-average growth for coated products. While cold-rolled strip production overall increased annually by 1.9 per cent on average in Europe from 1983 to 1998, the share of metallic coated sheet rose by an average 8.1 per cent in the same period. In 1998 metal and organically coated sheet accounted for over two thirds of cold-rolled strip output.

At Thyssen Krupp Stahl AG, Europe's second biggest producer of coated sheet, coated products account for over 70 per cent of total cold-rolled strip production. In future this share is set to increase to over 80 per cent and a decision has already been taken to expand capacity accordingly. The biggest investment is a new hot-dip galvanizing unit with an annual capacity of 450,000 tonnes in Dortmund. With this unit, in which around 250 million marks is being invested, TKS will have coating facilities with an aggregate annual capacity in excess of 5.8 million tonnes.

But the idea is to boost not just the quantity but also the quality of coated products. To this end Thyssen Krupp Stahl AG is setting up a surface center in Dortmund to bring together all the company's research and development activities in the field of surface finishing. Known as the Dortmunder Oberflächen Centrum (DOC), the center will cooperate closely with the research group Fraunhofer-Gesellschaft (FhG), which will delegate project groups to the new center from its material and beam technology institute - IWS, Dresden, and its institute for thin films and surface engineering - IST, Braunschweig. The DOC will be one of Europe's biggest centers for the key technology of surface engineering.

The DOC comprises a technology center, housing all the necessary laboratories, and two test buildings. In the larger of the two test buildings an 80 meter long pilot plant is being set up, capable of handling the full range of future-oriented processes for the pretreatment and coating of sheet. This includes cleaning processes using high pressure, ultrasound and corona techniques and secondary cleaning with plasma. For coating and plasma polymerization, chambers are available for PVD (Physical Vapor Deposition) and CVD (Chemical Vapor Deposition) together with further facilities for depositing silicon oxides and for UV hardening. "We can process sheet up to 300 millimeters wide and up to 0.7 millimeters thick at speeds of up to 60 meters per minute," says Dr. Wolfgang Müschenborn, head of research/central quality and testing at TKS and director designate of the DOC. The pilot plant is the centerpiece of the joint project "New coating systems for steel strip" which is receiving support from the federal ministry for research.

The second test building will be rented out to the Fraunhofer research teams. They will use plasma, laser and electron beam coating processes to optimize surfaces in the depth range from nanometers to millimeters. The technology center will feature ultra-modern equipment such as a four-kilowatt mobile neodymium/YAG laser and a coating unit capable of handling large parts in heights of up to 1.2 meters and diameters of 1.2 meters.

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