Site:               Georg Fischer Disa A/S
                    17, Herley Houedgade
                    DK-2730 Helev
                    Denmark

Date Visited:       March 31, 1996

WTEC Attendees: P.H. Mikkola (report author)

Hosts: Peter D. Sorensen, President Dr. Preben N. Hansen, General Manager

Other: B. Smith, General Motors

BACKGROUND

Georg Fischer Disa A/S is a joint venture group that is both part of the A.P. Moller Group and of Georg Fischer GF of Switzerland. Georg Fischer Disa in total employs 1,473 people, 530 in Denmark. The manufacturing facility visited is located just outside of Copenhagen, Denmark. Georg Fischer Disa has sales of about $250 million. Its operations are divided into five business units: (1) Foundry Planning -- Schaffhausen, Switzerland; (2) Foundry Machines -- Denmark and Michigan; (3) Foundry Plant Engineering -- Schaffhausen and India; (4) Shotblast Machines -- Karlsoube, Germany, and Oklahoma; and (5) International Sales and Service -- Chicago, Paris, Germany, the United Kingdom, and Japan. Georg Fischer Disa employs about 1500 people worldwide. About 76% of total sales are in Europe and 15% in the United States. Disa, which owns half of Georg Fischer Disa, is a member of A.P. Moller, which is the largest shipping company in Denmark. Its cargo line is Maersk.

The company Disa is well known for its disamatic, high production rate, flaskless molding machines. There are 1138 Disa molding lines of varied sizes in operation worldwide. This makes Disa the largest green-sand molding machine supplier in the world. It combined with the George Fischer group to form Georg Fischer Disa in November 1995.

A recent effort has been in development of a green sand technology to produce consistent quality aluminum castings.

MANUFACTURING

The Georg Fischer Disa manufacturing area is dedicated to manufacturing molding and related equipment for the casting industry. In Denmark it manufactures flaskless molding machines of varied sizes. The major use of these molding machines is to produce iron castings by this vertical flaskless technique. The molding machines operate up to 400 molds/hour. The focus has been to minimize production costs, to extend uptime, and to improve quality and customer operations. At the time of the WTEC visit there were 1,138 Disa molding lines in production worldwide, accounting for 42% of all green sand iron castings poured in the United States. This figure was only 0.6% for aluminum.

Disa operates a 40,000 m2 plant to manufacture and assemble machines in Denmark. All equipment is "hot" cycled prior to shipment. The manufacturing plant includes two full sand systems and an advanced process development and research area.

ADVANCED DEVELOPMENT AND RESEARCH

Disa has a well-equipped process development lab working on methods for production of quality aluminum castings. The lab has two molding machines, varied pouring techniques, and process monitoring equipment. This lab creates the type of environment that would attract engineers interested in advanced process development. The knowledge of the personnel on aluminum metallurgy and process requirements was impressive for an equipment manufacturing company.

Disa's green-sand development work is concentrated in the area of vertical flaskless operations. The company has developed a gravity pour pressure assist feeding system to assure quality and improve yield of sand castings. The technique applies a relatively low pressure (0.1 to 0.3 bars) on the top of the riser shortly after castings are poured. This technique has proven to feed castings soundly while improving yield. This concept is shown in Fig. Disa.1.

Disa also has developed a process for mold filling using an electromagnetic pump. This technique assures that high quality oxide-free molten metal is used to fill mold cavities. This concept is shown in Fig. Disa.2. In both pressure feeding and electromagnetic filling, computer simulations are used to predict results, and extensive experimentation validates the concept.


Fig. Disa.1. Gravity-pour pressure-assist feeding systems.


Fig. Disa.2. Concept of mold filling using an electromagnetic pump.

Disa is working on a third concept to enhance the cooling of aluminum by development of a magnetite molding sand. The cooling power approaches that of zircon sand, which is greater than that of silica. The molding media is crushed magnetite ore, bentonite, and water. The sand can be recycled, and after breakdown it can be used as iron ore in steelmaking.

The dendrite arm spacing (DAS) for Na-modified melt treatments is in the range of 38 µm for the magnetite/clay cast products. A complete overview of comparisons is in Table Disa.1.

Table Disa.1
Comparison of Cooling Power of Various Mold Materials*
[Table]
* Calculated solidification times using measured DAS values (DAS is an average of 5 readings). All tests taken from 36 mm diameter test cylinders, cut 22 mm from cold end (opposite feeder).

SUMMARY

Georg Fischer Disa, in understanding the movement of the casting market from iron to light metals, has spent considerable resources to develop a high production molding technique for aluminum. The technique has yet to be proven in high production but appears to be a technically sound approach to overcoming the perceived weakness of sand-molded aluminum. With its sound engineering approaches, those application problems occurring during the installation and evaluation of this technique will get the attention of the company. Overall, Disa should be commended for working in this area of perceived high technical risk.

As with other WTEC hosts, Disa representatives expressed concern that engineering is no longer as desirable a profession as it has been in the past. The casting engineering education system in Europe includes a B.S. degree in engineering, followed by two years of special studies in castings to achieve a masters degree. The current trend is to reduce the work experience during the education process. Disa views this trend as a negative.

As the casting industry expands, Disa managers see India and China as high growth areas. They believe India has the advantage because of its improved management techniques.

The interaction of universities with business to do research is not well defined in Denmark or Europe in general. Very little company-sponsored work is done at universities. In addition, recent high unemployment among graduating engineers has resulted in fewer students selecting engineering careers, with the fine arts getting a greater percentage of students. The vision of the casting industry as one of poor working environments, hard work, long hours, and relatively low pay results in the best and brightest students going elsewhere.

REFERENCES

A.P. Moller. Brochure.
Disa Georg Fischer GF: Your Global Partner. Brochure.
"Disamatic Aluminum Project." January 1996. (copy of slide presentation.)


Published: March 1997; WTEC Hyper-Librarian