PBI NEFALIT® Millboard
The centrifugal casting process uses molten metal to make tubes for many industrial applications. Seals for the end of the die cast are critical for the casting processes, so tube casting companies need the right material for centrifuge sealing.
What Is Centrifugal Casting?
The centrifugal casting process is casting high-alloy tubes following this process:
- The die cast is closed at both ends with a refractory seal and metal cap.
- The inside wall of the die cast is covered with refractory powder to prevent the molten metal from sticking and make it easier to remove the cast when the process is complete.
- The die cast is preheated with a gas flame and rotated on an axis at high speed to offset gravitational force.
- The molten metal is ladled into one end of the cast.
- Centrifugal force shapes the molten metal into the tube shape.
This process is best for long cylindrical parts that have a length longer than the outside diameter. The interior dimension of the die cast determines the part’s outer diameter, and the amount of molten metal poured into the cast determines the inner diameter.
McNeil Is the Exclusive Supplier of PBI NEFALIT Millboard
McNeil is the exclusive distributor for Porteret Beaulieu Industrie (PBI) in the United States. PBI is the world’s leading manufacturer of asbestos-free millboards. We also distribute one of their top products — PBI NEFALIT millboard. This millboard is available in various temperature ranges, and it has been used for more than 15 years by the world’s leading tube casting companies for centrifuge sealing against molten metals for the centrifugal casting process.
PBI NEFALIT Millboard for Centrifugal Casting
The purpose of the seals is to prevent molten metal spillage and keep workers safe. The casting process places stress on the seals, including:
- Compression from the metal cap
- Thermal exposure to molten alloy
- Weight load from the molten metal
PBI NEFALIT millboard is made to endure these conditions. It can be formed into seal rings with an outer diameter between 2 and 25 inches and thickness from 0.25 to 0.5 inches. Compressibility — how soft or hard the material is — may also be important for some applications.
One spun tube needs two seals. The operator removes the end caps and seals when the casting process is complete. These seals can only be used once — no reuse or recycling. The metal tube that was just cast is extracted from the die cast, and the operator cuts the tube ends off for cleanliness.
Applications for Spun-Cast Tubes
Metal tubes made from centrifugal casting has several applications:
- Radiant heaters
- Roll shafts, such as furnace rolls and paper mill rolls
- Oil and chemical
Discuss Your Molten Metal Project With McNeil Today
Centrifugal casting seals made from PBI NEFALIT millboard can handle the high temperatures and compression from centrifugal force. As the sole distributor for PBI products, McNeil is the best place to find what you need for centrifugal casting. Reach out to us today to discuss your project or learn more.
Click image to enlarge