Greene, Tweed & Co., a maker of sealing materials headquartered in Kulpsville, Pa., has installed two high-specification Carbolite ovens to increase the capacity and consistency of the raw material sintering operation at its U.K. manufacturing facility.
The company uses several proprietary polytetrafluoroethylene (PTFE) formulations for its products, which are molded in both tube and bar form in the facility before being sintered and then machined to custom designs.
Carbolite, Hope Valley, U.K., supplied the ovens to join two existing 10-year-old units. The new ovens each have a maximum volumetric capacity of 61 ft3 (1.73 m3) and a maximum operating temperature of 797°F (425°C). According to Carbolite, temperature uniformity is guaranteed to be better than ±9°F (±5°C) but typically it is expected to be as good as ±5.4°F (±3°C).
The tube and bar being processed stand on rotating tables, ensuring that heat is applied evenly to all the material. The tables, which are perforated to improve air circulation throughout the chamber, rotate approximately once every two minutes. Heating is provided by Incoloy-sheathed, mineral-insulated rod elements located behind side duct sheets. Air is circulated by heavy-duty fan impellers on either side of the chambers.