Drake Plastics’ Product & Process Development team recently developed a process to produce seal segments for finish machining into split or segmented seals, bearings, labyrinth seals and thrust washers. Seal Segments can be made from 12 in. (300 mm) minimum up to 200 in. (5,000 mm) maximum diameter.
Seal Segments enabled Torlon 4301 to be used in a dynamic shaft seal assembly for the U.S. Navy. Testing was also conducted with Seal Segments made from Bearing Grade PEEK 450FC30, but Torlon’s higher PV capability lead to its qualification and Torlon being specified. The Torlon Seal Segments are sub-assembled onto stainless steel holders and the two halves are installed around an 18 in. (457 mm) shaft then coupled together.
Drake’s proprietary melt process yields physical properties superior to traditional compression molded materials and in line with data sheet values. Additionally, material test reports are provided for Seal Segments and 100% traceability is maintained. Material certs confirm the resin’s compliance to Mil, AMS or ASTM standards. Compression molded materials are not certified to these stringent requirements. Seal Segments reduce material cost and machining time by eliminating the need to split over sized compression molded tube or nesting arcs in extruded plate stock. Seal Segments are available in all Torlon and PEEK grades, and offer reduced machining times while delivering the best mechanical and wear properties these high performance polymers offer.
Seal Segments enable two-piece splits rather than multiple-piece segment construction improving both the cost to manufacture, and the performance of the seal by reducing leak paths.
Seal Segments, the newest form of machinable shapes, is another example of Drake’s commitment to serving customers needs in the leanest way possible. Tooling costs are low for custom sizes (cross-section, radius and arc length), and lead-times are modest. According to Steven Quance, Drake’s President, “this development will accelerate the adoption of high performance polymer bearings and seals into large rotating equipment by reducing cost and improving quality and consistency.”
Potential applications include: split wear rings and seals greater than 12 in. diameter—especially large centrifugal pump seals, turbo compressor labyrinth seals, turret bearings and seals, marine shaft seals, blast furnace seals and any other applications which require large seals or bearings from the ultra-high performance polymers, PEEK or Torlon PAI.