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US 5,032,335 AGranted
Manufacture of sealing elements of composite sintered polymeric material
AssigneeMather Seal Company
InventorDavid Wilson
Life of this patent
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Abstract
A sealing element for use with a radial lip oil seal includes a mounting section formed of a first polymer and a sealing section formed of a second polymer. The sealing element sections are bonded together during a common sintering operation so that each polymer is sintered only once. This reduces molecular degradation of the polymers typically caused by multiple sintering operations.
Claims6
A method of forming annular sealing elements comprising the steps of:
- a. forming a first tubular preform by applying pressure in a range of 250 to 2500 PSI, without heat, to a confined mass of polymer powders comprising polytetrafluoroethylene;
- b. forming a second tubular preform by applying pressure in a range of 250 to 2500 PSI, without heat, to a confined mass of polymer powders comprising flourine-based polymer;
- c. arranging said first and second tubular preforms concentrically one within the other, to form a composite tube;
- d. applying pressure in the range of 2,000 to 20,000 PSI to said composite tube, to thus compact the tube and form a mechanical bond across the polymer powders at the annular interface between the two preforms;
- e. heating the compacted composite tube to sinter the polymers and achieve coalescence of the polymers at their annular interface, and
- f. slicing through said heated compacted composite tube along radial planes so as to form said sealing elements.
3 more elements
Dependencies are inferred from the claim text.