Composite yarn for the manufacturing of braided packings, braided packing and process for forming the composite yarn
AssigneeManegro Administracao E Participacoes Ltda
InventorMarcello Cattaneo Adorno
Life of this patent
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Abstract
A composite yarn is for making braided packing for sealing pump or rotating valve shafts. The packing comprises an external layer and a core. Preferably, the external layer is made of expanded polytetrafluoroethylene (PTFE) impregnated with graphite, and the core is an aramide filament. The graphite impregnated, expanded PTFE gives the composite yarn good thermal conductivity, high capacity of friction reduction and good resistance to chemical attacks. The aramide filament has high mechanical strength. The composite yarn can be braided to form a packing where only the PTFE contacts the shaft, thus protecting it against uneven wear.
Claims24
Composite yarn (5) for forming braided packings (8), comprising an outermost layer which is a laminated yarn made of a first material (1) and a core made of a second material (2), said core including a filament.
Process for forming a composite yarn for forming braided packings, comprising an external layer made of a first material and a core made of a second material, comprising the steps of:
- (a) forming a laminate which includes at least one single yarn of said first material and at least one filament of said second material;
- (b) pressing the laminate formed in step (a);
- (c) folding the said at least one single yarn onto the said filament of the second material to form a final laminate;
- and
- (d) pressing the laminate formed in step (c).
Composite yarn for forming braided packings, comprising a laminated yarn and a core, said laminated yarn being made of polytetrafluoroethylene, said core including a filament of a material which is different from polytetrafluoroethylene, said laminated yarn surrounding said core.
Dependencies are inferred from the claim text.