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US 4,508,777 AGranted
Compressed non-asbestos sheets
AssigneeNichias Corporation
InventorsTsutomu Yamamoto, Masaaki Ashizawa, Kazuo Nishimoto, Yuji Sekiguchi
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AssigneeNichias Corporation
InventorsTsutomu Yamamoto, Masaaki Ashizawa, Kazuo Nishimoto, Yuji Sekiguchi
Estimating the term…
A compressed non-asbestos sheet which comprises at least two types of fibers selected from the groups consisting of inorganic fibers other than asbestos and/or organic fibers, natural rubber and/or synthetic rubber, rubber chemicals, and fillers. The group of inorganic fibers is divided into two subgroups, one subgroup consisting of glass fibers, ceramic fibers, etc., and the other subgroup consisting of carbon and metal fibers. The group of organic fibers consists of synthesized and naturally occurring polymeric fibers including polyamide-based fibers, etc. The compressed non-asbestos sheet includes at least one of the combinations of the first and second subgroups, the first subgroup and the group of organic fibers, the second subgroup and the group of organic fibers, the fibers belonging to the second subgroup, and the organic fibers.
A compressed non-asbestos gasket material sheet having an improvement which comprises in combination:
A material for manufacturing asbestos-free gasket sheets upon subsequent compression and heat-treating of the material, the material comprising, in combination:
A compressed non-asbestos gasket material sheet comprising at least two types of fibers selected from glass fibers, polyamide base fibers and cellulose base fibers, said fibers containing short fibers, each having an average diameter of 0.01 to 200 microns and an average length of 0.01 to 50 mm, in an amount of 30% or more of the total fiber volume, solid natural or synthetic rubber, rubber chemicals and fillers, wherein the total amount of fiber is 50 to 200 parts by weight per 100 parts by weight of rubber, and the amount of said natural or synthetic rubber to be added is 5 to 20% by weight.
A compressed non-asbestos gasket material which comprises 25-75% by weight of at least two types of fibers selected from at least one of two groups of inorganic fibers other than asbestos and a group of organic fibers, 5-50% by weight of rubber selected from the group consisting of natural rubber and synthetic rubber, the remainder being fillers and rubber chemicals, and which is prepared by uniformly mixing said fibers, said fillers and said rubber chemicals together with a solution of said rubber in an organic solvent, pre-forming the resulting mixture into a pre-sheet having a given thickness with the use of rolls, and hot-pressing the thus obtained pre-sheet under a reduced pressure and, then, under an elevated pressure.
Dependencies are inferred from the claim text.