A flat semi-finished product includes a filled fluoroplastics substrate in the form of a sheet, which is coated at least partially on at least one surface with a soft, thin coating of fluoroplastics. The substrate material of the sheet has a Shore-D hardness of at least 65 and the average layer thickness of the thin sheet coating is at most 20 .mu.m. A component, in particular a flat gasket, is made from the semi-finished product. A process for the production thereof is also provided.

A composite fluoropolymer material contains outer layers consisting essentially of conformable porous polytetrafluoroethylene (PTFE) and interior layers consisting essentially of rigid fluoropolymer material which may be a densified expanded PTFE, wherein the composite layers may optionally contain electrically conductive fillers. The composite is bonded together to form a sheet material that is sufficiently conformable to provide good seal between surfaces and is sufficiently rigid to make the material easy to handle and install. The material of the present invention is particularly suitable for use as a gasket where rigidity is needed, customization or modification of gasket shape is desirable, and/or where a wide, even sealing surface is sought.

An improved, chemically resistant gasket is constructed from a composite containing outer layers consisting essentially of conformable expanded polytetrafluoroethylene (PTFE) and interior layers consisting essentially of a densified expanded PTFE, wherein the composite layers may optionally contain electrically conductive fillers. The composite is bonded together to form a sheet material that is sufficiently conformable to provide good seal between surfaces and is sufficiently rigid to make the material easy to handle and install. The material of the present invention is particularly suitable for use as a gasket where rigidity is needed, customization or modification of gasket shape is desirable, and/or where a wide, even sealing surface is sought.

A surface mount technology compatible electromagnetic interference (EMI) gasket assembly includes an electrically conductive gasket material, a solderable electrically conductive support layer, and an adhesive or other mechanical assembly for affixing the electrically conductive gasket material to the support layer.

A spiral wound gasket having multiple windings of spirally wound strips of metal, fire resistant compressible filler material and oxidizer resistant compressible filler material is disclosed. The fire resistant filler material is arranged in a region toward the outside periphery of the gasket and the oxidizer resistant compressible material is arranged in a region radially closer to the inside periphery of the gasket. The gasket has excellent sealability characteristics from low to high gasket seating stresses, and is effective for use with corrosive chemicals while providing a measure of protection in fire situations.