Abstract: A friction material intended to equip a device for applying friction in a liquid medium, including a fiber mat impregnated with a heat-curable resin. The fiber mat consists of fibers whose length is greater than or equal to 12 mm, and is teased, coated and needled. The friction material features a porosity greater than or equal to 30% by volume and less than or equal to 60% by volume. The friction material includes activated charcoal loads whose specific surface is between 500 m2/g and whose mass content in the friction material is greater than or equal to 5% by weight and less than or equal to 15% by weight.

Abstract: A friction material intended to equip a device for applying friction in a liquid medium, including a fiber mat impregnated with a heat-curable resin. The fiber mat consists of fibers whose length is greater than or equal to 12 mm, and is teased, coated and needled. The friction material features a porosity greater than or equal to 30% by volume and less than or equal to 60% by volume. The friction material includes activated charcoal loads whose specific surface is between 500 m2/g and whose mass content in the friction material is greater than or equal to 5% by weight and less than or equal to 15% by weight.

Abstract: An annular friction liner, especially for use in a friction device of a motor vehicle, is made by an apparatus including a pair of adjacent conical rolls, a helical guide and a device for trimming a length of the continuous ring whereby a straight strip of friction material, having a width substantially equal to the required final width of the liner, is deformed into a continuous ring.

Abstract: A friction liner having a flat, annular general form, for a friction device designed to operate in a liquid medium, consists in particular of a clutch friction wheel or a brake disc, especially for an automatic gearbox or associated with such a gearbox, or a synchronising ring or cone for a manual gearbox. Such friction devices are intended in particular for motor vehicles. The liner is made of a friction material consisting of a mat of fibers impregnated with a thermosetting resin. After a final curing step while the liner is being moulded under pressure, this material has a porous structure with intercommunicating cells. The liner includes zones having different controlled porosities.

Abstract: An annular friction liner, especially for use in a friction device of a motor vehicle, is made by a method in which a straight strip of friction material, having a width substantially equal to the required final width of the liner, is deformed into a continuous ring.