A method for densifying one or more porous substrates with pyrolytic carbon by chemical vapour infiltration, includes admitting, at the inlet of the densification furnace, a reactive gaseous phase including at least one pyrolytic carbon precursor; reacting at least a fraction of the reactive gaseous phase with the porous substrate or substrates; extracting, at the outlet of the densification furnace, gaseous effluents originating from the reactive gaseous phase; reintroducing, with the reactive gaseous phase admitted at the inlet of the densification furnace, at least a fraction of the gaseous effluents extracted at the outlet of the furnace, wherein the fraction of the gaseous effluents introduced with the reactive gaseous phase includes at least one polyaromatic hydrocarbon compound.

The invention relates to a method for applying sand to the inner radius of drum brake linings comprising the following steps: a) rolling a UV-curing adhesive onto the inner radius of a drum brake lining, b) applying a frictional grain, such as zircon sand, to the adhesive layer, c) removing the frictional grain not retained by the adhesive from the lining surface, and d) curing the coating by means of UV radiation.

A thermo-set resin composition comprising a Quebracho wood tannin extract, a furfuryl alcohol, a neoprene compound, a dimethicone, polyethylene glycol, abrasive particles, and a glycerol phosphate acidic ester and/or graphite. Further, a method of preparing the thermo-set resin composition including mixing Quebracho wood tannin extract with a furfuryl alcohol to form a primary mixture, adding additives and abrasive particles to the primary mixture, and reacting the primary mixture by adding a catalyst. The thermo-set resin composition is molded into a shape under heat and pressure to a Brinell hardness 8.5 daN/mm.sup.2 and 48 daN/mm.sup.2 and can be incorporated into a friction pad of a brake pad.

A friction material composition includes a binder, organic filler, inorganic filler and fiber reinforcement, and does not contain copper or contains copper in an amount of 0.5 mass % or less. The inorganic filler is one or more selected from y alumina having an average particle size of 10 nm to 50 μm, dolomite having an average particle size of 1 to 20 μm, calcium carbonate having an average particle size of 1 to 20 μm, magnesium carbonate having an average particle size of 1 to 20 μm, manganese dioxide having an average particle size of 1 to 20 μm, zinc oxide having an average particle size of 10 nm to 1 μm, magnetite having an average particle size of 1.0 μm or less, cerium oxide having an average particle size of 0.5 to 5 μm, and zirconia having an average particle size of 5 to 50 nm.

A friction material composition that does not contain copper, which has a high environmental load, or containing copper in such small amount as to be not more than 0.5 mass % and that enables decrease in brake vibration in braking at high temperatures when used in a friction material such that for an automobile disc brake pad, is provided. A friction material obtained by molding the friction material composition is also provided. The friction material composition contains a binder, an organic filler, an inorganic filler, and a fibrous base material, and the friction material composition contains no copper as an element or contains not more than 0.5 mass % of copper, and also contains 2 to 5 mass % of steel fibers that have fiber lengths of 2500 μm or less.

A wet friction material for use in a wet clutch includes a friction interfacing surface for experiencing frictional engagement with an opposed surface in the presence of a lubricant. At least a portion of the friction interfacing surface comprises fibrillated nanofibers, which define a nanofibrous web, and friction adjusting particles held by the nanofibrous web. A cured resin may adhere the fibrillated nanofibers and the friction adjusting particles to provide structural support for the friction material.

In relation to the NAO friction material free of copper component, this invention is to provide the friction material that prevents the occurrence of metal catch while securing sufficient wear resistance. In the friction material manufactured by forming the NAO friction material composition which is free of copper component, the above-described friction material composition does not contain metal simple substance or alloy and contains, as the lubricant, metal sulfide having 600 centigrade or higher decomposition temperature to be decomposed into metal and sulfur, 2.0-5.0 weight % of graphite and a zirconium silicate as an abrasive material. Here, the metal sulfide is not a molybdenum disulfide or a tungsten disulfide. Especially, the content of the metal sulfide is preferably 0.5-2.0 weight % relative to the total amount of the friction material composition.

The brake pad 10 includes a friction material 12 provided on the side of the disc 200 and a back plate 11 bonded to the friction material on the opposite side of the disc 200. A thickness of a peripheral region of the back plate on the side of a center of the disc is larger than a thickness of a peripheral region of the back plate on the side of an outer circumference of the disc. In the case where a minimum value of the thickness of the peripheral region of the back plate on the side of the center of the disc is defined as “h.sub.2 [mm]” and a maximum value of the thickness of the peripheral region of the back plate 11 on the side of the outer circumference of the disc is defined as “h.sub.1 [mm]”, h.sub.1 and h.sub.2 satisfy a relationship of “h.sub.2−h.sub.1<3”.

A friction material includes a fiber base material, a friction modifying material and a binder. The friction modifying material includes alumina particles including, as a main component, θ-alumina particles. The θ-alumina particles are contained in an amount of 1 mass % or more in the friction material.

A friction material with reduced storage time is described, comprising a binder composition based on a hydraulic binder and its use in brake pads and industrial applications.