A process for debundling a carbon fiber tow into dispersed chopped carbon fibers suitable for usage in molding composition formulations is provided. A carbon fiber tow is fed into a die having fluid flow openings, through which a fluid impinges upon the side of the tow to expand the tow cross sectional area. The expanded cross sectional area tow extends from the die into the path of a conventional fiber chopping apparatus to form chopped carbon fibers, or through contacting tines of a mechanical debundler. Through adjustment of the relative position of fluid flow openings relative to a die bore through which fiber tow passes, the nature of the fluid impinging on the tow, the shape of the bore, in combinations thereof, an improved chopped carbon fiber dispersion is achieved. The chopped carbon fiber obtained is then available to be dispersed in molding composition formulations prior to formulation cure.

The purpose of the present invention is to obtain a fiber-reinforced composite material molded article having high adhesive strength in a boundary portion between an insert portion comprising a fiber-reinforced resin substrate and an integrally molded portion molded integrally with the insert portion. A fiber-reinforced composite material molded article (1) containing reinforcing fibers and a thermoplastic resin and being provided with a first layer (23), a second layer (22), and a third layer (21) in this order, the thickness of each layer, the ratio of the total volume of reinforcing fibers (x2) having a fiber length of 3 mm to less than 100 mm with respect to the total volume of reinforcing fibers present in the layer, the ratio of the total volume of reinforcing fibers (y2) having a fiber length of 0.02 mm to less than 3 mm with respect to the total volume of reinforcing fibers present in the layer, and the volume content of fibers in each layer being controlled so as to be in specific ranges.

The purpose of the present invention is to obtain a fiber-reinforced composite material molded article having high adhesive strength in a boundary portion between an insert portion comprising a fiber-reinforced resin substrate and an integrally molded portion molded integrally with the insert portion. A fiber-reinforced composite material molded article (1) containing reinforcing fibers and a thermoplastic resin and being provided with a first layer (23), a second layer (22), and a third layer (21) in this order, the thickness of each layer, the ratio of the total volume of reinforcing fibers (x2) having a fiber length of 3 mm to less than 100 mm with respect to the total volume of reinforcing fibers present in the layer, the ratio of the total volume of reinforcing fibers (y2) having a fiber length of 0.02 mm to less than 3 mm with respect to the total volume of reinforcing fibers present in the layer, and the volume content of fibers in each layer being controlled so as to be in specific ranges.

A motorcycle tire 1 comprises a tread portion 2, sidewall portions 3, bead portions 4, a carcass 6 extending between the bead portions, and a tread reinforcing layer 7 disposed radially outside the carcass in the tread portion. The tread reinforcing layer 7 is composed of a helically wound strip 10 of parallel reinforcing cords 11 coated with topping rubber 12. The winding pitch Pm of the strip 10 in middle parts Mi of the tread reinforcing layer is less than the winding pitch Pc of the strip 10 in a central part Cr, and less than the winding pitch Ps of the strip 10 in shoulder parts Sh.

A cast-molded article in a composite material comprising a cured polymeric binder incorporating embedded particles of filler, characterized in that the binder incorporates randomly distributed fibers of polyamide, wherein the fibers have a length of 5-20 mm and a diameter of 0.05-0.2 mm and the fibers comprise 0.02-0.5 wt % based on the overall mass of the cast-molded article.

A cast-molded article in a composite material comprising a cured polymeric binder incorporating embedded particles of filler, characterized in that the binder incorporates randomly distributed fibers of polyamide, wherein the fibers have a length of 5-20 mm and a diameter of 0.05-0.2 mm and the fibers comprise 0.02-0.5 wt % based on the overall mass of the cast-molded article.

Surface-treated polymeric particles which are dispersible in water or an aqueous solution without the aid of any surfactant. Surface treatment of hydrophobic polymeric particles is carried out to increase the surface energy and to render the surfaces of the particles hydrophilic, thereby eliminating the need for a surfactant to disperse the polymeric particles in water or an aqueous solution. As such, a surfactantless slurry can be formed from the surface-treated particles for the fabrication of fiber-reinforced thermoplastic composite structures.

Surface-treated polymeric particles which are dispersible in water or an aqueous solution without the aid of any surfactant. Surface treatment of hydrophobic polymeric particles is carried out to increase the surface energy and to render the surfaces of the particles hydrophilic, thereby eliminating the need for a surfactant to disperse the polymeric particles in water or an aqueous solution. As such, a surfactantless slurry can be formed from the surface-treated particles for the fabrication of fiber-reinforced thermoplastic composite structures.

A ready-for-use metal reinforcer, for example, of the wire or cord type, made of brass-coated carbon steel, is capable of adhering directly by vulcanization to a matrix of unsaturated rubber such as natural rubber. The surface of the reinforcer is provided with nanoparticles of at least one sulfide of a metal chosen from cobalt, copper, iron, zinc and the alloys comprising at least one of these elements. Such a reinforcer can be used as the reinforcing element of a finished article made of rubber, such as a tire.

A ready-for-use metal reinforcer, for example, of the wire or cord type, made of brass-coated carbon steel, is capable of adhering directly by vulcanization to a matrix of unsaturated rubber such as natural rubber. The surface of the reinforcer is provided with nanoparticles of at least one sulfide of a metal chosen from cobalt, copper, iron, zinc and the alloys comprising at least one of these elements. Such a reinforcer can be used as the reinforcing element of a finished article made of rubber, such as a tire.