A coated proppant includes a solid core proppant particle and a heavy metal recovery coating, including heavy metal recovery crystals embedded within a polymer resin matrix. A process for the manufacture of a coated proppant includes providing a solid core proppant particle, and forming on the solid core proppant particle, a heavy metal recovery coating including heavy metal recovery crystals embedded within a polymer resin matrix.

A tennis racquet extending along the longitudinal axis and capable of being tested under a forward/rearward bending test and a torsional stability test includes a frame having a head portion, a handle portion, and a throat portion positioned between the head portion and the handle portion. The head portion forms a hoop that defines a string bed plane. At least the head portion and the throat portion of the racquet are formed at least in part of a fiber composite material. The throat portion includes a pair of throat elements. When the racquet is tested under the forward/rearward bending test, the racquet has a forward/rearward deflection with respect to the longitudinal axis of at least 9.0 mm when measured in a direction that is perpendicular to the string bed plane and perpendicular to the longitudinal axis. When the racquet is tested under the torsional stability test, the racquet has an angular deflection of less than 5.5 degrees about the longitudinal axis.

A drive shaft extends between axial ends and has at least one portion through which an outer diameter of the drive shaft changes through an infinite number of diameters, with the at least one portion extending across at least 15% of an axial distance between the axial ends of the drive shaft. A drive shaft with a generally spiral undulation at its outer periphery is also disclosed.

A semifinished product for making a composite fiber molded part is made by first spinning from a row of orifices of a spinning nozzle low-melting fibers of a thermoplastic. These low-melting fibers are then combined into a laminated semifinished product with high-melting reinforcement fibers of the same thermoplastic but having a melting temperature higher than the melting temperature of the low-melting fibers.

A sports racquet capable of being tested under a racquet vibration test, and including a frame extending along a longitudinal axis. The frame includes a head portion, a handle portion, and a throat portion positioned between the head portion and the handle portion. The head portion forms a hoop that defines a string bed plane. The throat portion includes a pair of throat elements. At least the head portion and the throat portion of the racquet are formed at least in part of a fiber composite material. The head portion including a forward hoop surface and a rearward hoop surface. The distance between the forward and rearward hoop surfaces defines a beam height distance. The head portion has a maximum beam height distance of at least 19 mm. When the racquet is tested under the racquet vibration test, the racquet has a vibration of no greater than 130 Hz.

A racquet includes a frame extending along a longitudinal axis. The frame includes head and handle portions, and a throat portion positioned between the head and handle portions. The head and throat portions are formed at least in part of a fiber composite material. The material includes a plurality of ply arrangements. Each of the arrangements includes one ply having a first plurality of fibers defining a first angle with respect to a composite axis, and another ply having a second plurality of fibers defining a second angle with respect to the composite axis. The first and second angles are substantially the same except the angles have opposite polarities with respect to the composite axis. The head portion includes at least three arrangements overlaying each other, and the first and second angles of at least two of the at least three arrangements are at least 35 degrees.

A method for repairing damage to a composite part includes creating an aperture through the composite part and preparing the surfaces surrounding the aperture on both sides of the part; inserting a plurality of resin impregnated fibers through the aperture and spreading the end portions of the plurality of fibers radially against the prepared surfaces on both sides of the part; and maintaining contact of the plurality of fibers with the prepared surfaces while the resin cures.

Methods and apparatus for manufacturing a thermoplastic structure include laying a first plurality of braided plies on a mandrel, and laying one or more unidirectional plies on the plurality of braided plies. A second plurality of braided plies is laid on the one or more unidirectional plies. The layup thereby forms a thermoplastic structure having combined braided and unidirectional plies.

Provided is a fixture rod that is excellent in bonding strength between a core material and a reinforcing fiber layer and has high rigidity and high durability against a deformation load. A fixture rod according to one embodiment of the present disclosure comprises: a core member containing a resin; and a reinforcing fiber layer provided on the core member, and is configured such that the resin of the core member and a resin of the reinforcing fiber layer are the same resin, or the resin of the core member and the resin of the reinforcing fiber layer are different resins, and a critical surface tension of each of the resin of the core member and the resin of the reinforcing fiber layer is 20 mN/m or more.

A method for producing a composite tank is disclosed. The tank has a continuous fiber reinforcement, a prismatic shape, and a thickness e for the storage of a pressurized gas in an internal cavity of the tank. The tank comprises fibers extending between two non-contiguous faces of the tank through the internal cavity. The method includes: (i) obtaining a prismatic fibrous preform having a thickness e comprising three-dimensional continuous reinforcements throughout its thickness; (ii) impregnating an outer layer of the preform with a polymer over a thickness of less than of the thickness e so as to constitute a composite outer shell extending over all faces of the prism; and (iii) forming a sealed layer constituting an inner lining, having a thickness of less than 1/10th of the thickness e between the outer shell and the fibrous network contained in the cavity of the tank.