Abstract: The present invention relates to reinforcing glass yarns, the composition of which comprises the following constituents within the limits defined hereinbelow, expressed in percentages by weight:______________________________________ SiO.sub.2 58 to 62% Al.sub.2 O.sub.3 10 to 16% CaO more than 18% MgO more than 1.5% CaO + MgO less than 28% Na.sub.2 O + K.sub.2 O + Li.sub.2 O less than 2% TiO.sub.2 less than 1.5% Fe.sub.2 O.sub.3 less than 0.5% B.sub.2 O.sub.3 less than 2% F.sub.2 less than 2% ______________________________________this composition furthermore comprising less than 1% of other constituent(s) and comprising more than 0.5% of at least one of the three components F.sub.2, B.sub.2 O.sub.3 and Li.sub.2 O.These yarns have a composition providing an excellent compromise between its cost and its fiberizability.

Abstract: The subject of the invention is a device for manufacturing a composite yarn formed by the combination of continuous glass filaments and continuous filaments of a thermoplastic organic substance, comprising, on the one hand, at least one bushing which is fed with glass, the lower face of which is provided with a multiplicity of orifices from which a multiplicity of glass filaments is drawn, and is associated with a coating device and, on the other hand, at least one extrusion head fed with a molten thermoplastic organic substance, the lower face of which is provided with a multiplicity of orifices from which a multiplicity of organic filaments is drawn, the said head being associated with a drawing device comprising at least two drums and with a venturi device which projects the organic filaments into the sheet formed by the glass filaments, and means, common to the bushing and to the extrusion head, which enable the composite yarn to be assembled and drawn, for example by a winding device such as a bobbin win

Abstract: The subject of the invention is a process for manufacturing a glass strand mat, in which a binder is deposited continuously on a wad of glass strands. The strands are distributed on a moving conveyor, and then the wad is subjected to an oven treatment and possibly to calendering. The process consists of depositing on the wad of strands a liquid binder whose viscosity during deposition is less than approximately 40 millipascal seconds, the binder being formed by an aqueous solution of polyvinyl alcohol(s).

Abstract: The present invention relates to a device for coating a thread with a thermoplastic organic material. This device, which is mounted in the manner of a cross head at the end of an extruder, comprises an inlet aperture followed by a hollow punch, of which the conduit opens into a central duct, the said duct being connected to the extruder by way of a supply chamber, part of this device being movable or removable, and displacement of the said part enabling the said device to be opened and closed along its entire height, from its periphery to its axis. Application to the production of composite products.

Abstract: A process for producing tapered windings of glass threads consists, downstream from a drawing device of glass filaments joined into a thread, in making the thread pass to the end of the arm of a dancing roller, then winding it on a support attached by one of its ends to a rotationally driven spindle. The thread is distributed on said support with the help of a thread guide reciprocated in parallel to the axis of said support, so as to obtain a winding tapered over at least part of its height.

Abstract: An apparatus and process for the production of a composite thread of glass and of organic material wherein continuous filaments of thermoplastic organic material are mixed in the form of a sheet with a bundle or sheet of glass filaments, with the speed of the thermoplastic filaments during their penetration into the bundle or sheet of glass filaments being greater than the speed of drawing of the glass filaments.

Abstract: The present invention relates to a process for manufacturing a composite thread formed of a plurality of filaments combined with a thermoplastic organic material, which consists in mechanically entraining a thread in a device mounted in the manner of a cross head at the end of an extruder and injecting the material in the direction of the thread and concentrically thereto at a constant maximum radial pressure of less than 50 bars.

Abstract: A method and apparatus for producing a composite thread formed by the association or blending of continuous glass filaments and continuous filaments thermoplastic organic matter. The thermoplastic filaments are, while in the form of a sheet, blended with a cluster or sheet of glass filaments after having been heated to a temperature in excess of their transformation temperature, stretched and then cooled in their stretched state.