Abstract: Discontinuous fibers are manufactured from a thermoplastic material having an elevated melting point by feeding molten thermoplastic material into a centrifugal chamber. The chamber includes a plurality of orifices through which the molten thermoplastic material is forced, thereby forming molten thermoplastic jets. Hot streams of gas are directed at these jets to convert the jets into thermoplastic fibers. Sizing agents including an emulsion or suspension in water, or an aqueous solution of active substances is sprayed onto the fibers. These sizing agents comprise no more than three active substances including a lubricating agent and an antistatic agent.

Abstract: A method of sizing insulating glass fibers, comprising: preparing glass fibers by a high temperature aerodynamic procedure in which glass fibers are drawn out by a gas current and collected in a hood; spraying a size diluted in water onto said glass fibers in said collection hood, said size consisting essentially of an epoxy resin, an amino hardening agent and, as additives, 0.1 to 2.0% of a silane and 0 to 15% of a mineral oil, each calculated on 100 parts of dry resin, wherein said epoxy resin is a condensation product of epichlorohydrin and bisphenol A having a polymerization index n of less than 1 and the equivalent molar mass of the hardening agent is less than 100 g and said size is free of formaldehyde and components which release formaldehyde when baked; and recovering a sized insulating glass fiber product.

Abstract: A size for insulating type glass fibers, comprising an epoxy resin of a glycidyl ether dispersable in water, an amino setting agent having a flash point over 180.degree. C. and, as additives, 0.1 to 2% of silane and 0 to 15% of a mineral oil, each calculated per 100 parts of dry resin.