Provided is a composition for a glass fiber having a high elastic modulus and satisfactory productivity. The composition for a glass fiber includes, in terms of mass %, 0% to 1% of Li.sub.2O+Na.sub.2O+K.sub.2O, and has SiO.sub.2/Al.sub.2O.sub.3 of from 1 to 4 and MgO/CaO of from 0.2 to 3.9 in terms of mass ratio.

A method of recycling glass fiber-reinforced polymer composite materials that can provide improved quality recycled glass fiber is described. More particularly, the method comprises pyrolysis of glass fiber-reinforced polymer composite scrap and/or end-of-life material and the subsequent immersion of the pyrolyzed glass fibers in a molten salt bath, e.g., comprising molten potassium nitrate. Immersion in the molten salt bath can eliminate char from the pyrolyzed fibers, as well as removing residual inorganic materials. In addition, immersion in the molten salt bath can strengthen the glass fiber, which can result in the recovery or avoidance of tensile strength losses normally incurred through traditional char removal processes.

Provided are a molded article that contains a polyarylene sulfide (PAS) resin and a glass fiber and allows a decrease in mechanical strength to be suppressed even in a hot water environment and under acidic conditions, a PAS resin composition capable of providing such a molded article, and methods for producing the same. More specifically, provided are a PAS resin composition including, per 100 parts by mass of a PAS resin, 10 to 100 parts by mass of a glass fiber having, in the glass fiber, an MgO content of 6 mass % or more, a CaO content of 16 mass % or less, and an R.sub.2O content (the R.sub.2O content representing the total content of LiO.sub.2, Na.sub.2O, and K.sub.2O) of 1 mass % or less, and 0.01 to 10 parts by mass of a silane coupling agent (C) blended as essential components; a molded article; and methods for producing the same.

A mineral wool insulating product which comprises a layer, notably a continuous layer, of mixed mineral wool fibres, the mixed mineral wool fibres comprising a binder, first mineral wool fibres and second mineral wool fibres, the first mineral wool fibres and the second mineral wool fibres have a difference of softening point.

An electronic-grade glass fiber composition includes the following components with corresponding amounts by weight percentages 51.0-57.5% SiO.sub.2, 11.0-17.0% Al.sub.2O.sub.3, >4.5% and ≤6.4% B.sub.2O.sub.3, 19.5-24.8% CaO, 0.1-1.9% MgO, 0.05-1.2% R.sub.2O=Na.sub.2O+K.sub.2O+Li.sub.2O, 0.05-0.8% Fe.sub.2O.sub.3, 0.01-1.0% TiO.sub.2, and 0.01-1.0% F.sub.2. A weight percentage ratio C1=SiO.sub.2/B.sub.2O.sub.3 is 8.1-12.7, a weight percentage ratio C2=B.sub.2O.sub.3/(R.sub.2O+MgO) is 1.7-6.3, and a total weight percentage of the above components is greater than or equal to 99%.

An electronic-grade glass fiber composition includes the following components with corresponding amounts by weight percentages 51.0-57.5% SiO.sub.2, 11.0-17.0% Al.sub.2O.sub.3, >4.5% and ≤6.4% B.sub.2O.sub.3, 19.5-24.8% CaO, 0.1-1.9% MgO, 0.05-1.2% R.sub.2O=Na.sub.2O+K.sub.2O+Li.sub.2O, 0.05-0.8% Fe.sub.2O.sub.3, 0.01-1.0% TiO.sub.2, and 0.01-1.0% F.sub.2. A weight percentage ratio C1=SiO.sub.2/B.sub.2O.sub.3 is 8.1-12.7, a weight percentage ratio C2=B.sub.2O.sub.3/(R.sub.2O+MgO) is 1.7-6.3, and a total weight percentage of the above components is greater than or equal to 99%.

Glass compositions suitable for fiber forming and glass fibers having a high modulus are disclosed. The glass composition may include SiO.sub.2 from about 48 to about 61 weight percent, Al.sub.2O.sub.3 from about 22 to about 27 weight percent, CaO from about 1 to about 11 weight percent, MgO from about 5 to about 20 weight percent, less than 5.5 weight percent Y.sub.2O.sub.3, up to 2.5 weight percent Li.sub.2O, and up to 1 weight percent B.sub.2O.sub.3. The glass compositions can be used to form glass fibers and incorporated into various composites.

Glass compositions suitable for fiber forming and glass fibers having a high modulus are disclosed. The glass composition may include SiO.sub.2 from about 48 to about 61 weight percent, Al.sub.2O.sub.3 from about 22 to about 27 weight percent, CaO from about 1 to about 11 weight percent, MgO from about 5 to about 20 weight percent, less than 5.5 weight percent Y.sub.2O.sub.3, up to 2.5 weight percent Li.sub.2O, and up to 1 weight percent B.sub.2O.sub.3. The glass compositions can be used to form glass fibers and incorporated into various composites.

The present disclosure provides a novel glass composition that has a low permittivity and is suitable for mass production. A glass composition provided satisfies, in wt %, for example, 40≤SiO.sub.2≤60, 25≤B.sub.2O.sub.3≤45, 0<Al.sub.2O.sub.3≤18, 0<R.sub.2O≤5, and 0≤RO≤12, and satisfies at least one of: i) SiO.sub.2+B.sub.2O.sub.3≥80 and SiO.sub.2+B.sub.2O.sub.3+Al.sub.2O.sub.3≤99.9; and ii) SiO.sub.2+B.sub.2O.sub.3≥78, SiO.sub.2+B.sub.2O.sub.3+Al.sub.2O.sub.3≤99.9, and 0<RO<10. Another glass composition provided includes SiO.sub.2, B.sub.2O.sub.3, Al.sub.2O.sub.3, R.sub.2O, and 3<RO<8 at the same contents as the above, and satisfies SiO.sub.2+B.sub.2O.sub.3≥75 and SiO.sub.2+B.sub.2O.sub.3+Al.sub.2O.sub.3<97, where R.sub.2O=Li.sub.2O+Na.sub.2O+K.sub.2O and RO=MgO+CaO+SrO.

The present disclosure provides a novel glass composition that has a low permittivity and is suitable for mass production. A glass composition provided satisfies, in wt %, for example, 40≤SiO.sub.2≤60, 25≤B.sub.2O.sub.3≤45, 0<Al.sub.2O.sub.3≤18, 0<R.sub.2O≤5, and 0≤RO≤12, and satisfies at least one of: i) SiO.sub.2+B.sub.2O.sub.3≥80 and SiO.sub.2+B.sub.2O.sub.3+Al.sub.2O.sub.3≤99.9; and ii) SiO.sub.2+B.sub.2O.sub.3≥78, SiO.sub.2+B.sub.2O.sub.3+Al.sub.2O.sub.3≤99.9, and 0<RO<10. Another glass composition provided includes SiO.sub.2, B.sub.2O.sub.3, Al.sub.2O.sub.3, R.sub.2O, and 3<RO<8 at the same contents as the above, and satisfies SiO.sub.2+B.sub.2O.sub.3≥75 and SiO.sub.2+B.sub.2O.sub.3+Al.sub.2O.sub.3<97, where R.sub.2O=Li.sub.2O+Na.sub.2O+K.sub.2O and RO=MgO+CaO+SrO.