Fibres for reinforcing mouldings bonded with cement - using mixt. of vitreous mineral and steel fibres, both with crystalline coating, to increase strength of mouldings

摘要

This is an addn. to 2945119, which described the mfr. of vitreous mineral wool fibres (I) with a surface coating of crystals. The novelty in the present invention is that steel fibres (II) are mixed with fibres (I) and are also provided with the crystalline coating. The fibre mixt. pref. contains 20-40 wt.% steel fibres (II). In the pref. mfg. process, an aq. suspension is made contg. fibres (I,II), followed by adding an alkyl-sulphamide-carboxylic acid (III), and then a basic mineral or metal salt with stirring, so a crystalline coating is formed on fibres (I,II). The addn. of steel fibres (II) to fibres (I) increases the mechanical strength of cement bonded mouldings contg. the fibres.