Abstract: Process for manufacturing solutions of alkylated amino formaldehyde resins having a free formaldehyde content of <0.5% by weight, based on the complete weight of the solution, wherein (a) an amino compound selected from the group consisting of melamine, guanamine, urea, toluenesulphoneamide and glycoluril is methylolated, (b) the methylolated amino compound is alkylated with at least one monoalcohol, (c) the surplus monoalcohol is removed quantitatively, and (d) the remaining residue consisting of or consisting essentially of the alkylated amino formaldehyde resin is dissolved in at least one aprotic solvent.

Abstract: The generation of dust in a longwall mining operation is suppressed by covering the hanging wall of the mine with a plastic sheeting, the sheeting being pinned against the hanging wall by the support units used in the mine and being held in association the support units in the form of a flat package formed by folding the sheeting in a zigzag fashion along its entire length.