Importance

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Abstract

Process for the manufacture of an abrasive material comprising at least two binder layers formed from at least one aqueous resol I prepared from a monohydric phenol and formaldehyde (molar ratio of phenol to formaldehyde 1:(1.1 to 2.5)) by the application of a first binder layer onto a carrier material, scattering abrasive particles thereon, drying the covering layer in a horizontal dryer to displacement resistance and thereafter cooling with an air stream, application of a second binding agent layer and in similar manner to the first step, drying to imprint resistance and thereafter cooling, whereby the heating and cooling are each effected by means of an air stream through slit nozzles arranged transversely to the direction of travel of the abrasive web and, after loosely forming the product into a roll, final curing is effected on the product in roll form, the coated carrier material being conveyed at speeds above 5 m/min through the dryers which have well defined and individually controllable heating and cooling zones and the air stream has a velocity of 5 to 200 m/s at the nozzle outlets and a temperature of 20 to 300.degree. C., the air being extracted through adjacent extraction nozzles.

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First Claim