PARTICLES OF PRECISELY PRESET SHAPE AND METHOD OF THEIR PRODUCTION

摘要

FIELD: material in the form of solid particles comprising binder, and method of their production. SUBSTANCE: if such solid particles contain grains of abrasive, they may be used in one-piece body abrasive items, abrasive items with an applied abrasive layer and nonwoven abrasive materials. Particles most fitting the specific task may be designed by changing their shape and composition. The offered procedure is a simple, quick and cheap method of production of particles, in particular, abrasive particles of a precisely preset shape. This procedure makes it possible to maintain the preset dimensions of abrasive particles with a high precision from lot to lot, due to which the spread in characteristics of abrasive items is reduced. Particles contain a binder. In one preferable version of the invention some grains of abrasive are distributed in the binder. Production of particles of precisely preset shape has the following operations: (a) use of a moulding fixture with a three-dimensional working medium, having at least one continuous surface at least with one hole giving access to the cavity under the surface of the mentioned three-dimensional working medium; (b) use of a means of application making it possible to introduce binder in the initial state containing thermosetting resin through the mentioned into the mentioned cavity; (c) use of means of at least partial hardening of the binder in the initial state in the hardening zone; (d) introduction of binder in the initial state of substance at least into a part at least of one of the mentioned cavity; (e) continuous motion at least of one of the mentioned cavity over the mentioned hardening zone up to at least partial hardening of the binder in the initial state to obtain a hardened fitted for further treatment binder, corresponding in shape to that part of the cavity into which the binder in the initial state was introduced; (f) extraction of the binder at least from one of the mentioned cavity, and (g) transformation of the binder to a particle of the preset sha