SU281202A1 - METHOD OF MANUFACTURING AN ABRASIVE TOOL ON ORGANIC LINK - Google Patents

Description

The invention relates to the production technology of an abrasive tool, mainly abrasive wheels for cutting and wiping.

Methods are known for making abrasive wheels on volcaite and bakelite bonds by mixing the abrasive grain with a suitable binding mass, molding and heat treatment, i.e., vulcanization or bakelization, respectively.

The disadvantages of limestone methods are the instability of the effective (working) hardness of the abrasive wheel, since the latter largely depends on the heat release in the cutting zone and the length of the arc of contact of the circle with the material being processed. In addition, the high tenacity of the abrasive grain and the low heat resistance of the binder lead to a decrease in the strength of the grain in the wheel, i.e. an increased wear of the abrasive wheel.

The aim of the invention is to obtain a tool of increased heat resistance and stable hardness.

This is achieved by the fact that, before mixing with the binding mass, abrasive grains are coated with an adhesive film, for example, based on silicone resins that withstand a temperature of 400-500 ° C.

Abrasive grains covered with adhesive composition in a ratio of 3-4 weight. including composition per 100 weight. including abrasive grain, then dried and sifted, followed by heat treatment, corresponding to the composition used.

Further preparation of the mixture, molding and heat treatment are carried out in the usual manner.

As adhesive compositions suitable for film application, the following can be used, for example: a mixture of a toluene solution of a polyorganosiloxane resin (varnish K-58) with epoxy resin ED-6; Egilsilicate-50

(pexane); toluene solution of methylphenyl polysiloxane resin, modified with epoxy resin with hardener additive (IPE-9 glue); toluene solution of methylchlorophenyl poly (xyloxane resin) with hardener (K-105 glue), etc.

The following is an example implementation of the proposed method. As an adhesive composition, the following is used (wt. H.): Epoxy resin ED-6100

50% solution of polyorganosiloxane resin in toluene (K-58 varnish) 43 Xylene43 Polyethylenepolyamits10

First, prepare a 70% solution of epoxy resin in xylene (with -heated heating on a water baps to a temperature of 50-60 ° C). A corresponding amount of K-58 varnish is added to a portion of the solution.

The mixture is stirred and triturated in a ball mill for 1.5-2 hours, then ethylene polyamiamine is added (after which the solution should be used for 30 minutes.

A portion of the grain of the electrocorundum of normal grain 40 is used to inject the prepared mixture at the rate of 3-4 weight. including mixtures per 100 weight. h. abrasive grain and mix thoroughly (for example, on the runner) until the moisture of all grains is uniform.

The moistened grain is poured on the opposite layer of 30-40 mm and dried to a temperature of 18-ZO C for 24 hours with i-periodic mixing in order to remove the lumps.

The dried grain is sifted through a sieve, corresponding to its grit size of the abrasive used, and the rest of the crumpled part on the sieve is subjected to additional light rubbing, after which it is attached to the bulk of the abrasive.

Sifted abrasive grain is subjected to heat treatment by soaking at a temperature of 200 ° C for 4-6 hours and cooling in air.

Then the abrasive grain is mixed with the binder, its mass, molded and heat treated in the usual way.

The heat-resistant film covering the abrasive grain, has good adhesion properties and low thermal conductivity, serves as a thermal insulator that separates the high thermal abrasive grain from the binder having a low heat resistance.

Subject invention

The method of making an abrasive organic bonded tool by mixing the abrasive grain with a binder mass, molding and heat treatment, characterized in that, in order to obtain a tool of increased heat resistance and stable hardness, the abrasive grains are covered with a film of adhesive compositions , for example, on the basis of silicone resins that withstand a temperature of 400-500 ° C.