PL157839B1 - Method for electrostatically feeding abrasive grain onto an adhesive coated substrate - Google Patents

Abstract

1. The method for electrostatic passing of abrasive grain onto an adhesive surface, where abrasive grain is poured onto the moving conveyor belt, and the conveyor belt with grain is horizontally or almost horizontally is put in between high voltage electrodes below the moving adhesive surface band, running between the same electrodes, consisting in that the abrasive grain (1) lying on the moving conveyor belt (2) is initially put into a zone of a weak intensifying electric field (3), and then into a zone of a strong electric field (4), where horizontal or almost horizontal vibration (5) of the said adhesive belt (6) also takes place.<IMAGE>

Description

REPUBLIC

POLAND

Polish Republic

PATENT DESCRIPTION

Application number: 275008

Date of notification: September 30, 1988 © PL © 157839 © BI © I ⁿ tCl ^5:

B24D 18/00 B24D 11/00

The method of electrostatic feeding of abrasive grain to the adhesive substrate

Application announced:

April 2, 1990 BUP 07/90

The holder of the patent:

Tool Industry Combine VIS "

^KL for ^errors and Art ^{kebab UL} Abrasives in Bielsko-Biala, PL

The following was announced about the grant of the patent:

July 31, 1992 VLO on 07/92

Inventors:

Bolesław Gaj, Bielsko-Biała, PL Stanisław Kochel, Bielsko-Biała, PL Józef Rusin, Buczkowice, PL Wiktor Konior, Bielsko-Biała, PL Zygmunt Los, Bielsko-Biała, PL kena ^Śl osarcz ^{yk B} ie ^| skoBiała ^{, PL} Jan Szczotka, Bielsko-Biała, PL \ 1. A method of electrostatic feeding of abrasive grain to an adhesive substrate, in which abrasive grain is poured onto a moving conveyor belt, and then the said conveyor belt with grain is inserted horizontally or almost horizontally between the electrodes of a high voltage below the moving web of adhesive substrate, running between the same electrodes, characterized in that the abrasive grain (1) lying on the moving belt of the conveyor (2) is initially introduced into the zone of a weak rising electric field (3) and then into the zone of a strong pulsating electric field (4), where there is also a vertical vibration (5) 1 ut> almost vertical of said web of adhesive substrate (6).

method of electrostatic feeding of Abrasive grain

ON THE ADHESIVE SUBSTRATE

Claims (2)

Patent claims 1. The method of electrostatic feeding of abrasive grain to the clet fences, in which abrasive grain is poured on the moving belt of the conveyor, whereby the aforementioned belt of the conveyor with the grain is guided horizontally or almost horizontally between the high-voltage electrodes below the moving adhesive substrate web running between the same electrodes , characterized in that the abrasive grain (1) lying on the moving belt of the conveyor (2) initially introduces into the zone of weak increasing electric field (3) and further into the zone of strong pulsating electric field (4), where vibration (5, vertical or almost vertical of said web of adhesive substrate (6). 2. The method according to p. The method as claimed in claim 1, characterized in that the pulsating electric field (4) and the vibration (5) of the k ^ 3 substrate (6) are simultaneously generated by spinning a polyhedral or similar at least one grounded roller - the electrode (7). The invention relates to a method of electrostatic feeding of abrasive grains to an adhesive substrate, in particular in the production of coated abrasive products. Two methods of electrostatic feeding of abrasive grain to a glued substrate in the production of coated abrasive products are known. In the first, known from the USSR patent description 396266 and the additional USSR application No. 745666, abrasive grain falls into a chamber or column, where it falls by gravity in a transversely directed electric field. The electric field is created in the space between two vertical electrodes. One string electrode is connected to a voltage source and the other is flat and grounded. the track of the vertically moving adhesive coated bulk product substrate. The abrasive grain is sprayed as a cloud between the electrodes and some of it settles on the substrate. The grain particles that have not received a sufficient electric charge or are heavier fall to the bottom of the chamber and are removed from there by a vibrating plate. The complementary invention of the USSR No. 745666 consists in additional heating of the electrode constituting the substrate track and electrostatic dedusting of the finished product in a separate electrostatic chamber, equipped with a blower. This method requires a large spacing between the electrodes and therefore a very high voltage. The dimensions of the device are large and only a part of the grain is placed on the ground. The heavy grain cloud falls to the bottom of the chamber and only the lighter fractions are caught by the substrate. In another known, non-powdered, but widely used method of electrosaatic feeding of abrasive grains onto a glued substrate, the abrasive grains are fed in a horizontal belt conveyor that runs along with the substrate web but below the web in the presence of a tctrostatic field that includes the substrate and the conveyor together. The grain conveyor is partially located in the electrosaatic field. The conveyor belt with loose grain enters the electrodes together with the parallel running ground. The grain on the conveyor is electrically charged and attracted to the substrate where it sticks to the adhesive layer. The excess grain runs on and falls off the conveyor. The conveyor belt in such methods is guided at the same speed as the substrate web and in the same direction. 157 839 In the above-described method, a significant part of the grain is discharged by the conveyor as technological waste, practically requiring the selection and re-adaptation of the waste material. This method does not provide a sufficiently strong fixation of the grain in the adhesive layer on the backing web, and its orientation is not favorable. It is an object of the invention to increase the efficiency of depositing abrasive grains on the adhesive substrate of the web of an abrasive blanket. The method according to the invention consists in pouring grain on the moving belt of the conveyor, then the said mobile belt of the conveyor with abrasive grain is introduced horizontally or almost horizontally into the electric field zone together with the web of adhesive substrate running in the opposite direction, but below this web, The abrasive grain mentioned in the conveyor belt is initially introduced into the zone of weak increasing electric field, where fine grain fractions are captured by the spike substrate, and coarser fractions of the abrasive grain feed remaining on the conveyor belt are introduced into the zone of strong pulsating electric field with simultaneous vibration tapes of the glued backing in the zone where the coarser fractions of the abrasive grain are trapped by the glue backing and driven into the glue layer. The strip of the cleat substrate on which the abrasive grains of coarser fractions are deposited goes further to the zone of weak low electric field, where increasingly finer fractions of the fresh abrasive grain feed are deposited thereon. These fine fractions can then be easily removed, for example by shaking, and the intermediate is then sent to drying or polymerization. The invention is explained in more detail on the example shown in the drawing, which schematically shows the method of electrostatic feeding of abrasive grains to the adhesive substrate. The abrasive grain 1 is poured onto the conveyor belt 2, preferably from the bunker 15, and then further transported to the zone of weak increasing electric field 3 below the adhesive substrate web with already deposited coarser fractions 16 of abrasive grains running in the opposite direction. the fractions of abrasive grain of the fresh feed are gradually captured and deposited unstable 17 on the adhesive substrate with a layer of coarse grain, then the coarser fractions of abrasive grain remaining in the conveyor belt are introduced into the zone of the positive pulsating electric field 4 and simultaneous vibrations 5 of the clean glue substrate 6, where these grains are rhythmically attracted to the glued substrate and hammered into the adhesive layer. The residual grain 21, of the generally heavier fractions, continues along with the conveyor belt and is further discharged into the process cycle. The conveyor belt 2 is curved electrically shaped drums 13 and 14. A weak and rising electric field is created between the high voltage electrode 9 fed from the high voltage source 8 and preferably obliquely or curved grounded electrode 10. Pulsating strong electric field 4 with simultaneous vibrations 5 of the block substrate 6 is preferably produced by spinning at least one earthed electrode roll 7 with a wavy or multi-walled surface. The vibration zone of the gluoic substrate is limited by electrically isolated guide rollers 11 and 12. The substrate web 17 with deposited coarse fractions of abrasive grain and impermanently deposited fine fractions of this grain is retryyoala under mechanical stress by guide rollers 11 and 20. The fine fractions are shaken off with a beater 19 and then clean The substrate web with deposited coarse grain fractions may be directed to drying or to the acci ream. By using the invention, the grain is firmly embedded in the adhesive substrate, and its orientation is permanently held in the still soft glue.