US2082182A

US2082182A - Manufacture of abrasive articles

Info

Publication number: US2082182A
Application number: US576414A
Authority: US
Inventors: Elmer C Schacht
Original assignee: Behr Manning Corp
Current assignee: Saint Gobain Abrasives Inc
Priority date: 1931-11-20
Filing date: 1931-11-20
Publication date: 1937-06-01
Anticipated expiration: 1954-06-01
Also published as: US2245301A; US2027308A; DE590459C; FR731457A; GB396385A

Description

June 1, 1937. E. c. SCHACHT 2,082,182

MANUFACTURE OF ABRASIVE ARTICLES Filed Nov. 20, 1951 amnion Maw Patented June 1, 1937 7' UNITED STATES PATENT OFFICE Application November 20,1931, Serial No. 576,414

4 Claims.

My invention relates to the manufacture of abrasive articlespand is particularly concerned with the production of flexible abrasive material of which one example is sand paper.

5 An object of the invention is to produce a sand paper having a maximum abrading efliciency by means of a process wherein the particles are dispersed to form a uniform coating upon the ad- 1 hesive surface of a web or carrier.

I have found that if an electrical field be provided between a hopper or other feeding source and the web to be coated, which field will be so sand distribution having the-maximum number of cutting points.

The invention is applicable in'the manufacture of both open coated and closed coated sand paper and may be used with varying grades and sizes of particles.

In the drawing:

i The figure is a diagrammatic view of the invent on.

Referring to the drawing, the numeral l 0 indicates a hopper in which are disposed the abrasive particles which, are preferably usually employed in the manufacture of sand paper.

The particle mixture comprises the customary under grade, control grade, and over grade" in which the control grade predominates.

Disposed below the hopper is a suitable gate H which will preferably be adjustable, so as to control the feed of ,the particles from the hopper. The particles are released from the hopper in controlled amounts to a web II, which is preferably provided with an adhesive surface l3. The web may consist of paper, cloth or a laminated material composed of paper and cloth, or in fact any usual backing or carrier known in the art is continuously fed in a preferably horizontal direction in accordance withthe arrow, being supported and carried over suitable rollers ll,-a nd that the lines of force created by the electrical field are substantially parallel to the web.

The field is created by reason of the spaced I electrodes I4 and I5, one of which will be charged and the other grounded. In the present instance, I have shown the electrode H as negatively charged and the terminal l5 grounded. Obviously this arrangement can be reversed.

The lines of force of this field, as stated, are parallel to the surface of the carrier and are disposed entirely at one side thereof and in the present instance above the carrier.

The strength of the field will be varied in accordance with the nature of the particles and the character of the coatingrequired, and can also be varied in accordance with the distance of the field from the web. 0

It should be understood also that the feed of 2 the particles may be regulated in accordance with the strength of the electrical field.

Upon reference to the drawing, it will be observed that by reasonof the lines of force set up in the field, the particles become charged and thus mutually repellent, causing them to shower or fan-out.

By reason of this process, I obtain a uniform I dispersement to produce a level sand distribution 30 having maximum number of cutting points.

The electrodes 14 and I5 may be agreater or less distance apart, depending upon the article .to be prepared, and the nature of the abrasive particles and, as stated, the strength of the field may be varied.

By reason of the process, the web having an adhesive surface is continuously coated and is only necessary that the feed and the strength and position of the field be suitably regulated, whence the positions of the particles is controlled.

In some cases, I find it desirable to employ a screen or shield Hi to confine the particles, although this is not essential.

My invention is adapted for the production of either open coated or closed coated paper and .while I have referred herein to sand specifically as the abrasive material, it will be understood that other abrasives of a particle nature are oper-' able with this invention. '5

It will be clear that the gravitational feed of the particles'from the hopper III and feed roller or gate ll, causes them to enter the electrical field and pass therethrough. Upon becoming charged the particles are mutually repellent and their direction is changed from that due to the gravitational force alone, to a resultant which is the combined effect of the gravitational force and the respective repellent actions of the particles to each other, plus the action of the lines of force. In this manner, the dispostion of the particles upon the carrier is controlled to produce the desired eifectsoi' uniform dispersement, resulting in an abrasive surface having the particles permanently associated and possessing a maximum cutting efliciency.

What I claim is:

1. In the art of preparing abrasive articles, wherein abrasive particles are depositedv upon the adhesive surface of a backing, the steps which comprise feeding the particles as individually vseparated bodies to and through an electrical field in which the electrodes creating the same are disposed entirely at one side of the carrier whereby the particles must pass through the field in their travel to the carrier, and passing the particles from the field to adhesive surface of the backing in a direction constituting an alteration of the action of the gravitational force due to the mutual repulsiveness' of the particles and to the lines of force created through the field on their way to the carrier,

and passing the particles from the field to the adhesive surface of the backing in a direction constituting an alteration of the action of the gravitational force due to the mutual repulsiveness of the particles and to the lines of force created by said field whereby the particles are applied to the adhesively coated backing in dispersed relation.

3. In the art of preparing abrasive articles, wherein abrasive particles are deposited upon the adhesive surface oi a backing, the steps which comprise continuously feeding the particles as individually separated bodies to and through an electrical field in which the electrodes creating the-same are disposed entirely at one side of the carrier whereby the particles must pass through the field in theirtravel to the carrier, and passing the particles from the field to acontinuously moving backing having an adhesive surface in adirection constituting an alteration of the action of the gravitational force due to the mutual repulslveness of the particles and to the lines of force created by said field whereby the particles are applied to the adhesively coated backing in dispersed relation.

4. In the art 'of preparing abrasive articles, wherein abrasive particles are deposited upon the adhesive surface of a backing, the steps which comprise continuously feeding the particles to and through an electrical field in which the electrodes creating the same are disposed entirely at one side of the carrier and having its lines of force parallel to the surface whereby the particles must pass through the field on their way to the carrier, and passing the particles from the field to a continuously moving backing having an adhesive surface in a direction constituting an'alteration of the action of the gravitational force due to the mutual repulsiveness of the particles and to the lines of force created by said field whereby the particles are applied to the adhesively coated backing in dispersed relation.

ELMER C. SCHACHT.