US2191803A - Abrasive material - Google Patents

Description

Patented Feb. 27, 1940 2,191,803

'UNITED STATES PATENT OFFICE 2,191,803 ABRASIVE m'mami.

Frank D. Oesterle, 'I'eaneck, N. 1., and George Zellar, Harrison, N. 1., assignors to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York No Drawing. Application July 2, 1938,

' Serial No. 217,216

Claims. (Cl. 51-280) This invention relates to an abrasive material well adapted to produce a uniform effect on and more particularly to an abrasive material curved and irregular surfaces. peculiarly adapted for use in finishing and're- With these and other objects in view, one emfinishing ornamental surfaces. bodiment of the invention may comprise a flexipurpose is to produce an ornamental appearance fabric, a body thereon of flexible and resilient upon a surface by means of coatings applied adhesivematerial, e. g., printers roller compound thereto, coatings of paint, varnish, enamel, and of glue and glycerine or soft rubber, and abrasive the like, oils, waxes and pastes of many kinds, grains embedded therein.

i0 platings of metal deposited by spraying, electro- Other objects and features of the invention will deposition, chemical deposition, etc., and others clearly appear from the following detailed dein almost indefinite variety. In a great many scription of embodiments thereof. instances of such procedures, an abrasive medium To make one preferred embodiment of the inmay be used to modify the original surface, the vention, a sheet of ordinary commercial unsurface of some intermediate coating thereon, or bleached muslin may be used as the base, say a the final surface. Purpose of such abrasive may muslin having 5Qx 56 threads to the inch. For be to remove larger or smaller irregularities, to corfvenience of use, it is preferred to apply the roughen or matt a surface to give anchorage to adhesive compound to one side only of this a coating to be applied thereto or to give a decloth base, although both sides may be coated There is a great variety of procedures whose ble base such as loosely woven or knitted textile 5 sired final matt appearance, "or to smooth or if desired. 20'

polish the surface. A preferred compound for use as the body coat To effect such abrasive results, it has long. on the cloth may have the following composition: been well known to use powdered abrasives, sand,

' Per cent emery, carborundum and the like attached to a laminar base, paper, cloth, felt, and such by 355 2352 25 means of common adhesives like glue, thus makwater I" about. 10

ing the well known sand paper, emery cloth, carborundum boards, and such. These abrasive and for some purposes there may be added to tools suffer from two familiar defects: they are the above about 3% of linseed oil which acts still generally, and the abrasive grains are rigidly ppa e t y to ug the O -P Without 30 secured by the adhesives commonly employed to hardening it. To preserve this compound against the backing. Hence, in use, especially on a'ourved attack by mold, or by flies and other insects, or warped surface, in some instances such abrathere may als be add enough o a Satu ated sive sheets will not conform properly to the sursolution of copper sulfate in water to give the face and unless great care is exercised the anradwhole a content of about 01% copper sulfate. '35 ing is-uneven. If the abrasive sheet is forced The above formula yields a compound giving to curve beyond its naturally limited ability, it aproduct as described below'which is-eminently may tend-to crack and the grains along the satisfactory for use in roughening and smoothsharply folded crack may form a saw edge which ilm varnished, japan ename 1 lacquered 40 may do difiicultly reparable damage. Also, the surfaces on sheet metal, especially where the 40 grains are in effect miniature planing t0o1s mount-, metal sheet has been formed into curved ored by the rigid adhesive on the backing sheet warped contours. which is itself rendered stiff and rigid by the The above described compound is one well absorbed or impregnating adhesive. Hence the known and commonly obtainable in commerce permissible pressure, to avoid too deep cutting, under the general name of printer's roller com- 45 i. e., unsightly scratching, is limited by those of pound", it beingused widely in the printing art the grains which protrude beyond the average as material for making rollers used in apparatus surface of the grains; and, because a few grains for both direct and offset printing. are therefore excessive in effect, the majority To apply the compound to the cloth or other 60 must be inefliciently used. base, the compound may be melted and made 60 An object of the present invention is-to produce suiilciently liquid to form a closely adherent coatan abrasive material of the'general nature de-. ing onthelcloth without at the same time satuscribed, which shall be highly emcient in use, f ung- 0; penetratingthe cloth completely. The durable, capable of acting under high pressure compoun d may be applied to-the cloth in any without producing objectionable scratching'faiid, convenlentlandsuitablemanner, e. g., by running the cloth over "a roller which dips into the surface of the melted compound, or by painting the melted compound or pouring it and spreading it on the cloth. I

The coated cloth may then be allowed to cool, dry and partially harden to still somewhat tacky surface state. Abrasive powder is then applied to the faintly sticky or tacky surface of the compound and the whole allowed to cool and harden completely.

A preferred abrasive for use as described above on lacquered metal or the like, is artificial aluminum oxide, such for example as that commercially known by the trade name Aloxite, with a grain size of 120 mesh. It may be applied to the tacky adhesive on the cloth by any suitable and convenient method, e. g., by sprinkling an excess on and shaking, or by passing the coated cloth in front of a dust blower charged with the abrasive, or'by passing the coated cloth over a roller located in a container filled with the abrasive.

The coated cloth thus loosely charged with abrasive is then preferably passed between rollers to embed the abrasive firmly in the resilient jelly-like layer of adhesive. Because of the jelly consistency and character of the resilient coating this is not ordinarily to be accomplished by pressure alone. Preferably the roller against which the uncoated rear face of the cloth runs is cold, even chilled by being-hollow and having cold water circulated through it, while the cooperating roller which runs against the abrasive and adhesive coated side is heated by any suitable and convenient means such as steam. The heated roller is preferably maintained at such a temperature, dependent among other factors on the speed of the coated sheet over it and the thickness and intrinsic hardness of the adhesive used, as will superficially melt the upper surface of the adhesive to receive and partially embrace the grains of abrasive, but will not melt the under surface of the adhesive enough to cause it to soak through the cloth.

The laminar product, after being thus calen-, dared, is then allowed to cool and harden completely and is then ready for use.

Theproduct made as above described, with the glue-glycerine adhesive whose ingredient proportions are specified above and with 120 mesh Aloxite as its abrasive, may be compared, "for illustration of its advantages, with an ordinary sand paper or emery cloth having plain glue as adhesive and 240 mesh silica sand or emery as abrasive. The sand paper or emery cloth is stiff. It cannot be bent to any reasonably snrall radius without the production of saw edged, cracked creases which are practically certain to produce unsightly scratching, especially if appliedto concavely curved work. The product of the invention is nearly as flexible and crumplable as the original cloth. It creases in much the same manner as the original cloth, in creases or f lds whose edges are not cracked, and hence not s wtoothed.

Although the product of the invention as described has an abrasive of 120 mesh, twice as coarse as the 240 mesh abrasive of the sand paper or emery cloth, it may be applied to and rubbed over a piece of work under even greater pressure than that which causes the sand paper or emery cloth described to produce objectionable scratches, without any such objectionable efiect.

Furthermore, the product of the invention may be used far longer before becoming useless resilient adhesive, so that any grain that 'pro-,

jects beyond the average level of the cutting points of the grains generally is relatively easily forced back into the resilient jelly until the cutting pressure is fairly evenly divided among 'all .the grains. In a sand paper, emery cloth or the like made in the ordinary fashion with a hard adhesive, the grains are rigidly held relatively to each other andto the backing. Hence any grains protruding beyond the average will not yield and retire, but will bear all the burden of the pressure in its neighborhood and so cut abnormally deeply until it has entered thework far enough to permit nearby grains to begin to cut.

The flexibility of the product of the invention arises primarily from the resilient, jelly-like nature of the adhesive. Hence even if the cloth, paper or ,other backing be saturated or coated with the adhesive on both sides and provided with abrasive on both sides, the flexibility and softness of the double sided product are but little less than in the one sided product, and are still far greater than with a hard adhesive such as glue.

In another method of making the product of the invention, the adhesive compound may be prepared and melted as before, and when melted maybe charged with the powdered abrasive by stirring the latter into the melted abrasive until evenly distributed therethrough. This mixture of adhesive and abrasive may then be coated upon a suitable base or backing in any suitable manner.

The invention is not limited to the use of a laminar backing or even to a flexible backing. Thus in the rifles used as sharpening instruments for scythes, sickles and the like in place of whetstones and which comprise a rigid core,

e. g., of wood, ordinarily of a. generally oval or elliptical cross section, and covered with an abraresilient freedom of motion relatively to each other, material jammed and caught between the grains during one working stroke of the rifle are apt to be released and shaken outat the next.

Where even more resilience is desired, e. g., in working on a corrugated or other analogous surface, a resilient wad-like or pad-like backing or abrasive charged compou d until saturated through and then cooled and hardened. Such a mass will then present fresh working surfaces wherever torn or cut apart. For such embodiments of the invention resiliently spongy masses may be used as a base, e. g., natural sponge, sponge rubber, or the like.

While in the adhesive compound described above the glue and glycerine are given in the ratio of two to one (60% to 30%), this proportion of these two ingredients may be varied from about one to one to 45%) to about five to one (75% to 15%) if it be desired to vary' the hardness and toughness of the compoundwithout taking away its resilient character. So also, the water content, given above as 10%, may be varied relatively to the total amount of glue and glycerine combined. The embodiments disclosed are illustrative and may be varied in many ways without departing from the spirit and scope of the invention as pointed out in and limited solely by the appended claims.

What is claimed is:

1. In a material for abrasive uses comprising a limply flexible base of textile threads and a granular abrasive of hard mineral substance, an adhesive compound to secure the abrasive to the base and comprising 45 parts to 75 parts dry glue and 45 parts to 15 parts glycerine and 5 parts to 15 parts water and 1 part to 5 parts linseed oil.

2. In a material for abrasive uses comprising a limply I flexible base or textile threads and a granular abrasive of hard mineral substance, an adhesive compound to secure the abrasive to the base and comprising 45 parts to 75 parts dry glue and 45 parts to 15 parts glycerine and 5 parts to 15 parts water and 1 part to 5 parts linseed oil and ,4 to A part copper sulfate.

3. In a material for abrasive uses comprising a limply flexible base of textile threads and a granular abrasive'of hard mineral substance, an adhesive compound to secure the abrasive to the base and comprising about parts dry glue and about 30 parts glycerine and about 10 parts water and about 3 parts linseed oil.

4. In a material for abrasive uses comprising a limply flexible base of textile threads and a granular abrasive of hard mineral substance, an adhesive compound to secure'the abrasive to the base and comprising about 60 parts dry glue and about 30 parts glycerine and about 10 parts water and about 3 parts linseed oil and about part copper sulfate.

5. In a material for abrasive uses comprising a limply flexible base of textile threads and a granular abrasive of hard mineral substance, an adhesive compound to secure the abrasive to the base and comprising 60 parts dry glue and 30 parts glycerine and 10 parts water and 3 parts linseed oil.

FRANK D. OESTERLE. GEORGE ZELLAR.