US2254531A - Coating apparatus - Google Patents

Description

Sept; 2, 1941.

H. P.-KIRCHNER ETAL COATING APPARATUS Filed Obi. 10, 1952 2 Sheets-Sheet 1 m M m m n NENNH N E R VHTE 0 N T Immc T K .O A E M YE R M NMY EOA HRR Y B Sept. 2, 1941. H. KIRCHNER ETAL COATINGAPPARATUS Filed Oct. 10, 1932 1f 3- z 5 c Z6 2 Sheets-Sheet 2 INVENTORS HENRY P. mam-ms: ROP'HE L.MEL.TON-

RAYMOND c. BENNER ATTORNEY the granular particles Patented Sept. 2, 1941 UNITED STATE PAT BN1 OFFICE o coarme srrsaa'rus Henry 2. Kirchner, mm. 1.. ma. menumond C. Bonner,

by meene assignments, Company, Niagara Falls, N. Y., a corporationuf Delaware.

Niagara Falls, N. Y aseignors,

'to The Carborundum Application October when, sci-n1 No. 637,010

'iClaims.

This invention relates to improved apparatus for the manufacture of granular coated webs of such materials as paper, cloth, or the like, ancthas for an object the. provision of improved means for securing a superior'productgreater s efliciency and/or lower cost ofproduction of-the coated article. Abrasive particles commonly used in the manufacture of abrasive coated fabrics are of two I generalgtypes; namely, elongated and blocim, M The formertype comprises splintery-grain, in

which the grain has one dimension longer than the others, and plate-like grain, in which the grain has one dimension materially smaller thanthe others. The blocky-type of grain has all of its dimensions substantially the same. We have"- found that abrasive coated webs made by orienting a large proportion of the elongated particles sin such a manner that their longer dimensions are norinaito the web to which they are attached, are decidedly faster cutting and more eflicient than coated webs in which the particles are haphazardly arranged, as happens in the usual method of coating webs, or in which but a relatively few of the particles are so oriented.

said granular particles readily susceptible to magnetic forces. This particular type of grain may be selected from the regular run of crushed" a layer of magnetic material such as metallic iron, iron oxide (Feaoi), or the like. In applying the magnetic material, the granular particles can be coated first with an adhesive such as lacquer, varnish vor the like and then coated with a layer of the magnetic substance. After the adhesive sets the grains are ready for use;

Our invention provides apparatus for positioning elongated, magnetically susceptible granular particles on adhesively coated materials in such a manner that a substantial proportion, fr quently exceeding fifty per cent (50%) of these.

. granular particles are uniformly and individually Thepresent invention relates to a machine for electro-magnetically securing such orientation of We have found that a relatively. large proportion of the granules used to coat webs can be oriented at will by the useof a new form of apparatus that we have invented; and which I avoids certain disadvanages inherent in the previously disclosed apparatus and methods. Our apparatus does not require-the employment of high voltages; itis rugged, easily built, easily operated, readily adjustable to varying conditions, and economical in operation. 'In addition, it has a numberof other advantages that will be more apparent after our invention has been explained.

Apparatus constructed in acoordance with our invention utilizes the magnetic susceptibility of granular particles of the type commonly used in the manufacture of granular coated webs or the readiness with which such particles can be made magnetic. While all granular particles are acted'upon to a greater orless' degree by magnetic forces, a very strong magnetic field is required to exert an appreciable force on some types of abrasive grain commonly employed .in

oriented socthat their largest dimensions are at a'predetermined angle with respect to the surface of the fabric'material.

Abetter understanding of our invention can be had by referring to the accompanyin draw- 1118 .11! which:

Figure 1 one form of our improved apparatus;

Figure 2 is, an enlarged view of the electro-- magnetic orienting zone of Figure 1; and

Figure 3-is. a diagrammatic side elevation of anotherform of our apparatus. Figure l of the drawings shows means A for holding and dispensing a roll 2 of the web P;-

means Bfor applying adhesive to one face of the web P; means 0 forapplying granular material to the adhesive side of the web P; means D for causing a preliminary set of the adhesive;

andmeans I: for drawing the web through the j coating apparatus and into a drying chamber.

, the manufacture of] abrasive fabric materials. We have found that suitable grain can be obtained by selecting particles each of which contains 'sumcient magnetic impurity The means A for holding anddispensing the web P comprises, as shown inthe drawings, a

framefil that supportsthe roll-2 of web P; an idler roll I for guiding the web; printing rolls 4 and 8 for marking the web-with any desired legend or identification; and an idler roll I for guiding. the web.

. The adhesive applyingmeans 13 comprisea as' shown in the dra'wingaidler rolls 0 guiding the web; a roll Ii positioned to 8 .for into so asto render apan l I-of adhesive: a roll 13- i'or maintaining is a diagrammatic side elevation of adhesive to the 'web.

' upper pole piece 24, the particles-are attracted ings, idler rolls I9 and 2| for guiding and positionin'g the web; an electromagnet 22 having upper and lower pole pieces 24 and 2! respectively, which are so designed as to produce a strong, concentrated ma netic field: an electromagnet 28 with upper and lower pole pieces 22 and 2! so designed as to produce a distributed magnetic field of relatively strong intensity at the area adjoining the field of magnet 22 and of gradually decreasing intensityat itsother end (as represented diagrammatically by the dotted lines of force) magnet 26 being so placed with.respect to magnet 22 that the two fields are substantially continuous and substantially vertical; an endless feed belt 41, positioned below and substantially. parallel to the web P, and enclosing the pulleys 42, 42a, 43 and 42; a hopper I! with an adjustable gate, 34 and a roll 21- for dispensing the granular material to the feed belt adhesive on the underside of the material P and adhere in an u ght or oriented position.

Upon passing out of the field of magnet 22 the coated web immediately enters the field of magnet 20, the two being preferably so positioned as to be practicallycontinuous, and leaves this field where it is of low flux density. The magnet 22, the upper pole piece 24 of which is close. to

- the upper side of the coated web, causes the abrasive particles to move upwardly and attach themselves to the bottom of the web in an oriented position; and the magnet 26, the pole pieces of which are symmetrically and evenly spaced from the web, insures that the particles are oriented vertically'as the paper passes between and out from the Poles of this magnet.

Immediately after leaving the grain deposition zone, the adhesive carried by the web is' subjected to a preliminary setting operation so that 4i; and variable speed driving means 44 and 4 for operating the feed belt 4|. 1

The means D for causing the adhesive to acquire a preliminary set comprises, as shown in' the drawings, an idler roll 49 and a fan blower 42 for supplying a large volume of air at'a low velocity to the adhesive and granular coated side coating apparatus into the drying chamber comprises, as shown in the drawings, one or more suction drums BI and 52; an idler roll 52; a rack 55 for supporting the web P; and an endless conveyor 84 for transporting loops of the web P to the rack 55. In the normal operation of the apparatus illustrated herein, a. roll of the uncoated web "P, such as paper or cloth, is rotatably mounted on the frame I and-the webis threaded over the roll I and between the printing rolls 4 and I and thence in contact with the idler rolls I, 4 and 4- to the pressure roll i3 and the adhesive roll II. The adhesive roll it ,dips into liquid adhesive tank l2 and by its rotation applies a layer of The adhesive 1y coated material P, passes between the brush drum ii and a vibrating brush it, which evenly distributes the, adhesive and smooths out any ridges. It is then guided by the idler rolls i8, I9 and 20 into a magnetic field-set up between the pole pieces of the electromagnets 22 and 26. g i

Granular particles are distributed from the grain hopper 25 onto the grain feed belt 4|, which moves through the magnetic field parallel to the web P and in the same direction as shown,

in an enlarged view as Figure 2. The field of magnet 22 energizes the granular particles, causing them to become, in effect, miniature magnets with poles at their extreme'ends or in other words, in such a manner that their magnetic axes lie along their major axes. Since the feed belt II is positioned nearer to the face of the to the upper pole 24 of this magnet and propelled toward it while so positioned that their major axis are coincident with the magnetic lines of force, which are substantially vertical. Thus the granules will be retained in their oriented position. The coated web then passes around the idler roll 4| and'suction drums II and I2 to a 'dryingrack II where the adhesive is permitted t'o-set fully.

'Fisure re esents. ification of apparatus adapted to orient granular particles that are fed into the magnetic zone by garvity. This apparatus comprises an electromagnet'll with pole pieces 12 and 14 of a design similar to those ofmagnet 2K0! Figure l: a

grain-deflecting member 'll; rolls 14, II and I. for guiding and positioning the'adhesive coated web through and away from the grain deposition zone; and grain dispensing means 25, 24 and I'I.

In the operation of this form of apparatus the granular particles fall toward the magnetic field, the'weaker part of which is positioned upward.

The particles, deflected toward the pole piece 12 by the grain deflector II, are, gradually charged magnetically and are then attracted toward pole piece ll while oriented with their major axes substantially horizontal. They are intercepted, however, by the adhesive coated web, and produce thereon a coating of particles so oriented that their major axes are normal to the web.

The coated web is immediately passed around.

roll 16 in such a manner that it will assumes horizontal position so that the orientation of the particles will not be destroyed by gravitational attraction. a

In the operation oi apparatus constructed as illustrated, the intensity of the magneticfield is adjusted to such a value that the abrasive particles on the feed belt 4| become charged and are propelled toward the pole piece 24 and strike the adhesive coating on the 'web P with vsuificient force to partially embed themselves and adhere thereto. Other factors remaining constant, we 4 have found that the field intensity required to magnetically propel the charged granules into engagement with the adhesively' coated web varies in proportion to the size or mass of the the teed belt; will remain and be carried into the bin 41. g

We have found it desirable, ihgeneral, to apthe longitudinally oriented granules strike the to ply a surplus of grain to the feedbelt It as this diagrammatically, a modassists in producing a coating of uniform density. Different densities of grain coatings can be obtained by varying the current that energizes the magnet so that the lifting power of the magnet is increased or decreased to raise more or less particles fromthe feed belt. The density of 'the coating of the granular material on the web also can be increased or decreased by. adjusting the upper pole of'the magnet closer to or further Surface o the granular material on the feed belt. w

Not all granular materials are equally afiected by magnetic forces, some being readily afiected and others being slightly afiected or requiring intense or highlyconcentrated forces to produce an appreciable eifect. Apparatus constructed in accordance with our invention is readily adaptable to these different degrees ofsusceptibility and is positive in action. When used with materialthat is readily susceptible to magnetic forces the intensity of the field set up between the poles of the magnet can beadiusted to produce a granular coated web of the desired characteristics. By adjustment of the intensity of the magnetic field to a higher concentration on greater fiux density less susceptible particles are caused to act in the same manner as more susceptible particles act in a lower intensity field.

Abrasive granular material, as delivered by the roll'crushers ordinarily used to break up the crude material, consists of grains of irregular shape and proportions. Such grain may-be designated in general as of tgvo types, blocky grain and elongated grain. Elongated grain may consist of splintery or needle-like particles having one dimension appreciably longer than the others It is the elongated type of material that is particularly susceptible to orientation and which can be advantageously f oriented since particles that are similar in all dimensions will act in much the same way regardless of the position they are caused to assume on the backing. Our

- apparatus willorient a large part if not substantially all of the elongated-grains which occur. If it is desired to make aparticularly sharp product, the elongated type of grain can be separated from the blocky particles, for example by an air separation and used exclusively.

While our. apparatus is not adapted to deposit and orient materials that are totally devoid of magnetic properties, it operates efficiently to dev posit and orient magneticgranular materials or non-magnetic materials that have been rendered,

magnetic. It is particularly adaptable to such materials in that the magnetic field has an ori-' enting influence greater than that of an electrostatic field in such materials. Moreover, in our apparatus, the very high voltages necessary for electrostatic apparatus are dispensed with. It has a further advantage over electrostatic ap aratus in handling materials that are electrically conductive, as well as being magnetic, since the conductivity of granular material interferes sume the desired normal position once they have become embedded in the adhesive.

In our apparatus, the magnetic granular material is projected onto the adhesive coatedweb as well as being oriented. The particles, in their travel toward-the adhesive coated surface. have become oriented with their longest dimensions substantially vertical to the surface so that they embed themselves in the adhesive in such position. In both forms. of apparatus illustrated, the

orientation at right angles to the face of the web is maintained as the web passes beyond the magnetic field. In the form of apparatus shown in Figure 2, the magnetic field of the magnet 20 is symmetrical so'that the lines of magnetic force are vertical. As the coated web passes from beyond this field, the force ofgravity tends to hold the particles with their longest axes vertical. In the form of apparatus shown in Figure 3, the magnetic lines of force below. the bottoms of the pole pieces are preferably normal to the surface of the web as it passes over the roller II and thus tends to retain the particles with their longest.

' axes normal to the face of the web. As the web or of platey particles in which two of the dimensions will be greater than the other. I

with the eiiicient operation of electrostatic'apparatus. I

Another .advantage which our apparatus has over previous machines resides in the fact that the granular materials are made to strike the I adhesive coated web endwise. when elongated particles are deposited by theaction of gravity, as is the case with apparatus heretofore know elongated particles tend to strike the adhesive in such a position that their long passes beyond the roller I3. and into horizontal position, the force of gravity tends to hold the particles in such oriented position until the adhesive has become at least'initialllLset. I

The electromagnets may be energized either by direct or by apulsating electric current such as a rectified alternating current. an'intermittent direct current or even. an alternating current.

Where a pulsating current is employed, thedirection of thepulsations should be great enough to effectively attract and orient the particles.

Other advantages will be apparent from the foregoing disclosure to those skilled in the art and while specific embodiments havebeen used to illustrate our invention, it is to be understood that the invention is not limited to those embodi i'nents but is defined by the appended claims.

intensity away from the concentrated field.

means for passing an electriccurrent around the cores of said magnetameans for supporting an adhesive coated web in the field and nearer the upper than the lower pole pieces of said magnets and with an adhesive coated side down, and

means for introducing granular material into said ,field between the lower pole pieces of the magnets and the adhesive coated web.

2; Apparatus for the manufacture-of granular coated webs comprising a' magnet with two oppositely positioned poles so located as to set up substantially horizontal magnetic field of relatively low intensity-at its upper side and of grad-' ually increasing intensity downward, means for v energizing said magnet, means for conducting an adhesive coated web into and downward nsion lies through said field nearer one pole ofthe magalong the plane of the web. Obviously such a position is contrary to that desired where a product having the long dimensions normal to the web is being made and it is diillcult to cause such particles to change their position and asnet with an adhesive coated side facing the more remote pole, and means for supplying granular material to said field from above to a place between an adhesive side of the ,web and the pole that the adhesive coated side faces but nearer to the opposite pole.

3. Apparatus for the manufacture of webs coated with oriented granular material compris ing means for supporting an adhesive coated web with the adhesive surface facing downwardly, means for projecting magnetically susceptible particles upwardly against the adhesive coatedsurface of the web. and magnetic means for orienting the particles with respect to the web.

4. Apparatus for the manufacture of webs coated with oriented granular material comprising a magnet having oppositely positioned poles for producing a magnetic field therebetween, means for supporting a web between said oppositely positioned poles and within'said metic field and nearer one of the said poles, said web being coated with an -adhesive on that surface facing the more distant pole. and means for.con-' veying magnetically susceptible granular material into the magnetic field adjacent the adhesively coated side of the web.

5. Apparatus for the manufacture of webs coated with oriented granular particles comprising a magnet having oppositely positioned upper and lower poles, means for passing between said magneticpola' a web coated with adhesive on its lower surface, a feed belt movable between the adhesive coated surface of the web and the said lower pole for conveying magnetically suseeptible granular particles. and means for pro- Jecting the particles upwardly from the feed belt against the adhesive coated. surface of the web asit passestosaid p ,8-' v 6. Apparatus for the manufacture of webs coated with oriented granular particles 6011113218! ing 'a magnet having'oppositely positioned upper and lower poles, means for passing a web coated on one surface with an adhesive between said poles with its. adhesivecoated surface positioned downwardly. and means for projecting magnetically susceptible granular particles upwardly against the downwardly facing adhesive coated surface of the web as it passes to said poles.

L'Apparatusfor. the manufacture of webs field adjacent the-adhe'sively coated surface of the web. 1

' HENRY P.

ROMIE L. HILTON.

RAYMOND C. DINNER.

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