US3671373A - Paint applicator or the like and method of making the same - Google Patents

Abstract

A PAINT APPLICATOR AND METHOD OF MAKING THE SAME COMPRISING AN OPEN-CELL, YIELDABLE SYNTHETIC FOAM BACKING MATERIAL HAING FLOCK ADHESIVELY SECURED DIRECTLY TO THE FOAM SURFACE, PROVIDING A FREE-FLOW PATH BETWEEN THE FLOCK AND THE INTERIOR OF THE FOAM MATRIX. THE INVENTION RELATES FURTHER TO A METHOD OF MAKING AN APPLICATOR OR THE LIKE HAVING THE ABOVE DESCRIBED CHARACTERISTICS.

Description

J. GREWE 3,671,373

PAINT APPLICATOR OR THE LIKE AND METHOD OF MAKING THE SAME `June 20, 1972 2 Sheets-Sheet `1 Filed Aug. ll, 1970 INVENTOR. JOSEF @REWE W/W/Qfau,

ATTORNEY June 20, 1972 J. GREWE 3,671,373

PAINT APPLICATOR OR THE LIKE AND METHOD OF MAKING THE SAME Filed Aug. ll, 1970 2 Sheets-Sheet 2 '4 2/ ATTORNEY United States Patent Oliice Patented June 20, 1972 3,671,373 PAINT APPLICATOR R 'I'HE LIKE AND METHOD 0F MAKING THE SAME Josef Grewe, Hagerstown, Md., assignor to Electra Flock, Inc., New York, N.Y. Filed Aug. 11, 1970, Ser. No. 62,844 Int. Cl. B44d 3/00 U.S. Cl. 161-64 14 Claims ABSTRACT 0F THE DISCLOSURE A paint applicator and method of making the same comprising an open-cell, yieldable synthetic foam backing material having flock adhesively secured directly to the foam surface, providing a free-ow path between the ock and the interior of the foam matrix. The invention relates further to a method of making an applicator or the like having the above described characteristics.

BACKGROUND OF THE INVENTION Field of the invention This invention is in the field of applicators for applying liquid coatings, and particularly to paint applicators.

The prior art It is known to apply paint to wall surfaces and the like through the use of applicators other than brushes, such as, for instance, paint rollers, etc. In certain forms of paint rollers, a pile material is employed as the work contacting substance to effect the transfer of paint.

The paint applicator may be formed by electrostatically depositing flock onto a cylindrical form which is used as the paint roller sleeve. Such sleeves are disadvantageous in that the paint holding capacity of the sleeve is quite limited, requiring frequent reapplication of paint thereto. Moreover, in view of the limited paint absorbing capacity of such apparatuses, there is a tendency, when the roller is dipped into a paint reservoir, for the paint to accumulate in certain portions or areas of the roller, such as, for instance, a portion of the roller which is lowermost when the roller is dipped into the reservoir. In painting with such an appliance, it will be readily apparent when viewing the painted surface that the paint density is not uniform, being greater in the areas tracked by the highly saturated portions of the roller. In such cases, in order to even out the coating, it is necessary that the roller be scanned several times over the same area to equalize the paint density.

Also, such rollers have the obvious defect of requiring frequent resaturation with paint, which resaturation materially increases the time required to cover a given area.

In certain high quality paint rollers, the painting surface is defined by pile integrally formed with a heavy absorbent backing. While such rollers are highly eicient in use and correct the deficiencies inherent in paint rollers having a low paint carrying capacity, the improved pile type rollers are extremely expensive, militating against their use by amateurs, their use being restricted, for economic reasons, to professional painters where high labor costs are a factor and where a roller sleeve will be carefully recleaned and reused.

In a compromise form of paint applicator, a fabric material of somewhat porous nature is provided with a pile or ock coating. The fabric is thereafter secured about a cylindrical foam matrix, which is in turn carried by the paint roller core or sleeve. It is the object of such device to permit the foam underlayer to act, to a degree, as a reservoir.

However, this type of roller has met with little commercial success for several reasons, including (a) the existence of a seam where the fabric is joined into an annulus, (b) the fact that the communication between the paint applying surface and the interior of the foam underlayer is quite restricted in view of the requirement that the fabric be adhesively supported on the foam and the fact that the foam is compressed and its paint holding capacity reduced by the cover fabric; (c) the fact that the pile or ock orientation, after the fabric is applied about the cylinder of foam, is distorted so that the pile assumes an undesired random, i.e. non-radial, orientation relative to the periphery of the applicator; (d) the tendency of the texture of the fabric matrix from which the pile is supported to be transferred or reproduced on the painted surface; (e) the inability of the fabric coated foam to conform accurately to irregularities of the painted surface.

An ideal paint applicator would constitute a quantity of ock material supported directly from a porous or open cell foam surface without any intervening ock carrier fabric, the flock being disposed normal to the surface.

The flock, while supported from the surface, should permit free passage of paint into the foam matrix so that the matrix may act as a reservoir. Such a construction would be inexpensive since both the Hock and foam materials are inherently inexpensive, and would provide all the advantages of the professional types of rollers hereinabove described.

Heretofore, however, no one has been able to produce such a device on either a commercial or non-commercial scale. A primary diliiculty has been the problem of permanently attaching the ock to the foam surface in such manner as to permit a substantially unimpeded How of paint from the interior of the foam to the ends of the flock. The basic problem has been that in attempting adhesively to connect the flock to the foam, the adhesive has sufliciently reduced the porosity of the foam at the hoek-foam junction to preclude the foam from acting as an effective reservoir for paint.

SUMMARY OF THE INVENTION This invention relates to a method of applying ock to a porous foam sleeve or like matrix in such manner that the foam may act not only as an effective carrier for the ock but also as an effective reservoir for paint to be fed to the flock.

The invention further relates to an article produced in accordance with the method.

Briefly, the method of the present invention involves the carrying out of a series of steps, the total effect of which is to provide a connection of ock to foam wherein the flock is securely attached to the external surface of the foam without materially impeding the ability of paint to flow to the pores of the foam and back through the pores to the tips of the ock. The method includes, as an important step, preliminary partial or complete saturation of the foam material with a fugitive uid substance. preferably, steam, water vapor, etc.

After the partial or complete saturation, the surface of the foam is subjected to an application of an adhesive substance which preferably does not form a continuous or impervious coating over the foam but, rather, is concentrated at the crests of the foam, i.e. the solid walls deining or surrounding the pores. The adhesive may be applied in this manner preferably by an electrostatic deposition, the concentration at the crests being the result of the greater proximity of the crests to the adhesive source than the floors or bottoms of the cells.

Preferably, the fluid material employed in the partial or total saturation step also functions to render the foam suillciently conductive to enable the foam to form an electrode for the electrostatic reception o-f the adhesive.

Preferably the solid content of the adhesive is such that when the solvent or base of the adhesive is driven off, the volume of the adhesive is materially lowered.

After the adhesive is applied to the foam, flock ma terial is caused to adhere to the tacky but not fully cured or set adhesive material which, as noted, is concentrated primarily at the crests of the foam material.

After the flock is secured to the adhesive, the fugitive fluid material is driven outwardly from the interior of the foam through the surface or boundary between the foam and the flock, and noted outward movement materially increasing the free-ilow characteristics which have, at least in part, Ibeen impeded by the presence of the flock securing adhesive. Preferably the fugitive fluid material is a solvent for the adhesive, further to increase the free-llow characteristics above noted.

The outward flow of the fluid together with the contracting tendency of the adhesive provide a nished product in which the foam material functions efficiently as a reservoir for paint, enabling paint to flow freely to the flocked surface when pressure is applied by the roller against the surface to be painted.

Preferably the saturating fluid is steam or water Vapor and the adhesive is a water based adhesive and the step which is employed to drive the fluid outwardly is a heatingdrying step which also functions to set or cure the adhesive.

Accordingly, it is an object of the invention to provide a method of forming a paint applicator or the like wherein flock material is attached directly to the surface of a foam material, the ilock being held by an adhesive material, which adhesive does not materially impede the flow of paint between the flock and the foam carrier, i.e. does not seal the surface of the foam.

A further object of the invention is to provide a paint applicator of the type described.

To attain these objects and such further objects as may appear herein or be hereinafter pointed out, reference is made to the accompanying drawings forming a part hereof, in which:

IFIG. 1 is a diagrammatic plan view of the stages employed in fabricating the paint applicators;

FIG. 2 is a diagrammatic side elevational view of the applicator flocking apparatus;

IFIG. 3 is a diagrammatic view of the adhesive applying apparatus;

FIGS. 4, 5 and 6 are modified diagrammatic sectional views through the applicator components in progressive stages of completion, respectively, after application of adhesive; after flocking; and after completion of the fabricating process.

Referring now to the drawings, it will be appreciated that while the `apparatus is shown and described in connection with the manufacture of a paint roller sleeve, the method and article of the present invention are not limited to the formation of cylindrical rollers. Rather, the apparatus is suited for a Wide range of paint applicator shapes and forms.

lIn FIG. 1 there is shown a diagrammatic plan view of a conveyor apparatus illustrating the sequence in which the steps of forming the applicator are carried out, the conveyor apparatus 20 progressively advancing the article through the Various production stages numbered 1 to 12.

Briefly, in stage 1 cylindrical cardboard tubes impregnated with a phenolic resin or like cores 21 are manually or automatically sleeved on core advancing varrns 22 comprising mandrels. The mandrels are electrically insulated from the conveyor apparatus.

Stage 2 is a core immersion station wherein the cores are dipped into water to render them electrically conductive.

`At stage 3 a thermoplastic adhesive is electrically applied to the exterior surface of the cores.

At stage 4 the cores are heated to cause the water to be driven oil" and thereafter to cause the electrostatically deposited adhesive material to melt and coat the external surface of the cores. Stage 4 includes a terminal cooling apparatus which hardens the coating of thermoplastic adhesive, rendering it no longer tacky.

fAt stage 5 foam sleeves are mounted over the coated cores.

At stage 6 the cores carrying the foam sleeves are subjected to steam saturation, to render the foam electrically conductive and for other purposes which will hereinafter be set forth.

At stage 7 an adhesive is applied, preferably electrostatically, to the external surface of the foam.

Stage 8 constitutes an electrostatic ilock application station, at which station dlock is electrostatically applied in a desired orientation and concentration to the external surface of the foam.

`Flockecl sleeves progress to stage 9, which is an air drying oven, to stage 10 which constitutes a cooling station, to stage 1=1 whereat the sleeves are vacuum cleaned to remove any non-adherent ilook, the cores being unloaded from the conveyor at stage 12. Y

The llrst five stages are essentially conventional and, thus, need not be described in detail, it being recognized that there are alternate methods or means for effecting the procedures carried out at such stations.

The primary novelty of the present invention is considered to reside in the succeeding steps, namely step 6 et seq.

Turning now to the preferred materials for use with the invention, it should be understood that the description of specific materials shall not be taken in a limitative sense but, rather, it should be -understood that the materials have been specifically defined, for purposes of compliance with the patent laws, as illustrating a preferred mode of operation.

The core constituting the tube 21 is preferably spirally formed of a series of kraft paper strips or of vulcanized fiber impregnated with a thermosetting resin or the like (i.e. a phenolic resin) for improved mechanical properties. Optionally but preferably, the tubes may be ground to provide a uniform surface.

At step 2, the ground core or tube is submerged in water for approximately ten seconds. The grinding procedure, in addition to providing uniformity, prevents water from being repelled from the surface, resulting in the formation of a continuous film on the surface of the tube.

It will be appreciated that the length of tube or core treated in accordance with the method need not and preferably does not conform to the ultimate desired length of paint applicator. Rather, elongated tubes are treated and subsequently cut to the finished lengths.

At stage 3 the cores having the adherent water illm are passed over a transversely extending conveyor 23, the surface of which conveyor is provided with an even sprinkling of a hot melt powder or adhesive, preferably comprising a polymer base of ethylene and vinyl acetate. The particle size of the powder is, illustratively, between .3 and .5 mm., with a melting point ranging between to 108 C. The powder, prior to deposit on the lateral conveyor 23, is preferably slightly conditioned with steam, to render it electrically conductive.

The conveyor belt 23 passes over a ilat grounded electrode. As the mandrels 22 are guided over the conveyor belt 23, the mandrels are contacted by a brush conductor having a high voltage charge of approximately 60 kv. DC negative against ground up. The mandrels 22 are rotated constantly as they proceed and the electrostatic eld forces the powder to leave the conveyor against gravity and deposit on the high voltage charged tubes which have been rendered conductive by the water film.

Additionally, the water film functions to maintain the particles on the surface of the tube rather than dropping free under gravitational influence.

The powder density can be varied as desired by modifying both the potential of the electrostatic field and the spacing of the mandrels from the conveyor and ground electrode.

The powder coated cores or tubes thereupon proceed to stage 4, at which stage the cores are heated in an infrared oven, driving olf the moisture and causing the powder to melt, to form an even adhesive film 24 (see FIGS. 4 and over the cores.

At the terminal end of stage 4, the cores are subjected to cooling influences which cause the film 24 of adhesive to harden. The cores containing the hardened adhesive layer proceed to stage 5, whereat foam sleeves 25 are manually or automatically slipped thereover.

The foam sleeve, in accordance with a preferred ernbodiment, is preferably a polyurethane foam of the cornmunicating or open cell type. Obviously other synthetic foams having properties generally similar to the polyurethane foam may be employed. The polyurethane foam preferred has a density of approximately 2 pounds per cubic foot. However, experiment has shown that less or more dense foam may be satisfactorily employed. Polyether foams have also been found highly suitable for use as the foam sleeve component 25.

The foam sleeves are preferably seamless since it has been determined that paint applicators formed with a `seamed sleeve leave a mark or impression each time the seam portion traverses the surface to be coated. The mark or impression may be the result of differential paint absorption of the foam at the seam or the differential flock receiving ability of the seam portion of the applicator.

The core with the foam sleeve applied enters a steam chamber 6 filled with saturated steam-water vapor mixture at approximately 200 F. The sleeve remains in the chamber for a period suflicient for the steam to llll the open cells and pores of the sleeve with moisture, preparing it for th succeeding step, notably, the electrostatic application of flock securing adhesive.

In FIG. 3 there is diagrammatically shown an apparatus for carrying out the flock securing adhesive application step of stage 7. In this stage, the sleeves 25 are negatively charged against ground at a potential of 90 kv. The normally insulative urethane foam is rendered electrically conductive by the steam, the charge being communicated to the foam sleeves as by a charged wire 26 or like commutator.

A liquid flock adhesive 28 is sprayed from positively charged atomizing nozzle or nozzles 27 which divide the liquid adhesive into a fine particle size and at the same time impart a charge to the atomized particles to render them subject to attraction to the sleeve 25.

The nozzles 27 are preferably located beneath the sleeves so that gravity counteracts movement of the particles toward the surface of the sleeve. The nozzles may be directed so as to discharge the atomized particles toward the sleeve or transversely, as shown in FIG. 3.

While a wide variety of flock adhesives may be suitably employed at stage 7, I have utilized as a preferred flock adhesive a water based acrylic emulsion with approximately 46% solids at approximately 600 cps. viscosity (#2 spindle 30 r.p.m. Brookfield Viscometer). The noted adhesive has anionic properties.

The adhesive should not be too viscous to be atomized by the nozzles and yet should preferably contain 40 to 50% solids for desired flock retention.

A suitable adhesive is available ready-mixed from Rohm & Haas, Inc., being identified by that organization as Flocking Adhesive E 269. Other adhesives which have successfully been employed include water based urethane systems and water based epoxys, etc. v

A spacing of spray nozzle from foam of approximately 18 inches to 22 inches (utilizing the potentials above noted) has been found highly satisfactory.

The electrostatic deposition of the adhesive 28 on the foam sleeve, while not the only way of satisfactorily applying the same, has been found particularly advantageous in that the adhesive is selectively received by the sleeve. Since the foam surface is made upof numerous valleys and crests, and since the crests are more closely proximate to the nozzles than the valleys, there is a greater tendency toward adhesive buildup at the crests, leaving the valleys more or less clear of substantial adhesive particles. In other words, the atomized particles are attracted to the closer crest portions of the foam rather than to the more distant valleys or interiors of the cells of the foam. Further, since the water based adhesive particles are conductive, they will lose their charge immediately upon being conductively attached to the foam surface. The crests of the foam, by reason of the addition of extra conductive material (the adhesive) continue to function as the principal attracting means for subsequently atomized adhesive particles.

In FIG. 4 there is diagrammatically shown an enlarged sectional view through the sleeve and core of articles emerging from stage 7, the electrostatic adhesive application stage. As will be seen, the principal adhesive concentrations are at the crests C of the foam, whereas there is a relatively limited accumulation of adhesive particles in the depth of the valleys. At this stage, the adhesive is tacky but not set or cured.

The adhesively coated sleeves are advanced to the flocking stage or station 8, whereat flock is electrostatically deposited on the rollers. The flocking station, more particularly shown in FIG. 2, comprises a hopper 29 which releases ilock particles 30 to the upper surface or flight 31 of a conveyor belt 32 stretched between drive and idler rollers 33 and 34.

A flock recovery system (not shown) may be employed to receive any flock not secured to the sleeves in the course of the electrostatic flock applying step.

The flock material employed may comprise nylon, acrylic, polyester, rayon or any other suitable fiber. Flock having an average length as short as .03" and as long as .500 has been satisfactorily employed. The denier of the flock may vary from about 3 to about 30. As an example of a satisfactory flock material, there may be mentioned a nylon flock having an average length of .200, 18 denier.

In the flocking operation, a counter electrode 35 is disposed immediately beneath the upper flight 31 of the conveyor, the electrode 35 being grounded. The sleeves 25 are contacted by a charging wire 36 to a negative against ground potential of from about 20 to about 40 kv. The spacing of the flock conveyor from the under surface of the foam sleeves preferably ranges from about 10" t0 about 12", although this spacing will desrably be varied in accordance with variations in the electrostatic field strength, density of flock deposition desired, flock size,

etc.

Flock which is disposed on the conveyor surface 31 will be attracted against the influence of gravity toward the surfaces of the sleeves which, as noted, are being constantly rotated by the mandrels. The elongated flock becomes, as is well understood, aligned with the electrostatic lines of force of the field and thus extends substantially radially from the surface of the foam. The magnified section, FIG. 5, illustrates diagrammatically the position assumed by the flock after it has become attracted and secured to the adhesively coated crest portions C dened by the prior adhesive application step.

Since the flock is attracted upwardly against gravitational forces, there is a tendency for loose flock, i.e. flock which may have impinged against a surface of the foam not covered by adhesive, to fall back to the conveyor. This tendency is augmented by the fact that such non-adherent flock, upon impingng against the surface of the foam, assumes the same charge as the foam surface and is electrostatically repelled back toward the conveyor.

It will thus be seen that the electrostatic method serves not only to induce adhesion of flock at a desired angle, i.e.

radial, but also serves to clear the sleeve of non-adhering ilock.

It will be evident from the preceding description that the flock impinging against the crest portions C is adhesively secured to the crests by the non-hardened, tacky adhesive material 28 and this flock is therefore able to resist the repelling forces.

The sleeves, still supported on the mandrels, leave stage 8 and enter stage 9 comprising a hot air drying oven.

It will be appreciated that the foam material is still partially or substantially saturated with the steam-moisture components introduced in step 6. The steam-moisture components in stage 8 performed the function of rendering the normally insulative foam sleeves subject to receiving an electric charge, to permit electrostatic deposition. As the sleeves enter the hot air drying oven, stage 9, they are subjected to relatively high heat, preferably in excess of the temperature required to melt the thermoplastic adhesive layer 24 which holds the sleeves to the cores.

The heat functions, in addition, to expand and rapidly force the steam-moisture mixture outwardly through the interstices of or the pores which communicate between the cells of the foam. The direct result of this egress of moisture is to open or clear the passages between the cells and the exterior of the foam sleeve. Thus, the moisture is driven outwardly through the surface of the foam and any adhesive accumulations or particles which may have clogged the pores are forced aside, the passages being dilated and cleared by the escaping steam. The clearing action is particularly effective where the fluid which is driven off is a solvent for the adhesive.

By thus driving the steam outwardly, there is provided a paint applicator article in which communication of paint from the flock to the interior of the foam supporting layer is assured, notwithstanding the presence of adhesive on the Hock surface.

In FIG. 6 there is depicted a magnified sectional view through the finished ock applicator, showing in this instance that the former adhesive layer 24 is integrated at 24 into the core 21 and sleeve 25. Also shown in FIG. 6, by means of arrows 37, are the egress passages for the expanding fluid, diagrammatically disclosing the manner in which any possible accumulations of adhesive are cleared from the pores of the foam.

A further effect of heating stage 9 is, of course, to cure, harden or set the ock supporting adhesive 28.

The applicators emerging from heat stage 9 are advanced through a cooling station 10 and thence to a vacuum cleaning station 11, whereat any unadhered or loosely adhered flock elements are removed.

The finished applicators are unloaded at station 12 for further processing, i.e. for severing into desired lengths and packaging.

From the foregoing description it will be evident that there is disclosed a method of manufacturing a paint ap plicator, such as a paint roller, wherein the flock material is secured directly to the surface of a foam material without the adhesion step interfering materially with the porosity of the foam at the junction between the flock and the foam. Paint received on the applicator may llow freely to and from the flock ends, permitting the foam matrix to act as a paint reservoir.

As noted previously, the steps of lling, partially or totally, the foam material with a fugitive fluid material such as water vapor, steam, or some solvent, etc. and the driving out of this uid prior to hardening of the ock securing adhesive is considered to be an important feature of the invention.

The fluid may serve the additional function of rendering an insulative flock receiving sleeve or matrix conductive for the electrostatic deposition of the ock material.

Further, the invention is considered to result in the provision of an improved article of manufacture which comprises, for the lirst time, a foam matrix to which ock is adhesively secured without the adhesive undesirably clogging the pores or passages communicating between the flock and the interior of the matrix.

It will be understood that other matrix materials having the desired porosity characteristics to permit their acting as a reservoir may be employed.

The present invention is not to be taken as limited to the particular materials employed, nor are the steps to be considered in any limited sense or sequence other than as defined in the appended claims, which are to be broadly construed within the spirit of the present invention.

Having thus described the invention and illustrated its use, what is claimed as new and is desired to be secured by Letters Patent is:

1. The method of forming a paint applicator or the like including an open cell matrix having a flock secured directly to the surface of the matrix while providing a free ow path between the ock and the interior of the matrix, comprising the steps of at least partially filling the matrix with a fluid medium, applying to an exterior surface of said matrix a quantity of adhesive material, causing a supply of flocking material to adhere Ito said adhesive material in a desired incidence and orientation, and thereafter driving said fluid medium outwardly of said matrix through said surface in advance of -nal setting of said adhesive, thereby to increase the porosity of said surface, and thereafter causing said adhesive to set.

2. The method of claim 1 wherein said fluid medium comprises a solvent for said adhesive.

3. The method of claim 1 wherein said matrix comprises a communicating cell foam material which is normally an electrical insulator and is rendered electrically conductive by said uid medium and said ocking material is caused to be deposited on said surface by an electrostatic process in which said conductive matrix forms an electrode.

4. The method of claim 3 and including the step of electrostatically depositing said adhesive material on said surface in a discontinuous pattern, whereby said adhesive is concentrated at the crests of said surface of said foam material.

5. The method of claim 2 wherein said adhesive is water based.

6. The method of claim 1 wherein said adhesive is a high shrink adhesive.

7. The method of forming a paint applicator or the like including a yieldable, open cell foam matrix having a flock adhesively secured directly to a surface thereof while providing a free flow path through said surface, which comprises the steps of at least partially lling said matrix with a fluid medium, applying to said surface a quantity of adhesive including a solvent, to dene a discontinuous coating concentrated at the walls of said cells, causing a supply of flocking material to adhere to said adhesive material in a desired incidence and orientation, and thereafter subjecting said flocked matrix to a curing step to cause said fluid to flow outwardly through said surface, thus to increase the porosity thereof and to drive said solvent from said adhesive.

8. The method of claim 7 wherein said matrix is initially insulative and is rendered conductive responsive to introduction of said fluid medium.

9. The method of claim 8 wherein said adhesive is electrostatically deposited, said concentration of said coating being occasioned by the greater proximity of said walls of said cells to the electrode which is at electrical potential opposite to that of said matrix.

10. The method of claim 7 wherein said fluid medium comprises water.

11. The method of claim 7 wherein said curing step comprises subjecting said article to heat.

12. The method of claim 11 wherein said matrix comprises an annulus supported on a relatively rigid core and a heat activated adhesive is interposed between saidmatrix and said core, and said heating step causes said heat activated adhesive to connect said core and matrix.

13. As an article of manufacture, a paint applicator or the like comprising an open cell foam matrix, adhesive material disposed at the peripheral portions of said matrix, ock material supported in said adhesive material and extending outwardly from the periphery of said matrix, said adhesive material defining openings therethrough in registry with the openings or interstices in the periphery of the matrix material to provide communication between said flock and ,the interior of said matrix, the openings in said adhesive material having been formed or enlarged by introducing into the body of said matrix a fluid material, thereafter applying said adhesive to said surface of said matrix and thereafter driving said iluid material outwardly through said adhesive, thereby to open or enlarge interstices in said adhesive material in the portions thereof References Cited UNITED STATES PATENTS 8/1964 Gilchrist 161-64 1/1964 Imhof 161-64 ROBERT F. BURNETI, Primary Examiner L. C. KOECKERT, Assistant Examiner

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