Surfacing sheet and method and apparatus for processing same

Nov. 29, 1960 w. m. rees etal 2,962,385

SURFACING SHEET AND METHOD AND APPARATUS FOR PROCESSING SAME

Filed Dec. 24, 1956 3 Sheets-Sheet 1

<img file="US2962385A_D0001.tif" />

Nov. 29,1960 w. M. REES etal 2,962,385

SURFACING SHEET AND METHOD AND APPARATUS FOR PROCESSING SAME

Filed Dec. 24, 1956 3 Sheets-Sheet 2

<img file="US2962385A_D0002.tif" />

<img file="US2962385A_D0003.tif" />

Nov. 29, 1960 w. m. rees etal 2,962,385

SURFACING SHEET AND METHOD AND APPARATUS FOR PROCESSING SAME

Filed Dec. 24, 1956 3 Sheets-Sheet 3

<img file="US2962385A_D0004.tif" />

United States Patent Office

2,962,385

Patented Nov. 29, 1960

2,962,385

SURFACING SHEET AND METHOD AND APPARATUS FOR PROCESSING SAME

Willis M. Rees and Robert W. Schultz, Newark, Ohio, assignors to Owens-Corning Fiberglas Corporation, a corporation of Delaware

Filed Dec. 24,1956, Ser. No. 630,389

Claims. (Cl. 117—45)

This invention relates to a painted or coated acoustical tile wallboard or wall surfacing unit and to a method and apparatus for applying paint, coating or decorative material to tiles, wallboards or surfacing units.

Various methods have been utilized for applying or imparting a finish, coating or decoration to wallboard surfaces including those known as acoustical board or tiles which are made of fibers of various kinds compacted or compressed to desired density and utilized as surface facings or surfacing units for sound insulation. Board or tiles of a fibrous character abound with many interstices or minute voids which function to attenuate or dampen sound waves to a substantial degree.

Fibrous boards or tiles may be painted or coated with nonbridging paint without undue impairment of the sound attenuating or sound damping characteristics. For example, a wall surfacing unit or tile formed of mineral fibers such as glass and coated with paint is replete with pores which function to attenuate or dampen sound waves even though the surface coating presents a visually unbroken or non-porous appearance.

It is a commercial practice to precut fibrous surfacing units or acoustical tile sections or sheets into predetermined sizes for ease of installation and the finish surface painted, coated or decorated at the plant of manufacture. Heretofore fibrous board sections or tiles have been painted in colors and with designs of repetitive character and of distinctive pattern and such designs have been attained through the use of stencils or applicator rolls formed with configurated surfaces to impart a definite design or pattern to each section.

In such methods heretofore practiced, the designs provided on the acoustical boards or tiles, while distinctive, are repetitive, and the sections when finally installed in edge-to-edge relation to form a complete wall surface impart an overall visual effect or impression akin to that of a checkerboard.

The present invention embraces the provision of a surfacing unit, tile or wallboard section preferably having acoustic or sound attenuating properties provided with a painted, coated or decorated surface area of nonrepetitive character and to a novel method and apparatus for applying the coating material or paint to the units, sections or acoustical tiles.

An object of the invention is the provision of a wallboard section, unit or tile provided with a finish material or paint which partially covers the surface area in a haphazard or random manner presenting a spattered pr stippled appearance wherein the painted areas or spots are separated or defined by unpainted regions or voids of various irregular outline providing a substantial area of the surface for efficient sound damping or attenuating purposes.

Another object of the invention is the provision of a novel method of applying a flowable surfacing material onto a fibrous board or section wherein an insufficient metered amount of surfacing material or paint is delivered onto the board surface to incompletely cover the surface whereby a non-uniform and non-repetitive ram dom effect or visual appearance is imparted to the surface resembling a so-called stippled finish.

Another object of the invention is the provision of a surfacing unit or tile provided with a surfacing material presenting an appearance of being stippled, the surfacing unit being of a material having efficient sound attenuation or noise absorption characteristics.

Another object of the invention is the provision of a fibrous surfacing tile or sheet in which the fibers are bonded together to provide a substantial degree of mass integrity or rigidity in the sheet so as to resist distortion or warping but which is of a density to provide a high degree of noise absorption whereby an assemblage of the surfacing sheets or tiles forms an efficient acoustical covering or surfacing for ceilings and side walls of rooms or chambers.

Still another object of the invention is the provision of wall surfacing sections or tiles having sound attenuation or noise absorption characteristics which may be fashioned or fabricated in defined sizes, each section or tile embodying a finish surface of nonuniform design of non-repetitive character whereby a plurality of the surfacing sections or tiles, when assembled to form a complete ceiling or sidewall of a room or chamber, presents a visual appearance of a continuous, softly stippled surface presenting highlights and graded shadows which effectively obscures the joints or abutting edge regions of the surfacing sections or tiles resulting in a unique decorative effect of a continuous or unbroken wall finish.

Another object of the invention is the provision of a surfacing sheet or acoustical tile formed of mineral fibers provided with the finishing surface of random or haphazard appearance wherein the finishing material contains a mold inhibitor to effectively resist deterioration of the surface finish.

Another object of the invention is the provision of a method for applying a finishing or coating material to a surface of a fibrous surfacing unit or tile wherein during the application of the coating or finishing material, the quantity of material delivered onto the unit or tile is metered, controlled or restricted whereby an insufficient amount of the surfacing material is delivered or applied to the surface whereby a large portion of the area is uncoated and the coated regions are of irregular contour in shape and size presenting a non-repetitive stippled appearance.

Another object of the invention is the provision of an apparatus for carrying out the method of the invention whereby the surfacing units, tiles or sheets are successively and automatically advanced through an applicator zone or station at which the metered quantity of paint or coating material is applied and the coated units, tiles or sheets conveyed through suitable drying ovens pr curing stations whereby the same may be processed economically without waste as the random surface appearance avoids rejections for defective surface des’gn.

Another object of the invention is the provision of a method and apparatus for underfeeding paint pr coating material to a surface in order to incompletely cover or coat the surface and subsequently applying one or more layers or coatings of paint or coating material to cover the entire area of the coating sheet providing a finished surface of non-repetitive design or appearance without materially decreasing or impairing the acoustical or sound attenuating characteristics of the surfacing sheet or tile.

Further objects and advantages are within the scope of this invention such as relate to the arrangement, operation and function of the related elements, and to combinations of parts, elements per se, and to economies of manufacture and numerous other features as will be

2,962, 3 apparent from a consideration of the specification and drawing of a form of the invention, which may be preferred, in which:

Figure 1 is a semi-diagrammatic view illustrating steps in the method of applying a coating or finishing material 5 to the surfacing units, sheets or tiles;

Figure 2 is a diagrammatic view illustrating a step in the method of the invention;

Figure 3 is a fragmentary isometric view of a portion

Of a surfacing unit or acoustical tile illustrating the coated 10 and uncoated regions thereof;

Figure 4 is a fragmentary sectional view through a surfacing unit or acoustical tile illustrating the irregular blotches or regions of coating material on the unit or tile; 15

Figure 5 is a side elevational view of a form of apparatus at the applicator station for delivering fluid material onto a surfacing unit or tile;

Figure 6 is an end elevational view of the arrangement shown in Figure 5; 20

Figure 7 is a top plan view of the applicator or material metering and delivering means, and

Figure 8 is a transverse sectional view through the material metering and applying means, the view being taken substantially on the line 8—8 of Figure 7.

While the method and apparatus of the invention are especially adapted for applying a novel finish to surfacing units, sheets or acoustical tiles formed of fibrous material such as boards or sheets fashioned of compressed glass fibers, it is to be understood that the novel surfacing units or tiles may be formed of other materials and that it is contemplated that the method and apparatus of the invention may be employed or utilized for delivering coatings onto surfaces of other materials.

Referring to the drawings in detail, Figures 1 and 2 illustrate in semi-diagrammatic form, steps in the method of processing a fibrous sheet, board, surfacing unit or acoustical tile in obtaining the surface finish or decorative motif of novel character. The surfacing units or tiles are preferably of a character having acoustic attenuating or sound damping characteristics and hence are formed of fibers or fibrous material compressed or compacted to a suitable density and thickness and mass integrity established by a suitable bonding material or binder holding or retaining the fibers in compressed or compacted condition.

Mats, sheets, boards or tiles formed of compressed mineral fibers as, for example, glass fibers have been found to be admirably suited as acoustic attenuating, wall surfacing materials, but it is to be understood that wallboards or surfacing sheets formed of other fibrous materials such as vegetable fibers or animal fibers may be utilized in forming the boards or sheets or tiles.

The surfacing units or tiles of the invention may be sized to standard dimensions such as blocks or sheets 12 square or of rectangular shape such as a size 12 x 24 and of a thickness and density suited to obtain a high sound attenuating efficiency. Where the units or tiles are fashioned of compressed mineral or glass fibers, the sheet or tile is preferably of a density between 8 and 12 pounds per cubic foot and each tile of a thickness of from approximately Vz to 1, although other densities and thicknesses may be utilized depending upon the character of use for the tiles.

In carrying out the steps of the method of the invention it has been found desirable, although not an imperative requisite to obtain a satisfactory decorative finish, to employ or use surfacing sheets or tiles having a smooth or uninterrupted planar surface area to receive the finish or coating material. Certain forms of surfacing sheets or units may be molded to present a substantially smooth surface, and where mats or boards of mineral fibers are compressed and cured while being retained between reticulated surfaces, the method may involve an abrading or smoothing operation in order to provide a smooth sur4 face to receive the decorative coating or finish material.

In the fabrication or manufacture of wallboards, surfacing sheets or acoustical tiles formed of glass fibers, the fibers are collected or accumulated. in a comparatively thick mass and a suitable binder or bonding material delivered into the mass. The mass of binder impregnated fibers is compressed to the desired density and delivered into a curing or drying zone to effect a setting of the binder while the mass of fibers is maintained in compressed condition.

Suitable binders may be employed such as thermoplastic resins, thermo setting resins such as phenolformaldehyde or ureaformaldehyde, or non-resinous binders such as starches, sugars or the like depending upon the environment of the installation in which the surfacing units or tiles are to be used.

In the process of forming and curing the binder impregnated’ units or tiles, they are conveyed through a curing oven while in compressed condition between conveyor flights of foraminous or reticulated character such as metal wire mesh or the like. As such conveyor flights are usually disposed in horizontal relation, the binder in the sheet or tile tends to gravitate toward the lower surface region resulting in an increased concentration 25 of binder adjacent the lower surface of the product.

When fibrous sheets or tiles formed in this manner are to receive a decorative coating by the process of this invention, it is desirable that the impression or score marks made by the mesh configuration of the conveyor 30 be removed from the surface region of the sheet or tile to be coated or finished. Figure 2 is illustrative of a method step of removing the conveyor score marks to obtain a smooth, substantially uninterrupted surface.

The fiber board, surfacing unit or tile 10 is engaged 35 by an abrading member 12, which, as shown, may be in the form of a sanding roll having an abrasive constituent on its peripheral surface suitable for removing a small amount of material of the board or tile of a major surface thereof. The conveyor impression marks 14 in the 40 surface of the product, by reason of the setting of the binder while the product is in engagement with a conveyor, are removed by the abrading or sanding roll 12 providing a smooth surface 16 to receive the finish or decorative material.

It has been found that the surface area of the board or tile adjacent the binder-concentrated region of the product is preferably abraded by the element 12 as the smooth surface 16 is in the zone of the binder concentration which augments the degree of smoothness of the surface to re50 ceive paint or finishing material.

The fibrous boards, sheets or tiles 10 are delivered in succession with the smooth surfaces 16 uppermost onto the upper flight 20 of a conveyor of the endless belt type supported on rollers 24, one of which may be connected 55 with a motor or other means for driving the conveyor with the upper flight 20 moving in a right-hand direction as viewed in Figure 1.

With reference to Figure 1, the surfacing sheet or tile 10 at the left end of the conveyor flight 20 is illus60 trated as advancing through an applicator station B, at which station the paint, coating or other finishing material is being delivered onto the smooth surface 16 of the tile.

The applicator at station B is arranged to deliver onto ⁸⁸ the surface 16 of the sheet or tile an amount of paint or coating material insufficient to cover the surface 16. One form of apparatus for applying the coating is illustrated in Figures 5 through 8 and will be hereinafter 7θ described. It has been found that delivering a restricted or metered amount of paint, coating material or other fluid material onto the flat or planar surface 16 of the tile results in a partially coated surface in which the coating is dispersed or distributed in the form of spots 75 or blotches 26 of random or haphazard sizes and shapes

2,962,888 separated or defined by uncoated voids or regions 28 shown in Figure 4.

Apparently due to the surface tension of the paint or coating material, the random or haphazard deposits thereof on the surface 16 present a stippled or postularlike appearance or design having no predetermined or defined pattern. Thus each blotch or spot 26 of paint or coating material is a slight protrusion elevated above the surface 16 of the tile resulting in an overall appearance of asperity or softly stippled area in graded shadows.

When a plurality of the surfacing units or tiles 10 so decorated or finished are placed in edge-to-edge abutting relation forming a wall or ceiling surface, the joints or meeting edges of the tiles are rendered inconspicuous, producing a finished wall or ceiling having a pleasing, completely random effect presenting no definite design or repetitive pattern. This visual effect results from the haphazard disposition of the irregularly sized blotches of paint or coating material and the absence of a repetitive design on the individual units or tiles.

The random or haphazard deposition of the spots or blotches of paint or coating material is effected by starving the surface 16 of paint by restricting or metering the same providing an insufficient quantity to coat the surface of the product as the units or tiles are continuously advanced through the applicator station.

The blotches 26 of paint or coating material preferably cover only a minor surface area of the sheet or tile 10 and a coating having non-bridging characteristics is preferred as it does not seal the surface and hence does not materially decrease or impair the sound attenuating or damping characteristics of the product.

The sheet or tile bearing the blotches 26 of paint or coating material is conveyed away from the applicator station B and advanced by the conveyor flight 20 through an oven or curing zone or station C where heat such as heated air is directed into contact with the paint or coating on the sheet or tile to set, cure or dry the same.

The entire surface area of the sheet or tile may be sprayed or painted with a non-bridging paint such as a water base paint to provide a protective coating over the entire surface but which does not seal the surface, as a non-bridging paint does not completely close the interstices in the surface. It has been found that the acoustical attenuating or sound damping efficiency is not materially impaired so long as an open or unsealed area of between 7% and 14% of the entire surface area is maintained.

The entire surface area 16 of the sheet or tile may be sprayed with a coating of paint at station D and the painted product advanced through a setting zone or curing oven E to set or dry the coating of paint applied at the station D. If desired, a second coating of nonbridging paint may be subsequently applied at station F by spray applicators or other suitable means. The product may then be passed through a third curing zone or oven G to dry or set the paint sprayed upon the sheet or tile at station F completing the finishing of the product.

The entire coated surface area 30 illustrated in Figure 3 is a random visual effect having no definite symmetry of design or pattern and the painted or decorated surface 30 of each sheet or title differs in visual appearance from the others coated by the same applicator.

A form of apparatus of the invention for carrying out the method of applying or delivering paint or coating material onto the surfacing units or tiles is illustrated in Figures 5 through 8. The apparatus is inclusive of a frame 35 consisting of upwardly extending members 37 joined by longitudinally extending or side members 39, 40 and transversely extending frame members 42 and 43.

Secured to the side frame members 40 are upwardly extending brackets 44 which form pivotal supports for means carrying the paint or coating applicator and metering means for restricting the paint or coating delivered onto the surfacing units or tiles. This means is inclusive of spaced plate-like members 48 and 49 joined by transversely extending members 51 and 52.

The members 48 and 49 are each provided with an extension or arm 54, the arms 54 being pivotally connected '5 respectively to the brackets 44 by means of stub shafts or bolts 56 whereby the means carrying the applicator is pivotally supported by the bolts 56. The plates 48 and 49 are provided with bearings journally supporting a shaft 60 upon which is carried the paint or coating ap10 plicator roll 62. One end of the shaft 60 is provided with a sprocket 64 connected by a chain 65 with a sprocket 67 mounted on a shaft 68, the latter extending into a housing 70 containing speed changing gearing or mechanism.

The speed changing mechanism (not shown) is provided with a pulley 72 connected by a driving belt 73 with a pulley 74 mounted on shaft 75 of a motor 76. The motor 76 is mounted upon suitable supports 78 carried by frame members 39. The motor drives the speed re20 ducing mechanism contained in the housing 70 and the roll applicator is driven therefrom at a comparatively slow speed.

A plate 80 is pivotally supported at 81 and journally supports an idler sprocket 83 which is engaged with the ²⁵ driving chain 65. The plate 80 is biased by a contractile spring 86 to exert tension upon the driving chain 65 to maintain the chain in taut condition. Each of the side frames or members 49 is formed with an extension 88 and the bar 44 and extension 88 of each side frame ³⁰ are provided with tracks or ways 90 which slidably support cross heads 92.

Journalled in bearings formed in the cross heads 92 is a shaft 94 arranged in parallelism with the shaft 60, the shaft 94 supporting a metering or fluid flow restrict³⁵ ing means or roll 96. A lever, bar or arm 98 is journally supported intermediate its ends upon the end region of the shaft 60 opposite that supporting the sprocket 64. The lower end of the lever 98 is provided with a shaft 100 carrying an idler sprocket 102.

⁴⁰ An end of the shaft 94 is equipped with a sprocket 104 and a chain 105 takes over the sprocket 104, sprocket 108 mounted upon the shaft 60 and the idler sprocket 102 as illustrated in Figures 7 and 8. In this manner the applicator roll 62 and the paint metering roll 96 are 45 driven in clockwise directions as viewed in Figures 5 and 8.

A strut or anchor member 11® is secured to one of tile side frames 49 and the distal ends of the strut 110 and lever 98 are connected by a contractile coil spring 50 112 as illustrated in Figure 5. The spring 112 urges the arm or lever 98 in a clockwise direction as viewed in Figures 5 and 8 about the axis of the shaft 60 biasing the sprocket 102 in a direction to tension the chain 105.

The slidable cross heads 92, forming journal supports 55 for the metering roll 96, are associated with means for adjusting the position of the roll 96 toward or away from the applicator roll 62. Secured to each of the cross heads 92 is a rod or member 116 which projects through an opening in the plate 51, the shaft 116 being threaded 60 as at 118 to accommodate a knurled adjusting nut 120.

Interposed between the plate 51 and the cross head 92 and surrounding the shaft 116 is an expansive coil spring 122 arranged to bias the cross heads toward the applicator roll 62. By manipulating the knurled screws 65 120, the cross heads 92 may be slidably adjusted along the tracks 90 to adjust the position of the metering means or roll 96 to vary the space 124 at the nip or bight existing at the juxtaposed regions of the rolls ¢2 and 96.

The space or distance 124 between the rolls 62 and 96 restricts, determines or meters the amount or thickness of film of paint or coating material carried by the applicator roll 62 and delivered onto the surfacing sheets, units or tiles 10 advanced longitudinally upon the con75 veyor flight 20 arranged beneath the applicator roll 62.

2,962,885

The paint or material to be distributed onto the units or tiles is conveyed or delivered into the nip region adjacent and above the rolls 62 and 96 by means of a tube 130 equipped with valve means 132 for regulating the rate of flow or delivery of the paint or coating material into the temporary reservoir of paint or coating material formed by the peripheral regions of the rolls 62 and 96 immediately above the restricted space 124 existing between the rolls.

The arrangement is inclusive of means for scavenging or scraping paint from the metering roll 96 so that an accurate metering of the film of paint adhering to the applicator roll may be accurately controlled. Mounted upon the extensions 88 of side frames 48 and 49 are .bearing supports 136 shown in Figures 5, 7 and 8. Disposed between the supports 136 is a bar or shaft 138 preferably of polygonal or square cross section and formed at its ends with tenons 140 journalled in the members 136.

Secured to the bar 138 are rods 144 terminating in portions 146 extending at right angles to the upright portions 144 and which are threaded to receive adjusting nuts 148. The portions 146 extend through openings provided in upwardly extending members 159 secured to the plate 51. Expansive coil springs 152 disposed between members 150 and adjusting nuts 148 bias the rod or shaft 138 in a counterclockwise direction as viewed in Figure 8.

Secured to one of the facets of the shaft 138 is a scraping bar or doctor blade 156, the edge 158 of which engages or contacts the periphery of the metering roll 96 to prevent paint or coating material from being carried around the periphery of the roll 96 at a region between the edge 158 of the blade and the metering openingl24. The expansive pressure of springs 152 serves to keep the edge of the blade 156 in intimate contact with the periphery of roll 96.

It is to be understood that other means may be employed to prevent conveyance of the paint or coating material around the metering roll such, for example, as an additional roll of circular cylindrical shape having its periphery in contiguous intimate contact with the peripheral surface of roll 96.

Means is provided to form a reservoir for the paint or coating material maintained adjacent the nip region of the applicator and metering rolls 62 and 96. Secured to the side frame constructions 48 and 49 are plates or members 162 provided with slots to receive securing bolts 164 for adjusting the positions of the members transversely of the frame.

Disposed beneath each of extending portions of the plates 162 are walls or abutments 166 formed of yieldable material such as rubber or flexible plastic having curved contoured edge regions 168 and 170 which fit the cylindrical peripheral surfaces of the rolls 62 and 96 respectively. By making the abutments 166 of yieldable material, the curved surfaces 168 and 170 may be flexed to snugly engage the peripheral regions of the rolls adjacent the nip region throughout the normal range of adjustment of the metering roll 96 and thus form a reservoir for the paint.

Each of plates 162 is provided with a threaded opening to receive a threaded portion 174 of an adjusting member 175, the end regions of the adjusting members 175 extending into metal members (not shown) embedded in the abutments or walls 166. The adjusting screws 175 may be manipulated to predetermine the pressure of the walls 166 against the rolls 62 and 96 to maintain intimate contact of the lower curved edges thereof with the applicator and metering rolls and prevent loss of paint longitudinally of the rolls.

A pair of knurled head screws 180 threaded into boss portions 181 welded to the side frame members 40 engage the lower surfaces of side frames 48 and 49 to limit the lowermost position of the applicator roll 62, the screws being locked in adjusted position by nuts 182.

Means may be provided for elevating the applicator mechanism to an out-of-use position. In the embodiment illustrated, a plate 187 joining the side frames 48 and 49 is equipped with a lug 188 to which is connected a piston rod 189 equipped with a piston 190 extending into an operating cylinder 191. By directing pressure fluid alternately into opposite ends of the cylinder 191, the applicator arrangement may be elevated or lowered as desired. An end of the cylinder 190 is pivotally anchored at 193 to a member 194.

In the operation of the applicator phase of the method, the screws 180 are first adjusted so that the applicator roll surface is in wiping contact with the smooth surface 16 of a surfacing sheet, unit or tile 10 so that the film of paint or coating material on the roll periphery will be delivered by the roll 62 onto the sheets or tiles. A supply of paint or other coating material is continuously delivered into the nip zone provided by the rolls 62 and 96 and abutment walls 166 through the feed tube 130, the rate of flow of the paint being regulated by the valve 132.

The position of the metering roll 96 with respect to the applicator roll 62 is adjusted by manipulation of the screws 120 to obtain the proper width of the opening 124 at the nip region of the rolls so as to restrict or meter the amount of paint or material moving through the opening 124 with the roll 62. The motor 76 is energized to rotate the applicator and metering rolls 62 and 96, and a motor (not shown) energized to continuously move the conveyor flight 20 in a right-hand direction to advance the surfacing units or tiles 10 successively beneath the applicator roll 62.

The metering roll 96 is adjusted to restrict the amount of paint or coating material delivered onto the sheets or tiles so as to incompletely coat the tiles. The tiles are underfed with paint whereby they are actually starved of paint and that delivered by the roll 62 forms blotches or spots of various sizes in random arrangement on the surface 167 with voids or uncoated portions between adjacent blotches.

With further reference to Figure 1, the partially coated tiles or surfacing units 10 are conveyed through a drying or curing zone C which may be heated to set or dry the paint delivered onto the tiles by the applicator at the station B.

The tiles may be advanced through a region D at which additional paint may be sprayed on the entire upper surface of the tiles covering the blotches or spots of paint previously deposited at the applicator station and the uncoated voids on the upper surfaces of the tiles. The paint should be of a nonbridging character to avoid sealing the interstices or pores in the tiles which would otherwise impair the sound attenuating properties.

The painted tiles may be advanced through a second drying or setting zone E and, if desired, an additional coating of paint over the entire surface of the tile may be applied or sprayed onto the tiles at station F and the tiles passed through a third curing zone or drying oven at station G. A water base paint has been found to be particularly satisfactory in carrying out the method of the invention and the paint may be tinted to obtain any colors. A mold inhibitor such as phenyl mercuric acetate to resist or prevent deterioration of the paint on the tiles.

It should be noted that an important phase in the method resides in restricting, limiting or starving the paint supply delivered onto the fibrous units or tiles in a manner obtaining a random or haphazard distribution of blotches or spots of paint of irregular contour and a complete absence of a distinctive repetitive pattern or design.

It is to be understood the step of abrading or smoothing a surface of a tile, illustrated in Figure 2, may be carried on with the tile supported on the conveyor flight 20 at a region in advance of the applicator station B, or the

2,062,385

10 material onto the planar area of the tile at said station in metered quantity to incompletely cover the planar area whereby the area is fashioned with randomly arranged coated and uncoated zones presenting a nonrepetitive pattern, advancing the material-bearing tile through a drying station to set the material, and applying a coating of material to the entire planar area of the tile.

6. The method of forming a decorative acoustical tile including the steps of advancing the tile to an applicator 10 station, continuously delivering a restricted amount of liquid paint onto a moving surface, continuously transferring paint from the moving surface onto a surface of the tile by wiping contact as the tile moves through the applicator station whereby the paint is disposed on the 15 surface in nonrepetitive irregularly-shaped random blotches separated by uncoated regions, and applying a coating of paint over the entire area of the surface covering the blotches and previously uncoated regions of the tile.

7. The method of forming a decorative motif on an 20 acoustical tile formed of glass fibers having a planar area including the steps of advancing the tile to an applicator station, delivering a metered film of liquid paint onto a moving surface, moving the surface in wiping contact with the tile to transfer the paint from the surface onto 25 the planar area of the tile at said station whereby the material is distributed on the surface in variously-shaped blotches in nonrepetitive random disposition, and coating the entire planar area including the blotches with a decorative material.

8. A method of forming a covering on individual acoustical tiles made of compressed fibers providing interstices in the tile surfaces including the steps of successively advancing the tiles to an applicator station, underfeeding a flowable coating material in film form onto 35 a surface of each of the tiles at said station whereby the material is distributed on the surfaces in nonrepetitive, irregularly shaped configurations, setting the material on the surfaces at a curing station, and applying a nonbridging coating over the configurations and entire area 40 of the surfaces to avoid sealing the interstices in the surfaces.

9. An acoustical wall surfacing tile formed of compressed glass fibers, a surface of the tile bearing irregular blotches of paint disposed in nonrepetitive random relation 45 thereon forming protuberances, and a coating covering the entire surface including the blotches of paint.

10. An acoustical tile including a unit formed of glass fibers bonded together and having a flat surface, a paint disposed oh the flat surface in spaced nonrepetitive ir50 regular blotches of varying sizes arranged in random disposition, and a coating material superposed on the blotches and covering the entire area of the flat surface.

11. An acoustical tile for use in fabricating wall surfaces comprising a unit formed of glass fibers compressed 55 to a density of between 6 to 12 pounds per cubic foot and the fibers bonded together to form a substantially rigid body having a flat surface, paint disposed on the flat surface in spaced nonrepetitive irregular blotches of varying sizes and shapes arranged in random disposition, and a 60 coating of nonbridging paint superposed on the blotches and covering the entire area of the flat surface.

12. Apparatus of the character disclosed including, in combination, a flowable material applicator roll, conveyor means arranged to advance flat fibrous bodies in a recti⁶⁵ linear direction successively adjacent to and tangent with the applicator roll, a support for the applicator roll, means for adjusting the said support to position the roll whereby the bodies receive flowable material by wiping 70 contact of the bodies with the roll, said applicator roll being arranged to receive flowable material from a supply, means for restricting the rate of delivery of flowable material to the applicator, said material restricting means being adjustable to underfeed material onto the bodies 75 whereby the material is distributed on a surface of the abrading operation may be performed with the tile supported on a means or conveyor disposed in alignment with or in advance of the conveyor flight 20.

While in the arrangement illustrated in Figure 1, the hapazardly arranged blotches of paint or material is first applied to a surface of an acoustical tile and the entire surface area subsequently covered or coated with paint, the entire surface area of a tile may first be sprayed or coated with one or more coats of paint and the haphazardly aranged blotches of paint deposited upon the painted tile surface. Through this method, the entire coated area or background may be of one color and the haphazardly arranged arranged blotches of paint superposed thereon of a different color, providing a dual color effect or appearance. In carrying out this form of the method, the acoustical tile bearing one or more coats on the entire surface area may be passed through an oven and the coat or coats of paint dried or set prior to the application of the haphazardly arranged blotches onto the painted surface of the tile.

It is apparent that, within the scope of the invention, modifications and different arrangements may be made other than is herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.