Apparatus for making decorative panels

[57] ABSTRACT

A sheet of building material having a decorative outer surface comprising an embossed panel with segments of different thickness and grooves formed in the outer surface between adjacent segments, said outer surface covered with a first ground coat of solid color, a second coat of stain applied and wiped to provide elongated streaks, a third solid color ground coat applied to the surface of said segments exclusive of said grooves and a finish coating comprising a printed pattern of wood grain. Apparatus for the production of said decorative panels includes means for applying a liquid coloring agent over said surface and wiping the same with an elongated belt of woven fabric movable relatively over the surface at a selected rate and biased into wiping contact with said surface by a rotary brush having a plurality of bristles, with free ends of bristles relatively movable with respect to the woven fabric belt and rotated to movingly penetrate at least some of the openings in said woven fabric thereby forming elongated streaks of coloring agent on said surface of said panel.

Claims, 6 Drawing Figures

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U.S. Patent sept. 30,1975

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U.S. Patent sept. 30,1975

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3,908,588

APPARATUS FOR MAKING DECORATIVE PANELS

This application is a division of copending U.S. Pat. application Ser. No. 287,682, filed Sept. 11, 1972, now U.S. Pat. No. 3,847,646.

The present invention relates to an apparatus for producing improved decorative building panel and more particularly a building panel having a decorative outer surface resembling that of V-groove wood planks laid side to side. The panel is formed with a plurality of segments of different thickness, and grooves are formed in the simulated joints between adjacent segments to make the panel have an appearance of actual V-groove type wood planks laid side by side.

In prior art paneling sheets decorated to resemble Vgroove wood planks laid side by side, difficulty has been encountered in providing suitable finishing techniques for the surfaces of the V-groove joints between adjacent plank sections. The deep relief of such joints greatly improves the appearance of the paneling, however, requiring a higher cost because of the difficulty of treating and properly finishing the surfaces of the grooves.

In wood grain decoration on panel sheets, the wood grain pattern is usually applied with a roll in a liquid form such as ink or other coloring agent, and the printing pattern is usually developed from a photograph taken of actual V-groove type wood planks laid side by side. Another difficulty has been encountered in obtaining uniform application of a wood grain printed pattern on the outer surface of a panel when segments of the surface are at different levels due to different thicknesses of portions of the panel sheet. Another problem has been the extremely difficult task of obtaining an authentic appearing stained panel having randomly oriented lines or streaks resembling those produced by the old time hand craftsman when using antique finishing techniques.

Still another object of the present invention is directed toward the provision of novel apparatus for the mass production finishing of decorative panel sheets including novel means for applying liquid coloring agents and subsequently wiping the same to provide a streaked effect having the appearance of a wiping stain.

Another object of the present invention is to provide a new and improved apparatus for producing paneling of the type described wherein the surfaces of the grooves formed in the panel are treated with stain and thereafter the stain is wiped slowly with a woven fabric biased into contact by rotary brush means to provide random orientated streaks.

The foregoing and other objects and advantages of the present invention are accomplished in a new and improved paneling sheet of building material having a decorative outer surface comprising segments of different thickness with grooves formed between adjacent segments. The surface of the panel sheet is covered with a first ground coat of solid color, a second coat of stain is applied and wiped with woven fabric to provide elongated streaks, a third solid ground color coat is applied only to the surface of the segments exclusive of the grooves, and a final or finish coat comprising a printed pattern of wood grain is then applied onto the segments.

A novel apparatus in accordance with the present invention provides means for applying a liquid coloring agent such as wiping stain over the surface of the panels passing through the same and for slowly wiping the stain with an elongated belt of woven fabric which is relatively movable over the surface at a controlled rate and which is biased into wiping contact against the surface of the panels by a rotary brush having a plurality of bristles. The outer free ends of the bristles are adapted to rotate and movingly penetrate through at least some of the openings in the woven fabric and engage the stain thereby forming elongated streaks resembling a hand wiped stain.

For a better understanding of the present invention reference should be had to the following detailed description taken in conjunction with the drawings in which:

FIG. 1 is a side elevational, schematic view of the new and improved machine for decorating the outer surface of a building panel in accordance with the features of the present invention;

FIG. 2 is a fragmentary sectional view taken substantially through lines 2—2 of FIG. 1;

FIG. 3 is a photograph of a sheet of paneling in accordance with the present invention taken after only the first solid color ground coat had been applied to the surface thereof;

FIG. 4 is a photograph of the paneling sheet taken after the application of a second coating of stain has been applied and wiped;

FIG. 5 is a photograph of the paneling sheet taken after a third solid color ground coat has been applied on the surface of the plank segments exclusive of the grooves between adjacent segments; and

FIG. 6 is a photograph of a finished panel sheet in accordance with the present invention taken after the final application of a wood grain, printed pattern.

Referring now more particularly to the drawings, a new and improved decorative, embossed building paneling sheet constructed in accordance with the present invention is shown in FIG. 6 and is generally referred to by the reference numeral 10. The finished sheet of paneling 10 is decorated to appear similar to actual Vgroove, tongue and groove type wood planks side by side and includes a plurality of segments or sections 12 resembling individual wood boards or planks, some of which are thicker than others as best indicated in FIG. 2 by the reference numerals 12α (thick section) and 12έ> (thinner sections).

Between each pair of adjacent sections 12 each of which resembles a surface of an individual plank or board of lumber, there is formed an indented, elongated groove 14 having a pair of inwardly sloped, angularly intersecting, opposite surfaces 16 to provide the same visual effect as a V-groove joint between adjacent boards or planks. As best shown in FIGS. 4 and 5, the surfaces 16 of the grooves 14 are embossed with grain patterns therein and accordingly are relatively difficult to finish on automatic equipment because of variations in the surface. It is desirable that the groove surfaces be finished to appear the same as actual wood after finishing is complete. It should be noted that many prior art panels have dark coloring of a solid nature in the grooves, which coloring detracts from the authenticity of the appearance of the finished panels and which does not accurately portray V-groove joints between planks.

The paneling sheets 10 are preferably formed with a hydraulic press, at relatively high temperatures and

3,908,588 pressure, and the materials used normally comprises wood fibers or chips which have been exploded into small size fibrous pieces. The pieces are mixed and heated with steam and finally are compressed under extremely high pressure and temperature with an embossed pressure plate to provide the section thickness variations and the authentic appearing V-groove joints with embossed grain patterns therein. The assignee of this application makes and sells paneling sheets of the same general type under the trademark “MASONITE,” however paneling sheet of other construction and materials such as fiber board, particle board, pressed wood, etc. may be utilized when decorated in accordance with the present invention to closely resembly V-groove wood planks or boards laid side by side.

In accordance with the present invention, blank paneling sheets 10 formed of pressed wood fiber material and the like with an outer surface embossed with Vgrooves therein as described, are first passed through a ground coating paint or color applicator station, preferably of the roll type such as shown and described in the U.S. Pat. Applications Ser. Nos. 244,623 filed Apr. 17, 1972 and Ser. No. 178,556 filed Sept. 8, 1971, which applications are assigned to the same assignee as the present application and which applications are incorporated herein by reference. After the paneling sheets 10 have been covered with the first solid color ground coat, the decorative surface of the paneling sheets appear as shown in the photograph of FIG. 3. The ground coat application provides a solid color base for the subsequent application of stain coloring agents, such as paint or ink in printed patterns. The color of the first coat is chosen to provide a base or background compatible with the type of wood which is to be resembled by the finished paneling sheets. It should be noted that the grooves 14 and the surfaces 16 thereof are formed with embossed grain patterns therein, however, the grain pattern does not stand out in deep contrast as shown in FIG. 3 after the application of the first ground coat. A single application of a solid color ground coat along does not particularly enhance the relief appearance of the grooves formed in the panels, and subsequent finishing steps in accordance with the invention produce a dramatic and pleasing change in appearance.

After the panels 10 have received the first solid color ground coat application which has been dried, they appear as shown in the photograph of FIG. 3. These panels are next passed through a stain applicator as indicated schematically in FIG. 1 and referred to generally by the reference numeral 20. The novel stain applicator 20 in accordance with the invention includes a plurality of support rolls 22 for carrying the ground coated panels 10 along a horizontal path as indicated. In addition to the individual support rolls 22 there is provided a first pair of pulling pinch rolls 24 and 26 which are adapted to move the panels 10 into and through,the stain applicator 20. The lower roll 24 of the first pair of pinch rolls is power driven by means of endless chain 28 which chain drivingly interconnects the roll 24 with the lower one of a second pair of pulling rolls 30 and 32 at the outlet or exit of the stain applicator. The endless chain 28 is drivingly engaged with a plurality of separate, lower support rolls 34, 36 and 38 which are spaced intermediate the pairs of pinch rolls at the entry and exit end of the apparatus. As indicated schematically in FIG. 1 a number of idler sprockets 40 are pro vided to maintain the proper tension on the chain drive, and each of the drive rolls 24, 30, 34, 36 and 38 is supported on a horizontal axle for free rotation as driven by the chain through a sprocket 42 in the roll shaft. The lower exit roll 30 is rotated at a controlled and adjustable speed by means of a drive chain 44 which interconnects a driven sprocket 46 on the roll shaft with a sprocket 48 on the output shaft of an electric motor powered, variable speed, main drive, gear reducer unit SO.

In an apparatus constructed in accordance with the present invention, the reduction gear unit 50 and/or electric drive motor was selected in order to provide a wide variable speed range of feed for the panels 10 moving through the apparatus 20. The drive unit was selected to provide a speed variation from a minimum of approximately 45 feet per minute to a maximum of over 180 feet per minute. The driven upper pinch rolls 26 and 32 are spaced above the respective lower, driven pinch rolls 24 and 30, and the upper rolls are adjustable in a vertical direction as shown by the arrows A so that the desired contact pressure may be maintained upon the paneling sheets 10 to pull them through at the desired speed. In this connection it should be noted that the contact pressure is increased somewhat at higher feeding speeds and may be reduced somewhat at lower feeding speeds because of the decreased tendency to slip.

In accordance with the present invention, a fast drying liquid stain of the proper color or tint is applied onto the upper decorative surface of the paneling sheets 10 as they move through the stain applicator 20. The stain is supplied from a liquid trough 52 extending across the sheets and having an elongated dam or weir 52α over which is flowed a thin curtain of stain. The liquid curtain of stain moves downwardly onto the panels guided by a sloped applicator strip 54. The stain is flooded over the entire upper surface of the moving panels 10 at a controlled flow rate and is spread and disbursed over the sections 12 and into the grooves 14 by means of a first squeegee type applicator 56 having a blade 58 formed of rubber or other flexible material capable of deflecting enough to move the stain down into the groove surfaces 16 and the grain patterns formed therein.

After the panels pass the first spreader blade 58, most of the stained surface is covered uniformly and the stain is evenly distributed. As the panels continue to move, they pass under a first rotary brush assembly 60 which includes a drum 62 having a plurality of radial bristles formed of polypropylene plastic material and having crimped or bent over outer ends for engagement with the panels. As indicated in FIG. 1, the drum and bristles are rotated in a counter-clockwise direction so that the relative bristle movement is counter to the direction of movement of the paneling sheets at the region .of contact between the bristles and panel. The rotary drum is adjustably movable in a vertical; direction (arrows B) to increase or decrease the amount of bristle contact with the stained surface of the panels. The drum 62 is driven to rotate at adjustable speeds varying in a range of 200 to 600 rpm. An electric motor 63 of variable speed and a gear reducer 64 are connected to drive the drum of the brush assembly through a belt drive 65.

The flexible squeegee-like blade 58 serves to distribute the stain over the entire surface of the paneling

3,908,588 sheets and removes much of the excess stain that is present. The rotating bristles on the drum 62 similarly serve to evenly distribute the stain over the entire surface of the paneling sheets while working the stain in thoroughly into the grain pattern indentations in the groove surfaces 16. Any excess stain remaining is also removed by the rotating bristles which act to help dry the stain by creating an air flow over the surface. As the rotating bristles pass over the panels in a direction contra to that of panel movement, the excess stain is sort of swept off and the stain is substantially uniformly distributed over the entire upper surface of the moving panel sheets 10 and is thoroughly worked into the indentations in the embossed grain pattern.

As the panels continue to move through the stain applicating apparatus 20, they pass beneath a second squeegeelike mechanism 66 having a blade 68 like that of the blade 58 formed of flexible material such as rubber. This blade removes any excess stain that may remain on the upper surface of the panels after passage through the first brush rolls assembly 60. The panels move past the second squeegee-like blade 68 and pass underneath a plurality of holddown disks 70 which are spaced apart on a transverse axle 72. The disks maintain the paneling sheets 10 in driving engagement against the drive rolls 34 and 36. The panels then pass under a second rotary brush assembly 73 similar to the first rotary brush assembly 60, and the brush action is similar and will not be described in detail herein. The second rotary brush assembly rotates in a counterclockwise direction and its speed is adjustable so that the drum 74 rotates in a speed range from 200 to 600 rpm with the tips of the bristles operating in a speed range of 267 feet per minute to approximately 1,100 feet per minute relative to the surface of the panels. The second rotary brush assembly is driven by a variable speed electric motor 75 and gear reducer 76 connected to the drum 74 by a belt drive 78.

After passage through the second rotary brush assembly 73, the stain is reduced to a thin, evenly distributed coating over the entire surface of the panel sheets 10 and is beginning to become dry and somewhat tacky. With the stain in the described condition, the panels move under a second set of holddown disks 80 spaced apart on a transverse axle 82 and move to a stain wiping station indicated generally by the reference numeral 84.

At the wiping station 84, the somewhat tacky, partially dry stain coating is wiped by an elongated belt 86 of woven stranded material to produce elongated, random streaks in the stain coat to provide an appearance like that shown in the photograph of FIG. 4. The stain coating is wiped to provide a random orientated streaked effect as might be provided in the olden days by an individual craftsman, and this streaked stain effect is especially noticeable on the surface 16 of the grooves 14 between adjacent plank segments 12. The wiped stain streaks on the surface of the segments 12 also provide some slight surface variation away from a completely planar surface, and when an additional solid color ground coating is applied following the stain wiping process, these surface variations in depth provide added authenticity for the final wood grain printed pattern.

The novel stain wiping station includes an idler supply or feed roll 88 for the wiping belt and a driven takeup roll 90. The belt is passed beneath a pair of idler rolls 92 and 94 adjacent the upper surface of the moving panels and spaced on opposite sides of a rotary brush roll 96 having a large number of radial bristles formed of polypropylene plastic material 3 to 3½ inches long and crimped or bent over at their outer free ends. The bristles are relatively stout and are approximately 0.014 inch in diameter. In general, the bristles on the drums 62 and 74 are similar and the drum 96 is movable vertically like the others (arrows B) to increase or decrease the area of bristle contact with the back side of the wiping belt 86.

The belt 86 passes over a tensioning idler roll 98 before it is wound up on the take-up roll 90 in a clockwise direction as shown. The wiping mechanism is powered by an adjustable speed electric motor 100 and gear reducer 102 via a belt drive 104 running to a pulley 106 on the shaft 108 supporting the brush roll 96. A belt tensioning idler 110 is provided to accommodate belt adjustments when the brush roll 86 is adjusted. A relatively constant speed ratio is maintained between the wiping belt 86 and the brush roll 96 by means of an interconnecting drive chain or belt 112 running from a pulley or gear 106 on the brush drum axle to a pulley or gear 114 carried on a shaft 116 mounted beneath the take-up roll 90. A knurled drive drum 118 on the shaft 116 drives the take-up roll 90 of the belt 86 in a clockwise direction as shown, to provide constant belt speed for the wiping belt. An idler 122 is provided to tighten or loosen the belt or chain 112 as needed.

In accordance with the present invention, the wiping of the stain by the belt 86 occurs at a relatively low speed so that only about 6 inches of belt travel occurs during the interval of time required for a panel 10 which is 8 feet in length, to travel across the wiping station. It has been found that a wiping speed of approximately this value works well and provides a desirable appearance. However, the motor 100 and gear reducer 102 permit a relatively wide range of belt speeds to be utilized so that speeds can be varied over a range of 6 to 1. It has also been found that the type of woven fabric used for the belt is an important factor in the finished appearance of the wiped stain, and different fabrics may require adjustments in wiping speeds. For example, heavy cotton duck No. S/55252 purchased from B. J. Seaman &amp; Co. of Chicago with minimal sizing or unsized works well. Hopsacking of a relatively rough weave with heavy fiber or strand size and relative large openings has worked effectively.

In accordance with the invention, the rotating bristles of the drum 96 urge and bias the woven wiping belt 86 into contact with the paneling sheets 10. The tip speed of the bristles is considerably slower than that of the bristles on the first and second brush assemblies 60 and 73. The tip speed of the bristles on the drum 96 is set up to be substantially the same as the speed of the slow moving belt 86 and the moving mass of bristles form a sort of resilient cushioning effect on the back side of the belt which urges the belt into wiping contact against the paneling sheets 10 moving therebeneath. This cushioning effect provides for a sort of randomness that the wiped streaks in the stain appear to have, and this is one of the effects that makes the wiped stain appear as an authentic hand wiped job. In addition some of the bristles which are moving at a tip speed ranging from 2.6 feet per minute to 15.5 feet per minute may randomly penetrate random openings in the weave of the belt 86 and come into contact with the stain to provide

3,908,588 a streaked effect therein. The belt 86 moves at about the same speed as the tips of the bristles of the rotary drum 96 which act as a biasing force on the belt to produce the wiped stain effect as if it were done by hand. FIG. 2 illustrates the belt 86 biased in wiping contact with the panel sheet 10 by the bristles of the brush drum 96, and the drum is movable vertically as indicated by the arrows B to increase or decrease the wiping contact area.

After the paneling sheets 10 have passed through the apparatus 20 of the invention and appear as shown in FIG. 4, they are passed through another solid color ground coat applicator wherein only the board or plank segments 12 are covered to provide a base for the final grain pattern printing application in ink. The grooves 14 and surface 16 thereof remain the same before and after the solid color ground coat application following the stain and wiping process. However, it should be noticed that the contrast between the solid color coated plank segments 12 and the grooves 14 is much greater than before as shown by the difference in appearance between the paneling in FIG. 5 and the partially finished sheets of FIGS. 3 and 4.

The paneling sheets 10 are then passed through a printing station wherein a wood grain pattern (FIG. 6) is applied onto the plank segments 12 and then a clear seal coat is applied over the entire decorative surface of the paneling sheets to produce the finished panels is illustrated, which panels closely resemble the actual thing.

The building panels may comprise wood particles and/or wood fibers formed under pressure and may also comprise plywood sheets or embossed plywood sheets wherein the decorative outer face is formed with sections of different thicknesses and grooves along the joints between the sections. Mineral filler or gypsum board panels may also be used in accordance with the present invention.

Referring to FIG. 4, the building panels 10 may be provided with only a solid color ground coat (FIG. 3) followed by the application of wiped stain on the apparatus 20. The panels appear as shown in FIG. 4 and are then covered with a final clear sealer coat. The resulting panels do not have a printed grain pattern as do the panels of FIG. 6, but instead have only the hand wiped stain appearance with streaks therein as shown in FIG. 4.

Another embodiment of a panel may be provided by eliminating the second solid color coating on the flat surfaces (FIG. 5) and following the wiping of the stain with the printing of a grain pattern on the flat surfaces. This type of panel is similar in appearance to the panel 5 of FIG. 6 but may have a slightly different subtle undertone closely related to the color of the first solid color coating.

Although the present invention has been described with reference to several illustrative embodiments 10 thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this invention.