US2341161A

US2341161A - Wood finishing

Info

Publication number: US2341161A
Application number: US392144A
Authority: US
Inventors: Watkins W Partee; Gray Milton
Original assignee: EL Bruce Co
Current assignee: EL Bruce Co
Priority date: 1941-05-06
Filing date: 1941-05-06
Publication date: 1944-02-08
Anticipated expiration: 1961-02-08

Description

Feb. 8, 1944. w. w. PARTEE ETAL WOOD FINISHING Filed May 6, 1941 RMN@ Mw. N

Patented Feb. s, 19`4 WOOD FINISHING Watkins w. rei-tee end Muten Gray, Memphis, Tenn., asslgnors to E. L. Bruce Co., Memphis, Tenn., a corporation of Delaware Application May s, 1941, serial No. seam 9 Claims.

Our invention relates to the manufacture of factory finished wood flooring in the form of strips .or blocks. In Patent #2,276,253, granted March 10, 1942, there is disclosed a machine and process for producing finished wood flooring that has a. finish that deeply penetrates the wood, as differentiated from wood finishes that merely lie on the surface of the wood, and that is tough and elastic, not readily scratched, of good lustre and .more durable than prior nishes.

In the above patent, the finishing composition, and stain (when required) and illler were separately applied and in an unheated condition to the cold wood in the order stated, said material being of such character that there was secured a final blending and combination of nish and/or stain, and/or iler in the surface and sub-surface of the wood, all of these materials drying as a unit in the later operations, leading up to and incident to the production of the nal finish and polish of the wood. After the finish and filler had been applied and rubbed into the wood, however, it has been necessary heretofore to subject the thus treatedwood to curing or air drying for at least 12 hours before applying the wax orA 4other polishing composition. This interim would vary in duration depending upon the lhumidity and temperature conditions prevailing at the time. This necessitated large storageA space for the semi-finished ooring and slowed down the output. In the present invention, the total time expended from the beginning to the end of the'operation is about 12 minutes in one integral and continuous operation as compared to as muchas three days by the prior process. In addition, the :final finish, while of the same general character, is superior.

The operation of the machine and process will be described in connection with the nishing of strip ooring although it is equally applicable to the finishing of block flooring or other Wood flooring. Generally speaking, the machine consists of a series of kinstrumentalities for treating the surface of the wood, which is kiln dried and has a smooth sanded face, the wood being continuously fed past these instrumentalities by a conveyor belt on which the strips of wood are supported. The composition is sprayed on the upper smooth sanded surface of the wood, brushed, heated by passing under a series of infra-red lamps, brushed again and rubbed in, then heated further under a series of infra-red lamps, subjected to further brushing, rubbing in,

Referring to the drawing for a more complete disclosure of the invention Figs. la'and 1b represent a plan view of the machine, 1b being a continuation in the same straight line as 1a, the entire machine being about 200 feet long; V

Fig. 2 is an enlarged transverse section on the line 2-2 of Fig. 1a; and

Fig. 3 is a similar view on the line 3-7-3 of Fig.1a.

The machine consists of side frames l and between these traverses the endless rubber belt 2, which overlies a sheet metal plate 3. The belt at each end is supported by pulleys 4 and 5 and is driven bythe motor 6 through th speed reducer 1, belt connection 8 and pulley 5. The flooring strips 9` are placed on the belt conveyor 2 by an operator and pass under a steel pressure roller l0 to insure a flat horizontal surface of flooring, as they pass under the spray booth Il, where the finishing composition and filler and color is applied. The strips are in tongue and groove engagement as seen in Figs. 2 and 3 and the longitudinal tongue side I3 may engage a y corresponding groove along-the side of the machine, spring steel at springs I3' on one side of the line, spaced about every 6 feet, keeping the strips of flooring together by forcing it to one side.

The particular 'type of composition that I apply to the surface of the floor is what is known as a penetrating seal finish, an example of such being disclosed in the patent lto F. H. Lyons 2,066,296, granted Dec. 29, 1936, except yfor the paraffin wax which should be practically eliminated. Compositions of this character contain such skin forming drying oils as linseed oil and China-wood oil and a resin, all in a volatile solvent such as naphtha. Such compositions have the property of rapidly penetrating the wood when applied. These compositions, after evaporation of the volatile solvent or vehicle, dry and harden, either by oxidation or polymerization. The usual silex ller and a dye or stain-can be thoroughly mixed with the nishing composition, the different ingredients being miscible with each other and applied by a mechanically operated spray in a predetermined quantity per unit of area to secure an even and uniform mtribution over the surface of the wood. When applied to maple flooring, a dense and closed pore wood,

and bufiing, then a coating of paste wax is applied and polished until dry and hard.

rather than red oak flooring, a less dense and open pored wood, the filler may be dispensed with. The coating composition may consist of a finish and stain, a :tlnish and ller, or finish,

L erties.

stain and nller. Some woods do not require a nller and when any wood is finished "natural no stain is used.

Immediately following, the spraying of the coating composition on the wood, the flooring which is moving on the belt conveyor at the rate of 17 feet per minute, is brushed by the revolving bristle brush I2, driven by the motor Il through the belt i5. This brush spreads the composition uniformly over the surface of the wood. 'I'he 'ilooring next meets the revolving burlap pad buffer' IB which further uniformly spreads and removes any surplus composition. All the successive brushes or pads. rotating on a vertical axis are driven through an independent motorand belt arrangement of the same kind as drives the brush' I2, and they can be swung up vertically Von a horizontal pivot, oi! of theV surface of the wood, for changing and cleaning brushes and pads.

Following the operations just described, the flooring enters the first infra-red light line l1, this particular line being about 30 feet long and containing a single row of 250 watt infra-red lamps 24. These lamps 24 are spaced about 5% inches on centers, 4-5 inches above the surface of the floor and maintain an oven heat of about 165' degrees F. The lamps are enclosed in a tunnel formed on the bottom by the belt or flooring and on thesides and top by sheet metal plates i8 supported on angle iron framing I9, the purpose of the tunnel being merely to conserve heat and avoid cross currents of air, which would deflect the rays.

The nooring, after it leaves the tunnel at a temperature of about 13o-135 degrees F., passes under a revolving bristle brush 2li, then passes under another revolving bristle brush- 2i. Thesetwo operations serve to rub the materials in and ll up the minute depressions, and also to dis' tribute them in a more uniform way, on the surface of the flooring, and to some extent remove the marks left by the previous distributing brushes which have operated on the surface of tilxixe Ifl'oorin'g before it entered the` nrst light l e of the composition and the forming of a nrmer final bond in the wood. Chemical changes in the composition are also started in the first section, the nnish setting up and holding the filler.

In the second heat section, substantially all of the solvents in the composition are removed by evaporation band the nnal set of the nnish and filler vis completed. In this heat section oxidation or polymerization of certain ingredients go to completion and this action is complete not only for the surface portion but for that portion of the composition that has penetrated deeply into the poresof the wood. v

If the temperature in the nrst section were i high,'thecomposition would set up too fast and, the composition could not be properly rubbed in. Also a high temperature might prevent satisfactory elimination of surplus filler.

'- The desirable results that are attained in the process by the use of infra-red rays is believed due to the fact that heat is produced within and throughout the entire thickness of finishing composition and the wood. The eilect seems to be that the wod is heated from the inside out,'as differentiated from mere surface heating of the wood by conduction from the outside in.

Since the composition used is of a character that penetrates the wood, the whole mass of composition is affected and not merely case hardened on the surface which condition would seal in the wood, the excess moisture in the wood, and the volatile components of the composition. There is also a more uniform distribution of the coating composition, when it is worked and rubbed in while in a heated condition.

After leaving the light section 23, the flooring meets the revolving

bristle brushes

28, 21 and 28 which further wor and rub in the composition. They also serve to lay the foundation for the final gloss and sheen by starting to polishl and buff the surface of the wood while it is still Warm.

The flooring nowk enters a second line 23 of infra-red lamps 25 which is spaced about 5 feet from the first line,4the tunnel being formed of plates Il, in substantially the same way as the tunnel in the line Il. The tunnel is of the same length as the first timnel and the lamp arrangement is otherwise the same as in the rst tunnel except that there are twice as many lamps in the two rows, as in the line I1. The oven temperature in the line 23 is about 210 degrees F. and the wood as it leaves the oven is about 172 desrees F.

Due to the different temperature conditions,

and the 'iiilferent progressive conditions of the impregnating composition in the two sections,

' ing composition. The heat also makes the nnishing composition more fluidi, reducing its viscosity so that it has increased penetrating prop- The solvent vehicle and carriers in the finish also start volatilizing. which causes drying Followingthese three brushes. is a high speed cylindrical bristle brush 2l driven by the motor 30, which removes any circular streaks from the prior brushes. Following this is another` revolving bristle brush ll that removes any foreign surplus material.

The next operation consists of a steel wool buifer 32 that reciprocates back and forth with the travel of the flooring along the line. This removes surplus filler, raised grain and extended particles of wood fibre that may be on the surface of the flooring.

Following the steel wool buffer, there is a regu-'- lated compressed air blower 33, directing a current of air on the surface of the flooring that removes all particles of steel wool and other loose material and also serves to cool to a certain degree, the surface of the flooring, in preparation for its reception of the waxing that is to follow.

The next operation on the ooring is to apply to the upper surface a coating of wax. This is done by means of a revolving roller I4 that has a felt pad applied over it and is warmed by contact with the heated flooring and so set that the movement of the flooring below the roller, revolves the roller which rotates through a quantity of paste wax in a pan or hopper 35. As the flooring'is fairly warni at this point the roller pad is kept constantly warm and thereby moist with melted wax. 'I'he temperature of the roller being slightly above the melting point of the wax en.

obtained. Heating of the wax may be augmented by a light focused directly on the wax, in the case of higher melting waxes.

The flooring then proceeds to four revolving bristle brushes 36, the purpose of these brushes being to thoroughly polish the surface of the flooring. These brushes are placed at predetermined distances so as t give sufficient time for the cooling of the flooring and so that the wax polishing operation may be completed before the flooring reaches the final bundling section table.

At several points of the finishing line, steel rollers 31 which are idle, are placed on top of the flooringto prevent any pieces from 4getting out of line and disrupting the continuous operation.

If desired, the bottom of theiiooring can have applied to it a coating of parafiin wax as it passes over the receptacle 38 carrying the liquid paraffln.

One of the advantages of our process arises out of the fact that the finishing composition and the wood is mechanically worked on while in a warmed or heated condition. This is particularly advantageous in connection with the penetrating seal type of finish as described herein. For example, the wood ller in normal use is applied cold and is rubbed into the cold surface of the wood. With the wood surface in a heated condition, the pores are more open than when the wood is -cold and the warmed or heated filler more readily enters and fills the pores and small openings in the wood, resulting in a better filled product. Excess moisture that is released from the wood by heating naturally seeks egress through the surface and aids in opening up the pores. Heating acts both on the finish and the stain in much the same manner, causing them to become thinner and to penetrate the wood more readily. The amount of effort required in rubbing in the ingredients of the finishing composition is greatly reduced when the wood is worked on while in a heated condition and a more even and uniform distribution of them is obtained, such evenness and uniformity of distribution being important for a good finish job.

Other means for heating the flooring than by infra-red lamps could be used but the infra-red lamps have been found satisfactory in use.

The apparatus disclosed herein has been claimed in Patent No. 2,288,585, granted JuneBO, 1942, and filed on the same date herewith.

We claim:

1. The method of nishing wood flooring in an uninterrupted series of successive operations while the flooring moves continuously along a production line the steps comprising, applying uniformly to the wood a composition containing the necessary finishing elements, said composi-l tion being a penetrating seal type of finish which contains a drying oil base, a resin and a volatile solvent, heating the wood and the applied composition by heat which penertates both the composition and the underlying wood in order to remove moisture, volatilize the solvent and set the composition in the wood, brushing and rubbing the finish-coated surface, while heated to effect removal of surplus composition from the surface and substantially uniform distribution of the composition in the surface pores of the wood, to thereby produce a smooth, sealed, iinished surface, and finally applying wax to the said surface of the wood .while the latter is still heated and brushing the waxed surface to polish it, the aforesaid operations being carried out in the order stated.

2. The method of claim 1 in which the heating is accomplished by radiation which is predominantly infra-red in wave length.

3. The method of finishing wood flooring in an uninterrupted series of successive operations while the flooring moves continuously along a production line the steps comprising, applying uniformly to the wood a composition containing the necessary finishing elements, said composition being a penetrating seal type of nish which contains a drying oil base, a resin and a volatile solvent, heating the wood and the applied composition by heat which penetrates both the composition and the underlying wood in order to remove moisture, volatilize solvent, and to aid in securing penetration of the composition into the wood, brushing the surface of the heated wood to rub in the finish material and iill the surface pores and minute depressions, heating o the wood again by application of the same penetrating type of heat in order to cause further the volatilization of solvent and polymerization or oxidation of the composition within the wood and on the surface thereof, again brushing and rubbing the finish-coated surface, while heated, to effect removal of surplus composition from the surface and substantially uniform distribution of the composition in the surface pores of the wood to thereby produce a smooth, sealed finish surface, the aforesaid operations being carried out in the order stated.

4. 'I'he method of claim 3 in which the heating in both heating steps is accomplished by radiation which is predominantly infra-red in wave length, and in which the initial heating step raises the temperature of the wood and composition to the order of -l35 F. and in the second heating the temperature of the wood and composition is raised to the order of 172 F., the duration of each of the heating steps being of the order of two minutes.

5. The method of claim 1 in which the flooring is moved along the production line at such a rate.that the entire finishing operation is completed in about twelve minutes.

6. The method of claim 1 in which the finish composition contains additionally a filler comprising solid particles suspended in the volatile solvent.

7. The method of claim 1 in which the finish coated surface of the flooring is brushed and rubbed after the application of the finish composition and before heating in order to evenly spread the finish composition on the surface to be nished.

a. The method of claim a in which the'nnish coated surface of the flooring is brushed and rubbed after the application of the finish composition and before heating in order to evenly spread the finish composition on the surface to be finished.

9. 'I'he method of finishing wood flooring in an uninterrupted series of successive operations while the flooring moves continuously along a production line the steps comprising, applying uniformly to the wood a composition containing the necessary finishing elements, said composition being a penetrating seal type of finish which contains a drying oil base, a resinand a volatile solvent, heating the wood and the applied composition by heat which penetrates both the composition and the underlying wood in order to remove moisture, volatilize solvent, and to aid in securing penetration of the composition into the wood, brushing the surface of the wood while heated to rub in the finish materiel and ml the surface -`pores and minute depressions, heating the wood again by application oithe same penetrating type of heat in order to complete the volatilization oi' solvent and also to complete thc polymerization or oxidation ot the composition.

plus composition from the surface and substeni0 tially uniform distribution o! the composition in the surface pores of the wood to thereby produceasmootmsealediinishsurface, andiinally applying wax tothe said surface of the wood while the latter is* still heated and brushing the waxed surface -to polish it, the aforesaid operations being carried out in the order stated.

I w. w. PARTEE. saumon GRAY.

DISCLAIYM ER 2,341,161.Watk1,ns W.- Partee and-Milton Gray, Memphis, Tenn. Woon FIN- IsmNG. Patent dated Feb. 8, 1944. Disclaimer led Sept. 22, 1947, by

the assignee, E. L. Bruce 0o. Hereby disclaims from the specification lines 46, 47, and 48, column .1, page 3, reading as follows:

and further disclaims claims 1, 3, 5, 6, 7, 8 and 9.

[Om'al Gazette October 28, 1.947.]