US2068892A - Method of coating surfaces - Google Patents

Description

Jan. 26, 1937. H. v. SCHWEITZER ET AL 2,068,892

METHODOF COATING SURFACES Filed June 6, 1932 3nventors:

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Patented Jan. 26, 1937 UNITED STATES PATENT OFFICE METHOD OF COATING SURFACES Application June 6, 1932, Serial No. 615,722

2 Claims.

The present invention relates to a method of applying glazes, enamels and similar coatings to earthenware, tile, metal and other non-absorbent materials.

Specifically, the invention pertains to the application of a liquid coating to a surface by means of spray nozzles, and the evaporation of a substantial portion of the liquid carrier after it has been discharged from nozzles, but prior to impingement of the solid matter in the coating on the surface being treated.

In the application of liquid coatings to tile and similar objects, care must be exercised that the surface be maintained in horizontal position prior to firing to prevent flow of the coating and subsequent uneveness of the coating. The mixture of the carrier liquid and solid matter should not be so fluid that a coating of substantial thickness will not form on the treated surface. It is go dimcult, however, where spray nozzles are used for applying the coating, to reduce fluidity without interfering seriously with the operation of the nozzle. 'In other words, the mixture being sprayed should not be so thick that the nozzles 5 will be clogged with solid matter. Since spray nozzles expedite the coating operation and insure uniform application thereof, it is obvious that this method of applying glaze to tile, for instance, is desirable. One of the purposes of this invention is to permit the use of a very fluid coating mixture and spraying apparatus for applying the mixture. At

the same time, means are provided for changing the consistency of the mixture in its passage from the spray nozzle to the surface being treated so that the solid material therein will adhere to the surface.

Another object of the invention is to provide for adjustment of the nozzles with respect to the surface, as well as adjustment of the evaporating means, which, in the embodiment illustrated, comprises a flame.

The invention will be more fully 'understood from the following description, reference being had to the accompanying drawing, in which:-

Fig. 1 is an elevation of one form of apparatus, showing the relation of the spray and flame nozzles and the means for adjusting their relative positions; and l 60 Fig. 2 is a partial view of a modified form of the apparatus.

Referring to the drawing, the surface to be coated is indicated at H. To simplify the description, this will be referred to hereinafter as 86 tile, although it is intended that any non-absorbcut surface or article fall within the generic term surface.

Disposed above the tile at a suitable distance therefrom is aspray nozzle l2 through which a mixture of liquid and solid glazing material is 5 discharged onto the tile. Ordinarily, in order to insure proper flow through the nozzle, the proportion of liquidin the mixture, is such that, when it strikes the tile, it has a tendency to flow and form an uneven film thereon. The propor- 1o tions of solids and liquid may, of course, be varied by means of valves l3, It on the spray nozzle, but not sufliciently to prevent spreading on the surface without danger of clogging the nozzle.

In Fig. 1 there is shown, to one side of the 15 spray stream and directed at an angle to the stream, a flame nozzle l5 supported by an adjustable bracket l6 having a slot l1 therein. Byioosening nut l8, bracket I6 may be raised or lowered with respect to supporting arm I9 to es- 2o tablish the desired relation betwen nozzles and I5. The spray nozzle is also adjustably secured to arm I9, being held in a bracket 2| which is fixed to arm l9 by means of nut 22. Slot 23 in arm I9 permits adjustment of the spray nozzle 25 with respect to its supporting arm.

In operation, the coating mixture is sprayed on the tile and. the flame directed toward the spray at an angle thereto. The flame stream crosses the spray at some distance from the spray 30 nozzle so as not to affect the latter nozzle. A substantial portion of the liquid in the sprayed mixture is thus evaporated. By the time the coating materiahreaches the tile, the consistency of the mixture has been so altered that there is but 35 little liquid' in the mixture and the tendency of the glaze to flow is greatly minimized. In fact, it is not necessary that the spray be directed downwardly against a horizontal surface since the glaze is only slightly moist when it strikes thel 40 tile and will adhere regardless of the position of the surface being treated. It is to be understood that the tile is further heated or baked in a firing oven properly to fuse the glaze on the tile.

In the modification illustrated in Fig. 2, twd 5 spray nozzles l2, 12'', are angularly disposed with respect to eachother, their stream axes intersecting substantially at the surface to which the coating is applied. The flame nozzle I5 is positioned between the spray nozzles and its axis 5 likewise intersects those of the spray stream at or near the surface H. In this form of the invention not only is a substantial portion of the liquid evaporated, but the surface is also heated, thus facilitating adhesion of the glaze.

ent material and directing a hot gaseous stream towards and interlectinz the stream of the grayedmixture afterithasbeensprayedbut prior to its impingement on the surface to alter the consistency of the mixture, thereby to effect adherence of the mixture to said surface without further flow thereof.

2. The method of applying fusible glazes, enamels, and similar coatings to earthenware, tile, metal, and other non-absorbent materials, which consists in spraying a mixture of liquid and the fusible matter on the surface of the nonabsorbent material and directing a flame towards and intersecting the stream of the sprayed mixture after it has been sprayed but prior to its impingement on the surface to alter the consistency of the mixture, thereby to effect adherence of the mixture to said surface without further flow thereof.

HOWARD V. SCHWEI'IZER. DAVIS A. CABLE.

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