JP5740001B2 - Waterproof ceiling tiles - Google Patents

Description

  The present invention relates to improvements in structural panels and specifically to ceiling tiles made from water slurries or aqueous pastes.

  Structural panels, especially permeable ceiling tiles, tend to become contaminated when exposed to water. One mechanism that arises when water drops come into contact with ceiling tiles is condensation in pipes and piping that exist in the space above the ceiling. Condensate may drip on the back of the ceiling tile and move to the visible appearance of the tile. Because water can take away contaminants from contacting surfaces, and often water drops travel through ceiling tiles and are used in recycled newspaper or other plant-based cellulosic materials and tile compositions Contamination can occur to ooze tannins from contaminants from other ingredients and bring such contaminants to the front of the tile.

  As is typical for most products, cost is important and there is a need for an economic solution to minimize water contamination on the exterior of structural panels, especially permeable ceiling tiles.

  The present invention provides an economic solution to water contamination on the visible surface of a structural panel due to moisture movement through the panel. More specifically, the present invention relates to the realization that the water droplets can evaporate before the liquid content of the water droplets can move through the panel by locally creating a barrier to the water droplets on the back of the panel.

  It has been discovered that commercially available materials used to impart water repellency to fibers are excellent media for achieving the objectives of the present invention. Such materials are widely available, non-toxic and relatively inexpensive at the limited coverage found to be effective in practicing the present invention. A preferred waterproof material can be applied to the back of the rigid mat from which the tile is manufactured using the water carrier by simple application of the water carrier. The very low coverage and consequently the low cost waterproofing and the ease of application make it possible to carry out the use even in the panel manufacturer's very inexpensive product line.

  The core mat or tile is preferably subjected to elevated temperatures for rapid forced drying or curing of the waterproof material before the water carrier can be absorbed through the core mat. Preferably, this drying process may be performed simultaneously with conventional process steps used to dry the finish coating or to paint the visible surface of the tile or panel.

FIG. 1 is an isometric view of a ceiling tile embodying the present invention. FIG. 2 is a schematic diagram of a process utilizing the present invention.

The present invention is applicable to various structural panels that can be used to cover walls or ceilings. One preferred form of structural panel is a ceiling tile or panel used for suspended ceilings. Other forms of structural panels include gypsum-based wall tiles and wallboard. Ceiling tiles made from a water slurry or paste and not lined with a water resistant film or sheet are particularly beneficial according to the present invention. In describing the manufacture of ceiling tiles incorporated into the present invention, reference is made to FIGS. 1 and 2 of the drawings. A rectangular ceiling tile 10 is configured to be used as a lay-in panel in a rectangular grid in a commonly known suspended ceiling system. Tile typically has a thickness between about 1/2 "to about 7/8" and a nominal of 2'x2 ', 2'x4', and 2-1 / 2'x5 ' It has area or metric conversion of these panel sizes. Suspended ceiling panels or tiles are typically manufactured from a water felting process or a pasty aqueous castable formulation. When panel 10 is derived from a water-condensation process, a typical approximate formulation is on a weight basis,
65% perlite fiber 18% paper fiber 7% unmodified starch binder, and 10% mineral cotton fiber.

  Mineral cotton content may vary considerably up to about 25%, in which case pearlite may be reduced accordingly. In addition to paper fibers, other cellulose sources such as wood or wood may be used. In the case of water-condensed products, these components are mixed properly in the water slurry and dispersed in the screen, or in the case of molded tiles, when similar components are dispersed in the pan, these components Is dewatered and / or dried in a rigid board. Thereafter, the exterior or front surface of the board or tile preform is coated with an exterior coating or paint, typically an aqueous material having some latex or other binder component. In the case of a water-filled mat or core, the finished surface of the mat may be ground to form a flat surface before finishing or coating with a top coating, if necessary. In addition, a primer, which may be viscosity based, may be applied to the surface of the mat, for example, prior to applying the finish coating. The tile 10 of FIG. 1 is shown in its orientation, with its underside appearance coating 11, visible surface, undercoat 12, water-reduced mat or core 13 and on its back or top as described below. A waterproof coating 14 is included.

  As described above, the appearance coating 11 on the finished surface of the tile 10 is typically an aqueous coating with a white pigment to provide high light reflectivity. It has been discovered that commercially available fiber waterproofing materials can be used to successfully waterproof the back of the tile 10 by coating the mat 13 with such materials. Surprisingly, it has been found that only a relatively small amount of such material is required to achieve satisfactory results. An example of a product suitable for practicing the present invention is a fluorocarbon polymer emulsion as marketed by Daikin Chemical Europe GmbH, Dusseldorf, Germany under the trademark TG-5601. This product is an aqueous emulsion that can be highly diluted with water while maintaining effectiveness even when the application rate is unclear. Depending on the dilution result of the original emulsion, about 1/5 to 1/4 gram / sq. It is a very light coating of ft waterproof solid. Despite such low concentrations of solids, it has been found that a surprising degree of waterproofness and resistance is achieved. Due to the disclosed solids coverage, the water droplets on the coating 14 simply bead-up and eventually evaporate.

  FIG. 2 shows an example of a process for carrying out the present invention. A dry mat or board 13 produced by a conventional water-condensation process having a solid content as described above is carried on a conveyor 20 in a spray chamber 21 to which an aqueous top coating or paint 11 is applied. The top coating or appearance coating 11 is upward in this process, but when the tile is installed on the ceiling, the top coating is downward. The mat 13 is conveyed from the spray chamber to the dryer 22 by a roller conveyor 23. A sprinkler 24 holding a plurality of spray nozzles extends between a pair of rolls of the conveyor 23 across the width of the conveyor. The sprinkler 24 sprays the lower side of the mat 13 using the diluted waterproof liquid 14 described above. The mat 13 coated with the top coating 11 and the waterproof material 14 is preferably conveyed simultaneously through a dryer 22 where the coatings are simultaneously dried and / or cured at a temperature of about 220 ° C., for example for about 45 seconds. Transported by Other methods of applying the top coating and waterproof material are conceivable. For example, roll coating or flooding may be utilized.

  Condensed water dripping from pipes and ducts in the space above the suspended ceiling or in the plenum can fall onto the back of prior art ceiling tiles, ultimately causing discoloration of the surface or appearance. This mechanism of discoloration or contamination can be attributed to the permeation of condensed water through the tile. The condensate can be contaminated by the surface through which it passes before it reaches the tile. Furthermore, if water permeates through the body of the tile, the water can leach out materials that cause contamination such as tannins present in paper or cellulose fibers. Since contaminated water can leach through the appearance coating, it contaminates the appearance coating. Without utilizing the present invention, it is common for water to pass through the tile, since in the presence of a water source, it is desirable that the ceiling tile be porous so as to exhibit sufficient absorption characteristics. Adding the desired porosity of a typical ceiling tile essentially leaves its original aqueous properties permeable to water.

  It is to be understood that this disclosure is exemplary and that various changes may be made by adding, modifying, or removing details without departing from the full scope of the teachings contained in this disclosure. It is. Accordingly, the invention is not limited to the specific details of the disclosure except to the extent that the following claims are necessarily so limited.

Claims (6)

A ceiling tile comprising a core, an exterior coating on the surface of the tile, and a waterproof coating on the back of the tile,
The core includes a filler, a binder, and the fiber component dried from an aqueous slurry or paste of fiber components;
Wherein the core is water-permeable, it includes a material which causes the exuded easy-contamination to the outside from the core by the water penetrating through the core,
The appearance coating contains a white pigment and exhibits high light reflectance by penetrating water,
The material of the waterproof coating is a fluorocarbon polymer emulsion, which is 1/5 to 1/4 gram / sq. A ceiling tile that is applied at a solid coverage of ft and functions to repel and bead the water droplets deposited on the back of the tile.   The ceiling tile of claim 1, wherein the fiber component comprises mineral fibers.   The ceiling tile of claim 1, wherein the appearance coating is a dry aqueous white paint layer. Said material waterproof coating, Drying, a material obtained by removing water by curing, ceiling tile according to claim 1. Producing a core by mixing the materials in the presence of water;
Drying the material to form a rigid board;
Look including the the steps of applying the aqueous waterproof coating material to the surface of the core opposite the exterior surface to the aqueous exterior coating and the surface of said core,
The material of the water-proof waterproof coating is a fluorocarbon polymer emulsion and is 1/5 to 1/4 gram / sq. A method of manufacturing a waterproof ceiling tile that is applied at a solid coverage of ft . 6. The waterproof ceiling tile of claim 5 , wherein the appearance coating and the waterproof coating material are applied and then dried simultaneously by exposing the applied coating material to a heated environment of 220 ° C. for 45 seconds. How to manufacture.

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