Patent Application
20070095279
The invention relates to plural component coating application, and more particularly to a workspace for plural component coating application.
Plural component coatings are commonly applied by spraying. However, the spray process can result in undesirable vapors and particulate in the air, which may be hazardous to the operator applying the coating. In the case of polyurethane coating, isocyanate vapors can be toxic if inhaled. Fresh air ventilators are commonly used by operators while spraying. However, the air in the shop where the coating is being sprayed may still contain vapors for some period after the spraying is finished. At this point, once the operator has removed the fresh air ventilator, he/she may unknowingly be exposed to lingering vapors.
It would be desirable to develop a simple means for containing such vapors within a work area in a shop and filtering the air in the work area to exhaust it away from the operator and the rest of the shop. A simple enclosure should have air flow patterns that keep air moving through the entire work area and toward the filter/exhaust. Preferably, the system should keep a lively flow of air through the enclosure without having to draw on massive volumes of make-up air (which must be heated, for example, in winter, or cooled, in summer, for operator comfort and optimum coating performance). However, reducing air volume brought into the enclosure will naturally have an effect on air velocity through the enclosure. Stagnant parts of the enclosure may not be effectively purged of pollutants. Accordingly, it is an object of the present invention to reduce air volume while maintaining lively circulation of air in the enclosure. To prevent “dead spots” in the air flow through the enclosure, the air must be controlled in its path, rather than being left to flow merely according to the pull pattern of the fan. As described herein, air can be specifically deflected into problem areas such as corners to correct the problem of “dead spots”.
Having regard to these objects, a spray enclosure is provided for plural component coating application. The enclosure, made up of four walls and a ceiling, uses framed panels cladded with protective film. The cladded walls make up a protected workspace. One wall (preferably, a front wall) will have an opening for entry and exit of an operator and the workpiece to be coated. One of the walls (preferably, again, the front wall) will have an air inlet portion that is covered by one or more louvered grilles. The grilles are special in that they contain double-deflection louvers. That is, the louvers are manipulable in two directions (in two axes) to deflect incoming air to the protected workspace. On an opposite wall, the enclosure has an air filter-fan-exhaust assembly for filtering and drawing air through the protected workspace to an exhaust. Importantly, the spray enclosure is designed to make the most efficient use of air by engineering the laminar air flow through the workspace.
The air inlet portion preferably extends across the width of the first wall. The grille preferably has two sets of louvers—one set running in a horizontal orientation (relative to the orientation of the wall), and a second set running in a vertical orientation (relative to the wall). The louvers are movable (either as a set or individually) between open and closed positions. The sets of louvers do not interfere with each other. As one potential option, the louvers of the grille may be pre-set by the enclosure fabricator to an orientation that will direct air into otherwise dead spots in the protected workspace.
The workpiece to be coated is preferably a vehicle surface (such as a truck bed). In this case, the opening in the wall should be sized for entry and exit of a vehicle. Surfaces on the vehicle may be sprayed while attached to the vehicle (with non-sprayed parts masked beforehand), or individual parts (such as a rear gate on a pickup truck or a running board) may be sprayed and then installed or re-installed on the vehicle.
Preferably, the spray enclosure is adapted for plural component spray by an operator. One example of plural component spray is polyurethane coating. This is particularly suitable for the present enclosure as the spray contains isocyanate vapor, which must be filtered and exhausted from the chamber to provide a safe environment for the spray gun operator. Although operators are required to wear fresh air masks while spraying, the surrounding air may still be hazardous when the spraying is completed and the operator removes his mask.
The spray enclosure may be sold as a kit for assembly on site.
As shown in the drawings, a spray enclosure 100 is provided. Preferably, the enclosure 100 is a simple framed structure which can be built on site, such as within an existing shop 110 (such as a autobody shop or a paint shop).
Air is drawn into the enclosure through air inlet portion 120. As can be best seen in
The grille itself is shown in
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact processes, components and applications shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention and the appended claims and their equivalents.
