| 摘要 |
<p>1,126,620. Coating apparatus. AEROCOAT S.A. 9 Nov., 1966 [12 Nov., 1965; 10 Dec., 1965; 18 March, 1966], Nos. 48020/65; 52534/65 and 11895/65. Heading B2L. In applying powder coatings to articles, the articles are conveyed through an enclosure 1, 2, 3, 4, provided with entry and exit openings 7, 8 through a plurality of streams of coating powder (from sprays 28, 29, 30, 31, 32, 33) forming with the air in the enclosure a fine cloud of the powder particles, the said cloud is maintained in continual rotational movement in the enclosure (arrows C) and the escape of powder not adhering to the articles is restrained by an inward flow of a gaseous medium through each of said openings. Preferably a reduced pressure is maintained in the enclosure by extracticn fans 105, 106, 107, 108 so that atmospheric air is drawn in through openings 7, 8 thus preventing escape of coating powder. The powder/air mixture withdrawn by each fan is divided into two sub-streams, one being exhausted to the atmosphere through .suitable filter means to retain the powder and the other is returned to the enclosure through manifold pipes 121, 122, 123, 124 and guided by suitable baffles 140, 142; 144; 145; 141, 143 respectively to produce a rotational motion to the medium within the enclosure. Corner baffles 146, 147, 148. 149 also assist in the rotational movement and provide pockets 151, in which the air is relative quiescent, for suction manifolds 150 of the extraction fans. Each spray unit is fed with coating powder from supply troughs 11, 12, 13, 14. these being of inverted trapezium shape with a discharge box 15, 16. 17, 18 at the base each of which has means for imparting vibration to the powder. The spraying heads are operated by compressed air and may be electrostatically charged relative to the articles to be coated. Further they may be moveable axially to adjust their working position. The bottom of the enclosure is V-shaped to form a trough 10 into which particles which do not adhere to the articles gravitate. Such particles are removed from the trough by suitable air ejectors and recycled to the spraying heads. The articles to be coated are conveyed through the enclosure on suitable hangers suspended from an overhead conveyor, the top of the enclosure having overlapping flexible strips 190, 191 (Fig 2, not shown) to allow the hangers to pass through.</p> |
