Coating apparatus

Abstract

Apparatus is described for coating deposition, particularly by chemical vapour deposition, on three dimensional glass articles such as bottles. The apparatus lends itself to incorporation in plant for a continuous production process for glass containers.

1 .- 14 . (canceled) 
     
     
         15 . An apparatus for coating three dimensional glass articles comprising:
 a tunnel, having a top and first and second sidewalls, suitable for arranging on a conveyor belt such that the conveyor belt transports the articles from an upstream end, at which articles enter the tunnel, to a downstream end, at which articles exit the tunnel;   a linear array of nozzles, arranged on at least one side wall to deliver a jet of gas, which jet traverses the path of articles conveyed through the tunnel;   at least one exhaust aperture arranged on a sidewall, the exhaust aperture being located closer to the downstream end than the linear array of nozzles; and   means for applying a negative pressure to the exhaust aperture.   
     
     
         16 . The apparatus according to  claim 15 , comprising a pair of arrays of inlet nozzles arranged with one array on each sidewall, substantially opposite each other in the tunnel. 
     
     
         17 . The apparatus according to  claim 16 , comprising a pair of exhaust apertures, arranged with one aperture on each sidewall, substantially opposite each other in the tunnel. 
     
     
         18 . The apparatus according to  claim 17 , wherein the distance between the pair of arrays of inlet nozzles and the pair of exhaust apertures is between 500 and 1000 mm. 
     
     
         19 . The apparatus according to  claim 15 , further comprising a damper plate, moveable to vary the effective size of an exhaust aperture. 
     
     
         20 . The apparatus according to  claim 15 , further comprising at least one reflective plate, arranged to direct heat radiating from the glass articles on to a linear array of nozzles. 
     
     
         21 . The apparatus according to  claim 15 , wherein the exhaust apertures are defined by a substantially vertical conduit comprising walls and a baffle plate extending from the tunnel and away from the downstream end to a wall of the conduit. 
     
     
         22 . The apparatus according to  claim 15 , wherein the cross-sectional area of the tunnel is between 1.5 and 2.5 times greater than the cross-sectional area of an exhaust aperture. 
     
     
         23 . The apparatus according to  claim 15 , wherein the kinetic energy density ratio of air flowing through the tunnel is between 0.1 and 3 times greater than the kinetic energy density ratio of gas exiting a nozzle. 
     
     
         24 . The apparatus according to  claim 15 , wherein at least one array of nozzles is arranged such that the velocity of gases exiting the nozzles includes a component that is substantially parallel with the general direction of articles conveyed through the tunnel. 
     
     
         25 . The apparatus according to  claim 15 , comprising at least one array of nozzles located at a first distance from the ends of the tunnel and at least one array of nozzles located at a second distance from the ends of the tunnel. 
     
     
         26 . The apparatus according to any preceding  claim 15 , further including means for heating at least one array of nozzles. 
     
     
         27 . The apparatus according to  claim 26 , wherein the means for heating at least one array of nozzles comprises an enclosure in which the array is located, and means for heating the interior of the enclosure. 
     
     
         28 . The apparatus according to  claim 27 , wherein the means for heating the interior of the enclosure comprises an electrical heating element.