Abstract: The present invention is a gauge and method for characterizing the surface venting of rollers. The gauge includes a smooth pliable saddle with a pick-up head positioned at a mid-point of the saddle. The pick-up head includes an opening which faces the outer surface of a roller when the saddle is draped over the roller. The roller's venting characteristics are determined by applying a vacuum to the pick-up head and measuring the equilibrium flow rate between the saddle and the outer surface of the roller.

Abstract: Apparatus for curtain coating a web or article includes a coating hopper, a support roller, guide rollers for leading the web to and from the support roller and an enclosure. Air which has been conditioned in respect of temperature, humidity and cleanliness is introduced into an upper region of the enclosure. Air flow controlling means are provided below the region into which the conditioned air is introduced. The flow controlling means serve to control the flow of air downwards so that it is uniform across a horizontal plane within the enclosure and has a speed of about 10 feed per minute in the region of the coating liquids in the curtain, that being a speed which will not cause disturbing effects on the liquids in the curtain. The enclosure prevents random air currents of uncontrolled velocity, temperature and cleanliness impinging on the liquids in the curtain and on the slide, which might otherwise adversely affect the product coating.

Abstract: A roller for conveying a web is manufactured by applying a layer of nickel to a steel roller and blasting the surface ofo the nickel layer with steel shot to create on the surface a deep texture with well rounded down features and sharp up features with peaks. The blasted surface is finished with a grinding action for removing the peaks to produce plateaus surrounded by interconnected channels. The interconnected channels of the surface allow air entrained between the roller surface and a web to be vented through the channels while the web is in contact with the roller.

Abstract: A stainless steel roller for conveying a web has a surface prepared by blasting the surface of the roller with steel shot to create on the surface a deep texture with well rounded down features and sharp up features with peaks. The blasted surface is finished with a grinding action for removing the peaks to produce plateaus surrounded by interconnected channels. The interconnected channels of the surface allow air entrained between the roller surface and a web to be vented through the channels while the web is in contact with the roller.

Abstract: An aluminum roller for conveying a web has a surface prepared by blasting the surface of the roller with steel shot to create on the surface a deep texture with well rounded down features and sharp up features with peaks. The blasted surface is finished with a grinding action for removing the peaks to produce plateaus surrounded by interconnected channels. Then the surface is hardcoated and polished. The interconnected channels of the surface allow air entrained between the roller surface and a web to be vented through the channels while the web is in contact with the roller.

Abstract: A roller for conveying a web is manufactured by applying a layer of nickel to a steel roller and blasting the surface of the nickel layer with steel shot to create on the surface a deep texture with well rounded down features and sharp up features with peaks. The blasted surface is finished with a grinding action for removing the peaks to produce plateaus surrounded by interconnected channels. The interconnected channels of the surface allow air entrained between the roller surface and a web to be vented through the channels while the web is in contact with the roller.

Abstract: An aluminum roller for conveying a web has a surface prepared by blasting the surface of the roller with steel shot to create on the surface a deep texture with well rounded down features and sharp up features with peaks. The blasted surface is finished with a grinding action for removing the peaks to produce plateaus surrounded by interconnected channels. Then the surface is hardcoated and polished. The interconnected channels of the surface allow air entrained between the roller surface and a web to be vented through the channels while the web is in contact with the roller.

Abstract: A stainless steel roller for conveying a web has a surface prepared by blasting the surface of the roller with steel shot to create on the surface a deep texture with well rounded down features and sharp up features with peaks. The blasted surface is finished with a grinding action for removing the peaks to produce plateaus surrounded by interconnected channels. The interconnected channels of the surface allow air entrained between the roller surface and a web to be vented through the channels while the web is in contact with the roller.