Method of painting building board by spray painting apparatus

Abstract

In a method of painting a building board being conveyed on a conveyor by means of a spray painting apparatus so that a plurality of colors of gradated or shaded patterns are formed, a plurality of spray guns are connected to a plurality of paint supply systems supplying different colors of paint, respectively. The spray guns are arranged in parallel to a direction in which the building board is conveyed. With the spray guns being reciprocated in a direction crossing the direction in which the building board is conveyed, each of the spray guns is intermittently turned on and off so that the paints of colors different from one another are sprayed from the spray guns onto the surface of the building board. The relation between a speed of the reciprocation of each spray gun and a speed of conveyance of the building board is expressed by L.ltoreq.P.times.N where L is a distance that the building board is conveyed during one reciprocation of the spray guns, P is an average arrangement pitch of the spray guns, and N is the number of the spray guns.

Dependencies are inferred from the claim text.