| 摘要 |
<p>Apparatus for applying a coating material, eg a foamable material, to a substrate 25, which moves past a coating head 20, comprises a holding tank 22 for the coating material, a load cell 23 for weighing the coating material in the tank 22 and a pump 24 for supplying the coating material at a controlled rate from the tank 22 to the coating head 20. The pump 24 is controlled by an electronic control unit 34, which is responsive to a first control signal 30 from the load cell 23 and a second control signal 29 from a tachogenerator 28 measuring the speed of movement of the substrate 25 past the coating head 20. The control unit 34 may also receive a control signal from a sensor 41 representative of the width of the substrate 25 and a reference signal indicative of the desired percentage of solids in the foamed compounds. In this way the desired weight "add on" of coating material can be controlled to a predetermined value. <IMAGE></p> |
