| 摘要 |
<p>Accurately predetermined quantities of liquid can be applied from a plurality of needle-like or capillary jets (17) to web or sheet material (14) which is moving continuously relative to said jets. The liquid is supplied to the jets (17) at superatmospheric pressure via respective electromechanical valves (20), which are controlled by computer to open and close rapidly so that discrete droplets of liquid are fired from the jets (17) in a succession of short pulses each of a duration of 0.5 to 15 milliseconds, and with a frequency of 50 to 500 Hz. Thus, small quantities of treatment liquids can be uniformly applied and, in specific cases where the liquid is colouring medium, pre-programmed patterns can be applied in simple and effective manner.</p> |
