| 摘要 |
A headbox comprising a distribution duct 1 and nozzle chamber 7 formed between side plates 9 and slice lips 8 is provided with pressure transducers 10 or velocity transducers within or in front of the nozzle chamber to measure the rates at which a fibrous papermaking suspension flows therethrough, a control device 11 for receiving the signals from the transducers and transmitting a control signal in response to the difference therebetween and a flow regulating device 12 which is controlled by the control signal. The pressure transducers may comprise piezoelectric, membrane, pressure head or Pitot tube - type sensors. Velocity measurement may be made using lasers. A more even web of paper over the whole web width is said to result. <IMAGE> |
