Doctor blade support beam - has heaters to induce bending to compensate for doctor blade deflection

摘要

The device gives more uniform film thickness when spreading plastic material on rollers by means of a doctor blade. The blade normally deflects under the load exerted by the material which is being spread on the roller. The doctor blade support beam is fitted with heaters which can be separately controlled. The heaters are fitted above and below the beam in a staggered manner. Temperature differences are induced to bend the beam and thus compensate for the deflection of the doctor blade. The overall deflection is cancelled out and the blade remains straight under load. A uniform film thickness is therefore produced on the roller.