Coil hardness measuring method for paper or cardboard winding machines - involving measuring changes in coil dia. and length of material, deriving packing density using formula, low-pass filtering to eliminate vibration effects

摘要

The method involves using the packing density of the coil as a measure of the hardness. The diameter of the coil is directly measured in steps from the displacement of the roller centre. The packing density is derived from the difference of the squares of the diameter (D1,D2) multiplied by pi and divided by 4 times the measured change in the length of the rolled material. High frequency disturbances of the diameter measurement caused by vibration of the coil centre are eliminated using a low-pass filter. ADVANTAGE - Coil hardness is determined using simpler and more reliable sensors.