| 摘要 |
1,121,784. Measuring surface friction properties of webs, electrically. CROWN ZELLERBACH CORP. Dec.20, 1966 [Jan. 3, 1966], No.56970/66. Heading G1N. An apparatus for continuously measuring the surface friction characteristics of a moving web (eq. polyolefin film) comprises means for feeding a reference strip 13 from a supply roll 14 at a constant velocity, means including a solenoid 35 and lever system 32, 33 for urging the strip 13 into contact with the moving web 11 to be tested, and means including a differential transformer 31 for measuring the relative frictional force produced between the strip and the web. The strip 13 is driven by a motor (not shown) coupled to a roll 16 and its contact pressure against the web 11 may be adjusted by placing weights on beams 22, 25. In operation the web is driven at several hundred feet per minute and the strip 13 is driven at a constant speed of approximately one inch per minute in the same direction. The friction developed between the engaging surfaces of the web and strip tends to move beams 22, 25 to the left the beams being free to move by virtue of their pivotal support by links 23, 32, 33 and by the action of a cantilevered spring arrangement 26. In moving to the left a cone of the differential transformer is also moved producing an electrical signal proportional to the relative frictional force which signal is fed to an indicator or recorder. The apparatus may for example be used to measure the degree of surface treatment of polyethylene film by an electrical corona discharge. The reference strip may be of paper, film or foil. |
