Extrusion International 6-2021

40 Extrusion International 6/2021 QUALITY CONTROL At the K 2019, KÜNDIG presented their of fl ine thickness gauge Filmtest in its third generation. The Filmtest 3G has established itself on the market in the meantime, new functions being added continuously. New feature: Sheet Weight (ISO 4591) In many labs, the quality of the fi lm is checked by cutting and measuring circular areas. The measured values of the circular areas from a sample must not exceed a speci fi ed tolerance band. The new Sheet Weight function, which has been included in the Filmtest 3G Quality Analyzer software this summer, calculates these measured values gravimetrically, according to ISO standard 4591. The Pro fi le Genius function has been part of the Quality Analyzer since the beginning. A harmonic analysis helps to signi fi cantly improve the fi lm quality. The graphic (Chart 3) shows a thickness pro fi le that was analyzed with the Pro fi le Genius function. The measurement process is very simple: the target values are entered or imported, the fi lm sample is automatically transported through the measuring unit and then falls into the basket of the scale. Afterwards, the thickness pro fi le, the square meter weight, the harmonic analysis and the measured values of the circular areas are calcu- lated and graphically displayed. Other useful functions include automatic export of the measurements, syncronisation of the production data with the existing job management, and access to the measured values anytime and anywhere, if desired. Sim- ple, precise and ef fi cient, that’s the Filmtest 3G. HCH. KÜNDIG & CIE. AG Joweid Zentrum 11, P.O. Box 526, 8630 Rüti ZH, Switzerland www.gauge.ch Quality Control Made Easy Professional quality control is required wherever something is produced, including, of course, in fi lm extrusion. However, the demands on such instruments have changed, it has to be ef fi cient, precise and easy to operate without having to undergo extensive training Chart 1: This fi lm sample has a length of 920 mm and a thickness of 3 2 μ m. The software calculates, with the currently selected settings, the followingmeasuring values for 8 circular areas Chart 2: The number of circular areas can be speci fi ed according to the sample length, or the software automatically determines as many circular areas as possible from the respective fi lm sample Chart 3: This chart shows clearly that the biggest disturbance in the pro fi le is the fi rst harmonic, represented by the purple graph. The pro fi le tolerances could be signi fi cantly reduced by centering the die Chart 4: This example shows a large in fl uence of the 6th harmonic. Possible reasons could be: an air ring that does not distribute the air evenly, or a calibration cage that pushes toomuch into the bubble