Extrusion International 1-2019

58 Extrusion International 1/2019 MEASUREMENT TECHNOLOGY This additional measurement system makes it possible to detect the EVOH layer of transparent and opaque multi-layer plastics. To determine the EVOH layer thickness, a wide infrared spectrum of the plastic is recorded and the resulting absorption of the EVOH polymer molecules is evalu- ated by using our modern analytical methods. New Barrier Layer (EVOH) Inline Thickness Measuring Device introduced SBI Produktion techn. Anlagen GmbH & Co KG Kaplanstr. 12, 2020 Hollabrunn, Austria www.sbi.at SBI mainly focuses with this measur- ing system on measuring PP/EVOH/PP sheets, but it is also possible to gauge other EVOH-polymer compounds with the help of extended analysis- algorithms. The new gauge measures the to- tal thickness of multi-layer sheets in microns (see diagram 1), the die bolts over the measuring width (see diagram 2), and in addition to it the EVOH layer distribution which is shown in diagram 3. The infrared measuring system is a relative measurement and yields the absolute EVOH layer thickness by the means of calibration. Nowadays it is essential to determine the EVOH layer distribution to deliver a consistent quality. In most case of applications, the EVOH thickness is determined in laboratories by micro- scopes. SBI delivers an in-line, non-contact and user-friendly thickness measure- ment to control the EVOH barrier layer during the production process. SBI is a popular producer of inline thickness measuring devices for film and sheet extrusion. The new developed gauge (KAPA- IR) contains the capacitive measurement process and in additiontoitalsoaspecialinfrared (IR) which is a sensor system that determines the EVOH (Ethylene vinyl alcohol) layer thickness KAPA-IR thickness measuring device for detecting the EVOH barrier layer Display for total thickness, bolt and EVOH thickness