The FG710S infrared sensor from NDC, Irwindale, Calif., is aimed at lithium ion battery separate film. The sensor is able to measure the thickness and basis weight of clear, voided, porous and translucent films. Thickness measurement of voided films has proven difficult due to density variation through the product. NDC’s patented developments use proprietary IR filters, algorithms and spectral shift of absorption curves to determine on-line thickness of micro-porous and voided films in the range of 10 to 40 microns.
The density of the film is calculated from the infrared thickness and basis weight measurements. For the wet-formed processes, the FG710S employs special infrared filter techniques to measure the oil content in PE battery film for the entire process, beginning with the wet cast film and after the first biax stretch. Finally the FG710S can be configured to measure the coextrusion components of multi-layer film products.