Differentiating between packaging material and geometry using the Syntouch Biotac

Abstract: Grip stiffness is an important property of carton board packaging. The structure of the packaging needs to withstand the handling of one or many consumers. A carton board packaging that feels stiff when handled conveys a sense of luxury to the consumer, one example of this is the packages containing new flagship smart phones. If a package is more or less stiff is at this moment subjectively interpreted by test panels. An objective method of measuring grip stiffness is sought after for repeat ability and speed. This master thesis investigates the influence of geometry and material parameters on the grip stiffness of a carton board packages. The purpose is to determine how the measured point loads differ between different geometries for one particular material.  Measurements are conducted using a tensile tester and a sensory device, Syntouch Biotac. Only two of the 19 sensors are analyzed in this thesis. Ther data analyzed in this thesis comes from experiments conducted by the author and experiments conducted during a bachelors thesis at Örebro University. The same equipment was used for both experiments. The authors experiments were aimed at finding how a rotation of the packaging would affect the results whereas no rotations were made during experiments not conducted by the author. The authors own experiments were also made using an actual human finger, but only on packages that were not rotated. A finite element study was performed to validate the results from the Syntouch Biotac. X-ray computed tomography was used to investigate if the damage done to the carton board material by a human finger was similar to the damage done to the carton board material by the Syntouch Biotac.  Results from the Syntouch Biotac show that it is possible to tell where along and how close to the edge of the packaging the Syntouch Biotac is touching the packaging and that it is possible to discern between materials if the surface weights are different enough. The X-ray computed tomography show that damages done to the carton material cone by either the Syntouch Biotac or a human finger, are not possible to tell apart with the method of analysis used in this thesis.