Statistical Problems on Estimating for Heat Seal Parameters

Recently we need to manage statistical process controls to maintain product quality based on the sensor technology such as small thermometers and displacement sensors, which can give as vast information on production parameters. In bag-making process, the strength of bags is very difficult to estimate without any distraction of products, and it sometimes needs a large sample size. In place of the destruction test we use the estimates by observations from important substitutional characteristics. In this article, we shall focus on the heat-seal time parameter which is considered as one of the most important substitutional characteristics. As we cannot directly observe heat-seal time, we measure several other variables, that may be used to estimate the function of these for the target parameters regarding heat-seal time. Therefore we measured the displacements of seal-bars and constructed the statistical model for estimating heat-seal time parameter from their displacement data. We found that displacement data behaves as the skewed cyclic function own the time and proposed new statistical model based on the nested trigonometric function.