Literature Review

Abstract

The plastic film industry began implementing profile control in the early 1970s (although not much of this work seems to have been published [354]). Profile control was first implemented to metal rolling machines in the mid-1970s [52, 320, 334]. The first implementation of profile control on paper machines occured in 1977 [318]; however, widespread use of such systems did not occur until the 1980’s [185, 316, 362]. The control of cross-directional variations in blade coaters became widespread in the early 1990s [46, 47, 348]. Here we review the literature on sheet and film process control, with particular attention to the effectiveness of existing techniques at addressing the characteristics of sheet and film processes covered in the previous chapter. First, we assess the effectiveness of various approaches to profile control, including linear control, model predictive control, and robust control. Then we review approaches for profile estimation, model identification, and on-line process monitoring.