The invention discloses a film thickness
control system based on
self positioning of a bolt and a self-positioning method of the bolt. The film thickness
control system comprises an
extrusion unit, a cooling forming unit, a drawing unit, a thickness measuring unit, a monitoring
control unit and a winding unit, wherein a collection module, a
processing module and a control module are arranged in the monitoring
control unit, film section thickness curve data are transmitted to the
processing module by the collection module, the film thickness is calculated and obtained by the
processing module, additionally, the position of each bolt of an extruder die is estimated, the
estimation deviation is reduced by self-positioning processing, and the control module is used for adjusting the longitudinal thickness and the transverse thickness of a film by virtue of a
frequency changer and a die adjuster. According to the film thickness
control system, the bolt of the die can be quickly positioned by self, and the adjustment is less during positioning, so that the influence of long-time bolt heating on normal production is avoided, and the problem of difficulty in returning to zero of the thickness deviation of a BOPP (Biaxially-oriented
Polypropylene) film can be avoided during manufacturing by accurate positioning of the bolt, so that the transverse thickness and the longitudinal thickness of the film are kept highly consistent.