| 摘要 |
A method of controlling a slot die comprises, while continuing to pass the extrudate through the fluid flow path and out the applicator slot, changing the position of the actuators with the controller to either increase the cross-directional thickness of the fluid flow path adjacent each of the actuators or substantially close the fluid flow path adjacent the actuators, and after changing the cross-directional thickness of the fluid flow path adjacent each of the actuators, while continuing to pass the extrudate through the fluid flow path and out the applicator slot, repositioning each of the actuators with the controller according to the set of discrete settings to resume operating the slot die with the actuators positioned according to the set of discrete settings. |
| 主权项 |
1. A method of controlling a slot die, the slot die including:
an applicator slot extending about a width of the slot die, wherein the applicator slot is in fluid communication with a fluid flow path through the slot die, means of adjusting a cross-directional thickness of the fluid flow path selected from a choker bar, a rotary rod with the applicator slot being between the rotary rod and an opposing die lip, and a flexible die lip on one side of the applicator slot, and a plurality of actuators spaced about the width of the slot die, wherein each actuator in the plurality of actuators is operable to adjust a cross-directional thickness of the fluid flow path at its respective location to provide a local adjustment of fluid flow through the applicator slot by local adjustment of a position of the choker bar, the rotary rod relative to the opposing die lip, or the flexible die lip, the method comprising: with a controller in communication with each actuator, wherein the controller is configured to set a position of each actuator according to one of a plurality of discrete settings, positioning each of the actuators according to a set of discrete settings selected from the plurality of discrete settings; and a plurality of measurement instruments, each one configured to provide a local measurement of the slot die corresponding to the cross-directional thickness of the fluid flow path at the location of the respective measurement instrument, the measurements being monitored by the controller; operating the slot die by passing an extrudate through the fluid flow path and out the applicator slot with the actuators positioned according to the set of discrete settings, the positioning of each actuator by the controller including adjusting the position of the actuator based on input from the measurement instruments; while continuing to pass the extrudate through the fluid flow path and out the applicator slot, changing the position of the actuators with the controller to increase the cross-directional thickness of the fluid flow path adjacent each of the actuators, and prior to the changing of the position of the actuators, observing a defect in a profile of the extrudate after the extrudate flows out of the applicator slot; and after increasing the cross-directional thickness of the fluid flow path adjacent each of the actuators, while continuing to pass the extrudate through the fluid flow path and out the applicator slot, repositioning each of the actuators with the controller according to the set of discrete settings to resume operating the slot die with the actuators positioned according to the set of discrete settings. |
