Abstract: Methods and systems of measurement for blown film lines are provided. The sensing system includes a terahertz (THz) sensor positioned adjacent to a film bubble extruded from a blown film die, and a sensor support configured to guide the THz sensor around the circumference of the film bubble to measure its film thickness.

Abstract: 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.

Abstract: A system comprises a 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, 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. The system further comprises a controller configured to set the position of each actuator according to one of a plurality of discrete settings for operation of the slot die. The controller is further configured to, using fluid dynamics and a digital model of the die, predict a set of discrete settings from the plurality of discrete settings corresponding to a preselected cross-web profile for the extrudate.

Abstract: A method of controlling a slot die comprises positioning actuators of the slot die with a controller according to a first set of discrete settings, 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 first set of discrete settings, and while passing the extrudate through the fluid flow path and out the applicator slot, changing the positions of the actuators with the controller to create patterned features in the extrudate.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method of controlling a slot die comprises positioning actuators of the slot die with a controller according to a first set of discrete settings, 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 first set of discrete settings, and while passing the extrudate through the fluid flow path and out the applicator slot, changing the positions of the actuators with the controller to create patterned features in the extrudate.

Abstract: A system comprises a 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, 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. The system further comprises a controller configured to set the position of each actuator according to one of a plurality of discrete settings for operation of the slot die. The controller is further configured to, using fluid dynamics and a digital model of the die, predict a set of discrete settings from the plurality of discrete settings corresponding to a preselected cross-web profile for the extrudate.

Abstract: A tethering apparatus for a watercraft includes an elongated flexible line, a spool and a biasing member adapted to urge the spool to automatically uptake portions of the elongated flexible line. A locking device is attached to an end portion of the elongated flexible line to assist in tethering the watercraft to a mooring structure.