System and method for roll-to-roll film tensioning for reduced separation force during bottom-up stereolithography

A tensioning system for use in a stereolithography manufacturing application, the system including:

• a build plate for supporting a three dimensional part being formed using a photo responsive resin;
• a base plate;
• a low surface energy release film extending over the base plate, the low surface energy release film configured to receive a quantity of photo responsive resin for forming a new material layer of the three dimensional part;
• a pair of tensioning rollers to which opposite ends of the release element are secured for applying a controlled tension force to the release element;
• a pair of motors for controlling rotational movement of the pair of tensioning rollers;
• an electronic controller for controlling the motors to vary a tension force applied by the tensioning rollers during fabrication of a new material layer and release of the new material layer from the low surface energy release film;
• and
• wherein a peel angle of the low surface energy release film and a tension applied to the low surface energy release film by the tensioning rollers is controlled by the electronic controller to reduce a separation force required to separate the release element from the new material layer when the new material layer is cured and being removed from the low surface energy release layer.

A method of controlling tensioning of a release element being used to support a photo responsive resin in a stereolithography manufacturing application, the method including:

• arranging a release element over a base plate, the release element for supporting a three dimensional part being formed using a quantity of photo responsive resin;
• controlling a pair of tensioning components operatively coupled to the release element to control a tension experienced by the release element as the release element is peeled from a newly formed material layer after a quantity of photo responsive resin being used to form the newly formed material layer has cured;
• and
• controlling the amount of release element that has been unwound such that a peel angle of the release film is maintained at least substantially constant while the release element is peeled from the newly formed material layer.