Film tensioning techniques for additive fabrication and related systems and methods
Techniques for film tensioning in additive fabrication are provided. According to some aspects, a film forming part of a container in an additive fabrication device may be tensioned by different forces along different axes. According to some embodiments, an adjustable tensioning system may be provided within an additive fabrication device that may couple to one or more components of a removable container comprising a film. The tension of the film may be adjusted by the additive fabrication device via the adjustable tensioning system and its coupling to the container.
1. An additive fabrication device configured to form layers of solid material on a build platform, each layer of material being formed so as to contact a container in addition to the surface of the build platform and/or a previously formed layer of material, the additive fabrication device comprising:
a container comprising a flexible film; and
a tensioning device coupled to an end of the flexible film and configured to apply tension forces across the flexible film, wherein said tension forces applied by the tensioning device include:
a first tension force applied along a first axis of the flexible film, and
a second tension force, different from the first tension force, applied along a second axis of the flexible film, the second axis being parallel to the first axis.
2. The additive fabrication device of claim 1 , wherein, along an axis perpendicular to the first axis and the second axis, the first axis is located further from ends of the flexible film than the second axis, and wherein the first tension force is greater than the second tension force.
3. The additive fabrication device of claim 1 , further comprising a plurality of mounting pins attached to the flexible film.
4. The additive fabrication device of claim 3 , wherein the plurality of mounting pins are arranged in a non-linear path.
5. The additive fabrication device of claim 3 , wherein at least some of the plurality of mounting pins are attached to opposing ends of the flexible film.
6. The additive fabrication device of claim 1 , wherein the tensioning device is configured to apply tension forces parallel to the first axis and second axis that increase from a first end of the flexible film to a midline of the flexible film and decrease from the midline of the flexible film to a second end of the flexible film along a direction perpendicular to the first axis and the second axis.
7. The additive fabrication device of claim 6 , wherein said increase from the first end of the flexible film to the midline of the flexible film is a non-linear increase.
8. The additive fabrication device of claim 7 , wherein the tensioning device is configured to apply tension forces to the flexible film such that a magnitude of the tension force at locations along the direction perpendicular to the first axis and the second axis is given by a curve of between 4th and 6th order as a function of distance of the location from the first end.
9. The additive fabrication device of claim 1 , wherein a portion of the flexible film is enclosed by the tensioning device.