Multi-material separation layers for additive fabrication
According to some aspects, a container is provided for use in an additive fabrication device configured to fabricate parts by curing a liquid photopolymer to form layers of cured photopolymer. The container may comprise a laminated multi-material layer having an elastic first layer that aids in separation of cured photopolymer from the container in addition to a barrier layer on an upper surface that protects the first layer from exposure to substances in the liquid photopolymer that may not be compatible with the material of the first layer.
1. A container for use in an additive fabrication device configured to fabricate parts by curing a liquid photopolymer to form layers of cured photopolymer, the container comprising:
an open-topped vessel having an interior bottom surface, at least a region of the interior bottom surface being transparent to at least one wavelength of actinic radiation; and
a laminated multi-material layer bonded to the interior bottom surface of the vessel and configured to facilitate separation of the cured photopolymer from an exposed surface of the laminated multi-material layer, the laminated multi-material layer comprising:
a first material layer bonded to at least a portion of the region of the interior bottom surface, wherein the first material layer comprises polydimethylsiloxane (PDMS);
a second material layer having an oxygen permeability of at least 10 Barrer and no greater than 60 Barrer, and forming the exposed surface of the container; and
a third material layer between the first and second material layers, wherein the third material layer is bonded to at least a portion of the first material layer and is bonded to at least a portion of the second material layer.
2. The container of claim 1 , wherein the second material layer comprises polymethylpentene (PMP).
3. The container of claim 1 , wherein the second material layer has a higher selectivity for oxygen than for any compound of the liquid photopolymer.
4. The container of claim 1 , wherein the first material layer has an oxygen permeability of at least 200 Barrer.
5. The container of claim 1 , wherein the second material layer has an oxygen permeability between 20 Barrer and 50 Barrer.
6. The container of claim 1 , further comprising a fourth material layer between the first material layer and the interior bottom surface, and wherein the first material layer is bonded to the interior bottom surface by being bonded to the fourth material layer, which is bonded to the interior bottom surface.
7. An additive fabrication device configured to fabricate parts by curing a liquid photopolymer to form layers of cured photopolymer, the additive fabrication device comprising:
at least one source of actinic radiation configured to produce actinic radiation that includes radiation of a first wavelength;
a photopolymer container, comprising:
an open-topped vessel having an interior bottom surface, at least a region of the interior bottom surface being transparent to the first wavelength of the actinic radiation; and
a laminated multi-material layer bonded to the interior bottom surface of the vessel and configured to facilitate separation of the cured photopolymer from an exposed surface of the laminated multi-material layer, the laminated multi-material layer comprising:
a first material layer bonded to at least a portion of the transparent region of the interior bottom surface, wherein the first material layer comprises polydimethylsiloxane (PDMS);
a second material layer having an oxygen permeability of at least 10 Barrer and no greater than 60 Barrer, and forming the exposed surface of the container; and
a third material layer between the first and second material layers, wherein the third material layer is bonded to at least a portion of the first material layer and is bonded to at least a portion of the second material layer.
8. The additive fabrication device of claim 7 , wherein the second material layer comprises polymethylpentene (PMP).
9. The additive fabrication device of claim 7 , wherein the second material layer has a higher selectivity for oxygen than for any compound of the liquid photopolymer.
10. The additive fabrication device of claim 7 , wherein the first material layer has an oxygen permeability of at least 200 Barrer.
11. The additive fabrication device of claim 7 , wherein the second material layer has an oxygen permeability between 20 Barrer and 50 Barrer.
12. The additive fabrication device of claim 7 , wherein the first material layer has a thickness between 1 mm and 10 mm.
13. The additive fabrication device of claim 7 , wherein the second material layer has a thickness between 0.001″ and 0.01″.
14. The additive fabrication device of claim 7 , further comprising a fourth material layer between the first material layer and the interior bottom surface, and wherein the first material layer is bonded to the interior bottom surface by being bonded to the fourth material layer, which is bonded to the interior bottom surface.
15. The additive fabrication device of claim 7 , wherein the first material layer and/or the second material layer is a fiber composite film.
16. The additive fabrication device of claim 7 , wherein the first material layer and the second material layer are transparent to the first wavelength of the actinic radiation.