MULTILAYER POLYMER SHEETS
Multilayer polymer sheets are provided, as well as related methods, systems, and appliances.
1 . (canceled)
2 . A method of making a multilayer dental aligner for repositioning a patient's teeth from a first arrangement toward a second arrangement, the method comprising:
providing a multilayer sheet comprising:
a first layer;
a second layer; and
a third layer; and
wherein the first layer comprises a first polymer having:
a flexural modulus greater than 150,000 psi;
an elongation at break of greater than 70%; and
wherein the second layer comprises a second polymer different than the first polymer, the second polymer having:
an elongation at break of greater than 200%;
providing a mold;
thermoforming the multilayer sheet over the mold to form a plurality of tooth-receiving cavities configured to receive and reposition the patient's teeth from the first arrangement toward the second arrangement; and
trimming excess material from the thermoformed multilayer sheet to form the dental aligner.
3 . The method of claim 2 , wherein the first polymer comprises a co-polyester, and wherein the second polymer comprises a thermoplastic polyurethane elastomer.
4 . The method of claim 3 , wherein the first polymer has a tensile strength yield of 4000 psi to 6500 psi.
5 . The method of claim 3 , wherein the first polymer has an elongation at yield of greater than 4%.
6 . The method of claim 3 , wherein the first polymer has a tensile modulus of greater than 150,000 psi.
7 . The method of claim 3 , wherein the first polymer has a light transmission of between 400 nm and 800 nm of greater than 75%.
8 . The method of claim 3 , wherein the first polymer has a light transmission between 400 nm and 800 nm of greater than about 75%.
9 . The method of claim 3 , wherein the second polymer has a hardness from 60A to 85D.
10 . The method of claim 3 , wherein the second polymer has an ultimate tensile strength of greater than 5000 psi.
11 . The method of claim 2 , wherein the first layer comprises a first polymer having an elastic modulus greater than the second polymer of the second layer.
12 . The method of claim 2 , wherein the first polymer comprises a co-polyester; wherein the second polymer comprises a thermoplastic polyurethane elastomer; and wherein the third layer comprises a third polymer comprising a co-polyester.
13 . The method of claim 2 , wherein the first polymer comprises a co-polyester; wherein the second polymer comprises a thermoplastic polyurethane elastomer; and wherein the third layer comprises a third polymer comprising a thermoplastic polyurethane.
14 . The method of claim 13 , wherein the first layer is disposed between the second layer and the third layer.
15 . The method of claim 2 , wherein the first layer is disposed between the second layer and the third layer.
16 . A method of making a multilayer dental aligner for repositioning a patient's teeth from a first arrangement toward a second arrangement, the method comprising:
providing a multilayer sheet comprising:
a first layer;
a second layer; and
a third layer; and
wherein the first layer comprises a co-polyester and wherein the second layer comprises a thermoplastic polyurethane elastomer;
providing a mold;
thermoforming the multilayer sheet over the mold to form a plurality of tooth-receiving cavities configured to receive and reposition the patient's teeth from the first arrangement towards the second arrangement; and
trimming excess material from the thermoformed multilayer sheet to form the dental aligner.
17 . The method of claim 16 , wherein the third layer comprises a co-polyester.
18 . The method of claim 16 , wherein the third layer is disposed adjacent to the first layer.
19 . The method of claim 18 , wherein the third layer is co-extruded with or laminated to the first layer.
20 . The method of claim 16 , wherein the multilayer sheet further comprises a fourth layer comprising a thermoplastic polyurethane elastomer.
21 . The method of claim 20 , wherein the first layer and the third layer are disposed between the second layer and the fourth layer.
22 . The method of claim 20 , wherein the third layer comprises a thermoplastic polyurethane elastomer.
23 . The method of claim 22 , wherein the first layer is disposed between the second layer and the third layer.
24 . The method of claim 16 , wherein the co-polyester of the first layer has a flexural modulus greater than 150,000 psi.
25 . The method of claim 16 , wherein the co-polyester of the first layer has an elongation at break of greater than 70%.
26 . The method of claim 16 , wherein the co-polyester of the first layer has an elongation at yield of greater than 4%.
27 . The method of claim 16 , wherein the co-polyester of the first layer has a tensile strength yield of 4000 psi to 6500 psi.
28 . The method of claim 16 , wherein the co-polyester of the first layer has having a tensile modulus of greater than 150,000 psi.
29 . The method of claim 16 , wherein the co-polyester of the first layer has a light transmission between 400 nm and 800 nm of greater than about 75%.
30 . The method of claim 16 , wherein the thermoplastic polyurethane elastomer of the second layer has a compression set of greater than 40% after 24 hours at 70° C.
31 . The method of claim 16 , wherein the thermoplastic polyurethane elastomer of the second layer has an elongation at break of greater than 200%.
32 . The method of claim 16 , wherein the thermoplastic polyurethane elastomer of the second layer has a hardness from 60A to 85D.
33 . The method of claim 16 , wherein the co-polyester has an elastic modulus greater than the thermoplastic polyurethane elastomer.