	US 12,337,533 B2
	Method for modifying a 3D printed object
Dirk Achten, Leverkusen (DE); Bettina Mettmann, Pulheim (DE); Thomas Buesgen, Leverkusen (DE); and Michael Kessler, Leverkusen (DE)
Assigned to Stratasys, Inc., Minnetonka, MN (US)
Appl. No. 17/760,816
Filed by STRATASYS INC., Eden Prairie, MN (US)
PCT Filed Sep. 25, 2020, PCT No. PCT/EP2020/076828 § 371(c)(1), (2) Date Mar. 16, 2022, PCT Pub. No. WO2021/063806, PCT Pub. Date Apr. 8, 2021.
Claims priority of application No. 19200320 (EP), filed on Sep. 30, 2019.
Prior Publication US 2022/0362991 A1, Nov. 17, 2022
Int. Cl. B29C 64/165 (2017.01); B29C 64/268 (2017.01); B33Y 10/00 (2015.01); B33Y 70/00 (2020.01); B29K 75/00 (2006.01); B29K 105/00 (2006.01)

CPC B29C 64/165 (2017.08) [B29C 64/268 (2017.08); B33Y 10/00 (2014.12); B33Y 70/00 (2014.12); B29K 2075/00 (2013.01); B29K 2105/0058 (2013.01); B29K 2995/007 (2013.01); B29K 2995/0077 (2013.01)]

20 Claims

1. A process for modifying an article comprising:

I) providing an article which is at least partially constructed from a build material comprising a thermoplastic polyurethane;

II) at least partially contacting the build material for a first predetermined duration with a first liquid including >80% by weight of a polar aprotic solvent based on a total weight of the first liquid;

III) contacting for a second predetermined duration regions of the build material contacted with the first liquid in step II) with a second liquid including >80% by weight of a polar protic solvent based on a total weight of the second liquid;

wherein a section of the article modified by the process has a higher tensile strength according to DIN 53504 or a higher breaking elongation according to DIN 53504 than a corresponding section on an unmodified but otherwise identical article.