Systems and methods for resin recovery in additive manufacturing

Patent metadata

Field	Value
Publication number	US-11247389-B2
Application number	US-201917263275-A
Country	US
Kind code	B2
Filing date	Apr 22, 2019
Priority date	Jan 7, 2019
Publication date	Feb 15, 2022
Grant date	Feb 15, 2022

Abstract

A method of producing multiple batches of objects by stereolithography, includes the steps of: (a) dispensing an initial or subsequent batch of dual cure resin into a stereolithography apparatus (11), the resin including a light polymerizable component and a heat polymerizable component; (b) producing an intermediate object by light polymerization of the resin in the apparatus (12), wherein the intermediate object retains excess resin on a surface thereof; then (c) separating excess resin from the intermediate object (13); (d) blending the excess resin with additional dual cure resin to produce a subsequent batch of dual cure resin (15); (e) repeating steps (a) through (c), and optionally repeating step (d), to produce additional object(s); and (f) baking the objects, together or separately, to produce multiple batches of objects (14).

First claim

We claim:

1. A method of producing multiple batches of objects by stereolithography, comprising the steps of:
(a) dispensing an initial or subsequent batch of dual cure resin into a stereolithography apparatus, said resin comprising a light polymerizable component and a heat polymerizable component;
(b) producing an intermediate object by light polymerization of said resin in said apparatus, wherein said intermediate object retains excess resin on a surface thereof, and wherein said stereolithography apparatus is a bottom up stereolithography apparatus; then
(c) separating excess resin from said intermediate object, wherein said separating step is carried out by centrifugal separation;
(d) blending said excess resin with additional dual cure resin to produce a subsequent batch of dual cure resin;
(e) repeating steps (a) through (c), and optionally repeating step (d), to produce additional object(s); and
(f) baking said objects, together or separately, to produce multiple batches of objects,
wherein excess resin is blended with additional dual cure resin in a volume ratio of from 10:90 up to 60:40 (excess resin:additional dual cure resin).

2. The method of claim 1 , wherein said light polymerization is exothermic.

3. The method of claim 1 , wherein steps (a) through (c) are repeated at least twice and step (d) is repeated at least once.

4. The method of claim 1 , wherein said objects comprise an open lattice.

5. The method of claim 1 , wherein said objects comprise dental models.

6. A method of producing multiple batches of objects by stereolithography, comprising the steps of:
(a) dispensing an initial or subsequent batch of dual cure resin into a stereolithography apparatus, said resin comprising a light polymerizable component and a heat polymerizable component;
(b) producing an intermediate object by light polymerization of said resin in said apparatus, wherein said intermediate object retains excess resin on a surface thereof, and wherein said stereolithography apparatus is a bottom up stereolithography apparatus; then
(c) separating excess resin from said intermediate object, wherein said separating step is carried out by centrifugal separation;
(d) blending said excess resin with additional dual cure resin to produce a subsequent batch of dual cure resin;
(e) repeating steps (a) through (c), and optionally repeating step (d), to produce additional object(s); and
(f) baking said objects, together or separately, to produce multiple batches of objects,
wherein excess resin is retained on said intermediate object in an amount by weight of at least 40 percent as compared to the weight of said intermediate object.

7. A method of producing multiple batches of objects by stereolithography, comprising the steps of:
(a) dispensing an initial or subsequent batch of dual cure resin into a stereolithography apparatus, said resin comprising a light polymerizable component and a heat polymerizable component;
(b) producing an intermediate object by light polymerization of said resin in said apparatus, wherein said intermediate object retains excess resin on a surface thereof, and wherein said stereolithography apparatus is a bottom up stereolithography apparatus; then
(c) separating excess resin from said intermediate object, wherein said separating step is carried out by centrifugal separation;
(d) blending said excess resin with additional dual cure resin to produce a subsequent batch of dual cure resin;
(e) repeating steps (a) through (c), and optionally repeating step (d), to produce additional object(s); and
(f) baking said objects, together or separately, to produce multiple batches of objects,
wherein said excess resin is free of wash liquid in said blending step.

8. A method of producing multiple batches of objects by stereolithography, comprising the steps of:
(a) dispensing an initial or subsequent batch of dual cure resin into a stereolithography apparatus, said resin comprising a light polymerizable component and a heat polymerizable component;
(b) producing an intermediate object by light polymerization of said resin in said apparatus, wherein said intermediate object retains excess resin on a surface thereof, and wherein said stereolithography apparatus is a bottom up stereolithography apparatus; then
(c) separating excess resin from said intermediate object, wherein said separating step is carried out by centrifugal separation;
(d) blending said excess resin with additional dual cure resin to produce a subsequent batch of dual cure resin;
(e) repeating steps (a) through (c), and optionally repeating step (d), to produce additional object(s); and
(f) baking said objects, together or separately, to produce multiple batches of objects,
said excess resin of step (b) having a viscosity greater than that of said dual cure resin of step (a), and said subsequent batch of dual cure resin of step (d) having a viscosity less than that of said excess resin.

9. A method of producing multiple batches of objects by stereolithography, comprising the steps of:
(a) dispensing an initial or subsequent batch of dual cure resin into a stereolithography apparatus, said resin comprising a light polymerizable component and a heat polymerizable component;
(b) producing an intermediate object by light polymerization of said resin in said apparatus, wherein said intermediate object retains excess resin on a surface thereof, and wherein said stereolithography apparatus is a bottom up stereolithography apparatus; then
(c) separating excess resin from said intermediate object, wherein said separating step is carried out by centrifugal separation;
(d) blending said excess resin with additional dual cure resin to produce a subsequent batch of dual cure resin;
(e) repeating steps (a) through (c), and optionally repeating step (d), to produce additional object(s); and
(f) baking said objects, together or separately, to produce multiple batches of objects,
wherein said initial batch and subsequent batches of dual cure resin have a viscosity of from 1,000 to 100,000 centipoise at 25 degrees centigrade.

10. A method of producing multiple batches of objects by stereolithography, comprising the steps of:
(a) dispensing an initial or subsequent batch of dual cure resin into a stereolithography apparatus, said resin comprising a light polymerizable component and a heat polymerizable component;
(b) producing an intermediate object by light polymerization of said resin in said apparatus, wherein said intermediate object retains excess resin on a surface thereof, and wherein said stereolithography apparatus is a bottom up stereolithography apparatus; then
(c) separating excess resin from said intermediate object, wherein said separating step is carried out by centrifugal separation;
(d) blending said excess resin with additional dual cure resin to produce a subsequent batch of dual cure resin;
(e) repeating steps (a) through (c), and optionally repeating step (d), to produce additional object(s); and
(f) baking said objects, together or separately, to produce multiple batches of objects,
wherein said excess dual cure resin of step (b) has a viscosity at least 1,000 centipoise greater than that of said dual cure resin of step (a).

11. The method of claim 1 , wherein said resin comprises a polyurethane, cyanate ester, epoxy, or silicone dual cure resins.

12. A method of producing multiple batches of objects by stereolithography, comprising the steps of:
(a) dispensing an initial or subsequent batch of dual cure resin into a stereolithography apparatus, said resin comprising a light polymerizable component and a heat polymerizable component;
(b) producing an inter

Assignees

• Carbon Inc

Inventors

• Converse Courtney F
• Light Allison
• Powell W Ryan
• Wojtaszek Mateusz Marek

Classifications

• B29C64/176

  Sequentially · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B33Y40/00

  Auxiliary operations or equipment, e.g. for material handling · CPC title

• B29C64/357 Primary

  Recycling · CPC title

• B29C64/124 Primary

  using layers of liquid which are selectively solidified · CPC title