WO2019203852A1

WO2019203852A1 - Compositions for removing resin from a 3-d printed object and methods of making and using same

Info

Publication number: WO2019203852A1
Application number: PCT/US2018/028674
Authority: WO
Inventors: Marc FARFAGLIA; Cassidy GRANT; Daniel Joshua HUTCHINSON
Original assignee: Postprocess Technologies, Inc.
Priority date: 2018-04-20
Filing date: 2018-04-20
Publication date: 2019-10-24

Abstract

Described are fluidic finishing solutions for removing unwanted resin and/or support material from a 3D printed object, such as an object produced by stereolithography, The compositions are aqueous solutions having a terpene, a hydrotrope, at least one glycol ether, an emulsifier, and a caustic agent. Also described are methods of using the finishing solutions.

Description

COMPOSITIONS FOR REMOVING RESIN FROM A 3D-PRINTED OBJECT AND METHODS OF MAKING AND USING SAME

FIELD OF THE DISCLOSURE

[0001] The disclosure generally relates to solutions for removing unwanted resin from an object made by additive manufacturing techniques such as 3D printing, and, more specifically, to fluidic chemical finishing solutions and methods of using such finishing solutions in order to remove unwanted resin by contacting the object with the fluidic finishing solution. BACKGROUND OF THE DISCLOSURE

[0002] 3D printing is a process whereby a computer controlled device (e.g., a printer) creates an object through additive manufacturing. As used herein, unless otherwise indicated, the term“object” refers to a 3D-printed object that is not in its desired final form. An object can be manufactured by stereolithography (SLA)“printing” techniques, and other methods known by those in the art. The additive manufacturing methods that are commonly used require additional material (“support material”) to be printed for the purpose of supporting portions of the object during printing. The support material also may be needed post- printing/pre-curing (or annealing). This support material buttresses the object to prevent issues like sagging. After printing, the unwanted support material and/or unwanted resin needs to be removed, and the processes that accomplish such removal are referred to as “finishing.” As used herein, unless otherwise indicated, the term“finishing” refers to removing unwanted material from a 3D-printed object so as to produce a finished part.

Finishing can include one or more processes, including, but not limited to, removing unwanted resin, removing unwanted metal powder, removing unwanted print material, and/or removing unwanted support material. In the 3-D printing industry, finishing may be referred to as“cleaning.”

[0003] The support material itself can have a complex geometry and can also be extensive, because it may support the object at a plurality of locations. Additionally, because additive manufacturing prints an object in discrete layers, the surface finish of an object is often rough because edges of the layers do not always align with each other, thus creating a rough, bumpy outer surface. This outer surface is unappealing from a visual standpoint and creates stress concentrations, which could result in cracks during testing or use, and thus lead to a premature failure if the rough surface is not made smooth during finishing. [0004] Some finishing solutions are organic based and often contain isopropanol

(IPA), which has a low flash point, making it dangerous to work with. Finishing solutions that use IPA or tripropylene glycol methyl ether (TPM) take 10 to 45 minutes to remove unwanted resin and thereby weaken the support material so that the support material is easily removed.

[0005] There has been a long felt need for a chemical finishing solution that is less toxic and less flammable.

SUMMARY OF THE DISCLOSURE

[0006] In this disclosure, we discuss liquid finishing solutions that chemically act on an object to finish the object Such a finishing solution may be used with or without mechanical finishing and/or force.

[0007] The present disclosure describes finishing solutions that may be used for removing unwanted resin (e.g., finishing) from a stereolithographic (“SLA”) 3D-printed object. Such a finishing solution may comprise:

(a) 1-20% by weight of a terpene, including all 0.1% values and ranges therebetween;

(b) 0.001-20% by weight of a hydrotrope, including all 0.001% values and ranges

therebetween;

(c) 1-10% by weight of a first glycol ether, including all 0.1% values and ranges

therebetween;

(d) optionally 1- 10% by weight of a second glycol ether, including all 0.1% values and ranges therebetween;

(e) 1-5% by weight of an emulsifier, including all 0.1% values and ranges therebetween;

(f) 1-15% by weight of a caustic agent, including all 0.1% values and ranges

therebetween; and

(g) water (e.g., the remainder of this finishing solution is water).

[0008] The present disclosure describes methods of using a finishing solution. One such method may comprise:

(a) submerging an object or a portion thereof in a finishing solution, such as, for example, the solution described above;

(b) agitating the finishing solution while the object is submerged; and

(c) removing the object from the finishing solution.

Another such method may comprise: (a) spraying an object or a portion thereof in a finishing solution, such as, for example, the solution described above; and

(b) removing the finishing solution from the object

BRIEF DESCRIPTION OF THE FIGURES

[0009] For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying figures.

[0010] Figure 1 A and Figure 1 B are each a photo of a 3D-printed object (a rook) prior to finishing. Figure 1 A shows the base and side of the object, and Figure 1 B shows the top and side of the object. Figure 1C and Figure 1 D are each a photo of the same 3D-printed object (the rook) after applying a finishing solution that is in keeping with the invention. Figure 1 C shows the base and side of tire object, and Figure ID shows the top and side of the object.

[0011] Figure 2 (A) is drawing of a machine that can be used to finish a 3D-prmted object with a finishing solution that is in keeping with the invention and (B) a cross-sectional view of the machine depicted in Figure 2A. The numbers in Figures 2 A and 2B identify: a support removal machine (100), a control panel (12), a lid (10), a front panel (8), a tank holding a finishing solution that is in keeping with the invention (28), a weir (20), computer (13), an input tank (18), an input tank liquid level (19), a liquid level sensor (26), an overflow across wall (36), an ultrasonic generator (70), and ultrasonic transducers (22).

[0012] Figure 3 shows a flow diagram of a method of using a finishing solution in keeping with the invention.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0013] Although claimed subject matter will be described in terms of certain embodiments, other embodimen ts, including embodiments that do not provide all of the benefits and features set forth herein, are also within the scope of this disclosure. Various structural, logical, and process step changes may be made without departing from the scope of the in vention.

[0014] Ranges of values are disclosed herein. The ranges set out a lower limit value (“LEV”) and an upper limit value (“ULV”). The LLV, ULV, and all values between the LLV and ULV are part of the range. [0015] The present disclosure provides finishing solutions tor removing unwanted resin from a 3D printed stereolithography (SLA) object and thereby weakening any support material that was associated with the removed resin. 3D printed objects are frequently partially cured to increase their rigidity prior to finishing. The resin/material that was not cured may be dissolved by a finishing solution of the present invention before the object is placed into an ultraviolet (“UV”) oven for final curing.

As used herein, unless otherwise indicated, the term“support material” refers to material that is operatively arranged to support portions of an object during an additive manufacturing process to create the object, but which is unwanted once the manufacturing process is complete. Support material and/or unwanted resin can be the same material as the object which is being manufactured, or can be a different material. Materials that can be removed during finishing include, but are not limited to, accura 25, accura 60, ClearVue, FORMLABS* (e.g., Clear, White, Tough, Castable, Flexible, Dental SO, and the like) photopolymer resin, and the like.

[0017] As used herein, unless otherwise indicated, die term“agitated” refers to effecting fluid movement by an outside force. Non-limiting examples of agitation include moving finishing solution via a pump, stirring, using longitudinal waves at an ultrasonic frequency, or combinations thereof.

[0018] Some finishing processes are mechanical in nature (e.g., abrasion techniques, such as sanding), some are chemical in nature, and others are a combination of mechanical processes and chemical processes.

[0019] In a conventional machine for removing support material, an unfinished 3D- printed object (or simply,“object”) may be subjected to a process to remove unwanted support material and/or unwanted resin, and thereby provide a finished part. In one such process, the object is placed in a tank (e.g., submerged or at least partially submerged) that has been filled (e.g, filled at least partially) with a liquid finishing solution. While the object is in the finishing solution (e.g„ submerged or at least partially submerged in the finishing solution), the object may be subjected to mechanical agitation, abrasion, and/or heating in order to remove unwanted resin from the object. Mechanical agitation may occur by moving the liquid finishing solution (e.g., via a pump) and½ by using ultrasound. In other such processes, the object is subjected to a liquid spray. In these processes, the object is placed in a chamber, and a pump is used to force the liquid finishing solution through one or more nozzles, which apply the finishing solution to the object and mechanically agitates the part. In both such processes, the liauid often includes chemical solvents to dissolve support material and/or unwanted resin, and thereby create a finished or nearly finished form of the object. Heat from a heat source may be used to maintain the finishing solution at a desired temperature. Under these conditions the support material and/or unwanted resin may be removed thermally, chemically, mechanically or via a combination of two or more of these general methods.

[0020] A finishing solution that is in keeping with the invention may be a mostly aqueous finishing solution for removing resin (e.g., finishing of) from an SLA 3D-printed object, build tray, or build plate. The finishing solution may comprise:

(a) 1-20% by weight of a terpene, including all 0.1% values and ranges therebetween; (b) 0.001-20% by weight of a hydrotrope, including all 0.001 % values and ranges

therebetween;

(c) 1 -10% by weight of a first glycol ether, including all 0.1% values and ranges

therebetween;

(d) optionally 1-10% by weight of a second glycol ether, including all 0.1% values and ranges therebetween;

(e) 1-5% by weight of an emulsifier, including all 0.1% values and ranges therebetween; and

(f) 1-15% by weight of a caustic agent, including all 0.1% values and ranges

therebetween; and

(g) water (e.g., the remainder of this finishing solution is water).

[0021] A terpene in a finishing solution that is in keeping with the invention may aid in dissolving organics found in resins frequently used in SLA printing techniques. Examples of tcrpenes suitable for a finishing solution in keeping with the invention include, but are not limited to, D-Iimonene, dipentene, terpinenes, menthol, pinene, thymol, boraeol,

phellandrene, p-cymene, and combinations thereof. For example, a finishing solution that is in keeping with the invention may be 1 -20% by weight a teipene, including all 0.1% values and ranges therebetween, relative to the total weight of the finishing solution.

[0022] A hydrotrope in a finishing solution that is in keeping with the invention may aid in solubilizing organic materials (e.g., the organic components of a finishing solution and resins) in water. Examples of hydrotropes suitable for a finishing solution that Is in keeping with the invention include, but are not limited to, sodium xylene sulfonate (“SXS”), xylene sulfonic acid, calcium xylene sulfonate, potassium xylene sulfonate, cumene sulfonic acid, sodium cumene sulfonate, toluene sulfonic acid, sodium toluene sulfonate, and combinations thereof. Additional examples include cumene sulfonate salts, sulfonic acid salts, and xylene sulfonate salts, and the like. Hydrotropes can be aqueous solutions comprising 1-50% hydrotrope by weight, including all 1% values and ranges therebetween. Such hydrotropes can be a mixture of isomers (e.g., stereoisomers, constitutional isomers, and the like). For example, a finishing solution that is in keeping with the invention may be 0.001-20% by weight a hydrotrope, including all 0.1% values and ranges therebetween, relative to the total weight of the finishing solution.

[0023] A glycol ether in a finishing solution that is in keeping with the invention can aid in dissolving organics found in resins that are typically used in SLA printing techniques. Examples of glycol ethers suitable for a finishing solution include, but are not limited to, methoxytriglyco I , ethoxytriglycol, butoxytriglycol, diethylene glycol n-butyl ether acetate, diethylene glycol monobutyl ether, ethylene glycol n-butyl ether acetate, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, DOWANOL™DPH 255, ethylene glycol phenyl ether, diethylene glycol monohexyl ether, ethylene glycol monohexyl ether, diethylene glycol monomethyl ether, ethylene glycol monopropyl ether, dipropylene glycol methyl ether, dipropylene glycol methyl ether acetate, dipropylene glycol n-butyl ether, propylene glycol diacetate, propylene glycol methyl ether, propylene glycol monomethyl ether acetate, propylene glycol n-butyl ether, propylene glycol phenyl ether, tripropylene glycol methyl ether, tripropylene glycol n-butyl ether, dipropylene glycol dimethyl ether, and combinations thereof. For example, a finishing solution that is in keeping with the invention may be 1-10% by weight a first glycol ether, including all 0.1% values and ranges therebetween, relative to the total weight of the finishing solution. A finishing solution that is in keeping with the invention may be 1-10% by weight a second glycol ether, including all 0.1% values and ranges therebetween, relative to the total weight of the finishing solution.

[0024] A finishing solution that is in keeping with the invention may comprise a combination of two glycol ethers, where the amount (e.g., by weight) of each glycol ether is the same or different In a preferred example, such a finishing solution can comprise dipropylene glycol monomethyl ether (DPM) and ethylene glycol monobutyl ether (EB).

[0025] An emulsifier in a finishing solution that is in keeping with the invention can aid in sustaining the length of time before such a finishing solution separates into organic and aqueous layers. Examples of emulsifiers include, but are not limited to, polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 80, sodium caprylate, and combinations thereof. For example, a finishing solution that is keeping with invention may be 1 -5% by weight an emulsifier, including all 0.1% values and ranges therebetween, relative to the total weight of the finishing solution. [0026] A caustic agent in a fmisMng solution that is in keeping with the invention can aid in increasing the pH of such a finishing solution. Examples of such caustic agents include, but are not limited to, sodium metasilicate pentahydrate, anhydrous sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, and combinations thereof. For example, a finishing solution that is keeping with invention may be 1-15% by weight a caustic agent, including all 0.1% values and ranges therebetween, relative to the total weight of the finishing solution. Caustic agent(s) may be added to a finishing solution to adjust the pH. A finishing solution of the present invention may have a pH of 10-14.

[0027} For example, the finishing solution can comprise:

(a) 1 -20% by weight D-limonene, including all 0.1% values and ranges therebetween·,

(b) 1-20% by weight 40% aqueous SXS, including all 0.1% values and ranges

therebetween;

(c) 1-10% by weight DPM, including all 0.1% values and ranges therebetween;

(d) optionally 1-10% by weight EB, including all 0.1% values and ranges therebetween; (e) 1-5% by weight polysorbate 80, including all 0.1% values and ranges therebetween; and

(f) 1-15% by weight sodium metasilicate pentahydrate, including all 0.1% values and targes therebetween; and

(g) water (e.g., the remainder of this finishing solution is water).

Such a finishing solution may have a pH of 10-14, including all 0.1 pH values and ranges therebetween. In a preferred example, the finishing solution can comprise:

(a) 10% by weight D-limonene;

(b) 10% by weight 40% aqueous SXS;

(c) 5% by weight DPM;

(d) 5% by weight EB;

(e) 1% by weight polysorbate 80;

(f) 8.6% by weight sodium metasilicate pentahydrate; and

(g) 60.4% by weight water (e.g., the remainder of this finishing solution is water);

Such a finishing solution has a pH of 10-14, including all 0.1 pH values and ranges therebetween.

{0028} The in vention may be embodied as a method of using a finishing solution. The steps of such a method may be sufficient to remove unwanted resin from a 3D-printed object, build plate, or build tray. The method can comprise: (a) to an object or a portion thereof, applying (e.g., by submerging the object) a finishing solution of the present invention;

(b) agitating the finishing solution during at least part of the application; and

(c) removing the object from the finishing solution,

Another method may comprise:

(a) spraying an object or a portion thereof in a finishing solution, such as the solution described above; and

(b) removing the finishing solution from the object.

[0029] In an example, applying the finishing solution may be accomplished by submerging in the finishing solution all or part of the object that requires finishing. When used herein, the word‘'submerged¹' refers to a situation where the object or merely a portion of the object is submerged at a depth sufficient to cover the object or portion thereof that requires finishing. The finishing solution can be stored in a holding vessel/eomainer/tank. Non-limiting examples of materials that the holding vessel/container/tank may be made from include stainless steel, glass, high density polyethylene, Teflon, Kalrez, Poly vinylidene

Fluoride (PVDF), and similar polymers.

[0030] Agitation can be induced by methods such as, but are not limited to, sonication

(e.g., via an ultrasonic transducer sending ultrasonic longitudinal waves into the finishing solution), a pump (e.g., using a pump to effect fluid movement), stirring, or a combination thereof.

[0031] Sonication may be performed at 0 to 1750 W, including all 0.1 W values and ranges therebetween, where amplitude may vary, and at a frequency of 20-100 kHz, including all 0.1 kHz values and ranges therebetween. In a preferred example, the frequency is 40 kHz. Sonicating a finishing solution that is in keeping with the invention can agitate the finishing solution such that the finishing solution does not separate into distinct phases and/or such that a force (e.g., friction across one or more surfaces of the object) is applied to the object, or to move the finishing solution. Such a finishing solution can be agitated for 1 60 minutes, including all 1 second values and ranges therebetween, prior to the object being submerged, and/or while the object is submerged.

[0032] Agitation by a pump can include pumping a finishing solution into a tank containing the object. For example, a pump may pump finishing solution into a tank at a rate of 1-20 gallon/minute, including all 0.1 gallon/minute value and range therebetween. By pumping finishing solution into the tank, an equal amount of finishing solution may be made to flow out of the tank over a weir and through a filtered drain. As the finishing solution is pumped into die tank, the force of die solution entering the filled tank mixes the finishing solution. A finishing solution may be agitated for 1 -60 minutes, including all l second values and ranges therebetween, prior to the object being submerged and/or while the object is submerged and/or while die object Is submerged.

[0033] Stirring can be performed by the use of an impeller, mechanical stirrer, stir bar, or the like. A finishing solution can be agitated for 1-60 minutes, including all 1 second values and ranges therebetween, prior to the object being submerged and/or while the object is submerged.

|00341 Additionally, any other method to induce fluid movement may be suitable to induce such agitation.

|0035| An object may be submerged (completely or partially) in a finishing solution that is in keeping with the invention and agitated during at least part of the submersion. An object may be submerged for a time sufficient to remove unwanted resin. During such submersion, the finishing solution may be agitated during the entire time of submersion or during part of the time that the object is submerged. The amount of time can be 1-60 minutes, including all 1 second values and ranges therebetween. The amount of time an object is submerged depends on the geometry of the object. That is, more complicated geometries may require additional submersion times. Often, an object can be adequately finished by submerging the object for a time that is between 1 and 30 minutes, including all I second values and ranges therebetween, and the finishing solution may be agitated for the entire duration of submersion or during part of the time that the object is submerged.

(00361 Agitation of the finishing solution induced by stirring, a pump, and/or other methods, may create friction between the finishing solution and the object being finished thereby causing removal of unwanted resin. Removal of the unwanted resin may be enhanced by ultrasonic transducers placed in the tank, such that the finishing solution vibrates, which is then imparted into the part. The ultrasonic transducers may be oriented tangentially (i.e., arranged on the side of the tank, where the transducers are tangential to the rotational flow in the tank) to the object such that efficient agitation is achieved when the part is oriented in any direction is achieved. The vibrating finishing solution may enhance removal of support material and/or unwanted resin by causing cavitation through direct interaction with the object. Such cavitation may be useful because cavitation enhances removal of unwanted support material and/or unwanted resin.

(00371 The temperature of the finishing solution may be kept at a desired

temncrature. It is considered that increasine the temnerature can increase the rate of solubilization of unwanted resin and the solubility of the resin in the finishing solution. For example, the finishing solution may be kept at a temperature of 55 -105 °F, including all 0.1 °F values and ranges therebetween, before the object is submerged and/or while the object is submerged.

[0038] A finishing solution that is in keeping with the invention can be recovered after the finishing operations are concluded. Steps for recovering the finishing solution may include allowing finishing solution to drip from the object back into a tank containing the finishing solution. The object may be rinsed with water or a similar solvent/solution. Such rinsing may be necessary to remove finishing solution that remains on the object Following application of the finishing solution, the object may be rough and tacky. T ackiness is related to uncured resin left on the surface. Such determination for roughness and/or tackiness may^¬ be determined by personal/operator preference. Such a determination can be made by personal/operator touch. When an operator deteimines that the object is too rough or too tacky, then the method may be repeated until the desired roughness and/or tackiness is/are achieved. When the object has the desired (or lack thereof) tackiness and roughness, the operator may determine that the object no longer requires additional finishing.

[0039] A general method of use can include:

(a) adding a finishing solution that is in keeping with the invention into a tank of a

machine (e.g., a machine used for finishing a 3-D printed object);

(b) using a heater that is arranged in the tank to heat the finishing solution to a desired temperature;

(c) using a pump to move the finishing solution within the tank;

(d) using an ultrasonic transducer arranged in the tank to provide ultrasonic longitudinal waves that agitate the finishing solution;

(e) contacting an object with the finishing solution for a desired time to remove unwanted resin from the object

[0040] Prolonged submersion in the finishing solution weakens the support material substantially by facilitating dissolution the unwanted resin. Fluid flow and ultrasonic agitation provide some mechanical force to loosen weakened support material, while also facilitating dissolution of uncured material (e.g., support material and/or resin).

[0041] A method of using a finishing solution that is in keeping with the invention may be accomplished by using a machine, such as, for example, the Post Process DEMI (Figure 2 shows a simplified schematic of a DEMI), CENT!, NANO, or PICO. Some machines, such as the Post Process NANO or the Post Process PICO, do not reouire a pump. However, additional agitation, such as from a pump, can reduce the amount of time needed to remove unwanted support material and/or unwanted resin. Using such a machine can involve:

(a) adding a finishing solution that is in keeping with the invention into a machine from the top of the machine by lifting a lid and pouring the finishing solution directly into a tank;

(b) mixing the finishing solution (e.g., mixing may be performed by a pump and/or

ultrasonic agitation) sufficiently to ensure the finishing solution does not separate;

(c) heating the finishing solution via a submerged heater arranged in the tank, in order to heat the finishing solution to a desired temperature;

(d) pumping the finishing solution using a pump that may be arranged below the tank, in order to move the finishing solution through the tank and thereby agitate the solution and/or object.

[0042] The machine may be filled with finishing solution using an automated filling feature having a pump and reservoir. A liquid level sensor may be positioned in the tank. When signals from that .sensor indicate the liquid level is too low, a pump may be caused to move fluid from the reservoir to the tank. The solution should be premixed before being added to the reservoir, in addition, the finishing solution may need to be mixed after the finishing solution has been added to the machine in order to prevent separation of the components.

[0043] A method of removing support material and/or unwanted resin may include placing a 3D-printed object within a tank of a machine, such as, for example, depicted in Figure 2B, which shows a simplified schematic of a Post Process DEMI machine. A desired run time may be determined and/or selected, and the pump started so that the finishing solution is circulated through the tank by the pump. The method can involve:

(a) placing an object in the finishing solution;

(b) circulating the finishing solution through the tank to cause the object to rotate within the finishing solution; and

(c) directing ultrasonic energy waves at the object in the finishing solution so as to

provide agitation.

[0044] The ultrasonic waves may be provided at a selected first agitation frequency.

Ultrasonic waves reflecting off of the object may be detected by a sensor, and the amplitude of the reflected waves may be measured. Based on the measured amplitude, a second ultrasonic frequency may be selected, for example, using database analysis from prior tests, zeroed in benchmarking procedures, and/or optimization techniques, and then ultrasound waves having the selected second ultrasonic frequency may be directed at the object

[0045] When agitated by the second ultrasonic frequency, the amplitude of the reflected ultrasonic waves may be detected by a sensor. This process may be repeated until the detected amplitude indicates that a resonant frequency of the support material and/or unwanted resin has been reached. As support material and/or unwanted resin is removed, the resonant frequency of the remaining support material and/or unwanted resin may change, and so the process of selecting an ultrasonic agitation frequency may need to be repeated from time to time. When the desired run time has been reached, the object may be removed from the tank and inspected to determine whether additional run-time is needed. Additional runtime may be needed if the object is“tacky” or too rough.

[0046] in another example of the invention, the finishing solution may be applied to the object by spraying the finishing solution on the object. Spraying can include using a machine capable of spraying the object or using a .spray bottle (e.g., a bottle having an atomizer nozzle). In another example, finishing of the object can be performed on a bench top using a mixer (e.g., a stir plate and magnetic stir bar or a mechanical stirrer and a tank (e.g., a flask or beaker) to hold the finishing solution (and object being finished).

[0047] The following example is presented to illustrate the invention. It is not intended to be limiting in any matter.

EXAMPLE 1

[0048] This example describes a method of using a finishing solution that is in keeping with the invention. The object in Figure 1 A and Figure IB was printed by SLA processes known in the art. The object (Figure 1 A and Figure I B) was finished using a finishing solution having:

(a) 10% by weight D-limonene:

(b) 10% by weight 40% aqueous SXS;

(c) 5% by weight DPM;

(d) 5% by weight EB;

(e) 1% by weight polysorbate 80;

(t) 8.6% by weight sodium melasilicate pentahydrate; and

(g) 60.4% by weight water.

That finishing solution had a pH of about 10-14. A finishing machine called a Post Process Nano (“PPN”) was used. The holding tank of the PPN was filled with the finishing solution, and the object was placed in the finishing solution. 1¾e finishing solution was heated to a temperature of 70 °F and the finishing solution was agitated via ultrasonic transducers for 5 minutes at room temperature and 40 kHz. After 5 minutes, the object was removed from the finishing solution and rinsed with water. The finished object is shown in Figure 1C and Figure ID.

Claims

CLAIMS:

1. A finishing solution for removing resin and/or support material from an object, the finishing solution comprising:

1-20% by weight of a terpene;

0.001-20% by weight of a hydrotrope;

1-10% by weight of a first glycol ether;

optionally 1-10% by weight of a second glycol ether:

1-5% by weight of an emulsifier:

1-15% by weight of a caustic agent; and

water.

2. The finishing solution of claim 1 , wherein the terpene is selected from the group consisting ofD-limonene, dipentene, terpinenes, menthol, pinene, thymol, bomeol, phellandrene, p-cymene, and combinations thereof.

3. The finishing solution of claim 1, wherein the hydrotrope is selected from the group consisting of sodium xylene sulfonate, xylene sulfonic acid, calcium xylene sulfonate, potassium xylene sulfonate, cumene sulfonic acid, sodium cumene sulfonate, toluene sulfonic acid, sodium toluene sulfonate, and combinations thereof.

4. The finishing solution of claim 3, wherein the hydrotrope is a mixture of hydrotrope isomers. 5. The finishing solution of claim 4, wherein the hydrotrope is an aqueous solution comprising 1-50% by weight a hydrotmpe.

6. The finishing solution of claim 1, wherein the first glycol ether is selected from the group consisting of methoxylriglycol, ethoxytriglycol, butoxytriglycol, diethylene glycol n-butyl ether acetate, diethylene glycol monobutyl ether, ethylene glycol n-butyl ether acetate, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, DOWANOL™ DPH 255, ethyleneglycol phenyl ether, diethylene glycol monohexyl ether, ethylene glycol monohexyl ether, diethylene glycol monomethyl ether, ethylene glycol monopropyl ether, dipropylene glycol methyl ether, dipropylene glycol methyl ether acetate, dipropylene glycol n-butyl ether, propylene glycol diacetate, propylene glycol methyl ether, propylene glycol monomethyl ether acetate, propylene glycol n-butyl ether, propylene glycol phenyl ether, tripropylene glycol methyl ether, tripropylene glycol n-butyl ether, dipropylene glycol dimethyl ether, and combinations thereof.

7. The finishing solution of claim 1, wherein the second glycol ether is selected from the group consisting ofmethoxytriglycol, ethoxytriglycol, butoxytriglycol, diethylene glycol n- butyl ether acetate, diethylene glycol monobutyl ether, ethylene glycol n-butyl ether acetate, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, DOWANOL™ DPH 255, ethylene glycol phenyl ether, diethylene glycol monohexyl ether, ethylene glycol monohexyl ether, diethylene glycol monomethyl ether, ethylene glycol monopropyl ether, dipropylene glycol methyl ether, dipropylene glycol methyl ether acetate, dipropylene glycol n-butyl ether, propylene glycol diacetate, propylene glycol methyl ether, propylene glycol monomethyl ether acetate, propylene glycol n-butyl ether, propylene glycol phenyl ether, tripropylene glycol methyl ether, tripropylene glycol n-butyl ether, dipropylene glycol dimethyl ether, or combinations thereof.

8. The finishing solution of claim 1 , wherein the first glycol ether is dipropylene glycol monomethyl ether and the second glycol ether is ethylene glycol monobutyl ether.

9. The finishing solution of claim 1, wherein the emulsifier is selected from the group consisting of polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 80, sodium caprylate, and combinations thereof.

10. The finishing solution of claim 1, wherein the caustic agent is selected from the group consisting of sodium metasilicate pentahydrate, anhydrous sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, and combinations thereof. 11. The finishing solution of claim 1 , wherein the finishing solution has a pH of 10-14.

12. The finishing solution of claim 1, wherein:

the terpene is D-iimonene;

fhe hydrotorpe is 40% aqueous sodium sylnee sulfonate: the first glycol ether is dipropylene glycol monomethyl ether;

the emulsifier is polysorbate 80;

the caustic agent is sodium metasilicate pentahydrate; and

water.

13. The finishing solution of claim 12, further comprising a second glycol ether, wherein the second glycol ether is 1-10% by weight ethylene glycol monobutyl ether.

14. The finishing solution of claim 13 comprising:

10% by weight D-limonene;

10% by weight 40% aqueous sodium xylene sulfonate;

5% by weight dipropylene glycol monomethyl ether;

5% by weight ethylene glycol monobutyl ether;

1% by weight polysorbate 80;

8.6% by weight sodium metasilicate pentahydrate; and

60.4% by weight water; and

the finishing solution has a pH of 10--14.

15. A method of removing resin and/or support material from mi object comprising:

(i) submerging an object in a finishing solution comprising:

1-20% by weight of a teipene;

0.001-20% by weight of a hydrotrope;

1 -10% by weight of a first glycol ether;

optionally 1-10% by weight of a second glycol ether;

1 -5% by weight of an emulsifier;

1-15% by weight of a caustic agent; and

water;

(ii) agitating the finishing solution during at least part of the submersion; and

(iii) removing the object from the finishing solution.

16. The method of claim 15, wherein the finishing solution comprises:

10% by weight D-limonene;

10% by weight 40% aqueous sodium xylene sulfonate;

5% hv WMoht dinmiwlftnft trlvml mnnnmpthvl ethftr 5% by weight ethylene glycol monobutyl ether;

1% by weight polysorbate 80;

8.6% by weight sodium metasilicate pentahydrate; and

60.4% by weight water; and

the finishing solution has a pH of 10 -14.

17. The method of claim 15, wherein the agitating is induced by sonication, a pump, stirring, fluid movement, or a combination thereof.

18. The method of claim 15, wherein agitating the finishing solution occurs for 1 -60 minutes prior to the object being submerged.

19. The method of claim 15, wherein the object is submerged for 1-60 minutes and the finishing solution is agitated for the duration of the submersion of the object.

20. The method of claim 15, further comprising:

(i) recovering finishing solution from the object by allowing the finishing solution to drip from the object into a tank, and

(ii) rinsing the object with water.

21. The method of claim 15, wherein the object is a manufactured object, build plate, or build tray.

22. The method of claim 15, wherein the finishing solution is at a temperature of 55-105 °F.

23. The method of claim 21 , wherein the finishing solution is at a temperature of 55-105 °F before the object is submerged and/or the finishing solution is at a temperature of 55-105 °F while the object is submerged.