Finishing solution and method for removing unwanted material from the surface of an object using the finishing solution

Abstract

The present invention relates to compositions and methods of use that can remove unwanted material or resin from 3D printed objects. The present invention relates to a compound or finishing solution that removes unwanted material. The unwanted material or resin is generated during the 3D printing process. In one embodiment, the finishing solution includes a first glycol ether, a second glycol ether, and / or a high-flashpoint hydrocarbon. The finishing solution has a flashpoint of at least 93.3°C. In another embodiment, the finishing solution includes a third glycol ether, a high-flashpoint alcohol, and / or a glycol ether acetate.

Description

[Technical Field]

[0001] The following disclosure relates to compositions for removing unwanted material from the surface of an object. In particular, the disclosure relates to compositions for removing unwanted material, such as uncured material and / or resin, from the surface of an object created by additive manufacturing techniques such as three-dimensional (3D) printing. The disclosure also relates to methods of using the compositions or solutions used in removing unwanted material, such as uncured material or resin, from the surface of an object. [Background technology]

[0002] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 000,670, filed March 27, 2020, which is incorporated herein by reference in its entirety. Summary of the Invention [Problem to be solved by the invention]

[0003] 3D printing processes such as three-dimensional printing (e.g., selective laser sintering (SLS), stereolithography (SLA), fused deposition modeling (FDM), material jetting (MJ), and electron beam (e-beam) printing) offer significant advantages for many applications. 3D printing processes enable the production of parts with complex geometries that are difficult to produce using traditional manufacturing techniques. 3D printing processes also enable the efficient production of small batches of parts. However, some 3D printing processes produce parts that require the removal of unwanted material, such as uncured material or resin. Unwanted material may be generated between multiple prints during the 3D printing process and may be needed to support the part being printed. After the printing process is complete for the currently printed part, the unwanted material must be removed before the part can be used for its intended purpose.

[0004] The unwanted material itself may have complex geometric shapes and may be used to support multiple parts of the object. This can result in the unwanted material being spread across a large area of ​​the object. Additionally, because 3D printing involves printing the object in individual layers, the object's surface finish may be rough. This is because the edges of each layer do not line up precisely with each other, creating a rough, raised outer surface. This outer surface may be unsightly, have stress concentrations, or irregularities, and must be removed before testing or use.

[0005] However, finishing solutions for 3D printed parts are typically organic solvents with low flash points. One example is isopropanol (IPA). These solutions may require precautions when working with them. There has been a long-standing need for chemical finishing solutions that can overcome these limitations.

[0006] The present disclosure provides compositions or finishing solutions and methods for removing unwanted material (e.g., uncured material and / or resin) from the surface of an object, such as one created by 3D printing technology. The present disclosure further provides a product in which the finishing solution is used to provide a cleaned object, with the unwanted material removed from the surface of the object.

[0007] In one embodiment, the finishing solution comprises a first glycol ether, a second glycol ether, and / or a high flash point hydrocarbon, and the finishing solution has a flash point of at least 200° F. In other embodiments, the finishing solution may also comprise a third glycol ether, a high flash point alcohol, and / or an acetate salt of a glycol ether.

[0008] In another embodiment, a method for removing unwanted material from the surface of an object (e.g., a 3D-printed object) is provided. The method includes providing a finishing solution comprising a first glycol ether, a second glycol ether, and / or a high-flashpoint hydrocarbon, wherein the finishing solution has a flash point of at least 200°F (93.3°C). The method includes immersing the object in the finishing solution, agitating the object while the object is immersed in the finishing solution, and removing the object from the finishing solution. This removes the unwanted material from the surface of the object and leaves it in the finishing solution.

[0009] In a further embodiment, an object is provided that has unwanted resin removed from its surface after being partially cured and cleaned. The partially cured and cleaned object is formed by the following steps: providing a finishing solution having a first glycol ether, a second glycol ether, and / or a high-flash point hydrocarbon, the finishing solution having a flash point of at least 200°F (93.3°C); immersing the partially cured object having unwanted material thereon in the finishing solution; agitating the partially cured object while immersed in the finishing solution; and removing the partially cured object from the finishing solution, thereby leaving the unwanted material removed from the surface of the object in the finishing solution to form the partially cured and cleaned object.

[0010] The foregoing summary is provided to more readily explain selected concepts that are further described below in the Detailed Description of the Invention. The summary is not intended to identify key features or essential features of the claims, nor is it intended to be used as an aid in determining the scope of the claims. [Brief explanation of the drawings]

[0011] Exemplary embodiments are described herein with reference to the following drawings: [Figure 1] FIG. 1 is a flow chart illustrating an exemplary method of using a finishing solution. [Figure 2A] FIG. 2A is a perspective view of an apparatus used to finish a 3D printed object with a finishing solution according to an embodiment of the present invention. [Figure 2B] FIG. 2B is a schematic cross-sectional front view of the device shown in FIG. 2A. [Figure 3A] FIG. 3A is a photograph of an object (a rook, a type of chess piece) fabricated by stereolithography (SLA) with resin, showing the object before the application of a finishing solution. [Figure 3B] FIG. 3B shows the cleaned object after immersion of the object shown in FIG. 3A in a finishing solution. [Figure 4] 4 is a graph showing the amount of unwanted material (unwanted resin) removed from an uncured object by a solution (shown as % resin by weight in the solution) while the object is immersed in the solution. The graph contrasts examples of the present invention (i.e., Examples 1, 2, and 5) with three comparative examples. DETAILED DESCRIPTION OF THE INVENTION

[0012] While the disclosed compositions and methods are representative of various embodiments, specific embodiments have been illustrated (and described below), and it is therefore to be understood that the disclosure is exemplary and that it is not intended to limit the scope of the claims to the specific embodiments described and illustrated herein.

[0013] As noted above, there are several considerations to address when working with commercially available finishing solutions, such as isopropanol (IPA), to remove unwanted material from 3D printing polymers, resins, plastic materials, and parts. For example, some conventional finishing solutions have low flash points, requiring safety precautions. Additionally or alternatively, some conventional finishing solutions have challenges, such as high vapor pressure, being expensive, requiring large amounts of material to remove a given amount of unwanted material, or requiring time to remove the unwanted material, or a combination of these challenges. Therefore, there has long been a need for a chemical finishing solution that overcomes these limitations.

[0014] Disclosed herein are improved compositions or finishing solutions and methods for making and using them.

[0015] Although the present disclosure is described in terms of particular embodiments, it is understood that other embodiments, including embodiments that do not provide all of the advantages and features described herein, are within the scope of the present disclosure. Various structural, logical, and process changes can be made without departing from the scope of the present disclosure.

[0016] The present disclosure may be embodied as one or more compositions or finishing solutions configured to remove unwanted material from polymer, resin, plastic materials, or parts produced by 3D printing, such as 3D printed stereolithography (SLA) objects and / or resins formed from brittle materials, associated with the removed resin. In one example, SLA and other methods involve a curing process using a laser during the printing process. In such 3D printing processes, some uncured or unwanted material may remain on the surface of the printed object. The amount of uncured or unwanted material on the surface of an object, such as a 3D printed object, may vary based on the type of printing process used or the type and structure of the object being produced. In one example, the uncured or unwanted resin is removed from the surface of the object using a finishing solution according to an embodiment of the present disclosure, thereby providing a cleaned object, or in one example, an object that is at least partially cured.

[0017] After removing unwanted material (e.g., uncured resin) from the surface of the object, the object can be "post-cured" using a UV oven. In other words, the unwanted material may be dissolved by the finishing solution of the present embodiments before the object is placed in an ultraviolet (UV) curing chamber for final curing.

[0018] Removing unwanted or uncured material before final curing has the advantage that the printed object can be cured normally (e.g., within a predicted or set time).

[0019] (definition) As used herein, the term "object" may also refer to a 3D printed object that is not in its desired final form (e.g., a 3D printed SLA object).

[0020] As used herein, the term "finishing" can refer to the removal of unwanted material from the surface of an object produced by 3D printing (e.g., a 3D printed object) to produce a finished part or an incompletely finished (semi-finished) part. The finishing process can include one or more steps, including, but not limited to, removing uncured material, removing unwanted resin, removing unwanted metal powder, removing unwanted printing material, and / or removing unwanted support material. In the 3D printing industry, finishing is sometimes referred to as "cleaning."

[0021] As used herein, the term "waste material" can include uncured material or waste resin (e.g., on the surface of a 3D printed object). The waste material can be the same material as the object being produced, or a different material.

[0022] Materials that can be removed by the finishing solution include, but are not limited to, Accura 25, Accura 48HTR, Acurra 60, Accura ABS, Accura Bluestone, Accura ClearVue, Accura Extreme, Accura SL 5530, e-Stone, Figure 4 ELAST-BLK, Figure 4 ELAST-BLK 10, Figure 4 TOUGH-BLK 20, Figure 4 TOUGH-GRY 10, VisiJet Clear, VisiJet Flex, FORMLABS® (e.g., Clear, White, Tough, Castable, Flexible, Dental SG, etc.), photopolymers, carbon (CE, DPR 10, EPU 40, EPU 41, EPX, RPU 70, UMA 90, PR 25), Somos 9120, Somos Element, Somos EvoLVe, Somos PerForm, Somos These include ProtoGen18420, Somos ProtoTerm, Somos Taurus, Somos Watershed, Water Clear Ultra, and Somos NeXt.

[0023] As used herein, the term "agitated" can refer to motion caused by an external force. Non-limiting examples of "agitating" with respect to the finishing solution include using a pump to move the finishing solution, stirring, using ultrasonic longitudinal waves, or a combination thereof, etc.

[0024] (composition or finishing solution) The improved composition or finishing solution for post-treatment removal of unwanted or uncured material can include a first glycol ether. In certain examples, the first glycol ether can be combined in solution with a second glycol ether and a third glycol ether, where the first, second, and third glycol ether compounds are different from one another.

[0025] In some examples, the finishing solution may further comprise a high flash point ester. As used herein, a high flash point ester may refer to an ester compound having a flash point of at least 200°F (93.3°C).

[0026] In some embodiments, a first glycol ether is mixed in solution with a different second glycol ether and a high-flash point ester. In some embodiments, such a finishing solution can include (a) 20-60 wt. % of the first glycol ether, (b) 20-60 wt. % of the second glycol ether, and (c) 1-20 wt. % of the high-flash point ester. As a result, the total weight percentages of the first glycol ether, the second glycol ether, and the high-flash point ester add up to 100%. That is, the total weight percentages of this composition can ignore any additional compounds or impurities present in the finishing solution.

[0027] In one embodiment, the finishing solution can include (a) 20-60 wt. % of a first glycol ether, (b) 20-60 wt. % of a second glycol ether, (c) 20-60 wt. % of a third glycol ether, and (d) 0-20 wt. % of a high-flash point ester, such that the total weight of the first glycol ether, second glycol ether, third glycol ether, and (optional) high-flash point ester equals 100%. That is, the total weight percentages of these compositions can ignore any additional compounds or impurities present in the finishing solution.

[0028] In other examples, a first glycol ether may be mixed in solution with a second, different glycol ether, a high flash point hydrocarbon or alcohol, and (optionally) a high flash point ester. As used herein, a high flash point hydrocarbon or alcohol may refer to a hydrocarbon or alcohol having a flash point of at least 200°F (93.3°C).

[0029] In one embodiment, such a finishing solution can include (a) 20-60 wt. % of a first glycol ether, (b) 20-60 wt. % of a high-flash point hydrocarbon or alcohol, and (c) 20-60 wt. % of a high-flash point ester, such that the total weights of the first glycol ether, the high-flash point hydrocarbon or alcohol, and the high-flash point ester add up to 100%. That is, the total weight percentages of these components can ignore any additional compounds or impurities present in the finishing solution.

[0030] In yet another example, the first glycol ether can be mixed in solution with a high flash point hydrocarbon and a high flash point acetate of an alcohol or glycol ester. As used herein, a high flash point acetate of a propylene glycol ester can refer to an acetate of a propylene glycol ester having a flash point of at least 200°F.

[0031] In one embodiment, such a finishing solution can include (a) 20-60 wt % of a first glycol ether, (b) 20-60 wt % of a high flash point hydrocarbon, and (c) 20-60 wt % of a high flash point alcohol or acetic acid of a glycol ester, such that the combined weight of the first glycol ether, the high flash point hydrocarbon, and the high flash point alcohol or acetic acid of the glycol ester is 100%. That is, the total weight percentages of these compositions can be ignorant of any additional compounds or impurities present in the finishing solution.

[0032] Examples of glycol ethers (i.e., primary, secondary, and tertiary glycol ethers) include, but are not limited to, the following glycol ethers and glycol ether acetates: 2-butoxyethanol (EB), dipropyl glycol monomethyl ether (DPM), dipropylene glycol methyl ether acetate (DPMA), ethylene glycol monohexyl ether (also known as 2-(hexyloxy)ethanol, 2-hexoxyethanol, HEX), methyl carbitol (also known as 2-(2-methoxyethoxy)ethanol, MC), dipropylene glycol n-propyl ether (DPnP), ethyl carbitol (also known as 2-(2-ethoxyethoxy)ethanol, EC), butyl carbitol (also known as 2-(2- Butoxy(ethoxy)ethanol, PC), dipropylene glycol butyl ether (DPnB), triethylene glycol dimethyl ether (also known as 1,2-bis(2-methoxyethoxy)ethane), ethyl 2-(2-ethoxyethoxy)acetate (ECA), ethyl 2-(2-butoxyethoxy)acetate (BCA), dibutyl carbitol (also known as diethylene glycol dibutyl ether, DC), triethylene glycol monomethyl ether (TM), tripropylene glycol methyl ether (TPM), tripropylene glycol n-butyl ether (TPnB), triethylene glycol monoethyl ether (TEGM), DPG (dipropylene glycol), tetraethylene glycol dimethyl ether (TTGD), and / or triethylene glycol monobutyl ether (also known as butoxytriglycol).

[0033] In one embodiment, the high flash point hydrocarbon or alcohol can include higher linear alpha olefins or internal olefins, such as 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and higher olefin mixtures having carbon numbers ranging from C20 to C24, C24 to C30, or C20 to C30. Additionally or alternatively, the high flash point hydrocarbon or alcohol compound can include hexadecane, 2-phenoxyethanol, and / or benzyl alcohol.

[0034] In one embodiment, the high flash point ester can include ethyl benzoate (EBZ), propyl benzoate (PBZ), dimethyl adipate (DMA), dimethyl propanedionate, dimethyl succinate, dimethyl glutarate, and / or butyl benzoate. In one embodiment, the high flash point ester is a high flash point methyl ester.

[0035] In certain examples, high flash point acetate salts of glycol esters can include, for example, dipropylene glycol methyl ether acetate, ethylene glycol monohexyl ether, ethyl 2-(2-ethoxyethoxy)acetate (also known as ethoxycarbitol acetate), and / or ethyl 2-(2-butoxyethoxy)acetate (also known as butylcarbitol acetate), and the like.

[0036] (Composition / Characteristics of the finishing solution) In one example, the finishing solutions described herein have a flash point of at least 200°F (93.3°C), 210°F (98.9°C), or 220°F (104.4°C), and in some embodiments, a flash point of no more than 392°F (200°C), 302°F (150°C), or 248°F (120°C).

[0037] In one embodiment, the finishing solution has a flash point of 93.3°C (200°F) to 200°C (392°F), 93.3°C (200°F) to 150°C (302°F), 93.3°C (200°F) to 120°C (248°F), 98.9°C (210°F) to 200°C (392 ... The flash point finish solutions are specified to be within the ranges of 0°F (0°C) to 150°C (302°F), 98.9°C (210°F) to 120°C (248°F), 104.4°C (220°F) to 200°C (392°F), 220°F to 150°C (302°F), or 104.4°C (220°F) to 120°C (248°F). This is advantageous in that it allows for reduced amounts of equipment or safety protocols to be required when using the finish solution to remove unwanted material compared to commercially available compositions such as isopropanol alcohol (IPA). Additionally, such flash point finish solutions can also be configured for use in a spray form as described herein.

[0038] In one embodiment, the finishing solution has improved product life compared to certain commercial finishing solutions, such as IPA, whereby more of the unwanted resin or material is removed before a given volume of the finishing solution described herein becomes saturated (compared to using the same volume of a commercial finishing solution, such as IPA), and the finishing solution can be recycled as needed for reuse.

[0039] For example, the finishing solutions described herein can dissolve at least 2, 3, 4, 5, 6, 7, 8, 9, or 10 times more unwanted resin or material than a conventional commercially available finishing solution, such as IPA (assuming various conditions, such as time, temperature, and / or agitation, are similar to the conventional conditions).

[0040] In one embodiment, the finishing solutions can remove unwanted material or resin more quickly than conventional IPA, thereby removing more resin or unwanted material (e.g., measured by volume % or weight %). The finishing solutions described herein can also remove more resin or unwanted material than conventional commercial finishing solutions in a given time period, or can be described as removing a given amount (volume % or weight %) of unwanted material in a shorter time period.

[0041] In one example, the finishing solution may have an improved odor (or no odor) compared to commercially available solutions such as IPA.

[0042] In one embodiment, the finishing solution is non-cytotoxic.

[0043] In one embodiment, the finishing solution is less costly to use compared to commercially available solutions such as IPA.

[0044] (How to use) In the method of using the finishing solution according to the present invention, an unfinished object (e.g., a 3D printed object) is subjected to a process to remove unwanted material to provide a finished part.

[0045] In one embodiment, the method of use involves placing the object in a tank filled (e.g., at least partially filled) with the finishing solution, i.e., immersing the object in the finishing solution.

[0046] While the object is in the finishing solution (e.g., immersed in the finishing solution), the object may be subjected to mechanical energy such as agitation, abrasion, and / or heating to remove unwanted resin. The mechanical energy, "agitation," is induced by moving the finishing solution (e.g., via a pump) and / or by using ultrasound.

[0047] In another variation of this process, the object can be sprayed with a finishing solution. In this process, the object is placed in a chamber and the finishing solution is sprayed, for example, using a pump to apply force to the liquid through one or more nozzles. The finishing solution is applied to the object, and the object is mechanically agitated. In the dipping and spraying process, the liquid can include a chemical solvent to dissolve unwanted material, thereby creating a finished or nearly finished object.

[0048] The finishing solution can be maintained at a desired temperature using heat from a heat source, and under these conditions, unwanted material can be removed thermally, chemically, mechanically, or via a combination of two or more of these methods.

[0049] 1 is a flowchart illustrating a method of using a finishing solution in one embodiment. Each step of this embodiment of the method is sufficient to remove unwanted material from a 3D printed object, build plate, or build tray. Referring to the method illustrated in FIG. 1, in step 1, the finishing solution is applied to the entire object or a portion thereof (e.g., the object is immersed in the finishing solution).

[0050] Application of the finishing solution can be accomplished by immersing all or a portion of the object to be finished in the finishing solution. As used herein, the term "immersed" refers to immersion to a depth sufficient to cover all or a portion of the object to be finished in the finishing solution.

[0051] The finishing solution can be stored in lines / containers / tanks made of materials including, but not limited to, stainless steel, glass, high density polyethylene, Teflon, Kalrez, polyvinylidene fluoride (PVDF), and the like.

[0052] In step 2 of Figure 1, at least a portion of the object is immersed in and / or agitated in the finishing solution. The agitation and / or vibration may be induced by, but is not limited to, sonication (e.g., via an ultrasonic transducer that sends longitudinal ultrasonic waves into the finishing solution), pumping (e.g., used to create fluid movement), stirring, or a combination thereof.

[0053] The ultrasonic treatment may be performed at a power of 1750 W or less, and can be performed at a power of 1750 W or less and determined in increments of 0.1 W. The power during ultrasonic treatment may be temporarily changed. The frequency at this time is 20 to 100 kHz. The frequency is 100 kHz or less and determined in increments of 0.1 kHz. Preferably, the frequency is 40 kHz.

[0054] Sonicating the finishing solution can agitate the finishing solution to prevent it from separating into separate phases and / or apply force to the object or agitate the finishing solution. Applying force to the object can aid in removing and / or dissolving unwanted material.

[0055] The finishing solution of this embodiment may be stirred for 0-60 minutes. The stirring time is the time before and / or while the object is immersed, and may be determined in 1-second increments, such as 1-60 minutes, 10-30 minutes, 1-15 minutes, 15-30 minutes, 30-60 minutes, etc.

[0056] The ultrasonic waves can provide a first frequency selected for solution agitation. When the finishing solution is agitated by the first frequency, the amplitude of the reflected ultrasonic waves is detected by a sensor, and the amplitude of the reflected waves is measured. Based on the measured amplitude, ultrasonic waves of a second frequency are selected, for example, based on a database. Then, ultrasonic waves having the selected second frequency are directed toward the object. In this way, ultrasonic waves of the second frequency are selected to optimally agitate the finishing solution.

[0057] This process can be repeated (e.g., via sensor feedback) until the detected amplitude indicates that the resonant frequency of the unwanted material has been reached. As unwanted material is removed, the resonant frequency of the remaining material may change. Therefore, the process of selecting a frequency for ultrasonic agitation may need to be repeated from time to time.

[0058] When the desired run time is reached, the object may be removed from the tank and inspected to determine if additional work needs to be performed. If the object is "sticky" or too rough, additional run time is required.

[0059] 2A and 2B, agitation by pumping may include pumping a finishing solution into a tank 28 containing the object. For example, the finishing solution may be pumped into the tank 28 at a rate of 1 to 20 gallons per minute, which may be determined in increments of 0.1 gallons per minute. As the finishing solution is pumped into the tank 28, an amount of finishing solution equal to the amount pumped into the tank flows out of the tank 28 and over the weir 20 into the input tank 18. The solution that flows into the input tank 18 flows through a filter, into a drain, and back to the inlet of the pump.

[0060] As finishing solution is pumped into tank 28, it mixes with the finishing solution already in the tank. The finishing solution is agitated for 0-60 minutes before and / or while the object is immersed. Agitation times can be specified in 1-second increments, such as 1-60 minutes, 10-30 minutes, 1-15 minutes, 15-30 minutes, 30-60 minutes, etc. Agitation before immersing the object facilitates mixing of the finishing solution.

[0061] After the object is immersed, agitation can be used to aid in the removal of unwanted material. Fluid movement can be induced by any method suitable for inducing agitation as described above (e.g., such as that induced by ultrasonic generator 70).

[0062] The finishing solution can be agitated using an impeller, mechanical agitator, stirring rod, etc. The finishing solution is agitated for 0-60 minutes before and / or while the object is immersed. The agitation time can be determined in 1-second increments, such as 1-60 minutes, 10-30 minutes, 1-15 minutes, 15-30 minutes, 30-60 minutes, etc.

[0063] The object is immersed in the finishing solution, and at least a portion of the immersion solution may be agitated. The object is immersed for a time sufficient to remove unwanted resin. While the object is immersed, the finishing solution may be agitated for all or part of the time the object is immersed. The immersion time may be set in 1-second increments within a range of 0 to 60 minutes, such as 1 to 60 minutes, 10 to 30 minutes, 1 to 15 minutes, 15 to 30 minutes, 30 to 60 minutes, etc.

[0064] The time required to remove unwanted material from an object depends on the object's shape. For example, more complex shapes may require additional immersion time. In most cases, objects are properly finished by immersing them for 1-30 minutes (immersion time can be measured in seconds). The finishing solution may be agitated during all or part of the immersion time.

[0065] Agitation of the finishing solution, whether caused by stirring, pumping, and / or other methods, creates friction between the finishing solution and the object being finished, which can facilitate removal of unwanted material. Removal of unwanted material may be enhanced by ultrasonic transducers located within the tank, which vibrate the finishing solution as it is applied to the object.

[0066] In one embodiment, the ultrasonic transducer may be positioned on the side of the tank and oriented tangentially to the rotating flow of the finishing solution within the tank. This arrangement of the ultrasonic transducer can achieve efficient agitation of the finishing solution and the immersed object. The ultrasonic waves generated by the ultrasonic transducer can induce cavitation on the surface of the unwanted material, facilitating its removal. In other words, the mechanical agitation caused by the cavitation removes the unwanted material. Thus, cavitation is advantageous in increasing the efficiency of removing unwanted material.

[0067] The finishing solution may be heated to or maintained at a desired temperature to enhance solubilization of unwanted resins. For example, the finishing solution may be maintained at a temperature of up to 55°C (131°F) before and / or while the object is immersed. The temperature of the finishing solution may be within the range of 20°C (68°F) to 55°C (131°F) in 0.1°C (0.1°F) increments. At higher temperatures, such as above 55°C (131°F), care must be taken to ensure proper handling.

[0068] The finishing solution can be recovered after the finishing operation is complete. The step of recovering the finishing solution may involve dripping the finishing solution-containing liquid medium from the object into a tank. The object may be rinsed with water or another suitable solvent. Such a rinsing step is necessary to remove any remaining finishing solution from the object surface.

[0069] After application of the finishing solution, the object may be rough and tacky. The tackiness comes from uncured resin remaining on the object surface. Such a determination of roughness and / or tackiness is based on the preference of the individual / operator. Also, such a determination can be made with the individual / operator's involvement. If the operator determines that the object is too rough or too tacky, the method as described herein can be repeated until the desired roughness and / or tackiness is achieved. If the object has the desired tackiness and roughness (or is not tacky), the operator can determine that the object does not require additional finishing.

[0070] 1, in step 3, the object can be removed from the finishing solution to provide a (e.g., partially cured) cleaned object. In optional step 4, the cleaned object may be additionally rinsed or dried.

[0071] In another embodiment, the method can involve spraying the object (or a portion of the object) with a finishing solution, and then removing the finishing solution from the object.

[0072] 2A and 2B illustrate an example of an apparatus for finishing 3D printed objects configured for use with a finishing solution according to one embodiment described herein, respectively, and a cross-sectional front view of the apparatus shown in FIG.

[0073] 2A and 2B show a part finisher 100, a control panel 12, a cover door 10, a front panel 8, a tank 28 configured to hold a finishing solution (as described herein), a weir 20, a computer 13, an input tank 18, a liquid level sensor 19, a wall 36, an ultrasonic generator 70, a tank manifold 14, and an ultrasonic transducer 22.

[0074] The part finisher 100 finishes a 3D printed object by (a) adding a finishing solution to a tank 28 of the machine 100 (e.g., the machine 100 is used to finish the 3D printed object), (b) using a heater located within the tank 28 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 22 located relative to the tank to provide ultrasonic longitudinal waves and / or cavitation within the tank to agitate the finishing solution, and (e) exposing the object to the finishing solution for a desired time to remove unwanted material from the object.

[0075] Immersion in the finishing solution facilitates dissolution of the unwanted resin and substantially weakens the unwanted material. The fluid flow and ultrasonic agitation provide mechanical forces to loosen the weakened unwanted material while also facilitating dissolution of the unwanted material (e.g., uncured material and / or resin).

[0076] In one example, using a finishing solution is accomplished by using a machine manufactured by PostProcess Technologies, Inc. Examples of such machines include DEMI (FIG. 1 shows a simplified diagram of DEMI), CENTI, and FORTI. An embodiment of a machine that uses a finishing solution to remove unwanted material from a 3D printed object is disclosed in U.S. Patent Application Publication No. 2017 / 0348910, filed June 1, 2016, the entire disclosure of which is incorporated herein by reference.

[0077] Additional agitation, such as with a pump, can reduce the time required to remove unwanted material. Use of such a machine can include the following methods: (a) adding the finishing solution from the top of the machine 100 by lifting the lid (or other suitable mechanism for covering the tank 28, such as the cover door 10 shown in FIGS. 2A and 2B) and pouring the finishing solution directly into the tank 28; (b) thoroughly mixing the finishing solution (e.g., by pumping and / or ultrasonic agitation) to prevent separation of the finishing solution; (c) heating the finishing solution to a desired temperature by heating it via a submersible heater located within the tank; and (d) pumping the finishing solution using a pump located below the tank to agitate the solution and / or the object so that the finishing solution moves through the tank.

[0078] The machine is filled with finishing solution using an automatic filling mechanism having a pump and a reservoir. A liquid level sensor 19 may be located in the tank 28 or the input tank 18. If a signal from the liquid level sensor indicates that the liquid level is too low, the pump moves fluid from the reservoir to the tank 28. The finishing solution may be premixed before being added to the reservoir. Additionally, the finishing solution needs to be mixed after it is added to the tank 28 to prevent separation of the components.

[0079] A method for removing unwanted material includes placing a 3D printed object in a tank of a machine, such as that shown in FIG. 2A. Once a desired run time is determined and / or selected, the method can operate a pump such that a finishing solution is circulated through the tank by the pump. The method can include (a) placing the object in the finishing solution, (b) circulating the finishing solution through the tank 28 to rotate the object in the finishing solution, and (c) directing ultrasonic energy waves at the object in the finishing solution to provide agitation and / or cavitation.

[0080] In other examples, the finishing solution may be applied to the object by spraying it onto the object. Spraying can be accomplished by using a machine capable of spraying the object or by using a spray bottle (e.g., a bottle with a spray nozzle). Embodiments of machines that use finishing solutions to remove unwanted material from 3D printed objects are disclosed in U.S. Patent Application Publication No. 2019 / 0202126, filed December 17, 2017, the entire disclosure of which is incorporated herein by reference.

[0081] In another example, the finishing of an object is performed on a benchtop using a mixer (e.g., a stir plate, magnetic stir bar, or mechanical stirrer) and a tank (e.g., a flask or beaker) to hold the finishing solution (and the object being finished). The object may be placed in the tank holding the finishing solution. While the object is in the finishing solution, the mixer applies a force to the finishing solution, which causes the finishing solution to agitate in the tank and also applies a force to the object, which moves unwanted material away from the object.

[0082] Figures 3A and 3B illustrate how a finishing solution removes unwanted material from a 3D-printed object to provide a partially cured and washed object. Specifically, the figures show photographs of an object (a rook, a type of chess piece) fabricated by resin-assisted stereolithography (SLA). Figure 3A shows the object before the application of the finishing solution. Figure 3B shows the object after immersion in the finishing solution. The post-immersion object is a partially cured and washed 3D-printed object with unwanted material (e.g., uncured resin) removed.

[0083] (Example) Various exemplary finishing solutions are disclosed herein. Additionally, three comparative examples representative of currently commercially available finishing solutions are also disclosed herein for reference and comparison. TIFF0007795787000001.tif129168

[0084] TIFF0007795787000002.tif120153

[0085] TIFF0007795787000003.tif120153

[0086] TIFF0007795787000004.tif111154

[0087] TIFF0007795787000005.tif94154

[0088] TIFF0007795787000006.tif92153

[0089] TIFF0007795787000007.tif148153

[0090] TIFF0007795787000008.tif67162

[0091] TIFF0007795787000009.tif67162

[0092] TIFF0007795787000010.tif60162

[0093] Figure 4 shows a graph comparing the finishing solutions disclosed herein (i.e., Examples 1, 2, and 5) with the commercial comparative examples (i.e., Comparative Examples 1, 2, and 3). Specifically, Figure 4 shows the relationship between the elapsed time of the finishing process and the amount of resin removed by the finishing solution (wt % of resin in solution) for each finishing solution.

[0094] As shown in FIG. 4, the embodiments of Examples 1, 2, and 5 all removed more unwanted resin from the surface of 3D printed objects in the same or shorter time (i.e., washing >30% of the resin into solution in 10 minutes) than the commercially available forms of Comparative Examples 1, 2, and 3. As shown in FIG. 4, after immersing and agitating the objects in the finishing solution / detergent for 10 minutes, the embodiments of Examples 1, 2, and 5 were able to have solutions containing approximately 30%-40% of the unwanted resin in the finishing solution. In contrast, the comparative examples only had 5-15% of the unwanted resin present in the finishing solution, removing less material over the same time period. Thus, after immersion and agitation for 10 minutes under the same operating conditions, the embodiments disclosed herein were able to dissolve at least two, three, four, or five times as much unwanted resin or material as the commercially available finishing solutions of Comparative Examples 1-3.

[0095] Additionally, the embodiments shown in Examples 1, 2, and 5 all remove more resin before the solution becomes saturated compared to the commercial comparative example.

[0096] One or more embodiments disclosed herein may be referred to individually and / or collectively for convenience by the term "invention." Furthermore, the scope of the present specification is not intended to be limited spontaneously by any particular invention or inventive concept. Furthermore, while specific embodiments have been illustrated and described herein, it should be understood that any subsequent configurations designed to achieve the same or similar purpose may be substituted for the specific embodiment shown. The present disclosure is intended to cover any and all subsequent adaptations or variations of the various embodiments. Combinations of the above-described embodiments, as well as other embodiments not specifically described herein, will be apparent to one skilled in the art upon review of the present specification.

[0097] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0098] As used herein, the terms "for example," "such as," or "including" are meant to introduce examples that further clarify the general subject matter. Unless otherwise specified, such examples are provided solely as an aid in understanding the exemplary disclosed embodiments herein and are not intended to be limiting in any way. These terms do not imply any preference for the disclosed embodiments.

[0099] This Abstract is provided to comply with 37 CFR § 1.72(b) and is presented with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Moreover, in the foregoing Detailed Description, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all features of any of the disclosed embodiments. Accordingly, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as defining separately claimed subject matter.

[0100] It is intended that the foregoing detailed description be regarded as illustrative and not limiting. It is also to be understood that the following claims, including equivalent constructions, are intended to define the scope of the present disclosure. The claims should not be construed as limited to the described order or elements unless expressly stated to that effect. Accordingly, all embodiments that come within the scope and spirit of the following claims and equivalents thereto are claimed with the disclosure.

Claims

1. 1. A finishing solution configured to remove unwanted material from a surface of an object, comprising: 20-60 wt. % of a first glycol ether; 20-60 wt. % of a second glycol ether; 20-60% by weight of a hydrocarbon having a flash point of at least 93.3°C; The finishing solution has a flash point of at least 93.3°C.

2. 1. A finishing solution configured to remove unwanted material from a surface of an object, comprising: 20-60 wt. % of a first glycol ether; 20-60 wt. % of a second glycol ether; 20-60 wt. % of a third glycol ether; The finishing solution has a flash point of at least 93.3°C.

3. 3. The finishing solution of claim 2, wherein the third glycol ether is triethylene glycol dimethyl ether or tetraethylene glycol dimethyl ether.

4. 1. A finishing solution configured to remove unwanted material from a surface of an object, comprising: 20 to 60 wt. % of a first glycol ether; 20 to 60 wt. % of a second glycol ether and / or 20 to 60 wt. % of a hydrocarbon having a flash point of at least 93.3°C; the finishing solution has a flash point of at least 93.3°C; The finishing solution, wherein the second glycol ether is tripropylene glycol methyl ether or triethylene glycol monomethyl ether.

5. 1. A finishing solution configured to remove unwanted material from a surface of an object, comprising: 20 to 60 wt. % of a first glycol ether; 20 to 60 wt. % of a second glycol ether and / or 20 to 60 wt. % of a hydrocarbon having a flash point of at least 93.3°C; 1-20 wt. % of an ester having a flash point of at least 93.3°C; The finishing solution has a flash point of at least 93.3°C.

6. 6. The finishing solution of claim 5, wherein the ester having a flash point of at least 93.3°C is dimethyl adipate.

7. 1. A finishing solution configured to remove unwanted material from a surface of an object, comprising: 20 to 60 wt. % of a first glycol ether; 20 to 60 wt. % of a second glycol ether and / or 20 to 60 wt. % of a hydrocarbon having a flash point of at least 93.3°C; and 20-60% by weight of an alcohol having a flash point of at least 93.3°C; The finishing solution has a flash point of at least 93.3°C.

8. 1. A finishing solution configured to remove unwanted material from a surface of an object, comprising: 20 to 60 wt. % of a first glycol ether; 20 to 60 wt. % of a second glycol ether and / or 20 to 60 wt. % of a hydrocarbon having a flash point of at least 93.3°C; the finishing solution has a flash point of at least 93.3°C; the first glycol ether is any one of the group consisting of butyl carbitol (also known as 2-(2-butoxyethoxy)ethanol), methyl carbitol (also known as 2-(2-methoxyethoxy)ethanol), and ethyl carbitol (also known as 2-(2-ethoxyethoxy)ethanol); A finishing solution, wherein the hydrocarbon having a flash point of at least 93.3°C is neoden-14 (also known as 1-tetradecene).

9. providing a finishing solution according to any one of claims 1 to 8; immersing the object in a finishing solution; agitating the object while it is immersed in the finishing solution; and removing the object from the finishing solution while leaving the unwanted material removed from the surface of the object in the finishing solution. A method of removing unwanted material from the surface of an object.

10. warming the object while immersed in the finishing solution; 10. The method of claim 9, further comprising removing the object from the finishing solution and washing and / or drying.

11. 10. The method of claim 9, further comprising removing the object from the finishing solution and curing the object in an ultraviolet (UV) chamber.

12. 10. The method of claim 9, wherein the object is immersed in the finishing solution and agitated for 1 to 60 minutes.

Images