Apparatus and methods for off platform spinning in additive manufacturing

Abstract

Methods of separating excess resin from an object include additively manufacturing an object on a build platform, the object (115, 415) carrying excess resin therein and / or thereon; removing the object from the build platform; placing the object in a cradle (100, 400) and / or cradle support (155, 455), optionally wherein a surface 110, 140) of the cradle aligns with a surface of the object (125,145) and contacts the surface of the object when the cradle and / or cradle support moves under centripetal force; placing the cradle and / or cradle support in a spinning apparatus; centrifugally separating excess resin from the object; and removing the cradle, cradle support, and / or object from the spinning apparatus, at least a portion of the excess resin being separated from the object.

Description

[0001] APPARATUS AND METHODS FOR OFF PLATFORM SPINNING IN ADDITIVE MANUFACTURING

[0002] CROSS REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority from U.S. Provisional Application No. 63 / 619,511, filed January 10, 2024, the disclosure of which is hereby incorporated by reference in its entirety.

[0004] Field of the Invention

[0005] The present invention concerns methods and apparatus for producing objects by additive manufacturing. In particular, the present invention relates to methods and apparatus for removing excess resin from objects produced by additive manufacturing.

[0006] Background of the Invention

[0007] A group of additive manufacturing techniques sometimes referred to as "stereolithography" create a three-dimensional object by the sequential polymerization of a light polymerizable resin. Such techniques may be "bottom-up" techniques, where light is projected into the resin on the bottom of the growing object through a light transmissive window, or "top down" techniques, where light is projected onto the resin on top of the growing object, which is then immersed downward into the pool of resin. The introduction of more rapid stereolithography techniques sometimes referred to as continuous liquid interface production (CLIP), coupled with the introduction of "dual cure" resins for additive manufacturing, has expanded the usefulness of stereolithography from prototyping to manufacturing (see, e.g., U.S. Patent Nos. 9,211,678; 9,205,601; and 9,216,546; J. Tumbleston, D. Shirvanyants, N. Ermoshkin et al., Continuous liquid interface production of 3D Objects, Science 347, 1349- 1352 (2015); and U.S. Patent Nos. 9,676,963, 9,453,142 and 9,598,606).

[0008] Stereolithography resins are generally viscous. As a result, excess, unpolymerized, resin may adhere to the surface of additively manufactured objects after they have been produced. This resin generally needs to be removed for further processing or use, but removal of such residual resin can be difficult.

[0009] Residual resin can be removed by centrifugal separation, such as described in PCT Publication No. WO2019 / 209732, U.S. Publication No. 2023 / 0330937; U.S. Publication No. 2021 / 0323234; and U.S. Patent No. 11,491,725, the disclosures of each of which are incorporated herein by reference in their entirety. High spin speeds can, however, cause distortion of the object, and low spin speeds can result in insufficient removal of residual resin.

[0010] Accordingly, there remains a need for new approaches to separating residual resin from additively manufactured objects.

[0011] Summary of the Invention

[0012] According to some embodiments, a method of separating excess resin from an object includes (a) additively manufacturing an object on a build platform, the object carrying excess resin therein and / or thereon; (b) removing the object from the build platform; (c) placing the object in a cradle and / or cradle support, optionally wherein a surface of the cradle aligns with (e.g., is an inverse of) a surface of the object and contacts the surface of the object when the cradle and / or cradle support moves under centripetal force; (d) placing the cradle and / or cradle support in a spinning apparatus; (e) centrifugally separating excess resin from the object; and (f) removing the cradle, cradle support, and / or object from the spinning apparatus, at least a portion of the excess resin being separated from the object.

[0013] In some embodiments, the surface of the cradle comprises a convex contour that aligns with (e.g., is the inverse of ) a concave contour of the surface of the object when the object is in the cradle; and / or the cradle comprises a concave contour that aligns with (e.g., is the inverse of) a convex contour of the surface of the object when the object is in the cradle.

[0014] In some embodiments, the cradle and / or cradle support comprises at least one (e.g., a plurality of) drainage hole(s) and / or channel(s) for directing excess resin removal.

[0015] In some embodiments, the surface of the cradle substantially aligns with the surface of the object (e.g., wherein the contour of the surface of the cradle is the inverse of the contour of the surface of the object). In some embodiments, the centripetal forces on the surface of the object are substantially equally distributed when centrifugally separating the excess resin from the object.

[0016] In some embodiments, the cradle comprises a first cradle portion configured to contact a first surface of the object, and optionally the cradle comprises a second cradle portion configured to contact a second surface of the object. In some embodiments, a surface of the first cradle portion aligns with (e.g., is the inverse of) the first surface of the object, and optionally a surface of the second cradle portion aligns with (e.g., is the inverse of) the second surface of the object. In some embodiments, the cradle and / or the cradle support is attached to or forms part of a transfer frame that attaches to a portion of the spinning apparatus, and placing the cradle and / or the cradle support in the spinning apparatus further comprises placing the transfer frame in the spinning apparatus.

[0017] In some embodiments, the transfer frame comprises a plurality of cradles and / or cradle supports; and a plurality of objects is additively manufactured, removed from the build platform, and placed in the plurality of cradles and / or cradle supports. In some embodiments, (e) and (f) are performed for the plurality of objects.

[0018] In some embodiments, the method includes warming the excess resin sufficiently to reduce the viscosity thereof during the centrifugally separating step.

[0019] In some embodiments, the method includes a gas or liquid to the excess resin in an amount sufficient to reduce the viscosity thereof during the centrifugally separating step.

[0020] In some embodiments, the centrifugally separating step is carried out in a gas at ambient pressure or a pressure less than ambient pressure.

[0021] In some embodiments, the centrifugal separation is carried out at a speed of from about 100, about 200 or about 400 revolutions per minute (rpm) to about 600, about 800, about 1,000 or about 1,200 rpm.

[0022] In some embodiments, the method further includes (g) collecting the centrifugally separated excess resin; (h) optionally combining the centrifugally separated excess resin with additional resin; and then (i) additively manufacturing at least one additional object from the centrifugally separated excess resin, optionally in combination with the additional resin.

[0023] In some embodiments, the object is an intermediate object produced from a dual cure resin, and the method further comprises further curing the object after step (e) to produce a finished object.

[0024] In some embodiments, the object comprises a lattice and / or includes one or more internal channels or cavities and has at least one surface opening in fluid communication with the channel or cavity, and excess resin within the channel or cavity flows out of the channel or cavity through the at least one surface opening during the centrifugal separation step.

[0025] In some embodiments, the object is a footwear insole and the surface of the cradle aligns with (e.g., is the inverse of) a surface of the insole when the insole is in the cradle.

[0026] In some embodiments, the object is a saddle and the surface of the cradle aligns with (e.g., is the inverse of) a surface of the saddle when the saddle is in the cradle.

[0027] According to some embodiments, an apparatus useful for separating excess resin from an additively manufactured object includes (a) a rotor; and (b) a cradle and / or a cradle support, optionally attached to or part of a transfer frame, wherein the cradle and / or cradle support, and optionally the transfer frame, is configured to reversibly attach to the rotor and be centrifugally spun by the rotor. In some embodiments, a surface of the cradle aligns with (e.g., is an inverse of) a surface of the object and contacts the surface of the object when the cradle moves under centripetal force.

[0028] In some embodiments, the object is a footwear insole or a saddle (e.g., a bicycle saddle).

[0029] In some embodiments, the cradle and / or cradle support is attached to or part of the transfer frame and the transfer frame reversibly attaches to the rotor.

[0030] In some embodiments, the surface of the cradle comprises a convex contour that aligns with (e.g., is the inverse of ) a concave contour of the surface of the object when the object is in the cradle; and / or the cradle comprises a concave contour that aligns with (e.g., is the inverse of) a convex contour of the surface of the object when the object is in the cradle.

[0031] In some embodiments, the surface of the cradle substantially aligns with the surface of the object (e.g., wherein the contour of the surface of the cradle is the inverse of the contour of the surface of the object). In some embodiments, the centripetal forces on the surface of the object are substantially equally distributed when centrifugally separating the excess resin from the object.

[0032] According to some embodiments, a combination of an additively manufactured apparatus and a product is provided comprising the apparatus described above and the additively manufactured object within the cradle and / or the cradle support.

[0033] According to some embodiments, a transfer frame includes a base portion configured to attach to a spinning apparatus; a cradle (e.g., a cradle embodiment of the invention) and / or a cradle support (e.g., a cradle support embodiment of the invention) connected to the base portion. In some embodiments, the cradle support comprises a basket portion attached to the base portion and optionally including the cradle therein.

[0034] Brief Description of the Drawings

[0035] Figures 1A-1C schematically illustrate certain cradle embodiments of the present invention.

[0036] Figures 2A and 2B are different views of a computer-aided drawing of a cradle embodiment of the present invention.

[0037] Figure 3 is another view of a computer-aided drawing of a cradle embodiment of the present invention. Figure 4 schematically illustrates one possible cradle and transfer frame configuration for the present invention.

[0038] Figures 5A and 5B are pictures of a particular transfer frame and cradle embodiment of the invention.

[0039] Detailed Description of Illustrative Embodiments

[0040] The present invention is now described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art.

[0041] Like numbers refer to like elements throughout. In the figures, the thickness of certain lines, layers, components, elements or features may be exaggerated for clarity. Where used, broken lines illustrate optional features or operations unless specified otherwise.

[0042] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an” and “the” are intended to include plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements components and / or groups or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups or combinations thereof.

[0043] As used herein, the term “and / or” includes any and all possible combinations or one or more of the associated listed items, as well as the lack of combinations when interpreted in the alternative ("or").

[0044] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and claims and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and / or clarity. It will be understood that when an element is referred to as being “on,” “attached” to, “connected” to, “coupled” with, “contacting,” etc., another element, it can be directly on, attached to, connected to, coupled with and / or contacting the other element or intervening elements can also be present. In contrast, when an element is referred to as being, for example, “directly on,” “directly attached” to, “directly connected” to, “directly coupled” with or “directly contacting” another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature can have portions that overlap or underlie the adjacent feature.

[0045] Spatially relative terms, such as “under,” “below,” “lower,” “over,” “upper” and the like, may be used herein for ease of description to describe an element’s or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus the exemplary term “under” can encompass both an orientation of over and under. The device may otherwise be oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly,” “downwardly,” “vertical,” “horizontal” and the like are used herein for the purpose of explanation only, unless specifically indicated otherwise.

[0046] It will be understood that, although the terms first, second, etc., may be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer and / or section, from another element, component, region, layer and / or section. Thus, a first element, component, region, layer or section discussed herein could be termed a second element, component, region, layer or section without departing from the teachings of the present invention. The sequence of operations (or steps) is not limited to the order presented in the claims or figures unless specifically indicated otherwise.

[0047] As used herein, a “plurality” of any element refers to two or more of such elements and may include 3, 5, 10, 20, 30, 40, 50, 100, 1000, 10,000, or more, and includes any range defined therebetween. All patents or published patent applications referenced are herein incorporated by reference in their entirety. In the case of conflicting terminology, the present application controls.

[0048] Provided according to embodiments of the present invention are methods of separating excess resin from an additively manufactured object. Such methods include (a) additively manufacturing an object on a build platform, the object carrying excess resin therein and / or thereon; (b) removing the object from the build platform; (c) placing the object in a cradle, optionally wherein a surface of the cradle aligns with (e.g., is an inverse of) a surface of the object and contacts the surface of the object when the cradle moves under centripetal force; (d) placing the cradle in a spinning apparatus; (e) centrifugally separating excess resin from the object; and (f) removing the cradle and / or object from the spinning apparatus, wherein at least a portion of the excess resin has been separated from the object.

[0049] (a) Additively Manufacturing Object(s) on a Build Platform

[0050] Techniques for producing an object, including “green” intermediate objects, from such resins by additive manufacturing are known. Suitable techniques include bottom-up and top- down additive manufacturing, generally known as stereolithography. Such methods are known and described in, for example, U.S. Patent No. 5,236,637 to Hull, U.S. Patent Nos. 5,391,072 and 5,529,473 to Lawton, U.S. Patent No. 7,438,846 to John, U.S. Patent No. 7,892,474 to Shkolnik, U.S. Patent No. 8,110,135 to El-Siblani, U.S. Patent Application Publication No. 2013 / 0292862 to Joyce, and U.S. Patent Application Publication No. 2013 / 0295212 to Chen et al. The disclosures of these patents and applications are incorporated by reference herein in their entirety.

[0051] In some embodiments, the additive manufacturing step is carried out by one of the family of methods sometimes referred to as continuous liquid interface production (CLIP). CLIP is known and described in, for example, U.S. Patent Nos. 9,211,678; 9,205,601; 9,216,546; in J. Tumbleston et al., Continuous liquid interface production of 3D Objects, Science 347, 1349-1352 (2015); and in R. Janusziewcz et al., Layerless fabrication with continuous liquid interface production, Proc. Natl. Acad. Sci. USA 113, 11703-11708 (October 18, 2016). Other examples of methods and apparatus for carrying out particular embodiments of CLIP include, but are not limited to: U.S. Patent Application Pub. No. US 2017 / 0129169 (May 11, 2017); U.S. Patent Application Pub. No. US 2016 / 0288376 (Oct. 6, 2016); U.S. Patent Application Pub. No. US 2015 / 0360419 (Dec. 17, 2015); U.S. Patent Application Pub. No. 2015 / 0331402 (Nov. 19, 2015); U.S. Patent Application Pub. No. US 2017 / 0129167 (May 11, 2017); U.S. Patent Application Pub. No. US 2018 / 0243976 (published Aug 30, 2018); U.S. Patent Application Pub. No. US 2018 / 0126630 (published May 10, 2018); U.S. Pat App Pub. No. US 2018 / 0290374 (Oct. 11, 2018); PCT Patent Pub. No. WO 2015 / 164234 (see also U.S. Patent Nos. 10,259,171 and 10,434,706); and PCT Patent Pub. No. WO 2017 / 210298 (see also U.S. Pat. App. US 2019 / 0160733).

[0052] In general, any additive manufacturing process that results in excess and / or undesired resin on and / or within an additively manufactured object may be used.

[0053] In an additive manufacturing process, the formed object is typically attached to a build platform, also referred to as a carrier, either directly and / or indirectly through a support structure, including polymeric supports and / or intervening material layer(s). Such build platforms are known in the art and are described in references cited herein. In typical additive manufacturing processes, a build platform is placed directly into a spinning apparatus and excess resin is removed from the additively manufactured object with the object(s) attached to the build platform. However, in some cases, the object may require additional support during spinning. Accordingly, in the present invention, the additively manufactured object(s) are removed from the build platform and placed in, on, and / or adjacent to a cradle apparatus, such that the object(s) contacts at least a portion of the cradle when the cradle is spun in a spinning apparatus.

[0054] While any suitable resin can be used in the methods described herein, in some embodiments dual cure resins are used. Such resins are known and described in, for example, U.S. Patent Nos. 9,676,963, 9,453,142 and 9,598,606. Particular examples of suitable dual cure resins include, but are not limited to, Carbon Inc. medical polyurethane, elastomeric polyurethane, rigid polyurethane, flexible polyurethane, cyanate ester, epoxy, and silicone dual cure resins, all available from Carbon, Inc., 1089 Mills Way, Redwood City, California 94063 USA. In general, any resin that has a sufficiently low viscosity such that it may be removed from the object under the operation of centripetal force may be used.

[0055] A variety of suitable objects may be used in the methods of the invention, including but not limited to saddles (e.g., bike saddles), footwear (e.g., insoles), and the like. In some embodiments, the additively manufactured object is a footwear insole and a surface of the cradle aligns with a surface of the insole when the insole is in the cradle. In some embodiments, the additively manufactured object is a saddle and a surface of the cradle aligns with a surface of the saddle when the saddle is in the cradle.

[0056] In some embodiments, the object includes one or more features (e.g., a surface feature) that is distorted if excess resin on and / or in the object is removed while the object is spun on the build surface and / or is not supported by a cradle. In some embodiments, the object comprises a lattice and / or includes one or more internal channels and / or cavities and has at least one opening on a surface that is in fluid communication with the channel(s) and / or cavity. Such openings are configured such that excess resin within the channel and / or cavity may flow therethrough and out of the channel / cavity during the centrifugally separating step.

[0057] (b) Removing the Object from the Build Platform

[0058] The additively manufactured object(s) may be removed from the build platform by any suitable method, including by a human, automated (e.g., via a scraper), or robotic process.

[0059] (c) Placing the Object(s) in a Cradle

[0060] The additively manufactured object(s) that are removed from the build platform may be placed in a cradle (or multiple cradles) by any suitable method, including by a human, automated, or robotic process. As used herein, a “cradle” is a support element that contacts at least one surface of an additively manufactured object while spinning in a spinning apparatus. In some embodiments of the invention, a surface of the cradle aligns with (e.g., is an inverse of) a surface of the object and contacts the surface of the object when the cradle moves under centripetal force. The support of the object by the cradle during spinning may reduce or eliminate distortion of the features under centripetal force.

[0061] Examples of certain cradle embodiments are shown in Figures 1A-1C. Cradle 100 includes a first cradle portion 105 that contacts a first surface 110 of the additively manufactured object 115 when the object is placed in the cradle 100 and the cradle 100 is spun under centripetal force. When not under centripetal force, the additively manufactured object 115 may or may not contact (or may not fully contact) the first cradle portion 105 but once the cradle 100 is placed in the spinning apparatus (not shown) and spun, the additively manufactured object 115 will contact the first surface 110 of the first cradle portion 105.

[0062] In some embodiments, the first cradle portion 105 may include a concave portion 120 that aligns with (e.g., is the inverse of) a convex portion 125 on the first surface 110 of the additively manufactured object 115. Alternatively, or additionally, the first cradle portion 105 may include a convex portion 130 that aligns with (e.g., is the inverse of) a concave portion 135 on the first surface 110 of the additively manufactured object 115. For example, the concave portion 120 of the first cradle portion 105 will contact the convex portion 125 of the additively manufactured object 115 and / or the convex portion 130 of the first cradle portion 105 will contact the concave portion 135 of the additively manufactured object 115 while under centripetal force. While the surface of the first cradle portion 105 need not perfectly align with, or form a perfect inverse of, the first surface 110 of the additively manufactured object 115, the contour of the first cradle portion 105 may align with the first surface 110 sufficiently to prevent significant distortion of the first surface 110 when the object 115 is spun in a spinning apparatus (not shown).

[0063] In some embodiments, a face of the first cradle portion 105 substantially aligns with (e.g., is substantially the inverse of) a face (here, first surface 110) of the additively manufactured object 115. Thus, a face of the first cradle portion 105 may be flush with a face of the additively manufactured object 115 during spinning. This may allow for the distribution of the centripetal forces on the face (first surface 110) of the additively manufactured object 115 to be substantially equal when the object 115 spun in a spinning apparatus. In this configuration, distortions of the object 115 during spinning may be reduced or prevented.

[0064] Referring to Figure 1C, in some embodiments, cradle 100 includes a second cradle portion 140 that is configured to contact a second surface 145 of the additively manufactured object 115. In particular embodiments, a surface of the first cradle portion 105 aligns with the first surface 110 of the additively manufactured object 115, and optionally, a surface 150 of the second cradle portion 140 aligns with a second surface 145 of the additively manufactured object 115. In some embodiments, however, the second cradle portion 140 is not present, or does not align with (or form the inverse of) the second surface 145 (e.g., forms a flat surface) since the centripetal forces press the additively manufactured object 115 against the first cradle portion 105. Additional cradle portions (not shown) that contact additional portions of the additively manufactured object 115 may also be present, if desired. In some embodiments, the cradle 100 only includes the first cradle portion 105.

[0065] In some embodiments, the cradle 100 may include a cradle support 155 including a first support portion 160, a second support portion 165, and / or a third support portion 170 (and any additional support portions not shown) that may support the first cradle portion 105 and / or the additively manufactured object 115. One or more of these support portions may be omitted however in some embodiments. For example, the first cradle portion 105 may be attached directly to a transfer frame or spinning apparatus (not shown).

[0066] Referring to Figure IB, in some embodiments of the invention, the first cradle portion 105 may include one or more, or a plurality, of drainage holes 175 therein. The second cradle portion 140 in Figure 1C or any other cradle portion(s) may also include one or more, or a plurality, of drainage holds as described with respect to the drainage holes 175 in Figure IB. Such drainage holes / apertures 175 may be configured to allow the excess resin that is spun off the additively manufactured object 115 to flow through at least a portion of the cradle 100, thus facilitating resin removal and recovery. For example, the drainage holes 175 may be sized or positioned to receive resin flowing from the object 115 during a spinning process. In some embodiments, the drainage holes 175 may be aligned or partially aligned with openings or spaces in the object 115 such that the drainage holes 175 are in fluid communication (e.g., to provide a fluid pathway) with openings or spaces in the object 115 to facilitate resin removal from the object 115 via the drainage holes 175. Alternatively, or additionally, part or all of the cradle support 155 (e.g., the first support portion 160) may include one or more, or a plurality, of drainage holes 175 therein. The drainage holes 175 may be in any shape or configuration, including cross sections that are spherical, polygonal, or irregular, and the cradle and / or cradle support may include mesh or lattice-type portions. Alternatively or additionally to drainage holes, the cradle 100 (including the first cradle portion 105 and / or second cradle portion 140) may include channels or other surface features (not shown) that direct the excess resin away from the object 115, and optionally in a direction to facilitate resin recovery. In some embodiments, the channels or other surface features for directing resin away from the additively manufactured object are designed based on the structure of the additively manufactured object.

[0067] An example of a first cradle portion 105 is shown in Figures 2A, 2B, and 3. This cradle 100 is configured to support a bicycle seat (not shown) and so the surface of the first cradle portion 105 is the inverse of the bicycle seat. This cradle 100 also includes a plurality of drainage holes 175 therein.

[0068] In certain embodiments of the invention, an additively manufactured object is placed in the cradle support without a cradle therein. In some embodiments, the cradle support alone is needed to prevent distortion of the object.

[0069] The cradle 100 and / or the cradle support 155 may be formed of any suitable material, including but not limited to, polymer(s) and / or metal(s).

[0070] (d) Placing the Cradle in a Spinning Apparatus

[0071] In some embodiments, the cradle and / or cradle support may be placed directly in a spinning apparatus. In some embodiments, the cradle and / or cradle support is attached to or forms part of a transfer frame that attaches to a portion of the spinning apparatus, and placing the cradle and / or cradle support in the spinning apparatus further comprises placing the transfer frame in the spinning apparatus. In some embodiments, the transfer frame includes a base portion configured to attach or connect to a spinning apparatus; and the cradle and / or cradle support is attached to the base portion. Figure 4 is a schematic of a possible configuration of a transfer frame 480 having a cradle 400 (which includes first cradle portion 405), cradle support 455, and an additively manufactured object 415 in the cradle 400. The base portion 485 may be configured to fit within or attach to a spinning apparatus (not shown) and may include prongs, notches, or other features (not shown) that may facilitate attachment to the spinning apparatus. While the cradle 400 or the cradle support 455 may be directly attached to the base portion 485, in some embodiments, a basket portion 490 may be connected to the base portion 485 and may include the cradle 400 or cradle support 455 therein and attach to the base portion 485. The basket portion 490 may be a solid (with or without a plurality of drainage holes therein) or may be mesh or latticed as shown in Figure 4. The base portion 485 and the optional basket portion 490 may be formed of any suitable material, including but not limited to, polymer(s) and / or or metal(s).

[0072] In some embodiments, the transfer frame 480 includes a plurality of cradles 400 (and / or cradle supports) such that a plurality of objects 115 may be spun a single transfer frame 480.

[0073] Figures 5A and 5B are pictures of a transfer frame 480 having a cradle support 455 and cradle 400 (which includes first cradle portion 405) therein. The transfer frame 480 includes base portion 485 and basket portion 490.

[0074] (e) Centrifugally Separating Excess Resin from the Object

[0075] Once the cradle and / or cradle support is placed in or attached to a spinning apparatus, either alone or with a transfer frame, the spinning process is performed. In general, the spinning apparatus is a centrifugal separation device in a partly or entirely enclosed chamber. In some embodiments, the excess resin removed from the additively manufactured object is drained and optionally collected, continuously or in a batch-wise fashion, from the enclosed chamber. In some embodiments, the interior of the centrifugal separating apparatus is coated with a nonstick material, such as, for example, that described in US Publication No. 2015 / 0209198 Al, the disclosure of which is incorporated by reference herein.

[0076] In some embodiments, the excess resin may be warmed sufficiently to reduce the viscosity thereof during the centrifugally separating step. In addition, a gas and / or liquid may be applied to the excess resin in an amount sufficient to reduce the viscosity thereof during the centrifugally separating step. Such warming and / or application of gas / liquid may be performed before and / or during the centrifugal separation step. In some embodiments, the centrifugally separating step is carried out in a gas at ambient pressure or a pressure less than ambient pressure.

[0077] While a variety of rotational speeds may be used depending on the resin, the additively manufactured object, and other conditions (e.g., temperature and pressure), in some embodiments, the centrifugal spinning is carried out at a speed of from about 100, about 200 or about 400 revolutions per minute (rpm) to about 600, about 800, about 1,000 or about 1,200 rpm.

[0078] In some embodiments, methods of the invention further include collecting the centrifugally separated excess resin; optionally combining the centrifugally separated excess resin with additional resin; and then additively manufacturing at least one additional object from the centrifugally separated excess resin, optionally in combination with the additional resin.

[0079] In some embodiments, the spinning apparatus is an apparatus described in U.S. Patent No. 11,084,216, 11,478,988, 11,491,725, the disclosures of which are incorporated by reference in their entirety.

[0080] In some embodiments of the invention, provided are apparatus that are useful for separating excess resin from an additively manufactured object. Such apparatus may include (a) a rotor; and (b) a cradle, cradle support, and / or transfer frame of the invention, wherein the cradle, cradle support, and / or transfer frame is configured to reversibly or irreversibly attach to the rotor and be centrifugally spun by the rotor. In some embodiments, the cradle is attached to or part of the transfer frame and the transfer frame reversibly attaches to the rotor.

[0081] (f) Removing the cradle and / or object from the spinning apparatus

[0082] Once at least a portion of the excess resin (and in some cases, all the excess and / or undesired resin) is removed from the additively manufactured object, the object may be removed from the spinning apparatus, cradle, cradle support, and / or transfer frame. In some embodiments, no further processing is needed. In other embodiments, one or more additionally post-processing steps including washing and / or further curing may be performed.

[0083] In some embodiments of the invention, the additively manufactured object is an intermediate object produced from a dual cure resin, and the method further includes further curing the object after centrifuging / spinning. For example, in some embodiments, after excess resin has been separated from the intermediate object, the object is then heated. Heating may be active heating (e.g., baking in an oven, such as an electric, gas, solar oven or microwave oven, or combination thereof), or passive heating (e.g., at ambient (room) temperature).

[0084] While wash steps can be included in some embodiments of the present invention (either before and / or after the resin removal methods of the invention) in some embodiments, wash steps are avoided (particularly prior to the separating step), and hence the excess resin removed from the object is free of wash liquid.

[0085] The foregoing is illustrative of the present invention, and is not to be construed as limiting thereof. The invention is defined by the following claims, with equivalents of the claims to be included therein.

Claims

We claim:

1. A method of separating excess resin from an object, comprising:(a) additively manufacturing an object on a build platform, the object carrying excess resin therein and / or thereon;(b) removing the object from the build platform;(c) placing the object in a cradle and / or cradle support, optionally wherein a surface of the cradle aligns with (e.g., is an inverse of) a surface of the object and contacts the surface of the object when the cradle and / or cradle support moves under centripetal force;(d) placing the cradle and / or cradle support in a spinning apparatus;(e) centrifugally separating excess resin from the object; and(f) removing the cradle, cradle support, and / or object from the spinning apparatus, at least a portion of the excess resin being separated from the object.

2. The method of claim 1, wherein the surface of the cradle comprises a convex contour that aligns with (e.g., is the inverse of ) a concave contour of the surface of the object when the object is in the cradle; and / or the cradle comprises a concave contour that aligns with (e.g., is the inverse of) a convex contour of the surface of the object when the object is in the cradle.

3. The method of claim 1 or 2, wherein the cradle and / or cradle support comprises at least one (e.g., a plurality of) drainage hole(s) and / or channel(s) for directing excess resin removal.

4. The method of any one of claims 1-3, wherein the surface of the cradle substantially aligns with the surface of the object (e.g., wherein the contour of the surface of the cradle is the inverse of the contour of the surface of the object), optionally wherein the centripetal forces on the surface of the object are substantially equally distributed when centrifugally separating the excess resin from the object.

5. The method of any one of claims 1 -4, wherein the cradle comprises a first cradle portion configured to contact a first surface of the object, and optionally the cradle comprises a second cradle portion configured to contact a second surface of the object; and wherein a surface of the first cradle portion aligns with (e.g., is the inverse of) the first surface of the object, and optionally a surface of the second cradle portion aligns with (e.g., is the inverse of) the second surface of the object.

6. The method of any one of claims 1-5, wherein the cradle and / or the cradle support is attached to or forms part of a transfer frame that attaches to a portion of the spinning apparatus, and placing the cradle and / or the cradle support in the spinning apparatus further comprises placing the transfer frame in the spinning apparatus.

7. The method of claim 6, wherein the transfer frame comprises a plurality of cradles and / or cradle supports; and wherein a plurality of objects is additively manufactured, removed from the build platform, and placed in the plurality of cradles and / or cradle supports; and steps (e) and (f) are performed for the plurality of objects.

8. The method of any one of claims 1-7, further comprising warming the excess resin sufficiently to reduce the viscosity thereof during the centrifugally separating step.

9. The method of any one of claims 1-8, further comprising applying a gas or liquid to the excess resin in an amount sufficient to reduce the viscosity thereof during the centrifugally separating step.

10. The method of any one of claims 1-9, wherein the centrifugally separating step is carried out in a gas at ambient pressure or a pressure less than ambient pressure.

11. The method of any one of claims 1-10, wherein the centrifugal separation is carried out at a speed of from about 100, about 200 or about 400 revolutions per minute (rpm) to about 600, about 800, about 1,000 or about 1,200 rpm.

12. The method of any one of claims 1-11, further comprising:(g) collecting the centrifugally separated excess resin;(h) optionally combining the centrifugally separated excess resin with additional resin; and then(i) additively manufacturing at least one additional object from the centrifugally separated excess resin, optionally in combination with the additional resin.

13. The method of any one of claims 1-12, wherein the object is an intermediate object produced from a dual cure resin, and the method further comprises further curing the object after step (e) to produce a finished object.

14. The method of any one of claims 1-13, wherein the object comprises a lattice and / or includes one or more internal channels or cavities and has at least one surface opening in fluid communication with the channel or cavity, and wherein excess resin within the channel or cavity flows out of the channel or cavity through the at least one surface opening during the centrifugal separation step.

15. The method of any one of claims 1-14, wherein the object is a footwear insole and the surface of the cradle aligns with (e.g., is the inverse of) a surface of the insole when the insole is in the cradle.

16. The method of any one of claims 1-14, wherein the object is a saddle and the surface of the cradle aligns with (e.g., is the inverse of) a surface of the saddle when the saddle is in the cradle.

17. An apparatus useful for separating excess resin from an additively manufactured obj ect, comprising:(a) a rotor; and(b) a cradle and / or a cradle support, optionally attached to or part of a transfer frame, wherein the cradle and / or cradle support, and optionally the transfer frame, is configured to reversibly attach to the rotor and be centrifugally spun by the rotor, optionally wherein a surface of the cradle aligns with (e.g., is an inverse of) a surface of the object and contacts the surface of the object when the cradle moves under centripetal force.

18. The apparatus of claim 17, wherein the object is a footwear insole or a saddle (e.g., a bicycle saddle).

19. The apparatus of claim 17 or claim 18, wherein the cradle and / or cradle support is attached to or part of the transfer frame and the transfer frame reversibly attaches to the rotor.

20. The apparatus of any one of claims 17-19, wherein the surface of the cradle comprises a convex contour that aligns with (e.g., is the inverse of ) a concave contour of the surface of the object when the object is in the cradle; and / or the cradle comprises a concave contour that aligns with (e.g., is the inverse of) a convex contour of the surface of the object when the object is in the cradle.

21. The apparatus of any one of claims 17-20, wherein the surface of the cradle substantially aligns with the surface of the object (e.g., wherein the contour of the surface of the cradle is the inverse of the contour of the surface of the object), optionally wherein the centripetal forces on the surface of the object are substantially equally distributed when centrifugally separating the excess resin from the object.

22. A combination of an additively manufactured apparatus and a product, comprising the apparatus of any one of claims 17-21, and the additively manufactured object within the cradle and / or the cradle support.

23. A transfer frame comprising a base portion configured to attach to a spinning apparatus; a cradle (e.g., a cradle embodiment of the invention) and / or a cradle support (e.g., a cradle support embodiment of the invention) connected to the base portion; optionally wherein the cradle support comprises a basket portion attached to the base portion and optionally including the cradle therein.

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