Prosecution Insights
Last updated: April 19, 2026
Application No. 18/287,895

SLURRY FEEDSTOCK FOR EXTRUSION-BASED 3D PRINTING OF FUNCTIONALLY GRADED ARTICLES AND CASTING METAL/CERAMIC ARTICLE UNDER LOW PRESSURE AT ROOM TEMPERATURE, METHODS, AND SYSTEM THEREFOR

Non-Final OA §103§112
Filed
Oct 23, 2023
Examiner
GROUX, JENNIFER LILA
Art Unit
1754
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Solid Lab Sdn Bhd
OA Round
1 (Non-Final)
36%
Grant Probability
At Risk
1-2
OA Rounds
3y 7m
To Grant
84%
With Interview

Examiner Intelligence

Grants only 36% of cases
36%
Career Allow Rate
41 granted / 115 resolved
-29.3% vs TC avg
Strong +49% interview lift
Without
With
+48.6%
Interview Lift
resolved cases with interview
Typical timeline
3y 7m
Avg Prosecution
60 currently pending
Career history
175
Total Applications
across all art units

Statute-Specific Performance

§101
1.8%
-38.2% vs TC avg
§103
44.6%
+4.6% vs TC avg
§102
12.7%
-27.3% vs TC avg
§112
32.8%
-7.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 115 resolved cases

Office Action

§103 §112
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Election/Restrictions Applicant’s election without traverse of Group I, claims 20-23, in the reply filed on 10/03/2025 is acknowledged. Claims 24-28 and 34-44 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to nonelected inventions, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 10/03/2025. Drawings Fig. 1 is indicated in the “Brief Description of the Drawings” section as showing an embodiment of the present invention (PGPub [0051]) but is only described as showing an “existing additive method or technique” in comparison to the present invention depicted in Fig. 2 (PGPub [0206]). As such, Fig. 1 appears to show only prior art. If this is the case then Fig. 1 should be designated by a legend such as --Prior Art-- because only that which is old is illustrated. See MPEP § 608.02(g). Corrected drawings in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. The replacement sheet(s) should be labeled “Replacement Sheet” in the page header (as per 37 CFR 1.84(c)) so as not to obstruct any portion of the drawing figures. If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance. Specification The disclosure is objected to because of the following informalities: the brief description of Figs. 20 and 21 (PGPub [0071] and [0072]) refers to “the cavity of the mould of Fig. 1” but there is no mold or cavity in Fig. 1. Appropriate correction is required. Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claim(s) 20-23 is/are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 20, in the last three lines, recites the limitation "…containing the build material having selectively varied in composition, structure including infill pattern or any combinations thereof gradually over volume of the final part thereof in one or more directions." The limitation as written is generally unclear as to the intended meaning, at least partially due to grammatical/idiomatic errors possibly from a literal translation to English. Furthermore, the limitation appears to intend to encompass the build material having a selectively varied composition over a volume of the final part but the method as claimed provides no indication of where (by what step(s)) this variation is achieved and to the contrary requires that the printed slurry mixture is “substantially homogenous.” For further examination, the limitation will be interpreted to require that either a selectively varied composition is achieved, by any manner, or a structure including an infill pattern is produced, or both, thereby producing the “functionally graded article.” The indicated dependent claims are rejected for the reasons provided above. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claim(s) 20-22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yin et al., CN 106431357 A (D1 of European Search Opinion), in view of Tian et al., CN 111850336 A (D4 of European Search Opinion), and Huang et al., WO 2021202261 A1. Espacenet translations of Yin and Tian are provided and referenced below. Regarding claim 20, Yin discloses a method of extrusion-based three-dimensional, 3D, printing an article (3D printing a target part by extrusion, [0018], [0026]), characterized in that, the method comprising the steps: Providing a slurry feedstock (providing a ceramic paste, [0009], [0017]), including: Preparing a build material comprising a metal, a ceramic, or any combinations thereof (providing ceramic powder, [0010]-[0012], silicon carbide, [0040]), including: Providing the build material that is porous, non-porous, or any combinations thereof (the build material as set forth above, note that all types are encompassed by the limitation); and Providing the build material in an amount from 10 vol.% to 90 vol.% (60 wt.% ceramic powder in Example 2, [0040], which is equivalent to about 32 vol.% of the mixture for a SiC powder density of about 3.2 g/cm3, entirely within the claimed range); Preparing an organic polymer binder (binder, [0014]; methyl cellulose binder in Example 2, [0040]) selected from a group comprising a cellulose ester, a cellulose ether, and derivatives thereof (methyl cellulose in Example 2, [0040]), including: Providing the organic polymer binder in a concentration from 150 g/L to 550 g/L (7 wt.% binder, 19.95 wt.% water, 8.55 wt.% ethanol in Example 2, [0040], equivalent to a binder concentration relative to a solution amount of binder and solvent of about 195 g/L for a methyl cellulose density of 1.39 g/cm3 and ethanol density 0.789 g/cm3, entirely within the claimed range); Preparing an additive selected from the claimed group (dispersant, [0013], [0040]; lubricant, [0015], [0040]); and Preparing a volatile organic solvent (solvent including ethanol, [0016], [0040]); Mixing the feedstock components to form a substantially homogenous and flowable slurry mixture (mixing the raw materials for 1-3 hours to form the printable paste, [0017], [0019], [0032]) that is printed as a preliminary part of the said article (that is printed prior to further processing, [0020]-[0021]); Debinding the organic polymer binder from the preliminary part in a thermal decomposition treatment (drying the 3D printed blank, [0022], drying in oven, [0035]); and Subjecting the preliminary part having the organic polymer binder debound therefrom to sintering (subsequently sintering, [0022], [0040]) for producing a final part of the article (to produce the target parts, [0022]). Yin discloses the feedstock components of the slurry mixture are mixed to form the mixture but does not specifically disclose the additional step as claimed of forming first and second pre-mixes that are mixed to form the slurry mixture. In the analogous art directed to slurry preparation and subsequent printing and thermal debinding/sintering ([0010]-[0015], [0021]) by mixing of powder, additive, binder, and solvent components ([0016]-[0020]), Tian discloses preparing a slurry by first mixing powder and an additive to obtain a mixed powder ([0039]), i.e., forming a first pre-mix, separately mixing binder and solvent to form a solution, ([0040]), i.e., forming a second pre-mix, and then mixing the pre-mixes to obtain the slurry ([0040]) for subsequent printing, drying, and sintering ([0041]-[0043]). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the mixing step of Yin to include forming a first pre-mix by mixing the build material with the additive, forming a second pre-mix by mixing the organic polymer binder dissolved with the volatile organic solvent, and then mixing the first pre-mix and the second pre-mix to form the substantially homogenous and flowable slurry mixture, as taught by Tian, as a suitable alternative to mixing all of the components together for predictably achieving the intended result of providing a thoroughly mixed paste for printing. One of ordinary skill in the art would have expected the pre-mixing taught by Tian would only increase the homogeneity of the mixture and thus improve the mixing and/or beneficially reduce the necessary mixing time. Yin does not disclose the article/final part is functionally graded and “containing the build material having selectively varied in composition, structure including infill pattern or any combinations thereof gradually over volume of the final part thereof in one or more directions.” It is noted that none of the active process steps of the method as recited in claim 20 are clearly associated with the claimed effect, which is recited only in the preamble and as an intended result. The method recites no particular steps that would clearly lead to the functional grading. In the analogous art, Huang discloses 3D printing of functionally graded parts comprising metals and/or ceramics (Abstract, [00115]) following a similar process of preparation of a suspension/slurry, mixing for multi-material printing, 3D printing, and subsequent debinding and sintering (Figs. 1, 5). Huang teaches that preparing build materials as a suspension, i.e., slurry, allows powders to be easily mixed at different ratios and thus for controllable deposition of parts with a functional or compositional gradient ([0045], [0052]). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Yin such that the final part was functionally graded, containing the build material having selectively varied in composition, structure including infill pattern or any combinations thereof gradually over volume of the final part thereof in one or more directions, e.g., by varying a ratio of the build material powder in the printable slurry mixture, as Huang teaches providing the material as a slurry facilitates variation of the composition of the mixture in order to enable controllable deposition of parts with a functional gradient. Regarding claim 21, modified Yin discloses the method of claim 20. Yin does not disclose the method includes the step of forming two or more substantially homogenous and flowable slurry mixtures, each comprising a respective first pre-mix and a respective second pre-mix. Huang further discloses forming two or more substantially homogenous and flowable slurry mixtures (preparing two or more “inks,” which are mixed homogenous suspensions including powder, binder, solvent, [0047]-[0048], Fig. 1). Huang teaches that providing the multiple starting materials enables multi-material printing of a desired suspension where the composition of the mixed suspension can be changed dynamically to achieve a desired compositional gradient between different areas of the part ([0048]-[0049], [0052]). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further specify the method of Yin includes forming two or more substantially homogenous and flowable slurry mixtures so as to provide the capability of dynamic adjustment of the composition of the slurry mixture for achieving a compositional gradient across the printed part, as taught by Huang. The combination does not specifically disclose each of the two slurry mixtures comprises a respective first pre-mix and a respective second pre-mix. However, Tian as set forth above teaches forming the first substantially homogenous and flowable slurry mixture by the forming of a respective first and second pre-mix, and it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in the case of two or more mixtures to apply the same technique for each of the slurry mixtures formed of the same types of components to achieve the benefits set forth above of thorough mixing and improved homogeneity of the mixture. Regarding claim 22, modified Yin discloses the method of claim 21. Yin does not disclose a step of instantaneously mixing the two or more substantially homogeneous and flowable slurry mixtures in situ in a static or active mixer to form one substantially homogenous and flowable slurry mixture. The specification defines “instantaneously” to mean the time required for mixing to prepare the slurry feedstock from the components or mixtures in the static or active mixer (PGPub [0140]). Huang further discloses instantaneously mixing the two or more substantially homogeneous and flowable slurry mixtures in situ (mixing 15 the two or more suspensions 11 and 13, [0048], Fig. 1) in a static or active mixer (mixing actively or passively the two or more suspensions from two or more inlets, [0098]) to form one substantially homogenous and flowable slurry mixture (to form the resulting mixed printing suspension, [0048], [0098]). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further specify for the combination the step of instantaneously mixing the two or more substantially homogeneous and flowable slurry mixtures in situ in a static or active mixer to form one substantially homogenous and flowable slurry mixture in order to form the mixed printable slurry having a controllable variable composition from the multiple prepared starting materials, as taught by Huang. Claim(s) 23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yin et al., CN 106431357 A, in view of Tian et al., CN 111850336 A, and Huang et al., WO 2021202261 A1, as applied to claim 20 above, and further in view of Yang et al., US 6214279 B1 (D3 of Japanese Office Action). Regarding claim 23, modified Yin discloses the method of claim 20. Yin does not disclose a step of providing a support structure for an overhanging or cantilevered portion of the said functionally graded article, wherein the support structure comprises a substantially homogenous and flowable support mixture formed from a support material. In the analogous art, Yang discloses a method for 3D printing of composite parts (Abstract; col. 5, lines 47-64). Yang teaches providing a support structure for an overhanging or cantilevered portion of a printed article (col. 11, lines 26-43), wherein the support structure comprises a substantially homogenous and flowable support mixture formed from a support material (being formed from a low-melting material such as a wax discharged from a nozzle, col. 11, lines 26-43). Yang teaches support structures can be provided when and where needed for providing support for various features of a printed object, such as overhangs and suspended members (col. 11, lines 26-43). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Yin to include the step of providing a support structure for an overhanging or cantilevered portion of the said functionally graded article, wherein the support structure comprises a substantially homogenous and flowable support mixture formed from a support material in order to provide the capability of supporting various features of the printed object depending on its intended geometry, such as overhangs and suspended members, as taught by Yang. Providing support structures as taught by Yang enables the formation of more complex geometry. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US 20140183792 A1, Leu et al. has been cited as D1 in the Japanese Office Action for the corresponding application and discloses extrusion of functionally graded composite parts. WO 2021110827 A1, Bendixen et al. discloses paste extrusion of a functionally graded part, the pastes comprising similar materials/amounts and being mixed in a mixing chamber prior to extrusion and subsequent debinding and sintering (e.g., Figs. 6-7). Any inquiry concerning this communication or earlier communications from the examiner should be directed to JENNIFER L GROUX whose telephone number is (571)272-7938. The examiner can normally be reached Monday - Friday: 9am - 5pm ET. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Susan Leong can be reached at (571) 270-1487. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /J.L.G./Examiner, Art Unit 1754 /SUSAN D LEONG/ Supervisory Patent Examiner, Art Unit 1754
Read full office action

Prosecution Timeline

Oct 23, 2023
Application Filed
Oct 27, 2025
Non-Final Rejection — §103, §112
Feb 08, 2026
Interview Requested
Feb 25, 2026
Applicant Interview (Telephonic)
Mar 02, 2026
Examiner Interview Summary

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
36%
Grant Probability
84%
With Interview (+48.6%)
3y 7m
Median Time to Grant
Low
PTA Risk
Based on 115 resolved cases by this examiner. Grant probability derived from career allow rate.

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