DETAILED ACTION
In Reply filed on 09/16/2025, claims 1 and 2 are pending. Claim 1 is currently amended. Claims 3-5 are canceled, and no claim is newly added. Claims 1 and 2 are considered in this Office 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 .
Priority
This application repeats a substantial portion of prior Application No. 16/780351, filed 02/03/2020, and adds disclosure not presented in the prior application as follows:
[0027] of Instant Specification (c.f., a corresponding paragraph of the parent application 16/780351; of note, the limitation “a porosity of the 3D printed thermal expansion structure consist of a single porosity derived from the closed-cell foam material having the plurality of foamable microcapsules” (as recited in claim 1 lines 21-23) are supported by [0027] of Instant Specification, which was not presented in the prior application).
Because this application names the inventor or at least one joint inventor named in the prior application, it may constitute a continuation-in-part of the prior application. Should applicant desire to claim the benefit of the filing date of the prior application, attention is directed to 35 U.S.C. 120, 37 CFR 1.78, and MPEP § 211 et seq. The presentation of a benefit claim may result in an additional fee under 37 CFR 1.17(w)(1) or (2) being required, if the earliest filing date for which benefit is claimed under 35 U.S.C. 120, 121, 365(c), or 386(c) and 1.78(d) in the application is more than six years before the actual filing date of the application.
Claim Interpretation
Claim 1 recites the limitation “a/the heat deflection temperature (HDT) of the solid stereolithography material” in lines 20 and 22, respectively. In order to obtain HDT of a solid material, the test measures a temperature at which a specimen of the solid material loses its “load-bearing” capability, and thus, the HDT temperature varies depending on the load-bearing value. Such load-bearing value is not recited in the claim nor specification. For the purpose of examination, the HDT of the solid stereolithography material would be interpreted, at least, as disclosed in Instant Specification ([0030]).
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
Claims 1 and 2 are rejected under 35 U.S.C. 103 as being unpatentable over Poelma (US 20210023775) in view of Boud (“Expancel Microspheres,” available at https://www.boud.com/wp-content/uploads/2018/01/paints-and-coatings.pdf, open to public on or after 01/31/2018) and Rolland (US 20180264719).
Regarding claim 1, Poelma teaches a manufacturing method of a 3D printed thermal expansion structure (claim 7), comprising:
providing a mixed material (claim 7: polymerizable liquid), the mixed material comprises a liquid stereolithography material and a thermal expansion material, the thermal expansion material is distributed within the liquid stereolithography material, wherein the liquid stereolithography material comprises [thermoplastic polyurethane (TPU)] (claim 7: polymerizable liquid for stereolithography, comprising at least one photopolymerizable, at least one heat polymerizable component, and heat expandable microspheres; [0040]: any suitable filler, which may be solid or liquid, may include reactive or non-reactive thermoplastics (including but not limited to: poly(ether imides), maleimide-styrene terpolymers, polyarylates, polysulfones and polyethersulfones, etc.); [0029-0030]: dual cure resins into which microspheres can be added – e.g., [0078-0080]: FPU 50 (resin forming polyurethane) with microspheres 461 DU 40), the thermal expansion material comprises a closed-cell foam material, the closed-cell foam material having a plurality of foamable microcapsules ([0031-003-0035]: a closed-celled foam; e.g., [0078-0080]: microspheres 461 DU 40), wherein [the thermal expansion material is formed by pre-foaming a foamable raw material, and a volume of the thermal expansion material is 10-40 times of a volume of the foamable raw material];
utilizing a 3D printing stereolithography apparatus to form the mixed material into a solid object, the liquid stereolithography material of the mixed material is cured into a solid stereolithography material by the 3D printing stereolithography apparatus, and the solid object comprises the solid stereolithography material and the thermal expansion material, wherein the solid object is built by adding a layer of the mixed material upon a layer of the mixed material through 3D printing (claim 7: step (a) producing an intermediate object; [0044-0046]: production by additive manufacturing apparatus); and
heating the solid object to make the solid object expand to form the 3D printed thermal expansion structure (claim 7: step (c) heating the intermediate object), the solid object is provided into a heating apparatus for heating ([0062]: heating apparatus), wherein a heat deflection temperature (HDT) of the solid stereolithography material is lower than a heat expansion temperature of the thermal expansion material, wherein the heat deflection temperature of the solid stereolithography material is between 60 °C and 100 °C, the heating temperature of the heating apparatus being higher than an initial foaming temperature of the thermal expansion material and the thermal expansion material within the solid object being heated to foaming and expansion ([0078-0080]: the green object made from polyurethane resin FPU 50 with microspheres 461 DU 40 is heated to 120 °C; here, HDT of FPU 50 (70 °C)1 is lower than a heat expansion temperature of 461 DU 40 (101-146 °C)2, and the heating temperature of 120 °C is higher than the initial foaming temperature of 461 DU 40 (101°C)), wherein the solid object is enlarged proportionally to form the 3D printed thermal expansion structure (fig. 4 and [0070]);
wherein, the 3D printed thermal expansion structure and the solid object have a same configuration (fig. 4 and [0070]), wherein the solid object and the 3D printed thermal expansion structure are formed without making molds (claim 7), a volume of the 3D printed thermal expansion structure is 1.2-2.5 times of a volume of the solid object (e.g., [0079-0080]: volume expansion 20-25% (i.e., 1.2 to 1.25 times; here, the disclosed expansion range anticipates the recited expansion range).
Although Poelma is silent that a porosity of the 3D printed thermal expansion structure consist of a single porosity derived from the closed-cell foam material having the plurality of foamable microcapsules, it would have been obvious to one of ordinary skill in the art at the time of filing invention that when the green object, comprising only a single type of heat expandable microspheres (i.e., 461 DU 40), is exposed to one heating temperature long enough hours, the heat expandable microspheres would generate a single porosity due to its uniform gas forming reaction ([0078-0079, 0083, 0084-0086]).
Poelma does not specifically teach the bracketed limitation(s) as presented above, i.e., (A) the thermal expansion material is formed by pre-foaming a foamable raw material, and a volume of the thermal expansion material is 10-40 times of a volume of the foamable raw material, and (B) the liquid stereolithography material comprises thermoplastic polyurethane (TPU), but Boud and Rolland teach the limitations as follows:
Regarding deficiency (A), Boud teaches ExpancelTM microspheres, which results in a dramatic increase of the volume of microspheres when heated (page 2). Boud teaches that ExpancelTM microspheres can be delivered in a wide variety of different forms, and pre-expanded products are used in processes where no, or not sufficient, heat is generated during production (page 8). Also, ExpancelTM DE (dry, expanded) is very easy to disperse using general dispersing equipment (pages 7-8). Boud also teaches that the thermal expansion material is formed by pre-foaming a foamable raw material, and a volume of the thermal expansion material is 10-40 times of a volume of the foamable raw material (page 46-47: dry unexpanded microspheres “461 DU 40” has a particle size D0.5 of 9-15 μm, and its corresponding dry expanded microspheres “461 DE 40” has a particle size D0.5 of 20-40 μm; here, based on the ratio of the median particle size value, the pre-foamed expandable material “461 DE 40” is about 16 times (i.e., (30/12)^3 = 15.6) of a volume of the foamable raw material “461 DU 40”). Moreover, it is implied or at least obvious to one of ordinary skill in the art that “461 DE 40” would have the same or at least similar heat foaming temperature as/to the heat forming temperature of “461 DU 40” – i.e., the heat expansion temperature of 461 DU 40: 101 °C (median of 98 – 104 °C) for expansion starting temperature and 146 °C (median of 142 – 150 °C) for maximum expansion temperature (pages 46, 47) – because each of the dry unexpanded or dry expanded microspheres is made of the same material as evidenced by their common product numbers starting with 461 and ending with 40 (see pages 47 and 49: “461 DU 40” has the same Tstart and Tmax as the ones of “461 WU 40”).
Poelma and Boud disclose ExpancelTM microspheres as a heat expandable microsphere, and “461 DU 40,” the heat expandable microsphere of Poelma has its corresponding, commercially available, dry expanded microsphere “461 DE 40.” (Poelma: [0034-0035, 0078-0079]; Boud: as a whole for commercially available various heat expandable microspheres). Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing invention to substitute the ExpancelTM microspheres DU (dry and unexpanded, e.g., 461 DU 40) of Poelma with another known and commercial available pre-expanded microspheres prior to be mixed with the polymerizable liquid, similar to the form of ExpancelTM microspheres DE (dry and expanded version, e.g., 461 DE 40) as taught by Boud in order to obtain known results or a reasonable expectation of successful results of improving dispersibility of the microspheres in a polymerizable liquid and broadening a scope of a suitable polymerizable liquid in stereolithography, up to one which would not require much heat treatment during a post-printing process (Boud: derived from pages 7-8).
Regarding deficiency (B), Rolland teaches a method of forming a 3D object by additive manufacturing in a liquid interface as “continuous liquid interface production” (“CLIP”) (abstract, [0010-0011], figs. 1, 2). Rolland teaches that a photocurable polymerizable polyurethane liquid resin comprises thermoplastic polyurethane ([0120, 0129-0130]).
In the same field of endeavors of the liquid interface additive manufacturing using a photocurable polyurethane liquid resin (Poelma: [0044-0046, 0078-0079]; Rolland: abstract, [0010-0011, 0129-0130], figs. 1, 2 ), it would have been obvious to one of ordinary skill in the art at the time of filing invention to modify the polyurethane resin FPU 50 forming thermoplastic polyurethan of Poelma with another known polymerizable polyurethane liquid composition comprising thermoplastic polyurethane prepolymer as taught by Rolland in order to obtain known results or reasonable expectation of successful results of forming a solid 3D printed object comprising thermoplastic polyurethane with improved material consistency, and reduced shrinkage, warpage, and internal stress.
Upon the modification, the solid stereolithography made from the liquid composition comprising thermoplastic polyurethane would have about the same heat deflection temperature as the 3D intermediate article made of FPU 50 by having the same polyurethane component therein. Moreover, the expanded microsphere “461 DE 40” would have the same or similar heat expansion temperature as “461 DU 40.” Thus, modified Poelma still teaches the limitation “a heat deflection temperature (HDT) of the solid stereolithography material is lower than a heat expansion temperature of the thermal expansion material, wherein the heat deflection temperature of the solid stereolithography material is between 60 °C and 100 °C, the heating temperature of the heating apparatus being higher than an initial foaming temperature of the thermal expansion material and the thermal expansion material within the solid object being heated to foaming and expansion” (Poelma: [0078-0080]; Boud: pages 46-47; Rolland: [0129-0130]). Furthermore, through routine optimization and experimentation, it would have been obvious to one of ordinary skill in the art to optimize the amount of the thermal expansion material (e.g., dry expanded “461 DE 40” microsphere ) to have a desired expansion rate (e.g., 20-25 %) of the intermediate article within a scope of preserving integrity of the expanded article (Poelma: [0013, 0079-0080]: volume expansion at least by 20 % e.g., 20-25%; Boud: pages 7-8 and 46-47).
Regarding claim 2, modified Poelma teaches the manufacturing method of claim 1, wherein the thermoplastic material is in a range from 50 to 90 wt. % based on a weight of the mixed material; the thermal expansion material is in a range from 10 to 50 wt. % based on the weight of the mixed material (Poelma: claim 7: polymerizable liquid comprising at least one photopolymerizable component from 1 to 98 wt. %, at least one heat polymerizable component from 1 to 98 wt. %, and heat expandable microspheres from 1 to 10 wt. % or more). Here, although the disclosed wt. % ranges does not anticipate the recited wt. %, the disclosed ranges overlap with the recited ranges between 50 and 90 wt. % for the content of the thermoplastic material and between 10 and 50 wt. % for the content of the thermal expansion material. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) (MPEP 2144.05 I).
Response to Arguments
Applicant's arguments filed on 09/16/2025 have been fully considered but they are moot or not persuasive. It is noted that the applicant has modified the claims with the latest amendment dated 09/16/2025, and the arguments are based upon these changes.
Applicant’s arguments with respect to claim 1 regarding the limitation “the liquid stereolithography material comprises thermoplastic polyurethane” (lines 5-7) (which have been newly amended by the applicants) have been considered but are moot because the new ground of rejection have been made due to the newly added features from the applicant’s latest amendment. After further search and reconsideration, the Rolland reference is applied to the rejection. Thus, when Poelma’s teaching is modified in view of Rolland, modified Poelma does teach/suggest all the claimed limitations and the motivation to combine.
The Applicant argues (see pages 8-9 of Remarks) that modified Poelma (Poelma in view of Boud) does not teach or suggest the limitation “the heating temperature of the heating apparatus being higher than an initial foaming temperature of the thermal expansion material and the thermal expansion material within the solid object being heated to foaming and expansion” as (A) Poelma does not disclose the microsphere are prefoamed before being mixed in the polymerizable liquid, and (B) Boud does not disclose the initial foaming temperature of the expanded microspheres.
The Examiner respectfully disagrees with this argument. See above, the 35 U.S.C. 103 rejection of claim 1.
Regarding argument (A), in response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). In modifying Poelma in view of Boud, Poelma does not require to explicitly disclose the expandable microspheres are formed by pre-foaming a foamable raw material. Instead, Boud teaches the motivation to combine (pages 7-8) as addressed above. Moreover, the Applicant’s argument that “As a result, the unexpanded microspheres (DU) are less densely distributed within the polymerizable liquid, which does not improve the stacking stability during printing and may even hinder the heating expansion efficiency of the three-dimensional object” is mere allegation without support.
Regarding argument (B), although Boud does not explicitly disclose an initial foaming temperature of dry expanded (DE) microspheres (c.f., A table of page 47 shows Tstart and Tmax of dry unexpanded (DU) microspheres), it is implied or at least obvious to one of ordinary skill in the art that “461 DE 40” would have the same or at least similar heat foaming temperature as/to the heat forming temperature of “461 DU 40” – i.e., the heat expansion temperature of 461 DU 40: 101 °C (median of 98 – 104 °C) for expansion starting temperature and 146 °C (median of 142 – 150 °C) for maximum expansion temperature (pages 46, 47) – because each of the dry unexpanded (DU) or dry expanded microspheres (DE) is made of the same material as evidenced by their common product numbers starting with 461 and ending with 40 (see pages 47 and 49: “461 DU 40” has the same Tstart and Tmax as the ones of “461 WU 40”). Thus, Boud teaches the initial foaming temperature of the dry expanded (DE) microspheres, and collectively, modified Poelma teaches the addressed limitation.
Thereby, after reconsideration, claim 1 remain rejected.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Kvamme (US 20210145116 A1) teaches Methods for manufacturing three-dimensional components of articles with a composition comprising a plurality of foam particles suspended in a polymerizable liquid (abstract, figs. 12-14).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to INJA SONG whose telephone number is (571)270-1605. The examiner can normally be reached Mon. - Fri. 8 AM - 5 PM.
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/INJA SONG/Examiner, Art Unit 1744
/XIAO S ZHAO/Supervisory Patent Examiner, Art Unit 1744
1 FPU 50 Technical Datasheet: page 2: HDT of FPU 50 is 70 °C at 66 psi, available at https://docs.carbon3d.com/files/technical-data-sheets/tds_carbon_fpu-50.pdf.
2 A heat expansion temperature of 461 DU 40: 101 °C (median of 98 – 104 °C) for expansion starting temperature and 146 °C (median of 142 – 150 °C) for maximum expansion temperature. See page 47 of Boud (“Expancel Microspheres,” available at https://www.boud.com/wp-content/uploads/2018/01/paints-and-coatings.pdf.