Prosecution Insights
Last updated: April 19, 2026
Application No. 18/518,804

PROCESSES FOR PREPARING ASYMMETRIC HOLLOW FIBER MEMBRANES, ASYMMETRIC HOLLOW FIBER MEMBRANES AND USE OF ASYMMETRIC HOLLOW FIBER MEMBRANES

Non-Final OA §103§112
Filed
Nov 24, 2023
Examiner
GRAHAM, ANDREW D
Art Unit
1742
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Pam Membranas Seletivas Ltda
OA Round
1 (Non-Final)
60%
Grant Probability
Moderate
1-2
OA Rounds
3y 8m
To Grant
82%
With Interview

Examiner Intelligence

Grants 60% of resolved cases
60%
Career Allow Rate
218 granted / 363 resolved
-4.9% vs TC avg
Strong +22% interview lift
Without
With
+22.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 8m
Avg Prosecution
31 currently pending
Career history
394
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
54.8%
+14.8% vs TC avg
§102
18.6%
-21.4% vs TC avg
§112
20.6%
-19.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 363 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 1-5 in the reply filed on 1/6/2026 is acknowledged. Claims 6-21 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 1/6/2026. 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. Claims 1-5 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. Regarding claims 1-2 and 5, the suffix “-type” with respect to “mineral-type” and “silicone-type” renders the claim(s) indefinite because the claim(s) include(s) elements not actually disclosed (those encompassed by "-type"), thereby rendering the scope of the claim(s) unascertainable. See MPEP § 2173.05(d). Claims 3-4 are also rejected due to their dependence upon claim 1. 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 (i.e., changing from AIA to pre-AIA ) 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. Claim(s) 1-5 are rejected under 35 U.S.C. 103 as being unpatentable over Ji et al. (US 2003/0141251), hereinafter Ji, in view of Boddeker et al. (US Patent No. 4,340,428), hereinafter Boddeker. Regarding claims 1-2, Ji discloses a process for producing a membrane, as a hollow fiber (par. 0008), including cellulose acetate (par. 0049 – “fiber-forming polymer”, ref. claim 6), comprising: (a) extrusion of a polymeric solution (“membrane casting solution in line 12 is extruded . . . into a hollow fiber”)(par. 0056; Fig. 1) containing cellulose acetate (par. 0049) and formamide (par. 0051 – dimethyl formamide is a specific formamide), and of an inner liquid (bore fluid 16) with precipitating features in relation to the polymeric solution (par. 0058); (b) immersion in an outer coagulation bath of filtered water (“allowed to fall freely in the air before reaching a coagulation bath [20] containing water” – par. 0056) between 25 C and 80 C (par. 0061 discloses a range of temperatures of 30-80 C for the coagulation bath which substantially overlaps with the claimed range); (c) continuous removal of a formed fiber by a mechanical device (par. 0072 – “[a]fter passing through the coagulation bath, the hollow fiber . . . [t]he fiber was then collected by a take-up wheel” and par. 0057 - “take-up wheel 50”); (d) exposure of the formed fiber to a water bath (leaching bath 22 or 52) at a temperature of 20-99 C (par. 0062-0063); and (e) drying the fibers by changing solvents (par. 0062) followed by resting at room temperature (inherent, as when the fiber is done being processed, this will necessarily be the case). Ji does not explicitly disclose that the polymeric solution comprises clay mineral nanoparticles or acetone. However, Boddeker, as part of a similar process of producing a fibrous membrane from a casting solution, which like Ji above, includes cellulose acetate and a solvent. Specifically, Boddeker’s solution includes cellulose acetate, acetone, water, formamide (Boddeker, 2:15-2:20) in a ratio of 25% cellulose acetate, 45% acetone, 30% formamide, and “0.1 gram of bentonite for every 100 grams of casting solution” (Boddeker, 4:20-4:27). Boddeker explains that the incorporation bentonite results in high salt restraining capacity and long-term flux stability (Boddeker, abstract and 3:54-3:56) and also improves the castability of the solution and the homogeneity of the membrane (4:17-4:20). The acetone allows for the swelling of the bentonite or clay material (6:60-6:67). Accordingly, in order to likewise improve the castability of the membrane solution and the homogeneity of the resulting membrane, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to have modified the above from Ji to have specified that there is a clay filler (or bentonite) with acetone as to properly swell the bentonite being used as to achieve the desired effect. Regarding claim 3, Ji/Boddeker discloses the subject matter of claim 1, and further discloses the use of 25% cellulose acetate, 45% acetone, 30% formamide, and 0.1% bentonite (Boddeker, 4:20-4:27). Regarding claim 4, Ji/Boddeker discloses the subject matter of claim 1, and further discloses that the distance that the solution falls is about 2 to 3 inches (1 inch = 2.54 cm) (Ji, par. 0056), which would fall within the 0-100 cm range as claimed. Regarding claim 5, Ji/Boddeker discloses the subject matter of claim 1, and further discloses spraying a polymer onto the dry fibers (Ji, par. 0053). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANDREW D GRAHAM whose telephone number is (469)295-9232. The examiner can normally be reached Monday - Friday 7:30AM-4:00PM (CST). 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, Christina Johnson can be reached at (571) 272-1176. 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. /ANDREW D GRAHAM/Primary Examiner, Art Unit 1742
Read full office action

Prosecution Timeline

Nov 24, 2023
Application Filed
Jan 23, 2026
Non-Final Rejection — §103, §112 (current)

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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
60%
Grant Probability
82%
With Interview (+22.1%)
3y 8m
Median Time to Grant
Low
PTA Risk
Based on 363 resolved cases by this examiner. Grant probability derived from career allow rate.

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