Prosecution Insights
Last updated: May 04, 2026
Application No. 17/919,598

System and Process for Membrane Fouling Control, A Membrane Fouling Control Additive, an Upgrade Kit and an Upgrade Method

Non-Final OA §112
Filed
Oct 18, 2022
Priority
Apr 23, 2020 — EU 20171107.4 +2 more
Examiner
ELLINGTON, MARRIAH C G
Art Unit
1773
Tech Center
1700 — Chemical & Materials Engineering
Assignee
S A Lhoist Recherche Et Developpement
OA Round
3 (Non-Final)
43%
Grant Probability
Moderate
3-4
OA Rounds
0m
Est. Remaining
70%
With Interview

Examiner Intelligence

Grants 43% of resolved cases
43%
Career Allowance Rate
12 granted / 28 resolved
-22.1% vs TC avg
Strong +27% interview lift
Without
With
+27.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
32 currently pending
Career history
60
Total Applications
across all art units

Statute-Specific Performance

§101
1.0%
-39.0% vs TC avg
§103
45.0%
+5.0% vs TC avg
§102
12.5%
-27.5% vs TC avg
§112
38.1%
-1.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 28 resolved cases

Office Action

§112
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 Applicant’s claim for the benefit of a prior-filed application under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged. Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 11/26/2025 has been entered. Response to Amendment The amendment filed 11/26/2025 has been entered. Claims 1, 2, 5, 6, 11, 13, 15, 16, 17, 20, 21, and 23-27 remain pending in the application, with claims 20-21 and 23-27 being withdrawn. Response to Arguments Applicant’s arguments, see Remarks, filed 11/26/2025, with respect to the rejection(s) of claim(s) 1 under 35 U.S.C. 103 have been fully considered. The prior art rejections are no longer applied to the instant claims due to the amended language of claim 1 regarding the dynamic protective layer (DPL) maintained by transmembrane pressure (TMP), which Examiner interprets to exclude DPL maintained by means other than TMP, such as functional group interaction between DPL and membrane and/or adhesive and/or reactive interaction between DPL and membrane surfaces. See the 112 (b) section, particularly Interpretation A, for further discussion of claim interpretation. 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, 2, 5, 6, 11, 13, 15, 16, and 17are 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 1 recites “a particle size distribution d9o of the fouling control particles is smaller than or equal to 15 µm, wherein d9o refers to the size at which 90% of the distribution is below the d9o and the dynamic protective layer is formed and maintained on the membrane by a transmembrane pressure generated across the membrane as a result of conducting the liquid to be filtered through the membrane and/or by the permeate flux.” It is unclear if it is meant that transmembrane pressure (TMP) is the only force by which the dynamic protective layer is maintained. In light of the specification, p 15 ¶6 supports “the dynamic protective layer is formed and/or maintained on the membrane by a transmembrane pressure”, but the passage does not exclude contribution of other forces. Remarks p 4 ¶4 contextualize the intended scope “The balance of pressure and flow, combined with the features of the particles themselves, causes the particles to accumulate and remain stably positioned on the membrane surface through mechanical hydraulic forces only,”, but this language is not included in the claim nor in the specification. For the purpose of compact prosecution and clarity of record, Examiner notes claim interpretations of the exclusivity of TMP as an (exclusive) maintaining force can be interpreted differently in light of the following embodiments : Specification p 7 ¶2 “In one embodiment, the fouling control particles are inert. Within the meaning of the present invention, the term "inert" means that the fouling control particles do not change their properties in the dynamic protective layer on the membrane during the operation mode.” With exclusivity support under this interpretation in the form of inert fouling control particles, the previous rejection of record is overcome due to the tunable surface and interaction of the dynamic protective layer with the membrane. If this is the intended scope, Examiner asks for clarification that the embodiment of Specification p 7 ¶3 is specifically excluded. Examiner also suggests positively reciting inert characteristics or, if supported by the disclosure, “solely” maintained by TMP. If this is the intended scope, the claimed combination of d9o ≤ 15 µm exclusively maintained by TMP would be allowable. Examiner suggests either positively reciting the allowable subject matter in the withdrawn claims, such as excluding forces other than TMP for dynamic protective layer maintenance, or cancellation of the withdrawn claims. Specification p 7 ¶3 “In one embodiment, the fouling control particles are reactive or functionalized. Within the meaning of the present invention, the terms "reactive or functionalized particles" means preferably that the surface of the fouling control particles have specific charges or groups which absorb foulants and/or which attach to the membrane surface” Under this interpretation, TMP is only one force contributing to the maintained dynamic protective layer, potentially among other forces, such as attachment to the membrane surface due to reactivity. The previous rejection of record is silent to the impacts and effects of transmembrane pressure. While analogous art positively teaches TMP plays a role in dynamic particle layer assembly and maintenance for sub-10 micron antifouling particle (See US 2011/0186513 Al [0165-0167]), it teaches away from cleaning the layer with a backwash. If the intended scope is that the forces maintaining the dynamic layer comprise TMP (among others), Examiner asks for clarification positively reciting such. Claims 2, 5, 6, 11, 13, 15, 16, and 17 depend on claim 1 and are also rejected. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US 20170349759Al teaches preparing a sub- 10 micron d90 precipitate of earth alkali carbonate, including calcium and hydromagnesite. US 2020/0101422 Al teaches a backwash step for a filtration system with a composite layer overlaid on a membrane, the composite including particles of calcium carbonate and magnesium carbonate US 4,207,183 teaches nucleation crystals to reduce semi-permeable membrane fouling. EP 2 322 581 B1 teaches hydromagnesite composition synthesis. WO 01/27036 teaches a suspension of particles of a filtration aid, deposited in a layer on the membrane to catch pollutants. US-3996131-A teaches a "dynamic membrane" may be defined as a microporous layer deposited on a porous substrate during or prior to use in a separation process by pressure through the microporous layer. A dynamic membrane is usually particulate and easily removed from the porous substrate US-20110186513-A1 teaches antifouling particles can be added to the feed water inhibit membrane fouling, as the treatment proceeds forming layers, and differential between feed water pressure and permeate side to enable the treatment US-20120211421-A1 teaches calcium based components as suitable filter aids, where filter aids are inert aids and act to form a pre-coat barriers such as polymer membranes. Any inquiry concerning this communication or earlier communications from the examiner should be directed to MARRIAH ELLINGTON whose telephone number is (703)756-1061. The examiner can normally be reached Monday - Friday, 9:00 am - 4:00 pm EST. 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, Ben Lebron can be reached at (571) 272-0475. 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. MARRIAH ELLINGTON Examiner Art Unit 1773 /BENJAMIN L LEBRON/Supervisory Patent Examiner, Art Unit 1773
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Prosecution Timeline

Oct 18, 2022
Application Filed
Apr 02, 2025
Non-Final Rejection — §112
Jun 25, 2025
Response Filed
Sep 28, 2025
Final Rejection — §112
Nov 26, 2025
Request for Continued Examination
Nov 28, 2025
Response after Non-Final Action
Apr 03, 2026
Non-Final Rejection — §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

3-4
Expected OA Rounds
43%
Grant Probability
70%
With Interview (+27.1%)
3y 3m (~0m remaining)
Median Time to Grant
High
PTA Risk
Based on 28 resolved cases by this examiner. Grant probability derived from career allowance rate.

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