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 . 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.
Election/Restrictions
Claims 19-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim.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 03/26/2026.
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.
Claims 1-15 are rejected under 35 U.S.C. 103 as being unpatentable over Low (Low, I. M. (2018). Advances in Ceramic Matrix Composites (2nd Edition). Elsevier. pp. 93-119.) in view of Gardiner (Gardiner, Ginger. “The spread of spread tow,” Composites World. Published 04/26/2018.).
Low teaches a method of manufacturing a ceramic matrix composite, the method comprising: laying up a plurality of plies to form a fiber preform of required shape, wherein the plies comprise carbon fibers, and infiltrating the fiber preform with ceramic matrix precursor or ceramic matrix material to embed the carbon fibers in a ceramic matrix (See sections 5.2 and 5.3).
Low does not expressly disclose using spread tows of carbon fibers having a height-to-width aspect ratio of less than about 0.1 such that the ceramic matrix composite comprises a smooth and/or flat surface devoid of undulations from rounded tows.
Gardiner teaches a method of forming a composite material, the method comprising using a spread tow of carbon fibers to lay up a preform (e.g. via automated tape laying or automated fiber placement techniques) (See p. 1). When spread tows are used instead of rounded tows, a resulting composite surface is inherently “devoid of undulations from rounded tows” as claimed.
It would have been obvious to one of ordinary skill in the art at the time of filing to use spread tows when forming the preform of Low. The rationale to do so would have been the motivation provided by the teaching of Gardiner that spread fibers are ubiquitous in the art (“According to sources at a global carbon fiber producer, 80% of carbon fiber now used worldwide is spread before further processing”) and predictably provide reduced weight, more efficient load-carrying ability, and improved surface finish for aesthetic appeal (See pp. 1-2).
Regarding the claimed aspect ratio of less than 0.1, Examiner notes that this particular relationship is not commonly provided in the prior art. Instead, it is commonplace in the art to provide a specified areal density (g/m2), which is also a function of thickness and width. While the Gardiner reference does not expressly discuss aspect ratios, the reference provides a detailed discussion about the flexibility of using spread tows and provides some exemplary thickness and width values which show that the instantly claimed aspect ratio would have been obvious to one of ordinary skill in the art at the time of filing. More specifically, Gardiner discloses thicknesses of 0.02mm for 15 g/m2 spread tow (p. 1) and 0.03mm for 30 g/m2 spread tow (“Industrialization and cost” section, p. 5), and exemplary widths of 25mm (p. 1 and p. 6), 10mm, or 11mm (“Controlling areal weight and crack propagation” section, p. 6). Any combination of these exemplary values yields an aspect ratio in the instantly claimed ranges in claims 1 and 2.
Regarding claim 3, the spreading of the tow forms a flat tape, which comprises a generally rectangular cross-section as claimed.
Regarding claim 4, both Low (See section 5.3.1) and Gardiner (“Spreading and weaving: Parallel developments” section, pp. 2-5) teach 2D woven fabrics.
Regarding claim 5, Low discloses various infiltration techniques, including chemical vapor infiltration, slurry infiltration, reactive melt infiltration, and combinations thereof (See Section 5.2).
Regarding claim 6, Low discloses chemical vapor infiltration in which a coating comprising the ceramic matrix material is deposited on the fiber preform (See section 5.6).
Regarding claim 7, Low discloses slurry infiltration in which ceramic matrix material particles are embedded in the fiber preform (See section 5.8).
Regarding claim 8, Low discloses slurry infiltration in which a preceramic polymer is infiltrated into the fiber preform as part of the slurry followed by pyrolysis (See Slurry infiltration + PIP method in section 5.2).
Regarding claim 9, Low teaches silicon carbide (SiC) as a ceramic matrix material throughout the disclosure (See section 5.2, for example).
Regarding claim 10, Low teaches discloses reactive melt infiltration in which the ceramic matrix precursor comprises molten silicon (Si), which flows through the fiber preform and undergoes a reaction with carbon to form a silicon carbide (SiC) ceramic matrix (See section 5.7.2).
Regarding claim 11, Low and Gardiner do not expressly disclose 2 to 10 layers of carbon fiber per tow. However it would have been obvious to one of ordinary skill in the art at the time of filing to select such a property of a spread tow as a routine matter of design choice. Applicant has not demonstrated any new or unexpected result which arises from this particular tow thickness, and the mere selection of a particular thickness as expressed by the number of carbon fibers rather than mm or microns does not patentably distinguish the instantly claimed method from the prior art.
Regarding claim 12, the exemplary thicknesses of Gardiner, 0.02mm (20 micron) and 0.03mm (30 micron) lie within the instantly claimed range.
Regarding claim 13, Gardiner teaches that using spread tows improves surface aesthetics, as detailed above. Low and Gardiner do not expressly disclose a value for surface undulations, however since the combination of Low and Gardiner combine to teach an identical method using identical materials, it is reasonable to conclude that properties of the resulting composite would fall within the claimed range absent any showing from the Applicant that the smoothness is achieved in some manner other than by virtue of the materials used in the claimed method.
Regarding claim 14, the Gardiner reference uses spread tows throughout the composite rather than only at a surface portion thereof. However since the use of non-spread tows is also well-known and conventional in the prior art, the use of such a technique anywhere else in a composite does not patentably distinguish the instantly claimed method from the prior art. It is clear from the prior art that both spread tow and non-spread tow fiber layup are ubiquitous in the art such that one of ordinary skill in the art can readily utilize either one, or both, for a particular application as needed.
Regarding claim 15, there is no mention of a non-spread tow section in the Gardiner reference. One of ordinary skill in the art would reasonably conclude that the composites presented by Gardiner are formed only with spread tows.
Claims 16-18 are rejected under 35 U.S.C. 103 as being unpatentable over Low (Low, I. M. (2018). Advances in Ceramic Matrix Composites (2nd Edition). Elsevier. pp. 93-119.) in view of Gardiner (Gardiner, Ginger. “The spread of spread tow,” Composites World. Published 04/26/2018.) as applied to claim 1 above, and further in view of Wu (US 2023/0087214).
Low and Gardiner combine to teach a method of manufacturing a ceramic matrix composite using spread carbon fiber tows, as detailed above.
Low and Gardiner do not expressly disclose a method of producing the spread fiber tows, the method including heat treating the plurality of plies, particularly to a temperature of at least 1600°C prior to cutting.
Wu teaches a method of making spread carbon fiber tows, the method comprising: (A) providing a carbon fiber tow, (B) heating and spreading the carbon fiber tow, (C) adjusting tension and spreading of the carbon fiber tow, (D) passing the spread carbon fiber strands through a splitter to form spaced carbon fiber strands, (E) cutting the spaced carbon fiber strands, (F)adjusting tension of the spaced carbon fiber strands, (G) adding a sizing material, and (H) heating the sized carbon fiber strands (See [0012]).
It would have been obvious to one of ordinary skill in the art at the time of filing to use the method of Wu to produce the spread fiber tows disclosed by Gardiner, since Wu teaches that such a method was recognized in the prior art as being suitable for such a purpose. Wu also teaches that spreading fiber tows reduces costs and improves flexibility (See [0009]-[0011]), consistent with the teachings of Gardiner.
Regarding claim 16, either one of the first heating step (B) or the second heating step (H) comprises a heat treatment which occurs before a spread fiber tow is laid up.
Regarding claim 17, the heating and cutting of Wu read on the instantly claimed heat treating and cutting steps.
Regarding claim 18, Low teaches that carbon fibers are routinely treated at temperatures above 1600°C (See section 5.3.2).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CARSON GROSS whose telephone number is (571)270-7657. The examiner can normally be reached Monday-Friday 9am-5pm Eastern.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Michael Orlando can be reached at (571)270-5038. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/CARSON GROSS/Primary Examiner, Art Unit 1746
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