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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114 was filed in this application after appeal to the Patent Trial and Appeal Board, but prior to a decision on the appeal. 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examination under 37 CFR 1.114 and the fee set forth in 37 CFR 1.17(e) has been timely paid, the appeal has been withdrawn pursuant to 37 CFR 1.114 and prosecution in this application has been reopened pursuant to 37 CFR 1.114. Applicant’s submission filed on 30 June 2026 has been entered.
Response to Amendment
This office action is responsive to the amendment filed with the request for continued examination on 30 June 2026. As directed by the amendment: claims 13-15 have been amended. Claims 19 & 20 were canceled by previous amendment. Thus, claims 1-18 & 21-22 are presently pending in this application, with claims 1-12 currently withdrawn as directed to a non-elected invention.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim 15 is rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 15, as originally filed, recited a limitation wherein “the polymeric powder comprises at least one polymer selected from a group consisting of: polyvinylidene fluoride, polyethylene, polypropylene, polyamide, polyethylene terephthalate, and a combination thereof”.
In the response filed 30 June 2026, applicant amended the group of polymers in claim 15 to further include “polyphenylene sulfide”. In the accompanying remarks, applicant points to “the originally-filed claims”, FIG. 1, and “paragraphs [0015],[0017], and [0023]” for amendment support. However, the application as originally filed, including the above cited portions, does not appear to sufficiently support the use of polyphenylene sulfide for the polymeric powder as is now being claimed.
The originally filed claims (including claim 15 and similar claim 5) do not recite polyphenylene sulfide. Paragraph 23 & FIG. 1 relate to the pressure rating of the pipe, providing support for the amendment to claim 13, but do not recite any particular polymeric materials.
Paragraph 15 does recite polyphenylene sulfide (PPS), but as an example material for the inner liner layer, not for the polymeric powder of forming the semi-consolidated core layer.
Paragraph 17 provides a list of polymeric powder materials, but this list does not include polyphenylene sulfide, and otherwise reflects the set of materials recited in the original claim.
While paragraph 17 recites “in some embodiments, the polymeric powder may be of a polymer similar to the hollow liner material”, this does not inherently suggest that all of the listed liner materials are also necessarily disclosed for the polymeric powder.
See MPEP § 2163(II)(A)(3)(b): "To establish inherency, the extrinsic evidence ‘must make clear that the missing descriptive matter is necessarily present in the thing described in the reference, and that it would be so recognized by persons of ordinary skill. Inherency, however, may not be established by probabilities or possibilities. The mere fact that a certain thing may result from a given set of circumstances is not sufficient.’" In re Robertson, 169 F.3d 743, 745, 49 USPQ2d 1949, 1950-51 (Fed. Cir. 1999).
As a result, the claim contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor, or a joint inventor, at the time the application was filed, had possession of the claimed invention.
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 13-18, 21 & 22 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 13 recites “wherein the thermoplastic pipe has a pressure rating in a range of 1500 to 2900 psi”. It is unclear what standard or testing conditions are to be used to determine the “pressure rating”, causing the scope of the claims to take on an unreasonable degree of uncertainty. The term “pressure rating” might be seen as describing a burst strength (i.e., a pressure at which the pipe bursts / fails) or might be seen as describing a “design” pressure rating or “maximum allowable” pressure rating, etc. Even among these options, there remains significant uncertainty:
In the context of a burst pressure rating, a pipe may have a “short term” burst pressure, a “long term” burst pressure, or this may refer to a maximum “cyclical pressure rating” for a given service life, etc.
In the context of “design” or “maximum allowable” pressure ratings, these are values set by industry code or legal regulation or are otherwise set by a manufacturer, conventionally based on a design burst pressure divided by some specified factor-of-safety. However, the factor-of-safety used varies based on application or context: some common piping codes may use safety factors ranging from 1.5-2.5 depending on the pipe construction and usage, while some industries may use lower safety factors (e.g., aerospace applications where weight is a primary concern) or higher safety factors (e.g., high-pressure piping applications may require a safety factor of 4.0).
A declaration by Abderrahim Fakiri, one of the inventors of this application, was filed with applicant’s response on 30 June 2026. Item 16 of the declaration references the new pressure rating limitation and states “I hereby declare that the pressure rating is a design pressure rating”, which fails to resolve the issue for several reasons.
First, an applicant may not add a special definition or disavowal after the filing date of the application. While an applicant may point out or explain in remarks where the specification as filed contains a special definition or disavowal, it does not appear that such a special definition or disavowal was present in the as-filed specification. [MPEP § 2173.01(I)].
Moreover, even if the term “pressure rating” were to be interpreted as a “design pressure rating”, since neither the specification nor the claims sets forth which standard is to be used to determine such a “pressure rating”, a person having ordinary skill in the art would not be reasonably apprised of the metes and bounds of the claimed invention.
In the absence of a defined standard, one could arbitrarily define the pressure rating of any pipe merely by specifying a convenient factor-of-safety (e.g., a pipe with a short term burst strength of 5000 psig could be given a rating of 4000 psig @ 1.25 safety factor, 3000 psig @ 1.67, 2500 psig @ 2.0, 2000 psig @ 2.5, 1000 psig @ 5.0, etc.).
Claims recited in the section heading above but not specifically discussed are rejected due to dependency upon at least one rejected claim.
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.
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.
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.
Claims 13-18 & 22 (as understood) are rejected under 35 U.S.C. 103 as being unpatentable over Moreau et al. (US 2015/0300537 A1; hereafter Moreau) in view of Wood et al. (US 2013/0056108 A1; hereafter Wood), Hyson (US 2017/0066209 A1), Iyer et al. (US 5,102,690; hereafter Iyer), de Rothschild et al. (US 2014/0030459 A1; hereafter de Rothschild), and Conley et al. (US 2010/0266789 A1; hereafter Conley).
Regarding claim 13, Moreau discloses (e.g., fig. 9) a thermoplastic pipe comprising:
a liner layer (12; “tube 12”),
a core layer (18) formed from a prepreg fiber layer (i.e., incl. reinforcing fibers 20 and binding fibers 24; see various embodiments in figs. 2-8) that is wound around the liner layer (para. 40: “braided, helically wound, knitted, or wrapped about the tube 12”) and heated (i.e., see abstract and para. 69: heated “…to a temperature… equal to or greater than a peak melting temperature of the binding fibers to at least partially melt the binding fibers…”); and
an outer layer (28) over the core layer (see fig. 9),
wherein the prepreg fiber layer comprises a reinforcing fiber arrangement (i.e., reinforcing fibers 20, braided or knitted, etc.) and polymeric fibers (24; see paras. 44 & 45) wherein the polymeric fiber impregnates the reinforcing fiber upon being heated to form the core layer (see paras. 41 & 49, etc.),
wherein the polymeric fibers (24) have a melting temperature (i.e., a “peak melting temperature” / “melting point”) at least 5°C below the melting temperature of the liner layer such that the polymeric material of the fibers impregnates the reinforcing fiber arrangement upon being heated without impacting the liner layer (see para. 85, lines 18-21 & para. 86: “FIG. 13B is an end view of the hose assembly 10 that does not have the reinforcing layer 18 and the fibers embedded in the outer peripheral surface of the tube 12. In this embodiment, the polymeric material, which defines the outer peripheral surface 14 of the tube 12, typically has a peak melting temperature up to 100°C greater than the peak melting temperature of the binding fibers 24. In one embodiment…the outer peripheral surface 14 of the tube 12 has a peak melting temperature from 15 to 100°C greater that a peak melting temperature of the binding fibers 24”);
wherein the prepreg fiber layer comprises at least one material selected from the group consisting of carbon fiber, glass fiber, aramid fiber, and basalt fiber (see para. 42: the reinforcing fibers may comprise glass fiber [e.g., E-glass, S2 glass, C glass, R glass, silica, quartz, etc.], aramid fibers [“e.g. NOMEX® and KEVLAR® fiber”], and “Basalt fiber”).
Examination Note: to promote compact prosecution with respect to the fiber material, it is also noted that Wood, de Rothschild and Hyson each also teach the use of glass, aramid and carbon fibers; and Iyer teaches the use of at least glass and carbon fibers.
With respect to the limitation wherein the prepreg layer has a fiber volume percent of 20% to 80%, Moreau discloses (para. 50; claims 13 & 28) that the prepreg material for forming the core layer (i.e. commingled braid 26) may comprise a (reinforcing) fiber volume percent of 55 to 95%, or otherwise from 65 to 85%, each of which substantially overlaps with the claimed range of “20% to 80%” and, as set forth in MPEP § 2144.05(I), in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists.
Regarding the limitation of “a prepreg fabric layer” comprising “a fabric”, it is noted that the term “fabric” has several common and accepted definitions, of varying scope. One common and accepted definition is “a material made of fibers, a textile or cloth”. In this sense, the prepreg commingled fiber layer of Moreau, which may be braided, helically wound, or knitted about the liner layer to form the core layer, might reasonably be seen as a prepreg fabric layer comprising a fabric (i.e., the material made from at least the reinforcing fibers).
Another common and accepted definition of “fabric” is “a cloth made by weaving, knitting, or felting fibers”. As understood, the term as used in the relevant art would normally be understood to have this sense, i.e., distinguishing a fabric from a tow or yarn, etc. However, applicant’s own specification appears to suggest the first, broader meaning may have been intended. See para. 17, lines 8-11: “In some embodiments, the fabric may be a woven, a cross-ply, or a nonwoven fabric, or other fabrics apparent to those of ordinary skill in the art. In other embodiments, the fabric may be fibers that may include, but are not limited to, carbon fiber, glass fiber, aramid fiber, or basalt fiber.”. Thus, applicant’s own specification appears to suggest that the “fabric” can be a textile or cloth material (e.g., a woven, cross-ply, or non-woven fabric) or can be simply “fibers” (“In other embodiments, the fabric may be fibers…”).
While the prepreg fiber layers of Moreau may be seen as reading on a prepreg fabric layer, to promote compact prosecution, an additional teaching of a prepreg fabric layer is provided below.
Moreau does not explicitly disclose the core layer to be “a semi-consolidated core layer” formed from such a prepreg fabric layer, wherein the prepreg fabric layer comprises a fabric coated with a polymeric powder wherein the polymeric powder impregnates the fabric upon being heated to form the semi-consolidated core layer, wherein the polymeric powder has an average particle size diameter in a range of 1 to 500 microns, wherein the thermoplastic pipe has a pressure rating in a range of 1500 to 2900 psi.
Moreau also does not explicitly disclose the outer layer to be a shrink wrap outer layer, wherein the shrink wrap outer layer shrinks upon being heated to push molten polymeric powder into the fabric, wherein the polymeric powder has a melting temperature at least 5°C below the melting temperature of the shrink wrap outer layer such that the polymeric powder impregnates the fabric upon being heated without impacting the shrink wrap outer layer.
Wood teaches (fig. 1) a thermoplastic pipe comprising a liner layer (2; “innermost pipe 2”, paras. 113 & 114), a core layer (4, “reinforcing overwrap 4”) formed from a prepreg fabric layer that is wound around the liner layer and heated (see paras. 73-79,81-84: the core layer may comprise a thermoplastic [or thermosetting] resin first material and a reinforcing second material, whereby the combined layer may be wrapped around the liner layer [para. 78], and may be heated so that the first material softens or melts, enabling bonding to the liner layer [para 79]; see also paras. 116 & 122); and an outer layer (5; “protective sheath 5”) over the core layer, wherein the prepreg fabric layer comprises a fabric (para. 81 suggests the fibrous reinforcing material may be provided “in the form of a fabric…and consolidated by heat and/or pressure”, paras. 82 & 83 suggest the polymeric material may define a matrix in which the fibrous reinforcing material is arranged, and the layer “may comprise a fabric, tape, or tow”; para. 78 otherwise suggests “a tape, mat or woven structure”) and a polymeric matrix material (see para. 74, 82, 83, etc.) distributed along the fabric which impregnates the fabric upon being heated to form the core layer (e.g., see para. 81).
Wood also teaches that the reinforcing fibers of the prepreg fabric layer may comprise glass, aramid, and/or carbon fibers (paras. 83 & 116) and the resulting prepreg / composite layer may have a fiber volume from 20 to 70% (para. 116).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the thermoplastic pipe of Moreau such that the core layer is formed from a prepreg fabric layer that is wound around the liner layer and heated, wherein the prepreg fabric layer comprises a fabric which is impregnated by a polymeric matrix material upon being heated to form the core layer, in view of the teachings of Wood, as the simple substitution of one known prepreg fiber arrangement (e.g., the arrangements of Moreau, wherein the reinforcing fibers are provided as yarns which are then wound / knitted / braided around the liner layer) for another (i.e., the arrangement of Wood, wherein the reinforcing fibers are provided as a fabric, in a mat or woven structure, etc.) to obtain predictable results (e.g., faster or otherwise more efficient wrapping of the core layer about the liner layer as a fabric rather than requiring handling of individual yarns; and/or providing additional reinforcement / stability in the transverse direction of the wrap, as is provided by a fabric relative to a single yarn, etc.).
Hyson teaches a thermoplastic pipe (10; figs. 1 & 6) comprising:
a liner layer (11; “a region 11 of 100% thermoplastic material that defines the bore of the pipe…”, para 32, lines 4-7; fig. 2);
a consolidated core layer (12) comprising a commingled braid of thermoplastic filaments and reinforcing fibers (14) that is wound around the liner layer (see fig. 3; para. 41: “A fiber reinforced thermoplastic circumferential zone 12 of the pipe 10 is manufactured by braiding a plurality of tows…of co-mingled thermoplastic filament and reinforcing fibers or filaments”) and heated (see para. 45); and
a shrink wrap outer layer (13) over the consolidated core layer (para. 43; “16” in fig. 4), wherein the shrink wrap outer layer shrinks upon being heated to push molten polymeric material into the fabric (see below).
Hyson teaches (para. 45) that, during manufacture, the pipe (including the core layer) is heated to a temperature which causes the thermoplastic (polymeric) fiber material to melt, and the heat shrink tape of the outer layer to shrink onto the outer surface of the core layer and compress the underlying molten thermoplastic. Hyson suggests that this compression helps to embed the braided fabric into the thermoplastic matrix during melting and consolidation.
Hyson further teaches (para. 49) that the reinforcing fibers of the core layer may be carbon fibers, glass fibers, or aramid fibers (e.g., “KEVLAR®”), among others; and also suggests that a suitable prepreg layer using carbon fibers may have a reinforcing fiber volume from 60% to 80% (para. 41).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the thermoplastic pipe of Moreau such that the outer layer covering the core layer is provided as a shrink wrap (i.e., a heat shrink wrap) outer layer wherein the shrink wrap outer layer shrinks upon being heated to push molten polymeric material into the fabric, in view of the teachings of Hyson, as the use of a known technique (providing such an outer layer positioned around a prepreg/commingled thermoplastic and reinforcing fiber layer as a shrink wrap layer, as in Hyson) to improve a similar device (the thermoplastic pipe of Moreau having such a prepreg/commingled thermoplastic material / reinforcing fiber core layer) in the same way (e.g., utilizing the heat-shrink properties of the material of the outer layer to compress the thermoplastic material of the core layer during heating, containing the molten thermoplastic and embedding the reinforcement fibers into the resulting thermoplastic matrix during consolidation, as suggested by Hyson).
Iyer teaches a method of forming a prepreg material whereby the fibrous reinforcing material (e.g., fibers 10) may be coated with a thermoplastic [or thermosetting] resin in the form of a powder (“polymer particles P1”) via a “dry powder impregnation” process.
Iyer explains that such a “dry powder process” may be “relatively simple and economical” (col. 3, lines 66 – 68), “can be used with any polymeric, metallic or ceramic matrix that can be produced in a powdered form” (col. 5, lines 24-26), is “a low-cost/high speed composite prepreg method” which “produces continuous fiber composite prepreg with fiber volume fractions controllable to within one percent”, “is continuous, requires no solvents, can be used with any fiber-matrix combination and is scalable to any prepreg size” (col. 5, lines 31-37).
Iyer teaches that the technique may be used with “particles of any size” (col. 5, lines 46-48), including “cohesive powders (approximate size <20 microns”) which may be difficult using other prior art techniques (col. 5, lines 42-46), though the average particle size is “preferably approximately the same as the dimensions of the fiber for optimum impregnation” (col. 3, lines 38-40).
Iyer explains that “The fluidization and transport of particles varies with their material properties and size. The acoustic fluidization of particles by size as well as their dispersability [sic] within the fiber tow is variable by the method of the present invention” (col. 10, lines 31-35), and that “the process is controllable by automated control. Instrumentation for measurement and control of acoustic energy, thermal energy, particle size, flow rates and tow speed can be added to the process. The system can be applied to any powder matrix used for composite materials since material physical properties (density, size, acoustic power, tow speed, etc.) can be used as the input for these control algorithms” (col. 10, lines 38-45).
In the illustrative example described by Iyer, the polymeric powder used had an average particle size diameter of 9.2 +/- 4 microns (col. 6, lines 3-6) , though Iyer also cites known prior art which uses polymeric powders having average particle size diameters of 250 microns (col. 2, lines 59-64), <20 microns (col. 3, lines 5-11), and 50 microns (col 3, lines 11-16). Each of these examples lies within or otherwise overlaps the claimed range of “1 to 500 microns”.
Regarding the reinforcing material / fibers of the prepreg material, in the illustrative example described by Iyer, carbon fibers are used (col. 6, lines 1-4), though Iyer also cites known prior art which used “glass rovings” (col. 2, lines 59-64; col. 3, lines 5-11) and, as noted, Iyer suggests this technique can be used with “any fiber-matrix combination”.
Iyer further teaches that “[t]he particles adhere to each fiber filament providing a uniform coating when subjected to heating so that the prepreg can be processed to any degree of consolidation downstream” (col. 5, lines 52-55), whereby “[t]he resulting prepreg is drapable and can be used in weaving or preform operations” (col 5, lines 55-57).
Iyer also suggests that “the method can tailormake prepreg tapes with any desired fiber-matrix volume fraction” (col. 7, lines 18-20) via control of process conditions such as tow velocity (col. 8, lines 51-54), and provides specific examples falling within the claimed range of 20% to 80% (e.g., table 3 shows examples having fiber volumes of 65.79% to 73.48%).
Additionally, Iyer suggests that, preferably, the particles are provided in an amount from about 10% to 65% by volume of the fiber volume or, most preferably, in an amount from 20 to 40% of the fiber volume (col. 10, line 67 – col. 11, line 2). Converting these ranges from particle volume per fiber volume (i.e., Vp/Vf) to fiber volume of the prepreg layer (i.e. Vf / (Vp+Vf)) yields a “preferred” fiber volume range of 60.6% to 90.9%, and a “most preferred” fiber volume range of from to 71.4% to 83.3%, each of which overlaps the claimed range of 20% to 80%, and, as previously noted, Iyer otherwise suggests that the method can “tailormake” prepreg tapes with “any desired fiber-matrix volume fraction”.
Finally, it is noted that Iyer acknowledges several other known techniques for forming prepreg materials including “fiber co-mingling” (col. 2, lines 46-55), which is the prepreg technique used in Moreau, and further recited by Wood (i.e., in para. 81), Hyson (above) and de Rothschild (below). Iyer explains that this technique produces an advantageously drapable “hybrid yarn”, but suggests that “[t]he high cost involved in producing the thermoplastic yarn and weaving it with the reinforcing fibers is a disadvantage”.
As would be understood by a person having ordinary skill in the art, such a dry powder impregnation process as taught by Iyer would result in a prepreg material wherein particles of the powder (e.g., polymeric powder) are randomly distributed along the reinforcing fibers which, as suggested by Iyer, may then be used for weaving (e.g., to make fabrics) or other preform operations, as is otherwise conventional in the art.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the thermoplastic pipe of Moreau (as otherwise modified above) such that the prepreg fabric layer is manufactured by a dry powder impregnation process (i.e., wherein the fabric is coated with the polymeric powder / wherein the polymeric powder is randomly distributed across the fabric), in view of the teachings of Iyer, to provide for low-cost / high-speed method of forming a prepreg material, without the use of solvents, which permits control over the fiber-matrix volume fractions, and which can be adapted for use with any fiber-matrix combination, etc. (each as suggested by Iyer).
It would have been further obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention, when modifying the thermoplastic pipe of Moreau in view of Iyer as above such that the prepreg fabric layer is manufactured by a dry powder impregnation process, to utilize a polymeric powder with any reasonable average particle size diameter, including those within a range of 1 to 500 microns (e.g., 50 or 250 microns as taught by the known prior art dry powder impregnation techniques section of Iyer; or 9.2 +/- 4 microns as used in the illustrative example of Iyer, etc.), in view of the teachings of Iyer, so as to optimize impregnation by utilizing powder with an average particle size approximately the same as the diameter of the fibers used for a particular application (as suggested by Iyer; e.g., using a 9.2 +/- 4 micron average particle size when using 7.2 micron diameter carbon fibers, as in the illustrative example of Iyer); and/or as a matter of routine engineering design utilizing particles of an average particle size diameter known from the prior art to be suitable for such applications (e.g., 50 microns and 250 microns, as taught by Iyer to be suitable in known prior art dry powder impregnation methods, etc.).
Regarding the limitation wherein the prepreg fabric layer has a fiber volume percent of 20% to 80%, as previously noted, Moreau discloses (para. 50; claims 13 & 28) that the prepreg material for forming the core layer (i.e. commingled braid 26) may comprise a (reinforcing) fiber volume percent of 55 to 95%, or otherwise from 65 to 85%, each of which substantially overlaps with the claimed range of “20% to 80%” and, as set forth in MPEP § 2144.05(I), in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists.
However, to promote compact prosecution, it is again noted that Wood teaches (para. 116) the use of a fiber volume of between 20-70 vol%, Hyson teaches the use of a reinforcing fiber volume from 60% to 80% (para. 41), and Iyer teaches that “the method can tailormake prepreg tapes with any desired fiber-matrix volume fraction” (col. 7, lines 18-20) via control of process conditions (col. 8, lines 51-54), provides specific examples (e.g., table 3 shows examples having fiber volumes of 65.79% to 73.48%) falling within the claimed range, and otherwise teaches a “preferred” and “most preferred” particle volume ranges which correspond to equivalent fiber volume ranges of 60.6% to 90.9% and 71.4% to 83.3%, respectively, each of which substantially overlaps the claimed range of 20% to 80%.
As a result, if not already seen as such, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to form the prepreg fabric layer with a fiber volume percent of 20% to 80%, in view of the teachings of Moreau, Wood, Hyson, and/or Iyer, each of which suggests a suitable fiber volume range within or otherwise overlapping the claimed range, and, as set forth in MPEP § 2144.05(II)(A), it has been held that "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See also Peterson, 315 F.3d at 1330, 65 USPQ2d at 1382 ("The normal desire of scientists or artisans to improve upon what is already generally known provides the motivation to determine where in a disclosed set of percentage ranges is the optimum combination of percentages.").
It is also noted that applicant’s specification does not appear to set forth any evidence of criticality or unexpected results arising specifically from the use of the claimed fiber volume range. Rather, the specification suggests only that “In one or more embodiments, the fiber may be present in a volume fraction of the core layer in the range from about 20 vol% to 80 vol%...” (para. 19), which would appear to suggest a preference rather than a critical value or range.
While the specification broadly notes that the level of consolidation can be tailored by altering the fiber volume fractions (e.g., para. 22), this is an expected or otherwise predictable result of modifying the fiber volume fraction generally, does not necessarily suggest any criticality or unexpected result and, in particular, does not sufficiently establish criticality or unexpected results commensurate in scope with the fiber volume range as now claimed.
De Rothschild is generally directed to methods of manufacturing composite products comprising commingled thermoplastic material (e.g., thermoplastic fibers 4) and reinforcing fibers (2; see figs. 1B-1D).
De Rothschild teaches that, by controlling of the melt phase / consolidation degree of the thermoplastic matrix component in a commingled thermoplastic / reinforcing fiber composite, one can control the degree to which the resulting thermoplastic matrix bonds adjacent reinforcing fibers, whereby void space may be intentionally included to achieve a specific flex/stiffness relationship of the composite (paras. 9 & 11-14).
In an illustrative example, De Rothschild teaches (e.g., para. 38) that commingled fibers (6) may be originally provided in an unconsolidated form (FIG. 1B) but, upon partial heating, the thermoplastic fibers begin to melt, flow, and adhere to the reinforcement fibers, wherein control of heat and pressure enables the melting thermoplastic fibers to form a bonding matrix.
De Rothschild further teaches (para. 38) that the above process can produce a “semi-consolidated” material (FIG. 1C) or a “fully consolidated” material (FIG. 1D).
De Rothschild suggests (para. 38) that “control of the degree, location, direction/orientation of the melt or consolidation of the matrix fibers allows for tailoring properties including, but not limited to flex, permeability, hardness, stiffness, toughness and impact resistance. Such control is possible over small areas and/or large areas of the same part while using the same fibers”.
De Rothschild further explains (para. 9) that, unlike certain cited prior art references, they have recognized that unconsolidated and semi-consolidated phases of commingled fiber materials “offer significant utility without further processing”. As can be seen from at least published claims 1, 3 & 12, de Rothschild teaches that a finished article may include such a semi-consolidated material.
De Rothschild suggests that the techniques and teachings therein are to be regarded as new “tools” that can “be applied broadly across the composites fields, especially within the self-reinforced composites fields” (para. 37). However, among the non-limiting examples provided, de Rothschild suggests such the teachings as applicable for forming elongate members such as cables (fig. 13, para. 52) and for forming “a fluid handling apparatus selected from a filter, heat exchanger and solar panel” (published claim 20).
Finally, while de Rothschild illustrates the teachings via commingled fibers, the reference explains that “it is to be understood that the teachings herein are generally applicable to other thermoplastic composite materials” (para. 6, lines 14-16).
A person of ordinary skill in the art would have reasonably recognized that a dry powder impregnated prepreg material, such as that taught by Iyer, is also a form of “commingled” thermoplastic and reinforcing fiber material, since the thermoplastic and reinforcing fibers are both present together in the same layer (e.g., they are not in separate discrete layers, as in a film-stacked laminate-type prepreg).
Additionally, as previously noted, Iyer suggests that a prepreg material formed by such a dry powder impregnation method “can be processed to any degree of consolidation downstream” (col. 5, lines 52-55).
In view of the above, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the thermoplastic pipe of Moreau (as otherwise modified above) such that the core layer formed from a prepreg fabric layer is formed as a semi-consolidated core layer, in view of the teachings of de Rothschild, to obtain a pipe having tailored mechanical properties (e.g., flex, hardness, stiffness, toughness, impact resistance, etc.) between those of a pipe having an unconsolidated core layer and those of a pipe having a fully consolidated core layer, especially considering that de Rothschild explicitly suggests that controlling the consolidation degree of a commingled thermoplastic and reinforcing fiber composite material allows for tailoring of such properties, and otherwise suggests that such composite materials may remain in a semi-consolidated state in a final article.
When the thermoplastic pipe of Moreau is modified as set forth above, the resulting combination is seen as reading on the additional limitations wherein the polymeric powder impregnates the fabric upon being heated to form the semi-consolidated core layer, wherein the shrink wrap outer layer shrinks upon being heated to pish the molten polymeric powder into the fabric.
Regarding the limitation wherein the polymeric powder has a melting temperature at least 5°C below the melting temperature of the shrink wrap outer layer such that the polymeric powder impregnates the fabric upon being heated without impacting the shrink wrap outer layer, Hyson teaches (para. 45) that the pipe (including the core layer) is heated to a temperature which causes the thermoplastic fiber material to melt, and the heat shrink tape to shrink onto the outer surface of the core layer and compress the molten thermoplastic. See also abstract of Hyson, lines 15-22.
As Hyson explicitly teaches that the heating temperature causes the thermoplastic of the core layer to melt while causing the heat shrink tape to shrink (rather than melt), such an arrangement reasonably suggests that the polymer (thermoplastic) has a lower melting temperature than the shrink wrap. As would be understood by one skilled in the art, heating the shrink wrap to its melting point would cause a loss of structural integrity and thus would not operate to compress the core layer as taught.
As previously noted, Moreau discloses that a first polymeric material (i.e., that of the liner layer) may have a peak melting temperature of up to 100° C, or otherwise from 15° to 100° C, greater than a polymeric material of a core layer intended to be melted during manufacture / consolidation (e.g., see paras. 82, 86, etc.).
As set forth in MPEP § 2141.03(I), "A person of ordinary skill in the art is also a person of ordinary creativity, not an automaton." KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 421, 82 USPQ2d 1385, 1397 (2007). "[I]n many cases a person of ordinary skill will be able to fit the teachings of multiple patents together like pieces of a puzzle." Id. at 420, 82 USPQ2d 1397. Office personnel may also take into account "the inferences and creative steps that a person of ordinary skill in the art would employ." Id. at 418, 82 USPQ2d at 1396.
When modifying the thermoplastic pipe of Moreau to include a shrink wrap outer layer as suggested by Hyson above, it would have been further obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to select appropriate materials such that the polymeric powder has a melting temperature which is at least some reasonable value below the melting temperature of the shrink wrap outer layer (e.g., between 15° and 100 °C below, in view of Moreau; within the claimed range of “at least 5°C”) such that the polymeric powder impregnates the fabric upon being heated without impacting the shrink wrap outer layer, in view of the combined teachings of Moreau and Hyson, to ensure that, during the process of (partially) consolidating the core layer at a temperature at or above the melting temperature of the polymeric powder, the shrink wrap continues to maintain sufficient structural integrity to provide the required compression.
Regarding the remaining limitation wherein the thermoplastic pipe comprises a pressure rating in a range of 1500 to 2900 psi, as noted in the grounds of rejection under 35 U.S.C. 112(b), it is not clear what standard or definition of “pressure rating” is to be used to determine the appropriate value for the purposes of the claim, causing the scope to take on an unreasonable degree of uncertainty. However, to promote compact prosecution, the following findings are noted.
Moreau discloses that the assemblies disclosed therein may be “exposed to extreme pressures” (para. 3), and otherwise discloses that certain dimensions, such as the inner diameter, outer diameter, and length can “vary depending on the intended use” of the pipe (para. 68). However, Moreau does not explicitly disclose the thermoplastic pipe to comprise a pressure rating in a range of 1500 to 2900 psi.
Conley teaches (figs. 1-11) a reinforced pipe comprising a thermoplastic inner liner layer (10; see para. 21: “can be made of any suitable polymer, such as a thermoplastic or an elastomer. Suitable materials, for example, may include one or more of…nylon, cross-linked polyethylene(PEX), polypropylene, … high-density polyethylene (HDPE), … etc.”), a core layer comprising reinforcements wound over the inner liner layer (12, 14; see para. 34), and an outer layer (20) covering the core layer.
Conley explains that “flexible pipes need to meet certain performance requirements, such as having sufficient strength to contain the high pressure fluid the pipe may be transporting” (para. 3). Conley suggests that “[f]or many hydrocarbon handling operations, a pipe may be acceptable that has a 3000 psi burst pressure… Other performance properties may be desired for other applications” (para. 57).
It is noted that a “pressure rating”, as understood, is conventionally determined by dividing a burst pressure value by a factor-of-safety (i.e., to ensure that a given pipe is operated in a safe pressure range during operation, and not near the burst [failure] pressure).
With respect to the claimed pressure rating range between 1500 psi and 2900 psi, a pipe with a burst pressure of 3000 psi may be considered to have a pressure rating of 1500 psi at a factor-of-safety of 2.0 (which is not uncommon, depending on the application); and may be considered to have a pressure rating of 2900 psi at a factor-of-safety of 1.03. Thus, a pipe with a burst pressure of 3000 psi may be considered to have a pressure rating of between 1500 psi and 2900 psi, with a corresponding safety factor falling between 1.03 and 2.0.
Furthermore, in Table I, Conley sets forth details of an example of a reinforced pipe and, in Table II, Conley sets forth corresponding performance data. In the example, a pipe with a short term burst pressure of 4892 psi is shown to correspond to a design operating pressure of 1500 psi. To the extent that the “design operating pressure” may be seen as reading on one possible definition of “pressure rating”, it is noted that a design pressure of 1500 psi is within or otherwise at least close to the claimed pressure rating range of “1500 to 2900 psi” and, as set forth in MPEP § 2144.05(I), a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985).
Alternatively, as with the 3000 psi burst pressure example above, a pipe with a short term burst pressure of 4892 psi may be seen to have a pressure rating of between 1500 psi and 2900 psi, with a corresponding safety factor falling between 1.69 and 3.26.
In the event that applicant intended the term “pressure rating” to mean “burst pressure”, as above, Conley teaches that a 3000 psi burst pressure is acceptable for many hydrocarbon handing applications. 3000 psi is reasonably seen as close to the claimed range of between 1500 psi and 2900 psi and, as noted, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the thermoplastic pipe of Moreau to have any reasonable pressure rating as may be required to ensure the pipe has sufficient strength to contain the high pressure fluid the pipe is intended to transport for a particular application (i.e., as a matter of routine engineering design), in view of the teachings of Conley, including embodiments wherein the thermoplastic pipe comprises a pressure rating in a range of 1500 to 2900 psi (e.g., by forming the pipe to have a 3000 psi burst strength, suggested by Conley to be a value “acceptable” for “many hydrocarbon handling operations”; with a corresponding safety factor falling between 1.03 [2900 psi] and 2.0 [1500 psi]).
Finally, to further promote compact prosecution with respect to this pressure rating limitation, it is noted that applicant's specification explains (para. 12) that “Reinforced thermoplastic pipe (RTP), due the lack of a consolidated intermediate layer, is generally capable of withstanding pressures of up to approximately 1500 psig (about 10342 kPa). On the other end of the scale, thermoplastic composite pipe (TCP), with a fully consolidated intermediate layer, is capable of withstanding pressure of up to approximately 10,000 psig (about 68929 kPa).”.
Examination Note: prior art references of record also broadly corroborate the pressure ranges admitted in applicant’s disclosure: Conley (cited above) recites a 1500 psi design pressure (4892 psi burst pressure) for a reinforced thermoplastic pipe (RTP), Li et al. (US 2011/0174410 A1) discloses RTP pipes with burst pressures of 15-28 MPa (2175 – 4061 psi), while Dyksterhouse (US 2014/0238525 A1) discloses that thermoplastic (TCP) composite pipes “can be pressure rated up to tens of thousands of pounds per square inch (PSI)” (para. 3).
As set forth in the grounds of rejection above, de Rothschild teaches that a semi-consolidated component may have tailored mechanical properties (e.g., flex, hardness, stiffness, toughness, impact resistance, etc.) between those of an unconsolidated component and those of a fully consolidated component.
When applied in the context of a thermoplastic pipe, a person of ordinary skill in the art would reasonably expect a semi-consolidated (i.e., SC-RTP) pipe to exhibit properties falling between those of an unconsolidated (RTP) pipe and consolidated (TCP) pipe. In this case, the claimed pressure rating range for the semi-consolidated (i.e., SC-RTP) pipe of 1500 to 2900 psi clearly falls between the expected values of an unconsolidated (RTP)(e.g., 1500 psig) and consolidated (TCP) pipe (e.g., up to 10,000 psig) and thus is within a range that would have been reasonably expected from such a construction.
As set forth in MPEP § 716.02(c), expected beneficial results are evidence of obviousness ["Expected beneficial results are evidence of obviousness of a claimed invention, just as unexpected results are evidence of unobviousness thereof." In re Gershon, 372 F.2d 535, 538, 152 USPQ 602, 604 (CCPA 1967)].
See also MPEP § 2144.05(II)(A): "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
In the instant case, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the thermoplastic pipe of Moreau such that the resulting semi-consolidated thermoplastic pipe has a pressure rating greater than that of an unconsolidated (RTP) pipe (e.g., on the order of 1500 psi) and less than that of a fully consolidated (TCP) pipe (e.g., on the order of 10,000 psi), including embodiments wherein the pressure rating may be in a range of 1500 to 2900 psi, since it has been held that were the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.
Regarding claim 14, the thermoplastic pipe of Moreau, as modified above, reads on the additional limitation wherein the polymeric powder is randomly distributed across the fabric in the prepreg fabric layer on one side or both sides of the fabric (i.e., when utilizing the dry powder impregnation process as taught by Iyer, the individual fibers would be coated on all sides by the polymeric powder, whereby a fabric layer formed from the fibers would comprise the polymeric powder randomly distributed on both sides of such a prepreg fabric layer).
Regarding claim 15, the thermoplastic pipe of Moreau, as modified above, reads on the additional limitation wherein the polymeric powder comprises at least one polymer selected from the group consisting of polyvinylidene fluoride, polyethylene, polypropylene, polyamide, polyethylene terephthalate, polyphenylene sulfide and a combination thereof.
In particular, Moreau discloses examples of polymers suitable for use as binding fibers (i.e., the original polymeric matrix material corresponding to the polymeric powder), including polyethylene, polypropylene, polyamide, polyethylene terephthalate (PET), or may otherwise comprise a fluoropolymer [para. 44].
To promote compact prosecution, it is also noted that Wood correspondingly discloses the use of polyamide (paras. 5 & 74); Iyer suggests that a dry powder impregnation process “can be used with any polymeric, metallic or ceramic matrix that can be produced in a powdered form”, and specifically teaches examples using polyamide powder (col. 6, lines 4-6: “a small diameter polyamide powder”; col. 7, lines 41-42: “a polyamide powder P”); and de Rothschild teaches the use of PET (polyethylene terephthalate), polypropylene (“PP Black”), and polyphenylene sulfide (PPS)(see table on pg. 1).
Regarding claims 16 & 17, with respect to the limitations wherein the liner layer has a thickness from 0.5 mm to 25 mm (claim 16) and wherein the liner layer has an outer diameter from 1 inch to 24 inches (claim 17), the liner layer of the thermoplastic pipe of Moreau has a thickness (i.e., a distance between the inner peripheral surface 16 and the outer peripheral surface 14) and an outer diameter (i.e., the diameter at outer peripheral surface 14).
Moreau does not explicitly disclose the thickness of the liner layer to be from 0.5 mm to 25 mm or the outer diameter to be from 1 inch to 24 inches, however, Moreau discloses that the thermoplastic pipe as a whole has an inner diameter, an outer diameter, and a length which “can vary depending on the intended use” (para. 68). In one example, Moreau suggests that the pipe can have an inner diameter of “two inches for use in applications that require transfer of greater volumes of fluid” (para. 68). When the inner diameter is two inches, as best understood, the outer diameter of the liner layer would reasonable be expected to fall within the claimed range of 1 inch to 24 inches.
Furthermore, as set forth in MPEP § 2144.04(IV)(A), it has been generally held that where the only difference between the prior art and the claims was a recitation of relative dimensions of the claimed device and a device having the claimed relative dimensions would not perform differently than the prior art device, the claimed device was not patentably distinct from the prior art device.
See also MPEP § 2144.05(II)(A): Smith v. Nichols, 88 U.S. 112, 118-19 (1874) (a change in form, proportions, or degree "will not sustain a patent") & In re Williams, 36 F.2d 436, 438, 4 USPQ 237 (CCPA 1929) ("It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions.").
Nevertheless, to promote compact prosecution, the following additional teachings are provided.
Wood teaches that the wall thickness of a liner layer (i.e., “pipe P1”) “may be at least 0.5 mm, suitably at least 0.8 mm, preferably 1 mm or more. The thickness may be less than 30 mm, suitably less than 15 mm, preferably less than 10 mm, more preferably less than 8 mm, especially less than 6 mm. The thickness is preferably in the range 1 mm to 5 mm.”.
Wood also teaches that the liner layer (i.e., “pipe P1”) may have an outside diameter of at least 2.5 cm [0.984 inches], suitably at least 7 cm [2.756 in], preferably at least 10 cm [3.937 in], more preferably at least 15 cm [5.906 in]. The diameter may be less than 50 cm [19.685 in], preferably less than 40 cm [15.748 in], more preferably less than 30 cm [11.811 in].
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the thermoplastic pipe of Moreau such that the liner layer comprises any reasonable thickness and any reasonable outer diameter as may be required for a particular application, including forming the liner layer to have a thickness from 0.5 mm to 25 mm (e.g., in the range of 1 mm to 5 mm as taught by Wood) and an outer diameter from 1 inch to 24 inches (e.g., between 5.906 inches and 11.811 inches as taught by Wood), as a matter of routine engineering design (e.g., to meet the required structural and/or flow requirements of such an application), especially considering that Moreau otherwise suggests that the dimension of the pipe can vary depending on the intended use.
Moreover, the selection of a liner layer thickness and outer diameter within the above claimed ranges would have otherwise been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention as the use of a known technique (i.e., selecting values in such ranges, as taught by Wood) to improve a similar device (i.e., the pipe of Moreau) in the same way (e.g., ensuring the resulting pipe has a sufficiently sized liner layer suitable for use in the applications suggested by Wood, etc.).
Regarding claim 18, Moreau discloses the additional limitation wherein the liner layer comprises a thermoplastic. In particular, Moreau discloses (para. 35) that the liner layer (12) may comprise, e.g., polyethylene, polypropylene, polyvinylchloride, PET, and polyamides, each of which is a thermoplastic. In fact, Moreau later specifically states that “the material of the outer peripheral surface 14 of the tube 12 is typically a semi-crystalline or amorphous thermoplastic polymer” (para. 38).
Regarding claim 22, the thermoplastic pipe of Moreau, as modified above, reads on or otherwise renders obvious the additional limitation wherein the fabric is selected from the group consisting of: woven fabric, cross-ply fabric, and nonwoven fabric.
As noted for claim 13 above, Wood teaches that the core layer / prepreg fabric layer reinforcing means may comprise a “mat or woven structure” (para. 78), and otherwise teaches that the reinforcing means may be “suitably in the form of a fabric” (para. 81; see also para. 83: “may comprise a fabric, tape or tow”). Thus, Wood reasonably teaches or renders obvious at least the limitation wherein the fabric is a woven fabric.
Additionally, it is noted that one common definition of “mat” is “A thin layer of woven, non-woven, or knitted fiber that serves as reinforcement to a material.”. Thus, under at least this definition, the disclosure in Wood of the layer being a “mat” may be seen as teaching or rendering obvious at least the fabric being a woven or non-woven fabric.
To promote compact prosecution, it is noted that de Rothschild teaches that such commingled thermoplastic and reinforcing fiber materials may be provided in the form of tows which are further processed into various fabrics by weaving, braiding, knitting, etc. (para 38, lines 16-20), and provides at least one illustrative example of a woven fabric (para. 52).
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Moreau in view of Wood, Hyson, Iyer, de Rothschild, and Conley as applied to claim 13 above, and further in view of Brisson et al. (US 2007/0125488 A1; hereafter Brisson).
Regarding claim 21, Moreau discloses that the prepreg layer may be helically wound around the liner layer (e.g., see para. 73). Similarly, Wood, when teaching the prepreg layer to be a prepreg fabric layer, also teaches that the prepreg fabric layer is wound around the liner layer (e.g., para. 78: “the reinforcing means…is preferably flexible and arranged to be wrapped around pipe P1. It may be elongate and comprise a tape, mat or woven structure which is arranged to be wound around pipe P1”).
However, neither Moreau nor Wood explicitly discloses that the winding is performed around the liner layer at an angle from 1 to 89 degrees in a clockwise or a counter-clockwise direction measured from a pipe axis.
Brisson teaches (figs. 1-10) a thermoplastic composite pipe (12) comprising a liner layer (22; see para. 28) and a composite thermoplastic matrix (34) / reinforcing fiber (35) layer formed from tapes/ribbons (32; i.e., elongate elements) wound around the liner layer, wherein the composite layer winding is performed at an angle (α; see fig. 3) from a pipe axis (X; fig. 2) in a clockwise or counterclockwise direction (R), such that the resulting composite layer is wound around the liner layer at such an angle in the clockwise or counter-clockwise direction measured from the pipe axis.
Brisson teaches that “it is well known that composites are anisotropic materials and…a variation of angles is important to lead the strength in the ideal and required way relating to the end use application” (para. 33), and suggests that a wide range of angles could be used “from 0° to 85° or even 90°…according to the specific constraints such as pressure resistance, flexural strength, tensile strength, related to each application…” (para. 34).
More specifically, Brisson teaches that if a pipe has a high tensile strength requirement but relatively low pressure resistance requirement (such as a subsea riser which has to support the weight of the piping string), the winding angle should be “minimal, that is close to the longitudinal axis…for instance in a range of about 20 to 25°”. Conversely, if a pipe has a high pressure resistance requirement but relatively low tensile strength requirement, the winding angle “has to be high, for instance in a range of about 60-80°, or 60-70° relative to the longitudinal axis” (para. 35).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the thermoplastic pipe of Moreau such that the prepreg fabric layer is wound around the liner layer at an angle from 1 to 89 degrees (e.g., from 20-25° for tensile-critical applications; 60-70° for pressure-critical applications) in a clockwise or counter-clockwise direction measured from the pipe axis, in view of the teachings of Brisson, in order to arrange the reinforcing fibers of the composite in a manner optimized for the particular application (e.g., low angles for tensile applications, higher angles for pressure applications, etc.).
Response to Arguments
Applicant's arguments filed 30 June 2026, and the Declaration of Abderrahim Fakiri [a joint inventor] under 37 C.F.R. 1.132 have each been fully considered.
The declaration argues (at item 10) that “Moreau, Wood, Hyson, De Rothschild, and Brisson do not teach the claimed prepreg fabric layer, which includes a fabric coated with a polymeric powder. Instead, they teach braided/woven fibers in a polymer matrix.”, and (at item 11) that “Iyer teaches a specific method of polymer powder distribution to produce a prepreg”. Applicant’s remarks recite a corresponding argument. These arguments are not found to be persuasive for several reasons.
First, these arguments amount to arguments against the references individually, rather than against the combination. 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).
As set forth in the rejection, the fibers of Moreau are originally disclosed to be provided in a commingled braid of reinforcement and thermoplastic fibers, which may be “braided” or “knitted” about the liner layer. Depending on the definition of “fabric” (discussed later), Moreau might already be seen to disclose a prepreg fabric layer, albeit one with a commingled fiber arrangement rather than a powder-coated fiber arrangement. Either way, Wood explicitly teaches a prepreg layer may be provided in the form of “a fabric, tape, or tow” or otherwise “a tape, mat or woven structure”, with a polymeric material distributed along the fabric, which may also be a commingled fiber type arrangement (though the thermoplastic fibers may be discontinuous while the reinforcing fibers are continuous), whereby it would have been obvious to utilize a fabric prepreg wound over the inner liner layer rather than a commingled fiber arrangement knitted/braided on the inner liner layer, for the reasons set forth in the grounds of rejection. It is noted that Hyson and De Rothschild also utilize commingled fiber prepreg arrangements, generally.
Iyer teaches a method of forming a prepreg material by coating reinforcement fibers with polymeric powder, and suggests that the impregnation process is “relatively simple and economical”, “can be used with any polymeric, metallic or ceramic matrix that can be produced in a powdered form”, is “a low-cost/high speed composite prepreg method” which “produces continuous fiber composite prepreg with fiber volume fractions controllable to within one percent”, “is continuous, requires no solvents, can be used with any fiber-matrix combination and is scalable to any prepreg size”.
Iyer acknowledges several other known techniques for forming prepreg materials including “fiber co-mingling”, which is the prepreg technique used in Moreau, and further recited by Wood, Hyson and de Rothschild, but Iyer explains that this technique has a disadvantage of a “high cost involved in producing the thermoplastic yarn and weaving it with the reinforcing fibers”. As set forth in the grounds of rejection then, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the thermoplastic pipe of Moreau such that the prepreg fabric layer is manufactured by a dry powder impregnation process (i.e., wherein the fabric is coated with the polymeric powder / wherein the polymeric powder is randomly distributed across the fabric) to provide for low-cost / high-speed method of forming a prepreg material, without the use of solvents, which permits control over the fiber-matrix volume fractions, and which can be adapted for use with any fiber-matrix combination, etc. (each as suggested by Iyer).
The test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981).
Returning to the issue of the term “fabric”, the declaration and remarks attempt to distinguish between a “fabric” and the “braided/woven fibers” of Moreau.
As explained in the grounds of rejection, the term “fabric” has several common and accepted definitions, of varying scope. One common and accepted definition is “a material made of fibers, a textile or cloth”. In this sense, the prepreg commingled fiber layer of Moreau, which may be braided or knitted about the liner layer to form the core layer, might reasonably be seen as a prepreg fabric layer comprising a fabric (i.e., the material made from at least the reinforcing fibers; a braided or knitted fabric).
Another common and accepted definition of “fabric” is “a cloth made by weaving, knitting, or felting fibers”. As understood, the term as used in the relevant art would normally be understood to have this sense, i.e., distinguishing a fabric from a tow or yarn, etc. However, applicant’s own specification appears to suggest the first, broader meaning may have been intended. See para. 17, lines 8-11: “In some embodiments, the fabric may be a woven, a cross-ply, or a nonwoven fabric, or other fabrics apparent to those of ordinary skill in the art. In other embodiments, the fabric may be fibers that may include, but are not limited to, carbon fiber, glass fiber, aramid fiber, or basalt fiber.”. Thus, applicant’s own specification appears to suggest that the “fabric” can be a textile or cloth material (e.g., a woven, cross-ply, or non-woven fabric) or can be simply “fibers” (“In other embodiments, the fabric may be fibers…”).
Applicant’s remarks appear to suggest that each of the references (other than Iyer) only teaches “braded and/or woven fibers”, but this is not found to be persuasive.
Applicant’s remarks suggest that “Moreau teaches fiberglass reinforcing fibers….braided or wound together”, but Moreau also teaches that the fibers may be joined by “knitting”. The structure formed by knitting or braiding the fibers around the liner layer may reasonably be seen as a fabric (i.e., a woven or knit fabric).
Applicant’s remarks suggest that “Wood teaches flat tape which comprises unidirectional continuous or jointed fibers of carbon, glass and/or aramid embedded in a PEEK matrix”, however, Wood explicitly discloses that the core layer may be formed from a “fabric” or otherwise “a tape, mat or woven structure”. Thus, the structure is not necessarily limited to “unidirectional continuous or jointed fibers” as suggested.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
To promote compact prosecution, the PTO-892 provided with this action includes several references teaching prepregs formed by scattering polymeric powder on a fabric layer formed from reinforcing fibers (e.g., US 2002/0037391 A1 to Harpell et al.; US 2004/0170554 A1 to Wadahara et al.; US 2019/0160762 A1 to Ono et al.).
With respect to the limitation of the pipe having a pressure rating of between 1500 and 2900 psi, the grounds of rejection have been amended in the action, as necessitated by applicant’s amendments, to address this newly claimed subject matter.
Finally, the declaration argues that “Wood teaches a TCP requiring very high-pressure resistance; therefore, a semi-consolidated pipe (SC-RTP) would not be suitable for use in Wood’s application. Hyson teaches a TCP requiring a very high bending radius; therefor, a semi-consolidated pipe (SC-RTP) would not be suitable for use in Hyson’s application”. Applicant’s remarks include corresponding arguments. These arguments are not found to be persuasive for several reasons.
First, as set forth in MPEP § 2123(I), "The use of patents as references is not limited to what the patentees describe as their own inventions or to the problems with which they are concerned. They are part of the literature of the art, relevant for all they contain." In re Heck, 699 F.2d 1331, 1332-33, 216 USPQ 1038, 1039 (Fed. Cir. 1983) (quoting In re Lemelson, 397 F.2d 1006, 1009, 158 USPQ 275, 277 (CCPA 1968)).
Next, as previously mentioned, these arguments amount to arguments against the references individually, rather than against the combination, and one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. The test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art.
Applicant points out that the claimed SC-RTP has a pressure rating and bending radius between those of TCP and RPT pipes, however, this would be an expected result of a semi-consolidated pipe. In particular, de Rothschild teaches that a semi-consolidated component may have tailored mechanical properties (e.g., flex, hardness, stiffness, toughness, impact resistance, etc.) between those of an unconsolidated component and those of a fully consolidated component. When applied in the context of a reinforced/composite thermoplastic pipe, a pipe having a semi-consolidated core layer (i.e. having properties between that of an unconsolidated and fully consolidated layer) would reasonably be expected to have properties, such as a pressure rating, falling between that of an unconsolidated pipe (e.g., 1500 psi) and a fully consolidated pipe (e.g., 10,000 psi). The claimed range of 1500 to 2900 psi clearly falls within the range of properties which would be reasonably expected for such a pipe.
As set forth in MPEP § 716.02(c), expected beneficial results are evidence of obviousness ["Expected beneficial results are evidence of obviousness of a claimed invention, just as unexpected results are evidence of unobviousness thereof." In re Gershon, 372 F.2d 535, 538, 152 USPQ 602, 604 (CCPA 1967)].
Conclusion
The prior art made of record in the attached PTO-892 and not relied upon is considered pertinent to applicant's disclosure.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Richard K Durden whose telephone number is (571) 270-0538. The examiner can normally be reached Monday - Friday, 9:00 AM - 5:00 PM 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 supervisors can be reached by phone: Kenneth Rinehart can be reached at (571) 272-4881; Craig Schneider can be reached at (571) 272-3607. 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.
/Richard K. Durden/Examiner, Art Unit 3753
/ROBERT K ARUNDALE/Primary Examiner, Art Unit 3753
Prosecution Insights