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, 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 2/19/2026 has been entered.
Claim Status
An amendment, filed 2/19/2026, is acknowledged. Claim 35 is amended; Claim 36 is canceled. Claims 35 and 37-67 are currently pending, claims 61-67 are withdrawn.
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.
Claim(s) 35, 37-39, 41-42, 45-60 are rejected under 35 U.S.C. 103 as being unpatentable over Hackner et al. (WO 2020/016240 A1)(of record) in view of Kruger (US 2021/0238717)(of record) and Zhang et al. (CN109175363A)(of record, machine translation previously provided).
With respect to Claim 35, the claim recites “heating the plurality of fibers at a heating rate higher than 50 K/min to a fixation temperature selected in the range of 50 to 98% of their melting point temperature; and cooling the plurality of fibers immediately after reaching said fixation temperature at a cooling rate higher than 50K/min.” Thus, the claim specifically limits the temperature of the fibers, not the temperature of the means of heating. Therefore, the claim is interpreted to limit the temperature of the fibers themselves, not the temperature of the means of heating. As a result, cooling “immediately” after the fibers reach any selected temperature within the range of 50-98% of the melting temperature of the fibers, meets the instant claim.
Hackner teaches a method of assembling a fiber network comprising a plurality of metal fibers, the method comprising steps of: providing a loose network out of the plurality of metal fibers (taking place where the method is being conducted, and thus, constituting an “assembling site”), fixing the plurality of metal fibers to one another by forming a plurality of contact points between the metal fibers by heating the plurality of fibers to a fixation temperature between 10 to 95% of the melting point of the metal fibers resulting in sintering, and then removing the fixed/sintered network of fibers from the heating apparatus, thus, resulting in cooling from the fixation temperature. (p. 3, ln. 30 to p. 4, ln. 26; p. 5, ln. 24-32; p. 13, ln. 1-18; p. 14, ln. 6-35; p. 55, ln. 26 to p. 57, ln. 2).
Hackner teaches wherein “the time for which the metal fibers are subjected to the predetermined temperature and pressure is not particularly limited and depends on the material of the fiber, on the applied pressure and on the temperature.” (p. 17, lns. 30-33). The reference teaches preferred, and therefore, optional, predetermined time of heating of 10 seconds or longer. (p. 17, lns. 33-35). Hackner, thus, teaches a time for heating at a predetermined temperature to achieve sufficient sintering. In other words, Hackner is drawn to the amount of time metal fibers are subjected to heating at a particular temperature rather than limiting the temperature of the fibers themselves. Accordingly, Hackner does not require holding, for any amount of time, the fibers at the fixation temperature, but instead requires holding the heating means at a temperature for an amount of time sufficient to cause the temperature of the fibers to be raised to a sintering temperature (i.e. the elapsed time of the heating step to a fixation temperature). After sintering, the sintered fibers are no longer subjected to a heating temperature and therefore, would necessarily begin cooling “immediately.”
Hackner is therefore, deemed to teach a method of assembling a fiber network comprising a plurality of metal fibers, wherein the method comprises providing a plurality of metal fibers at an assembling site, fixing the plurality of metal fibers to one another by heating to a temperature overlapping the claimed temperature range, and wherein the fiber network is removed from heating after obtaining sintering (i.e. the fibers reach a temperature sufficient to cause a desired amount of amount of fusing between individual fibers) and thus, would begin necessarily cooling “immediately after” reaching the desired fixation temperature.
Moreover, as the reference is drawn to achieving a controlled amount of sintering by heating to a temperature below the melting point to avoid deformation of the fibers, it would have been obvious to one of ordinary skill in the art to immediately begin cooling the fibers after sufficient sintering (i.e. fixation) has been achieved in order to prevent unwanted changes to the structure due to continued heating.
The reference, is silent as to the specific heating rate to a fixation temperature and cooling rate.
Kruger teaches a method of sintering an alloy, wherein the alloy may be sintered alternatively by conventional sintering and hot pressing or by a field-assisted sintering technology (“FAST” also known as spark plasma sintering, “SPS”), for example, at a pressure of 50 MPa with heating and cooling rates of 100 K/min each. (para. 32).
Zhang teaches a method of assembling a network of metal fibers, the method comprising spark plasma sintering a loose network of metal fibers, the sintering taking place under pressure and resulting in a nonwoven/felt type material comprising the metal fibers having formed contact points between the fibers with tailored properties such as porosity, permeability, and mechanical performance. (abstract; pgs. 1-3 of translation).
Thus, Kruger teaches the substitutability of sintering methods for metals pieces, wherein FAST/SPS sintering may achieve desired sintering in shorter time due to increased heating and cooling rates, thereby improving the efficiency of the method. Zhang, like Hackner, is drawn to sintering a plurality of metal fibers to form a fiber network, and teaches the benefit of using a FAST/SPS process to sinter the plurality of metal fibers to form a network with desired properties. Accordingly, it would have been obvious to one of ordinary skill in the art to substitute the sintering process of Hackner for a field-assisted sintering process as taught by Kruger and Zhang, the process comprising keeping the plurality of metal fibers under pressure and heating at a rate of 100 K/min to a fixation temperature and then cooling, immediately after sintering, at a rate of 100 K/min, in order to efficiently form fiber network with desired properties such as porosity and mechanical performance.
With respect to Claim 37, Zhang teaches a step of pre-sintering to prepare a loose network of metal fibers before the further sintering step described above. (pgs. 2-3 of translation). It would have been obvious to one of ordinary skill in the art to modify the method of Hackner in view of Kruger and Zhang, to perform a pre-sintering step, as taught by Zhang, in order to prepare a loose network of the metal fibers and enable a more tailored structure and properties after the primary sintering step. It would have been obvious to one of ordinary skill in the art to perform this pre-sintering step within the range of sintering temperatures disclosed by the prior art, for example, 10-95% of the melting temperature of the metal fibers as taught by Hackner (see above) to obtain at least a minimal degree of connection points between metal fibers. It would also have been obvious to one ordinary skill in the art to select from the overlapping portion of the ranges. Overlapping ranges, in particular, where the ranges of a claim overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05. Finally, as the instantly claimed “cleaning” step requires only a step of heating, such a pre-sintering step is deemed to constitute a “cleaning” step as instantly claimed.
With respect to Claims 38 and 42, Kruger teaches providing a protective argon atmosphere during various manufacturing steps, including a heat treatment step (para. 41). It would have been obvious to one of ordinary skill in the art to modify the method of Hackner in view of Kruger and Zhang to provide a protective inert gas atmosphere during one or more of the method steps, as taught by Kruger, in order to protect the metal from contamination and/or oxidation. In particular, it would have been obvious to one of ordinary skill in the art to provide such inert gas via flowing an inert gas at the manufacturing/assembly site and during a cleaning step, in order to obtain the protective benefits during respective method steps.
With respect to Claim 39, Kruger teaches an example of performing the FAST/SPS sintering step under vacuum (para. 32), thus, comprising reducing the atmospheric pressure at the assembling site. Accordingly, it would have been obvious to one of ordinary skill in the art to perform the cleaning/pre-sintering step of Hackner in view of Kruger and Zhang under a vacuum, as taught by Kruger, in order to prevent contamination and/or oxidation of the metal fibers during the step.
With respect to Claim 41, Hackner teaches applying pressure during the heating step, the pressure being 20 MPa or more, preferably 1000 MPa or less (p. 18, ln. 11-20). Additionally, Kruger and Zhang each teach wherein prior to and during fixing/sintering, a predetermined pressure is applied. (see rejection of claim 35 above). It would have been obvious to one of ordinary skill in the art to apply a predetermined pressure prior to and during a fixing/sintering step as taught by Hackner in view of Kruger and Zhang, in order to obtain a desired level of connections between metal fibers and thereby control the structure and properties of the network, including porosity and permeability.
With respect to Claim 45, Hackner teaches examples of using electron microscropy to determine characteristics/properties of the metal fibers. (see Figs. 5a to 5g). It would have been obvious to one of ordinary skill in the art to determine a desired fixation temperature resulting in a desired level of connections and the resulting structure and properties of the metal fiber network using electron microscopy to identify such structure/properties in manufactured samples at varying temperatures and selecting a temperature that obtained the desired features.
With respect to Claim 46, Hackner teaches selecting a temperature up to 95% of the melting temperature (see rejection of claim 35 above). It would also have been obvious to one ordinary skill in the art to select from the overlapping portion of the ranges. Overlapping ranges, in particular, where the ranges of a claim overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
With respect to Claims 47-48, Hackner teaches sintering the plurality of metal fibers for 10 seconds to 60 minutes, with applied pressure, to obtain a desired level of sintering and ensure a stable connection between fibers. (p. 17, ln. 30 to p. 18, ln. 10). Kruger teaches examples of sintering for 15 minutes. (para. 32). Zhang teaches sintering a plurality of metal fibers for 5-15 minutes (abstract).
Accordingly, it would have been obvious to one of ordinary skill in the art to select a fixation temperature for a fixation time from the disclosures of Hackner in view of Kruger and Zhang and from the overlapping portion of the ranges, for example 10 seconds to 15 minutes, in order to ensure sufficient connection/sintering of the metal fibers. Furthermore, based on the disclosed heating and cooling rates and sintering temperatures of the references, it would have been obvious to select a total time including heating, fixation, and cooling from the overlapping range of claims 47-48. Overlapping ranges, in particular, where the ranges of a claim overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
With respect to Claim 49, Hackner in view of Kruger and Zhang teach cooling the fibers at a cooling rate maintained at 100 K/min (see rejection of claim 35 above). As Hackner teaches a sintering temperature range of 10-95% of the melting temperature of the metal fibers, it would have been obvious to one of ordinary skill in the art to cool the metal fibers at this rate until the temperature is outside the scope of possible sintering, that is, below 10% of the melting temperature, in order to ensure that any sintering has ceased and to enable easier handling of the metal fiber network.
With respect to Claim 50, Hackner teaches wherein the metal fibers have a length of 1.0 mm or more, a width of 100 microns or less, and a thickness of 50 microns or less. (abstract).
With respect to Claim 51, Hackner does not teach any change in the width of the fibers along their length as compared with the initial width of the fibers before conducting the step of heating the plurality of fibers. Moreover, sintering at a temperature which may be substantially below the melting point of the metal fibers, as taught by Hackner, would not be expected to result in any substantial change in the width of the fibers. Finally, as Hackner in view of Kruger and Zhang teach a method comprising substantially the same steps, materials, and processing parameters, it would be expected to result in a metal fibers having the same properties, including the claimed relative width before and after the heating step. MPEP 2112.01.
With respect to Claim 52, Hackner teaches wherein the metal fibers before and/or after fixing them to one another show an exothermic event when heated in a DSC measurement. (para. 18).
With respect to Claims 53-55, Hackner teaches wherein the metal fibers may have a round or non-round cross section, for example, a rectangular, circular, oval, or elliptical cross section and is deemed to encompass a ratio of a small axis to a large axis overlapping the instantly claimed range. (para. 15, 29). Overlapping ranges, in particular, where the ranges of a claim overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
With respect to Claim 56, the claim recites “wherein the metal fibers are obtainable by…” and thus, does not require that the metal fibers are obtained by the stated process, only that they are could be obtained by such a method. “Claim scope is not limited by claim language that suggests or makes optional but does not require steps to be performed, or by claim language that does not limit a claim to a particular structure.” MPEP 2111.04. Moreover, Hackner teaches wherein the metal fibers are manufactured comprising subjecting molten metal material to a cooling rate of 100 K/min or higher, overlapping the instantly claimed range. (para. 43). It would also have been obvious to one ordinary skill in the art to select from the overlapping portion of the ranges. Overlapping ranges, in particular, where the ranges of a claim overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
With respect to Claim 57, Hackner teaches wherein the metal fibers may be amorphous or nanocrystalline. (para. 18).
With respect to Claims 58-59, the claims do not provide a scope limiting the “electrical contact” and “direct electrical contact.” Hackner teaches wherein the fixed metal fibers are in direct electrical contact, and thus, are deemed to be in electrical contact and direct electrical contact, meeting claims 58 and 59. (para. 20).
With respect to Claim 60, Hackner teaches wherein the metal fibers of the plurality of metal fibers in the network contain one of the elements selected from the group consisting of copper, silver, gold, nickel, palladium, platinum, cobalt, iron, chromium, vanadium, titanium, aluminum, silicon, lithium, combinations of the foregoing and alloys containing one or more of the foregoing. (para. 26).
Claim(s) 35, 37-39, 41-42, 45-60 are rejected under 35 U.S.C. 103 as being unpatentable over Hackner et al. (WO 2020/016240 A1)(of record) in view of Kruger (US 2021/0238717)(of record) and Zhang et al. (CN109175363A)(of record, machine translation previously provided) and Sasakuri (JP 2019080055A)(machine translation provided).
In the alternative to the above rejection of claims 35, 37-39, 41-42, 45-60, incorporated here by reference, if Hackner is not interpreted to teach a step of cooling the plurality of fibers immediately after reaching the fixation temperature, Sasakuri teaches a method of spark plasma sintering (SPS) a metal-containing powder to form a component, wherein the powder is heated to a sintering temperature (fixation temperature) and held for preferably 0 minutes before cooling begins, wherein 0 minutes “means that cooling starts immediately upon reaching the sintering temperature without substantially providing a holding time.” (pgs. 1-2 and 14 of translation).
As detailed in the rejection above, Kruger teaches the substitutability of sintering methods for metals pieces, wherein FAST/SPS sintering may achieve desired sintering in shorter time due to increased heating and cooling rates, thereby improving the efficiency of the method. Zhang, like Hackner, is drawn to sintering a plurality of metal fibers to form a fiber network, and teaches the benefit of using a FAST/SPS process to sinter the plurality of metal fibers to form a network with desired properties. Accordingly, it would have been obvious to one of ordinary skill in the art to substitute the sintering process of Hackner for a field-assisted sintering process as taught by Kruger and Zhang, the process comprising keeping the plurality of metal fibers under pressure and heating at a rate of 100 K/min to a fixation temperature and then cooling, immediately after sintering, at a rate of 100 K/min, in order to efficiently form fiber network with desired properties such as porosity and mechanical performance.
It would have further been obvious to one of ordinary skill in the art to modify the method of Hackner in view of Kruger and Zhang to begin cooling immediately upon reaching the sintering/fixation temperature, as taught by Sasakuri in order to improve the efficiency of the method and/or to improve the consistency of the method and thereby, the consistency/uniformity of the resulting component. (see Sasakuri, teaching that the workpiece is preferably cooled immediately after reaching the sintering temperature due to difficulties involved with maintaining/holding at the sintering temperature; pg. 14 of translation).
Claim(s) 43-44 are rejected under 35 U.S.C. 103 as being unpatentable over Hackner et al. (WO 2020/016240 A1)(of record) in view of Kruger (US 2021/0238717)(of record) and Zhang et al. (CN109175363A)(of record) and alternatively, further in view of Sasakura (JP 2019080055A), as applied to claim 35 above, further in view of Jia (US 20210323875)(of record).
With respect to Claims 43-44, Hackner in view of Kruger and Zhang and alternatively, further in view of Sasakuri, teach using a spark plasma sintering furnace (see rejection of claim 35 above) but are silent as to wherein the heating is carried out by one of the respectively claimed furnace types.
Jia teaches sintering a network of fibers wherein the sintering may be carried out using a variety of furnace types, including an induction furnace, infrared furnace, and specifically, teaches using high heating rates of 100 C/min in a hot isostatic pressing method or up to 500 C/min in a spark plasma sintering method. (para. 38, 45). Thus, Jia is deemed to teach the substitutability of sintering methods and furnaces for sintering a network of fibers. It would have been obvious to one of ordinary skill in the art to use an induction furnace or infrared furnace, as taught by Jia, at a suitable heating rate from the portion of the overlapping ranges. The substitution one of means for heating for another, capable of the same function and effect would be prima facie obvious to one of ordinary skill in the art. Furthermore, it would have been obvious to one of ordinary skill in the art to use a continuous form of such a furnace, in order to enhance the efficiency of the method.
Allowable Subject Matter
Claim 40 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: the prior art of record fails to teach wherein the step of cleaning comprises determining a compound to be removed and selecting a reduction of the pressure and/or the increase of the temperature based on a vapor pressure curve of the compound to be removed and comprises reduction of the pressure and/or increase of the temperature based on the vapor pressure curve either in a step wise or in a continuous manner.
Response to Arguments
Applicant's arguments filed 2/19/2026 have been fully considered but they are not persuasive.
Applicant argues that Hackner in view of Kruger and Zhang fail to teach the amended claim 35, as the references fail to teach cooling the plurality of fibers “immediately” after reaching a fixation temperature. Applicant points to portions of Hackner, Kruger, and Zhang disclosing process times that Applicant refers to as holding times and argues that the references teach holding at a fixation temperature and therefore, each fail to teach cooling immediately after reaching the fixation temperature. These arguments have been fully considered but are not found persuasive.
Claim 35 recites “heating the plurality of fibers at a heating rate higher than 50 K/min to a fixation temperature selected in the range of 50 to 98% of their melting point temperature; and cooling the plurality of fibers immediately after reaching said fixation temperature at a cooling rate higher than 50K/min.”
As discussed in the rejection above, the claim specifically limits the temperature of the fibers, not the temperature of the means of heating. Therefore, the claim is interpreted to limit the temperature of the fibers themselves, not the temperature of the means of heating. As a result, cooling “immediately” after the fibers reach any selected temperature within the range of 50-98% of the melting temperature of the fibers, meets the instant claim.
Applicant, therefore, mischaracterizes the teachings of the prior art as they relate to the claim limitations. Hackner teaches wherein “the time for which the metal fibers are subjected to the predetermined temperature and pressure is not particularly limited and depends on the material of the fiber, on the applied pressure and on the temperature.” (p. 17, lns. 30-33). The reference teaches preferred, and therefore, optional, predetermined time of heating of 10 seconds or longer. (p. 17, lns. 33-35).
Hackner is drawn to the amount of time metal fibers are subjected to heating at a particular temperature rather than limiting the temperature of the fibers themselves. Accordingly, Hackner does not require holding, for any amount of time, the fibers at the fixation temperature, but instead requires holding the heating means at a temperature for an amount of time sufficient to cause the temperature of the fibers to be raised to a sintering temperature (i.e. the elapsed time of the heating step to a fixation temperature). After sintering, the sintered fibers are no longer subjected to a heating temperature and therefore, would necessarily begin cooling “immediately.”
Note, dependent claim 47 requires wherein the steps of heating and cooling combine for a predetermined time period of 30 minutes or less and claim 48 requires where the time is equally split. Accordingly, claim 48 sets forth that the heating step may take place for a time of up to 15 minutes. This is the relevant time comparison to the “holding” time of the prior art references argued by Applicant. Hackner, as well as Kruger and Zhang teach heating times falling within or overlapping these ranges. See also MPEP 2144.05.
Hackner is therefore, deemed to teach a method of assembling a fiber network comprising a plurality of metal fibers, wherein the method comprises providing a plurality of metal fibers at an assembling site, fixing the plurality of metal fibers to one another by heating to a temperature overlapping the claimed temperature range, and wherein the fiber network is removed from heating after obtaining sintering (i.e. the fibers reach a temperature sufficient to cause a desired amount of amount of fusing between individual fibers) and thus, would begin necessarily cooling “immediately after” reaching the desired fixation temperature.
Moreover, as the reference is drawn to achieving a controlled amount of sintering by heating to a temperature below the melting point to avoid deformation of the fibers, it would have been obvious to one of ordinary skill in the art to immediately begin cooling the fibers after sufficient sintering (i.e. fixation) has been achieved in order to prevent unwanted changes to the structure due to continued heating.
Finally, for the purposes of compact prosecution, a new grounds of rejection over Hackner in view of Kruger, Zhang, and Sasakuri is made, as detailed above.
Conclusion
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/JOHN A HEVEY/Primary Examiner, Art Unit 1735
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