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 .
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.
Claims 1, 5, 7 and 9–12 are rejected under 35 U.S.C. 103 as being unpatentable over Wertz et al., US 2011/0259813 A1 in view of Moon, US 2019/0105589 A1.
Regarding claims 1 and 9, Wertz teaches a filter media 10 that can be used for air filtration. See Wertz Fig. 3, [0020], [0148]. The filter media 10 reads on the claimed “air filter medium.” The filter media 10 comprises a second layer 30 (also referred to as the meltblown layer or the nanofiber layer) that is porous and can be made from a fluororesin, such as polytetrafluoroethylene (PTFE). Id. at [0076], [0083]. The second layer 30 reads on the “porous fluorine resin membrane.” Note that a meltblown material is understood in the art as being a type of membrane. See e.g., Squires et al., US 2008/0032114 A1, [0008] (describing a covering including a membrane, which could be a meltblown layer).
The filter media 10 further comprises a first layer 20, which reads on the “collection layer.” See Wertz Fig. 3, [0076]. The first layer 20 is formed of a fibrous material including a glass fiber, as claimed. Id. at [0020], [0033], [0046].
The filter media 10 also comprises an intermediate layer 40 (also referred to as the adhesive layer), which may be an adhesive. See Wertz Fig. 3, [0022]. The intermediate layer 40 reads on the “air-permeable adhesive layer.” The intermediate layer 40 is air-permeable because air can flow through the filter media 10 from the first layer 20 through the second layer 30, with the intermediate layer 40 positioned in between. Id. at [0020]. The intermediate layer 40 has a basis weight ranging, for instance, from 3 to 10 g/m2. Id. at [0093]. The prior art range of 3 to 10 g/m2 overlaps the claimed range of 4 to 16 g/m2, establishing a prima facie case of obviousness. See MPEP 2144.05, subsection I. The intermediate layer 40 can have a thickness of 5 to 50 microns, which overlaps with the claimed range of 5.5 to 16 µm, establishing a prima facie case of obviousness. See Wertz [0092].
The first layer 20, the intermediate layer 40 and the second layer 30 are placed in this order from upstream to downstream of the filter media 10 configured to allow an air flow to pass through the filter media 10, as claimed, because the first layer 20 can be positioned upstream of the second layer 30 with the intermediate layer 40 being between the first and second layers 20, 30. See Wertz Fig. 3, [0020].
The initial pressure drop of the filter media 10 is 10 to 300 Pa at a permeate flow rate of 20 cm/s. See Wertz [0107], [0063]. The prior art range of 10 to 300 Pa at a permeate flow rate of 20 cm/s either overlaps with the claimed range of 250 Pa or less at a permeate flow rate of 5.3 cm/sec, or is close enough to the claimed range to establish a prima facie case of obviousness. See MPEP 2144.05, subsection I (a prima facie case of obviousness exists for overlapping ranges, and where the claimed ranges are merely close). Note that initial pressure drop would be expected to be higher with increased flow rate because increased fluid results in increased resistance. Therefore, the initial pressure drop of the filter media of Wertz would be expected to be less than 10 to 300 Pa when measured at a flow rate of 5.3 cm/sec compared to 20 cm/s as reported in the reference.
The filter media 10 is tested with fine dust particles having a diameter as small as 0.1 µm at a concentration of 200 mg/cm3 at a face velocity of 20 cm/s to measure the dust holding capacity, with the dust holding capacity being measured at the moment when the pressure drop across the media reaches 1,800 Pa. See Wertz [0063]. The holding amount of the filter media 10 is up to 500 g/m2. Id. at [0104]. Because of this relatively high dust holding capacity of 500 g/m2 (well above 20, 43.0 and 50.0 g/m2), the test performance of the filter media 10 is interpreted to read on or is close enough to render obvious the limitations of:
“when a test is performed in which polyalphaolefin particles are allowed to pass through the air filter medium at a concentration of 0.2 to 0.5 g/m2 and a linear velocity of 5.3 cm/sec and a holding amount of the polyalphaolefin particles held by the air filter medium and a variation of a pressure drop of the air filter medium are evaluated, the holding amount is 43.0 g/m2 or more from a moment when the holding amount reaches 20 g/m2 to a moment when the pressure drop of the air filter medium reaches PD1 + 120 Pa, where PD1 is the pressure drop of the air filter medium at the moment when the holding amount reaches 20 g/m2, the polyalphaolefin particles being polydisperse particles having a peak in number in a particle size range of 0.1 to 0.2 um” (claim 1)
“wherein when the test is performed, the holding amount is 50 g/m2 or more from when the pressure drop of the air filter medium is an initial value PD0 to when the pressure drop of the air filter medium reaches PD0 + 250 Pa” (claim 9)
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Wertz differs from claim 1 because it is silent as to the size of the glass fibers of the first layer 20. Therefore, the reference fails to provide enough information to teach “the glass fiber has an average fiber diameter of 0.5 to 2.0 µm,” as claimed.
But the first layer 20 can be manufactured using a wet laid technique. See Wertz [0069]. The first layer 20 comprises non-glass fibers, in addition to the glass fibers. Id. at [0033], [0046]. Also, the first layer 20 is attached to the nanofiber layer 30, which can be formed in a meltblown process. Id. at [0076].
With this in mind, Moon teaches a filter medium comprising a wet-laid nonwoven fabric layer that is attached to a melt-blown nonwoven fabric layer. See Moon [0011]. The wet-laid layer comprises glass fibers (in addition to other fiber types), with the glass fibers having a diameter of 0.1 to 2.0 µm. Id. at [0028], [0036].
It would have been obvious for the glass fibers in the first layer 20 of Wertz to have a diameter ranging from 0.1 to 2.0 µm because this is a suitable size for glass fibers in a wet laid layer attached meltblown layer in a filter media. The prior art range of 0.1 to 2.0 µm overlaps with the claimed range of 0.5 to 2.0 µm, establishing a prima facie case of obviousness.
Regarding claim 5, Wertz teaches that the filter media 10 can include a scrim placed between the adhesive layer 40 and the nanofiber layer 30 (as the first layer 20 is disposed on the scrim by adhesive disposed on the first layer 20). See Wertz [0140]. The scrim reads on the “first air-permeable supporting layer.”
Regarding claim 7, Wertz teaches that the second layer 30 (the “porous fluorine resin membrane”) is a porous polytetrafluoroethylene membrane because it is porous and can be made from PTFE. See Wertz [0083].
Regarding claim 10, Wertz teaches that the filter media 10 can be pleated. See Wertz [0142]. The pleated filter media reads on the “filter pleat pack comprising an air filter medium folded into pleats, wherein the air filter medium is the air filter medium according to claim 1.”
Regarding claims 11 and 12, Wertz teaches that the filter media 10 can be pleated and can be used in a filter assembly. See Wertz [0142], [0148]. The filter assembly reads on the “air filter unit comprising an air filter medium, wherein the air filter medium is the air filter medium according to claim 1” (claim 11) and the filter assembly using the pleated filter media reads on the “air filter unit comprising a filter pleat pack, wherein the filter pleat pack is the filter pleat pack according to claim 10” (claim 12).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Wertz et al., US 2011/0259813 A1 in view of Moon, US 2019/0105589 A1 and in further view of Smith, US 2018/0236384 A1.
Regarding claim 6, Wertz as modified teaches the limitations of claim 1, as explained above.
Wertz differs from claim 6 because it is silent as to the filter media 10 comprising a second air-permeable supporting layer placed on a downstream side in a direction of the airflow with respect to the second layer 30 (the “porous fluorine resin membrane”).
But Smith teaches a filter media comprising a cover layer that can be placed on the outflow side if the filter media. See Smith [0143]. The cover layer is beneficial because it can function as a dust loading layer, aesthetic layer and support layer. Id.
It would have been obvious to provide the cover layer of Smith on the downstream side of the filter media 10 of Wertz to improve dust holding capacity while improving aesthetics and support of the filter media 10.
With this modification, the cover layer of Smith reads on the “second air-permeable supporting layer placed on a downstream side in a direction of the airflow with respect to the porous fluorine resin membrane.”
Response to Arguments
35 U.S.C. 103 Rejections
The rejection is updated to address the newly added limitation of the collection layer being formed of a fibrous material including a glass fiber, wherein the glass fiber has an average fiber diameter of 0.5 to 2.0 µm.
Double Patenting Rejections
The double patenting rejections over U.S. Application No 18/027,453 are withdrawn because the Terminal Disclaimer filed December 30, 2205 is approved.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Izzi et al., US 2013/0327218 A1 [0053] (teaching a filter media with a blend of glass fibers for increasing permeability, where the blend comprises two or more of glass fibers of 0.3 to 0.5 microns, 1 to 2 microns, 3 to 6 microns, 6 to 10 microns, and 10 to 100 microns); Adamek et al., US 2009/0044702 A1 [0089]–[0090] (teaching that glass fibers between 0.1 to 16 microns are commonly used in filter media).
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T. BENNETT MCKENZIE
Primary Examiner
Art Unit 1776
/T. BENNETT MCKENZIE/Primary Examiner, Art Unit 1776