DETAILED ACTION
Election/Restrictions
Applicant’s election of claims 16-13 in the reply filed on April 30, 2026 is acknowledged. Because Applicant did not distinctly and specifically point out any supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)). Claims 33-40 are withdrawn from consideration.
Claim Objections
Claim 24 is objected to because of the following informalities: it recites “the central (or core) layer or inner layers has/have density of 1.1 kg/dm3 when the outer layers have density of 1.6 kg/dm3”, which should be ““the central (or core) layer or inner layers has/have a density of 1.1 kg/dm3 when the outer layers have a density of 1.6 kg/dm3”. Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 16-32 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter the inventor regards as the invention.
Claim 16 is indefinite because it recites a core with polygonal cells, each being “bounded on two sides by covering-layer planes” in lines 2-3. The meaning of this limitation is unclear because it is not clear if a “covering-layer plane” is a layer or a plane, which merely refers to a flat surface. As such, it is not clear if claim 16 requires covering layers to be present on each side of the cells (and honeycomb core) or not. For the sake of compact prosecution and because the preamble recites a “folded honeycomb core” rather than a sandwich panel, the term “covering-layer plane” is interpreted herein as only referring to a surface or geometric region, rather than a layer, and the recited “folded honeycomb core” is interpreted herein as only requiring a core, rather than a core and covering layers. Appropriate correction is required.
Claim 16 is further indefinite because it recites “the central (or core) or inner layers having a density of 30% to 90%” followed by “preferably, 50-70% of the density of the outer layers”, which is a narrower statement of range. A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). The claim is considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims. For the sake of compact prosecution, only the broader range is considered herein to be required by the claim. Appropriate correction is required.
Claim 24 is indefinite because it recites “the central (or core) layer or inner layers has/have density of 1.1 kg/dm3 when the outer layers have density of 1.6 kg/dm3”. Because it is phrased as “when the outer layers” have the recited density, the claim appears to imply that the inner and outer densities can change. However, given that claims 16 and 25 are directed to a product, rather than a process where certain parameters can change or some kind of structure with components that are still in flux (i.e. moving, growing, etc.), it is not clear how the product of claims 16 and 25 can have varying densities at different times. For the sake of compact prosecution, the limitation is interpreted herein as conditional, meaning that “the central (or core) layer or inner layers has/have a density of 1.1 kg/dm3 if the outer layers have a density of 1.6 kg/dm3”. Appropriate correction is required.
Claim 28 is indefinite because it recites “the central (or core) layer or inner layers of the co-extruded wall has/have a thickness of preferably at least 1/3 [of the total cell wall thickness]” followed by “more preferably 67% to 90%, of the total cell wall thickness or preferably at least 1/2 of the total cell wall thickness”, which includes narrower statements of range and which is indefinite for the same reasons as discussed above in the rejection of claim 16 with respect to the combination of broad and narrower recitations in the same claim. For the sake of compact prosecution, only the broader range is considered herein to be required by the claim. Appropriate correction is required.
Claim 29 is indefinite because it refers to “the ideal plane of a cell wall”, which appears to lack proper antecedent basis because “an ideal plane” a cell wall has not been recited or established as being present. Appropriate correction is required.
Claim 30 is indefinite because it recites that the thermoplastic sheet materials may be “a thermoplastic polymer selected from a group consisting of polyolefins, in particular polyethylene or polypropylene, polyesters, in particular polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate or polyetylene- 1,2-furandicaboxylate, polyamides, in particular polyamide 6 or polyamide 6,6,” and others. The quoted limitation recites a list that broadly includes each of polyolefins polyesters, and polyamides, which are each followed by a narrower list of specific types of the named polymer class. This limitation is indefinite for the same reasons as discussed above in the rejection of claim 16 with respect to the combination of broad and narrower recitations in the same claim. For the sake of compact prosecution, only the broader ranges are considered herein to be required by the claim. Appropriate correction is required.
Claims 17-32 are also rejected under 35 U.S.C. 112(b) because they depend from and require all of the limitations of claim 1.
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.
Claims 16-32 are rejected under 35 U.S.C. 103 as being unpatentable over Pflug (US PG Pub. No. 2021/0046719) in view of Ono (US Pat. No. 3,855,376). Evidence for claims 21-25 is provided by the Engineering Toolbox (The Engineering Toolbox, “Densities of Selected Solids”, 2021, p. 1-8).
Regarding claims 16 and 30-32, Pflug teaches a honeycomb core (10) comprising an array of hexagonal cells (i.e. “polygonal cells” that each form a “polygonal ring”) each having lateral cell walls (1-6) and being bounded by two, planar ends/sides where a covering layer may be attached (i.e. “covering-layer planes”) (Figs. 1, 15, 16; Abstract; par. 11, 62). The cells walls comprise a sheet material having a symmetric, three-layer structure that may be a thermoplastic, such as polypropylene, may be formed by co-extrusion, and includes a central core layer, which may be a foam layer, sandwiched between skin layers (par. 13, 18, 20, 29, 50). As shown in Figures 15 and 16 and discussed by Pflug, assembly of the core involves at least some folding operations (Figs. 15, 16; par. 97, 98) and, therefore, the core qualifies as a “folded honeycomb core”. Pflug further teaches that his core can be covered by one or more cover layers (par. 87).
The teachings of Pflug might be considered to differ from the current invention in that he does not explicitly teach a folded honeycomb core including all of the above-discussed features, wherein the cells are made up of a lower-density foam core and higher-density skins of the same thermoplastic. However, Pflug does teach that it is especially advantageous for the skins and core of a the cell walls having a honeycomb core to be made of the same thermoplastic so that the skins and core can be joined by thermoplastic welding (par. 128). Although Pflug teaches that cell walls including a foam core and skin layers may be made by co-extrusion instead of welding, one of ordinary skill in the art would understand that the same principle would apply, wherein foam and skin layers of the same thermoplastic material would bond together better if made of the same thermoplastic rather than dissimilar thermoplastics. Therefore, it would have been obvious to one of ordinary skill in the art to make a folded honeycomb core having hexagonal cells including lateral cell walls comprising co-extruded sheets of thermoplastic foam sandwiched between non-foamed thermoplastic skin layers of the same thermoplastic material, such as polypropylene, because Pflug teaches that such a structure and features are appropriate for his product, in order to form a strong bond between the foam and skin layers making up the cell walls, and because Pflug explicitly teaches that it is appropriate for the skin layers and core in the lateral cell walls forming his honeycomb core to be made of the same thermoplastic material. Although the thermoplastic polymers of the layers are molten or softened during extrusion, the layers, including the outer layers, are solid after cooling. Additionally, as Pflug makes no disclosure of the layers being something other than solid in his final product and discloses that the skin layers in such sheet materials are rigid (par. 50), the outer thermoplastic layers of the sheet material forming Pflug’s cell walls are presumed to be solid.
The teachings of Pflug differ from the current invention in that he does not teach specific densities or density differences between the core and outer layers in the sheet material that forms the cell walls in his honeycomb core. However, as noted above, Pflug teaches that the core and outer layers can be made by co-extruding thermoplastic layers.
Ono further teaches a thermoplastic sheet material comprising a foam thermoplastic core co-extruded with two outer thermoplastic layers (Abstract; col. 4, ln 53-col. 5, ln. 33; col. 9, ln. 43-47). The layers in Ono’s sheet material may include the same or different types of thermoplastics, and Ono discloses that the inner layer has an expansion ratio of 1.3 to 5 (Abstract; col. 9, ln. 43-48), which, if the same type of thermoplastic is used, equates to a core having a density that is about 20 to 77 % of that of the outer layers. Given the similarity of densities of the thermoplastic polymers involved, a sheet having dissimilar thermoplastic inner and outer layers would still also be expected to have a core of the taught expansion ratio range with a density that is close to the range of being 20 to 77 % of that of the outer layers. Thermoplastic sheet materials made according to Ono’s teachings are advantageous because they are lightweight structural materials that have excellent rigidity, shock-absorbing property, heat-resistance, sound-proof property, and sound absorbing property, and are free of interlayer separation (col. 1, ln. 50-57; col. 2, ln. 1-29). Therefore, it would have been obvious to one of ordinary skill in the art to use a co-extruded thermoplastic sheet material, such as that taught by Ono, which includes higher-density outer thermoplastic layers co-extruded with a thermoplastic foam inner layer having a density that is about 20 to 77 % of that of the outer layers wherein the outer and inner layers comprise the same type of thermoplastic, as the cell wall materials in Pflug’s honeycomb core because such a material is lightweight, does not suffer from unintended interlayer separation, and demonstrates excellent rigidity, shock-absorbing property, heat-resistance, sound-proof property and sound absorbing property.
To the extent that Ono’s thermoplastic layer structure is considered to differ from the current claims in that the term “co-extruded” is not explicitly used, it is noted that the recitation is a product-by-process limitation. Product-by-process claims are not limited by the recited processing steps, but rather the product implied by the recited procedure. See MPEP 2113. Ono’s sheet material, and the sheet material in the product of Pflug and Ono, meets the claim requirement because it has the implied structure.
Regarding claim 17, the teachings of the cited prior art might be considered to differ from the current invention in that the sheet material forming the cell walls is not explicitly taught to include outer layers having a greater yield strength than the central core layer. However, as noted above, it would have been obvious to utilize the same thermoplastic polymer for both the core and outer layers in the prior art product. As demonstrated by Ono, who teaches that a 3-layer acrylonitrile butadiene styrene (ABS) sheet including foam and outer layers arranged as discussed above has a decreased yield strength as compared to single-layer (unfoamed) ABS sheet (Table, beginning at col. 9, ln. 62) thereby demonstrating that the presence of the foam (and corresponding reduction in density) reduces the overall yield strength of a material, a lower-density, foamed core made of the same thermoplastic as the higher-density outer layers has a lower yield strength than the unfoamed outer layers. Alternatively, it would have been obvious to one of ordinary skill in the art to make the outer and core layers forming the cell walls in Pflug and Ono’s product from ABS because Ono discloses that ABS is used for various applications due to its large impact strength and can be used to make such sheet materials to be lightweight, include strongly-bonded layers, and have excellent quality (col. 5, ln. 67-col. 6, ln. 1; Ex. 1, 2). Therefore, the core layer of the prior art product has a lower yield strength than the outer layers in the ABS-containing product rendered obvious by the prior art.
Regarding claims 18 and 19, Ono teaches that a chemical blowing agent is used to form his foam layers (i.e. the core layer is made by “chemical foaming”) (col. 8, ln. 57-64).
Regarding claim 20, since claim 20 depends from claim 18, which was rejected on the basis of a foam formed by chemical foaming and not on the basis of a foam formed with low-density components, which is only optional in claim 18, further limitations related to a foam made with low-density components cannot distinguish the claimed invention over the cited prior art.
Regarding claims 21-25, as discussed above, it would have been obvious to configure the layers in the sheet material forming the cell walls of Pflug and Ono’s product to be ABS and to include a foamed core layer having a density of about 20 to 77 % of that of the outer layers. Ono discloses that a single-layer (unfoamed) ABS sheet has a density of 1.05 kg/dm3 (Table). Therefore, the foamed core layer in an ABS sheet material of Ono and Pflug may have a density in the range of about 0.21 to 0.81 kg/dm3.
As also discussed above, Pflug teaches that the co-extruded sheet material layers may be polypropylene. As evidenced by The Engineering Toolbox, polypropylene has a density of 0.91 to 0.94 kg/dm3 (p. 3). Therefore, a sheet material including unfoamed layers of polypropylene and a foamed polypropylene core having a relative density in the range of 20 to 77 % (i.e. due to having an expansion ratio of 1.3 to 5), as rendered obvious by Pflug and Ono, includes outer layers with a density of 0.91 to 0.94 kg/dm3 and a core with a density in the range of about 0.18 to 0.72 kg/dm3.
With respect to claim 24, it is noted that the prior art product is not required to have inner layers with a density of 1.1 kg/dm3 because it does not have outer layers with a density of 1.6 kg/dm3.
With respect to claim 25, it is noted that the prior art product is not required to have inner layers with a density of equal to or less than 0.9 kg/dm3 because it does not have outer layers with a density of exactly 1 kg/dm3. Additionally, the claimed combination of densities is obvious in view of the prior art product made of ABS because 1 kg/dm3, as claimed, is sufficiently close to 1.05 kg/dm3, as taught by the prior art. See MPEP 2144.05. As noted above, the inner layer in such a product is calculated to have a density in the range of 0.21 to 81 kg/dm3.
Regarding claims 26 and 27, the teachings of the cited prior art differ from the current invention in that a co-extruded sheet material of the recited thickness is not taught. However, as no criticality has been established, the recited thickness is a prima facie obvious selection of dimension that does not distinguish the claimed product over the prior art. See MPEP 2144.04. Additionally, it would have been obvious to one of ordinary skill in the art to select an appropriate thickness for the three-layer co-extruded sheet material (i.e. and cell walls), including selecting for the material to have a thickness of 1 mm, according to the properties required/desired of the final product being formed, as would be readily understood by one of ordinary skill in the relevant art.
Regarding claim 28, the teachings of Pflug and Ono differ from the current invention in that a honeycomb core including cell walls made of a sheet material with layers of the recited relative thicknesses is not explicitly disclosed. However, Ono does exemplify several of such sheet materials each having core layers that are 2/3 of the thickness of the sheet material, as a whole (Ex. 1, 2, 3). As such, it would have been obvious to one of ordinary skill in the art to configure the sheet materials forming the cell walls in the prior art honeycomb core to have a core layer having a thickness of 2/3, or about 67 %, of the thickness of the total layer (or cell wall) thickness because Ono demonstrates that such proportions are appropriate for his product and achieves lightweight sheet materials with well-bonded, strong foam layers that are excellent in quality (Ex. 1, 2).
Regarding claim 29, as shown in his figures the outer layers of the sheet materials forming the cells in Pflug’s honeycomb core are flat and planar (Figs. 1, 8, 10, etc.).
The teachings of Pflug and Ono might be considered to differ from the current invention in that neither explicitly discusses out-of-plane unevenness of the outer layers of the sheet materials forming the cells in Pflug’s or the combined prior art’s honeycomb core. However, Pflug does depict the outer layers of the sheet material forming the cell walls as being flat and planar, including having less variation than the thickness of the outer layers (Figs. 1, 8, 10, etc.). Accordingly, it would have been obvious to one of ordinary skill in the art to configure the outer layers of the sheet material forming the cell walls in Pflug and Ono’s product to be flat and planar, including wherein the outer layers have less out-of-plane unevenness than their thickness, because Pflug depicts such a structure as being appropriate for his product and makes no disclosure of the skin layers having a structure/texture/unevenness that is different (or greater) than what is shown.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JULIA L RUMMEL whose telephone number is (571)272-6288. The examiner can normally be reached Monday-Thursday, 8:30 am -5:00 pm PT.
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/JULIA L. RUMMEL/
Examiner
Art Unit 1784
/HUMERA N. SHEIKH/Supervisory Patent Examiner, Art Unit 1784
Prosecution Insights