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 Status
Claims 1-25 are pending.
Claims 3, 5, 7-9, 16, and 24-25 have been amended.
No claims have been cancelled.
Thus, claims 1-25 represent all claims currently under consideration.
Priority
Domestic Priority data as claimed by Applicant:
This application is a 371 of PCT/EP2022/076621 (09/26/2022)
Foreign Applications:
EUROPEAN PATENT 21306333.2 (09/27/2021)
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Objections
Claim 3 is objected to because of the following informalities:
In line 4, the semicolon needs to be replaced with a period at the end of the sentence. See MPEP § 608.01(m).
Claim 6 is objected to because of the following informalities:
In line 2, “in cast PMMA” should read “of cast PMMA”.
Claim 11 is objected to because of the following informalities:
In line 1, “the screw rotation speed” should read “a screw rotation speed”.
Claim 12 is objected to because of the following informalities:
In line 1, “the screw rotation speed” should read “a screw rotation speed”.
Claim 13 is objected to because of the following informalities:
In line 1, “the screw rotation speed” should read “a screw rotation speed”.
Claim 14 is objected to because of the following informalities:
In line 1, “the screw rotation speed” should read “a screw rotation speed”.
Claim 14 is objected to because of the following informalities:
In line 2, a period needs to be placed at the end of the sentence. See MPEP § 608.01(m).
Claim 20 is objected to because of the following informalities:
In lines 1-2, “the screw rotation speed” should read “a screw rotation speed”.
Claim 21 is objected to because of the following informalities:
In lines 1-2, “the screw rotation speed” should read “a screw rotation speed”.
Claim 22 is objected to because of the following informalities:
In lines 1-2, “the screw rotation speed” should read “a screw rotation speed”.
Claim 23 is objected to because of the following informalities:
In lines 1-2, “the screw rotation speed” should read “a screw rotation speed”.
Claim 23 is objected to because of the following informalities:
In line 2, a period needs to be placed at the end of the sentence. See MPEP § 608.01(m).
Appropriate correction is required.
Claim Interpretation
The abbreviation “PMMA” as recited in claims 5-6 will be interpreted as poly(methyl methacrylate), as defined in the instant specification (p. 1, line 16).
The term “cast PMMA” as recited in claim 6 will be interpreted as defined in the instant specification (p. 5, lines 11-15) as a grade or form of PMMA that is formed by casting methyl methacrylate, mixed with initiators and possibly other additives into a form or mold. Cast PMMA has a high molecular weight and high purity, but cannot be recycled mechanically as it depolymerizes at a temperature close to its processing temperature.
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked.
As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph:
(A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function;
(B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and
(C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function.
Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function.
Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function.
Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office Action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action.
This application includes one or more claim limitations that use the word “means” or “step” but are nonetheless not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph because the claim limitations recite sufficient structure, materials, or acts to entirely perform the recited function. Such claim limitations are: “the processing unit(s) configured for mechanically processing and heating said polymer(s)” in claim 1, “a unit configured for melting the polymer(s)” in claim 8, “a heated screw extruder configured for melting and heating the polymer(s)” in claim 9, “One or more processing unit(s) configured for heating and mechanically processing the polymer(s)” and “a control loop configured to control the one or more feeder(s) to adjust a feeding rate” in claim 17, and “a heated screw extruder configured for melting and heating the polymer(s)” in claim 18.
Because these claim limitations are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, they are not being interpreted to cover only the corresponding structure, material, or acts described in the specification as performing the claimed function, and equivalents thereof.
If Applicant intends to have these limitations interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, Applicant may: (1) amend the claim limitation(s) to remove the structure, materials, or acts that performs the claimed function; or (2) present a sufficient showing that the claim limitation(s) does/do not recite sufficient structure, materials, or acts to perform the claimed function.
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.
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 1-25 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.
Regarding claim 1, the phrase "such as" renders the claim indefinite because it is unclear whether the limitations following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
Regarding claims 2-16, these dependent claims do not resolve the indefiniteness of claim 1 detailed above.
Claims 12 and 21 recite the phrase “wherein the screw rotation speed is comprised between 100 and 50/d rpm where d represents the screw diameter (in meter, m)”. However, it is unclear as written what the term “/d rpm” is referring to. The instant specification does not adequately address this issue nor provide a range for the screw diameter (Specification; page 13, lines 29-31), and this ambiguity renders the instant claims indefinite.
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). In the present instance, claims 12 and 21 recite the broad recitation “where d represents the screw diameter” and the claims also recite the parenthetical limitation “(in meter, m)” which is the narrower statement of the range/limitation. The claims are 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.
Regarding claim 17, the phrase "such as" renders the claim indefinite because it is unclear whether the limitations following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
Regarding claims 8-25, these dependent claims do not resolve the indefiniteness of claim 17 detailed above.
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.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-15 and 17-25 are rejected under 35 U.S.C. 103 as being unpatentable over Tokushige et al. (US 3,959,357, IDS of 03-26-2024; published 05-25-1976), in view of J. S. Oosthuizen (“Development of a twin screw extruder with an integrated cooling roller system”; Master of Engineering Dissertation; published 11-2011).
Regarding claims 1 and 17, Tokushige teaches a method and apparatus for continuously thermally decomposing a synthetic macro-molecules composition consisting essentially of an organic polymer selected from the group consisting of polystyrene; copolymer of acrylonitrile, butadiene and styrene; polymethylmethacrylate; polypropylene; and polyethylene.
The Figure of Tokushige describes a diagrammatically preferred screw extruder apparatus for carrying out the method. The synthetic macro-molecule materials to be treated are supplied into hopper 1. The synthetic macro-molecule materials thus supplied are fed forwardly by a rotating screw 2 to be plasticized and thermally decomposed by internal heat generated by their subjection to the shearing and kneading action of said screw as well as by the external heat transmitted through the wall of the cylinder 3 of said extruder which is heated by any suitable heating means 12, 13, 14 such as electric heaters, wherein the melting of the said synthetic macro-molecule composition is carried out in said cylinder, and the heating of cylinder 3 is preferable to be carried out separately at the melting zone and the thermal decomposition zone (Abstract; Col. 1, lines 9-17 and 43-63; Col. 2, lines 3-37; claims 1 and 4; Figure).
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Tokushige does not explicitly teach measuring the heating power and/or energy consumed by said one or more processing unit(s) and measuring mechanical power and/or energy consumed by said one or more processing unit(s) and adjusting the feeding rate of the polymer(s) into the processing unit(s) depending on the measured consumed heating energy and/or the consumed mechanical energy, as recited in claim 1. Tokushige also does not explicitly teach a sensor for measuring the heating energy consumed by the processing unit(s), a sensor for measuring mechanical energy consumed by the processing unit(s); and a control loop configured to control the one or more feeder(s) to adjust a feeding rate as a function of the measured consumed mechanical energy and/or the measured consumed heating energy, as recited in claim 17.
However, Tokushige does teach that it is possible, according to the present invention, to adjust the degree of their thermal decomposition to control the mean molecular weight of the thermally decomposed products by regulating the feed velocity for the material, the temperatures for thermal decomposition and the degree of vacuum (Col. 3, lines 36-50 and 61-65). Thus, the skilled artisan would recognize that the feeding rate of the screw extruder of Tokushige is an important process variable that can be rationally adjusted to optimize the process.
Further regarding claims 1 and 17, Oosthuizen teaches that the extruder is indisputably the most important piece of machinery in the polymer processing industry, and screw extrusion machines are used extensively in the production, compounding, and processing of plastics. Extruders are big energy consumers, and unnecessary high energy consumption is caused by the use of incorrect equipment, unsuitable screw configurations, and poor operating parameters and conditions. The basic principal of extrusion is that the product is process by the transfer of mechanical energy to thermal energy. Incorrect mechanical configurations and operating parameters cause insufficient transfer of energy to the product, leading to a large energy input from external sources such as electrical heating elements, which increases the total energy consumption of the extruder (page 2, paragraphs 3-4; page 3, paragraphs 3-4).
Measuring the energy consumption of an extruder provides valuable information regarding the product being manufactured, including production costs and pre-conditioning requirements for optimization of the process. The energy consumption is measured by measuring the energy consumed by the drive system (mechanical energy) and the process temperature control zones. The process temperature control zones usually consist of two systems, one adding heat to the process and the other extracting heat from the process (page 100, paragraphs 1-2).
Energy consumption is determined by measuring the current supply to the electric drive (power converter) of the drive motor, the current supplied to the cartridge heaters and finally the temperature difference of the cooling water flowing through the barrel measured by thermocouple units, as well as the flow rate. The measuring equipment consists of data loggers with current transformers, thermocouples for measuring the water temperature, and a flow meter.
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Current transformers and data loggers are used to measure the current through the electric drive. The power consumed by the electric motor driving the extruder screws can be calculated and used to determine the Specific Mechanical Energy, since the power consumed by the heaters and the coolers are known (since the current is known), it is possible to calculate the Specific Thermal Energy (page 104, paragraph 5 and Figure 6-1; page 105; paragraphs 1 and 3, Figure 6-2; page 106, paragraph 1 and Figure 6-3).
Oosthuizen further teaches a test procedure that includes the adjustment of the feed rate and/or screw speed to enable the ascertainment of the extruder’s energy consumption profile at different screw speeds, throughputs and mechanical configurations, and these energy consumption profiles were analyzed and compared in order to find the most cost-effective and production enhanced configuration. The graphs show the specific mechanical energy (SME), specific thermal energy (STE), and the total energy usage (TEU) per throughput. Figure 6-13 indicates that for both tested configurations, the STE decreases with an increase in feed rate, and Figure 6-14 indicates that for both tested configurations, the SME decreases with an increase in feed rate. In addition, Figure 6-15 indicates that the total energy consumption reduces with an increase in feed rate, meaning that it is more cost-effective to run the extruder at high feed rates. Oosthuizen proves that it is possible to measure certain parameters during the extrusion process of the product in order to determine the energy consumed of an extruder for a given product. Oosthuizen concludes that the optimum operating point would be where the feed rate is a maximum and the energy usage is a minimum. A minimum energy usage will be where the STE as well as the SME values are a minimum. Reducing both the specific thermal as well as the specific mechanical energy of the extrusion process will reduce the cost per weight of the product increasing the profit margin of the product (page 108; paragraph 3 and Figure 6-6; page 112, paragraphs 1-2 and Figure 6-13; page 113, paragraph 2 and Figures 6-14 and 6-15; page 114, paragraph 5; page 116, paragraphs 4-5; page 118, paragraph 1).
Finally, Oosthuizen further teaches a twin screw extruder equipped with a control panel that enables the operator to set the desired temperature profile over the barrel, the screw speed, feed rate, and cooling roller speed (page 92, paragraph 1 and Figure 4-8).
The teachings of Tokushige and Oosthuizen are analogous because they both teach methods and systems comprising a screw extruder apparatus, and Oosthuizen explicitly teaches that screw extrusion machines are extensively used in the processing of plastics, in a manner consistent with Tokushige and the instantly claimed invention.
It would have been prima facie obvious to have modified the method and apparatus of Tokushige to incorporate the teachings of Oosthuizen to implement sensors and a control loop to measure the heating energy consumed and the mechanical energy consumed and adjust the feeding rate based on these measurements via the control loop with a reasonable expectation of success, because Tokushige teaches that the degree of thermal decomposition can be controlled by regulating the feed velocity for the material, and Oosthuizen teaches that it is possible to predictably measure these energy parameters during the extrusion process in order to determine the energy consumed to arrive at an optimum operating point where the feed rate is a maximum and the energy usage is a minimum. See MPEP § 2143(I)(A).
Therefore, it would have been prima facie obvious before the effective filing date of the claimed invention to have modified Tokushige to incorporate the teachings of Oosthuizen to arrive at the invention of claims 1 and 17. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, a depolymerization method and system with improved overall efficiency that minimizes energy usage by reducing both the specific thermal energy and the specific mechanical energy of the extrusion process to reduce the cost per weight of the product and increase the profitability of the process, as described above.
Regarding claim 2, Figure 6-14 of Oosthuizen indicates that the SME decreases with an increase in feed rate, and the optimum operating point would be where the feed rate is a maximum and the energy usage is a minimum. A minimum energy usage will be where the STE as well as the SME values are a minimum (page 113, Figure 6-14; page 116, paragraphs 4-5). Therefore, when considering Tokushige in view of Oosthuizen, the skilled artisan would be sufficiently motivated to increase the feeding rate when the measured consumed mechanical energy increases in order to minimize the overall energy usage of the extrusion process and arrive at a cost-effective extrusion process.
Regarding claims 3-4 and 6, Tokushige and Oosthuizen do not explicitly teach these claim limitations.
However, the skilled artisan could arrive at these claim limitations based on the combined teachings of Tokushige and Oosthuizen because Tokushige teaches that the degree of thermal decomposition can be controlled by regulating the feed velocity for the material (Tokushige; Col. 3, lines 36-50 and 61-65), and Oosthuizen teaches that the SME decreases with an increase in feed rate, and the optimum operating point would be where the feed rate is a maximum and the energy usage is a minimum (Oosthuizen; page 113, Figure 6-14; page 116, paragraphs 4-5).
Further regarding claims 3-4, the method and apparatus of Tokushige is not limited to specific grades or types of organic polymer, and includes the use of a broad range of polymers such as polystyrene and polymethylmethacrylate (claim 1). Tokushige further teaches that most of the synthetic macro-molecule materials contain substances hard to be thermally decomposed such as inorganic fillers etc (Col. 1, lines 30-32). As such, the skilled artisan would recognize that the method and apparatus of Tokushige can be applied to polymer(s) of various grades with a reasonable expectation of success.
Further regarding claim 6, the present application states that cast PMMA consumes more mechanical energy than other grades of PMMA (Specification; page 5, lines 23-24).
Therefore, in instances where the mechanical energy of the system increases as measured by the method and system of Tokushige in view of Oosthuizen, for example when the polymer(s) contains at least one grade requiring more mechanical energy compared with other grades of said polymer (as recited instant claims 3-4) or when the content of cast PMMA in the PMMA or polymers mixture increases (as recited in instant claim 6), the skilled artisan would be sufficiently motivated to adjust (i.e., increase) the feeding rate to arrive at a process that minimizes the overall energy usage and improves its cost-effectiveness with a reasonable expectation of success.
Regarding claim 5, Tokushige teaches that the method for continuously thermally decomposing a synthetic macro-molecule composition consists of an organic polymer selected from the group consisting of polystyrene; copolymer of acrylonitrile, butadiene and styrene; polymethylmethacrylate; polypropylene; and polyethylene. In addition, Example 1 of Tokushige teaches the continuously thermally decomposition of polystyrene, and Example 4 of Tokushige teaches the continuously thermally decomposition of polymethylmethacrylate (Col. 4, lines 12-16; Col. 5, lines 53-55; Examples 1 and 4; claim 1).
Regarding claims 7-10 and 18-19, the method and apparatus of Tokushige comprises supplying synthetic macro-molecule materials into the cylinder of an extruder having a screw which functions to shear, knead and transport said synthetic macro-molecule materials so that they are continuously thermally decomposed by internal heat generated by the shearing and kneading action to which they are subjected as well as by the external heat transmitted through the wall of said cylinder, wherein the melting of the said synthetic macro-molecule composition is carried out in said cylinder. In addition, Tokushige teaches that as the extruder a single-screw type or a twin-screw type of any known construction. Tokushige further teaches that it is preferable to use a twin-type screw for the whole extruder or only for the thermal decomposition zone in order to perfectly feed the residue (Col. 1, lines 49-65; Col. 3, lines 26-28 and 51-57; claims 1 and 4; Figure).
Regarding claims 11-14 and 20-23, Oosthuizen teaches screw extruder configurations with rotation speeds of 300, 400, 500, and 500 rpm (page 112, Figure 6-13; page 113, Figure 6-14 and Figure 6-15). These values reside within the ranges recited in claims 11-14, 20, and 22-23. MPEP § 2144.05(I) states that “[i]n the case where the claimed ranges ‘overlap or lie inside ranges disclosed by the prior art’ a prima facie case of obviousness exists.”
Further regarding claims 12 and 21, although the scope of these claims is not clear, Oosthuizen teaches several screw rotation speeds, as detailed above, and further teaches a control panel that enables the operator to set a desired screw speed. In addition, Oosthuizen teaches that the screw speed is a process variable for both STE and SME, and SME values are decreased with an increase in screw speed (page 92, paragraph 1; page 115, paragraphs 1-2; page 117, paragraph 6). Therefore, the skilled artisan would recognize from the teachings of Oosthuizen that the screw speed can be optimized in order to arrive at a cost-effective and energy-efficient process through means of routine experimentation that is non-inventive in nature. MPEP § 2144.05(II) states 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.”
Regarding claim 15, Tokushige teaches a method and apparatus wherein the heating of cylinder 3 is carried out at the melting zone and the thermal decomposition zone, and the thermal decomposition zone is at a temperature of 500-600 ºC. In addition, Examples 1-6 of Tokushige teach thermal decomposition temperatures of 500 ºC and 600 ºC (Col. 2, lines 35-39; claim 1; Examples 1-6 and Tables therein). This temperature range overlaps with the range recited in the instant claim. MPEP § 2144.05(I) states that “[i]n the case where the claimed ranges ‘overlap or lie inside ranges disclosed by the prior art’ a prima facie case of obviousness exists.”
Regarding claim 24, Examples 1-6 of Tokushige teach thermal decomposition conditions, wherein the degree of vacuum in the system (gauge pressure, mm Hg) ranges from –650 to atmospheric pressure (Col. 4, lines 24-30 and 50-55; Col. 5, lines 20-24 and 60-63; Col. 6, lines 8-19 and 35-45; Examples 1-6 and Tables therein).
Regarding claim 25, Tokushige teaches that when it is desired to return the product having high boiling points to cylinder 3 again for its further thermal decomposition, it is preferable to provide one of the discharge orifices at right angles to the thermal decomposition starting position (Col. 2, lines 47-52). Therefore, based on the teachings of Tokushige, the skilled artisan could arrive at a depolymerization system that comprises a recycling loop to recycle polymer(s) that have not been depolymerized, in a manner consistent with the instant claim.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Tokushige et al. (US 3,959,357, IDS of 03-26-2024; published 05-25-1976), in view of J. S. Oosthuizen (“Development of a twin screw extruder with an integrated cooling roller system”; Master of Engineering Dissertation; published 11-2011) as applied to claims 1-15 and 17-25 above, and further in view of Beghetto et al. (“Recent Advancements in Plastic Packaging Recycling: A Mini-Review”; Materials 2021, 14, 4782, pages 1-24; published 08-24-2021).
Regarding claim 16, claim 1 is rendered obvious over Tokushige and Oosthuizen, as detailed above.
The Examples of Tokushige teach the recovery of monomers in high yield (e.g., Example 4 teaches more than 95% of the liquid products was methyl methacrylate monomer), and Oosthuizen teaches that screw extrusion machines are extensively used in the production and processing of plastics (Tokushige; Col. 1, lines 9-17; claim 1; Examples 1-4; Oosthuizen; page 2, paragraph 4).
Although the skilled artisan could reasonably deduce that the recovery of high purity methyl methacrylate monomer as taught by Tokushige represents a process for recycling plastics or plastics mixtures, Tokushige and Oosthuizen do not explicitly teach this claim limitation.
Further regarding claim 16, though it does not appear that the claim preamble actually limits the process, regardless, this is well known in the art as taught by Beghetto.
Beghetto teaches that long-lasting plastic waste is a massive problem facing the scientific community and the quest for circular and sustainable approaches for plastic recycling is one of the most demanding for delivering a healthier world for future generations. Beghetto further teaches several methods for the recycling of polymeric plastic materials, including polystyrene and PMMA, based on chemical or mechanical methods. Beghetto further teaches that extrusion remains the most widely used method for processing both virgin and recycled plastic, wherein plastic flakes are fed into the extruder and pushed by a screw into a heated cylinder, thus melting the plastic. Beghetto further teaches the upcycling of LDPE from plastic bags using a twin-screw extruder. Mechanical recycling and chemical upcycling appear to be the most promising strategies, since incineration and landfill are more pollutant and, for the latter, plastic waste completely loses its value (Abstract; page 9, paragraphs 4 and 7; page 11, paragraph 6; page 17, paragraph 6).
It would have been prima facie obvious to modify Tokushige and Oosthuizen to incorporate the teachings of Beghetto to arrive at a process for recycling plastics or plastics mixtures with a reasonable expectation of success, because Tokushige teaches a screw extruder for the thermal decompositions of polymers including polystyrene and PMMA, Oosthuizen teaches that screw extrusion machines are extensively used in the processing of plastics, and Beghetto teaches that mechanical recycling and chemical upcycling, including strategies using screw extruders, appear to be the most promising strategies for addressing the growing scientific and world health problem of plastic waste. See MPEP § 2143(A).
Therefore, it would have been prima facie obvious before the effective filing date of the claimed invention to have modified Tokushige and Oosthuizen to incorporate the teachings of Beghetto to arrive at the claimed invention. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, a sustainable process for replacing synthetic plastics that addresses the global issue of long-lasting plastic waste, as described above.
Based on the combined teachings of the references, the Examiner submits that a person of ordinary skill in the art would have had a reasonable expectation of success of arriving at the instantly claimed process and system. Therefore, the invention as a whole would have been prima facie obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, and absent a clear showing of evidence to the contrary.
Conclusion
Any inquiry concerning this communication or earlier communications from the Examiner should be directed to Derek Rhoades whose telephone number is (703)-756-5321. The Examiner can normally be reached Monday–Thursday, 7:30 am–5:00 pm EST; Friday, 7:30 am–4:00 pm EST.
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/D.R./Examiner, Art Unit 1692
/AMY C BONAPARTE/Primary Examiner, Art Unit 1692
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