Canister for storing oxygen absorber and process of producing the same

Abstract

The present invention discloses a canister for storing oxygen absorber and a process for preparing the same The canister includes 40 to 60 % by weight of polypropylene (PP), 4 to 26 % by weight of low-density polyethylene (LDPE), 2 to 7 % by weight of high-density polyethylene (HDPE), 1 to 5 % by weight of copolymer and 1 to 2 % by weight of inert filler. The composition for preparing canisters includes a high OTR value and a low MVTR value. The canister of the present invention includes an iron-based or iron free oxygen absorber for oxygen absorption. The canister is leakproof, its interlock design prevents easy opening of lids, is self-activated, moisture independent and compact active packaging allows absorption of residual oxygen and functions efficiently even in presence of moisture and desiccants.

Description

[0001]“CANISTER FOR STORING OXYGEN ABSORBER” FIELD OF THE INVENTION: The present invention relates to a canister and more particularly to a canister for storing an oxygen absorber. BACKGROUND OF THE INVENTION: Protecting packaged foods, nutraceuticals, and medications from oxidative deterioration is essential for prolonging shelf life of products. Therefore, it is vital to remove oxygen from the packaging space and liquid food solvents. Various techniques have been known in the prior art to mitigate oxygen contact with food items, medications, and nutritional supplements. Conventional methods include refrigeration, vacuum packaging, controlled environment storage, nitrogen gas substitution, and the application of antioxidants. However, these techniques are not always effective; are often expensive and do not completely eliminate oxygen from the packaged goods resulting in product deterioration. Another approach includes storing the pharmaceuticals, nutraceuticals, food products in airtight containers with oxygen absorbers. The oxygen absorbers chemically react with oxygen to form stable compounds, thereby preventing oxidation and extending product shelf life. Various oxygen absorbers have been employed in the art including ascorbic acid-based, zeolite-based, activated carbon- based, enzyme-based, iron powder-based, and iron-free oxygen absorbers. Traditional absorbers, like iron-based and ascorbic acid-based absorbers, necessarily require moisture to initiate and reduce oxygen. Moreover, when oxygen absorber pouches or canisters are inserted in bottles with medicinal pills, they absorb moisture from both the bottle and the pills, rendering the pills brittle and jeopardizing their integrity. Though the oxygen absorbers function properly, the desiccation of the pills is a big issue. There is need of a solution that maintains the efficacy of oxygen absorption without diminishing the tablets' moisture levels. Additionally, in situations where both oxygen and moisture need to be removed, oxygen absorbers alone are insufficient. They need to be used with desiccants such as molecular sieve or silica gel; however, this diminishes the effectiveness of oxygen absorption as the desiccants remove the moisture required for the oxygen absorbers to function properly. Additionally, there is a risk of these absorbers spilling and contaminating the products. Therefore, an improved solution is required to ensure the effective functioning of oxygen absorbers in the presence or absence of moisture or with desiccants, while preventing spillage. One approach to address the above-mentioned issues is storing the oxygen absorbers in a packaging material. For this purpose, a packaging material that provides high oxygen transmission rate (OTR) and low moisture vapor transmission rate (MVTR) values is required. In the case of polymeric materials, the OTR is influenced by factors such as molecular weight, tacticity, thickness, polymerization process, co-polymer ratio, interfacial modifier concentration, processing temperature, and polymer density. Low molecular weight polymers provide better optical translucency and shorter polymeric chains that have higher oxygen transmission rate. Moreover, product thickness in polymeric packaging materials is crucial, as increased thickness enhances the transmission barrier, thus reducing the oxygen transmission rate. There have been attempts in the prior art to prepare polymeric compositions that facilitate oxygen transmission. The European Patent Application No. EP1066337A2 to Ching Ta Yen et al. describes a polymer composition suitable for packaging oxygen scavenger including oxidizable EMCM copolymer, polyethylene layer or other materials (polyamide), a copolymer of ethylene with a vinyl alcohol, polyethylene polyteraphthalate, etc. forming a complex packaging material. This material acts as a high oxygen barrier and also absorbs oxygen. However, the EMCM copolymer activation during packaging requires irradiation with a UV lamp. The United States Patent Application No. US5153038A to Koyama Masayasu and others discloses a plastic multi-layer vessel including oxygen absorber (metal powder), moisture resistant thermoplastic resin, gas barrier thermoplastic resin, etc. for scavenging oxygen. However, adding such powders or salts degrade the transparency and mechanical properties of the packaging materials and complicate the processing, especially for thin films. Moreover, these compounds and their oxidation products are absorbed by pharmaceutical, nutraceutical or food that may be harmful for human consumption. Thus, there is a need for a canister for storing an oxygen absorber that enables effective oxygen transmission in the presence or absence of moisture, with or without desiccants and prevents spillage of oxygen absorbers in the intended product packaging. SUMMARY OF THE INVENTION: The present invention relates to a canister for storing an oxygen absorber and a process for preparing the same. The canister for storing an oxygen absorber comprises a polymeric composition of 40 to 60 % by weight of polypropylene (PP), 4 to 26 % by weight of low-density polyethylene (LDPE), 2 to 7 % by weight of high-density polyethylene (HDPE), 1 to 5 % by weight of copolymer, and 1 to 2 % by weight of inert filler. The copolymer in the polymeric composition is selected from ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), cyclic olefin copolymers (COCs), and chlorotrifluoroethylene (CTFE). The inert filler in the polymeric composition is selected from calcium carbonate, china clay, talc and barium sulphate. The polypropylene used in the polymeric composition is a polyolefin polymer having molecular weight in the range of 12-18 KD; the low-density polyethylene (LDPE) and high-density polyethylene (HDPE) are polymers having molecular weight in the range of 200-500 KD and 6000-6700 KD respectively. The canister includes a cylindrical body secured by a circular lid and an oxygen absorber that is removably placed in the canister, having dimensions ranging from 30–100 mm in height and 20–50 mm in diameter. The canister is non- perforated and moisture independent. The lid of the canister features a dual click interlock mechanism, rendering the canister leakproof. The oxygen absorber placed in the canister is selected from iron-based oxygen absorbers and iron free oxygen absorbers. The canister for storing oxygen absorber possesses OTR of ≥500 cc / m² / day and MVTR of ≤0.5 g / m² / day. The canister enables ≥ 98% oxygen absorption within 24 hours at 0% relative humidity when used with iron-free oxygen absorbers. The canister is manufactured using an ultrasonic welding technique that ensures leakproof construction without micro gaps. The canister retains at least 95% oxygen absorption efficacy after accelerated aging for 12 months at 40°C and 75% relative humidity. The canister maintains 99.8% seal integrity at a processing speed of 120 canisters per minute in automated packaging lines. A process for preparing the canister includes the steps of a first step of primary blending of components, a second step of freezing the chains and molecules, a third step of secondary blending and a fourth step of mechanical testing and analysis of canisters. The first step of primary blending of components of the process includes mixing predefined ratio of components viz. low-density polyethylene (LDPE), high density polyethylene (HDPE) and polypropylene (PP) with a continuous addition of copolymer and inert filler in a biaxial rotating mixer for a predefined time of five minutes at a predefined temperature of room temperature and processing in counter- rotating twin screw extruder operated at a low speed to compound each batch at a predefined temperature of 185°C to 235°C for a predefined time of 60 minutes followed by mixing to ensure appropriate physical blending. The second step of freezing the chains and molecules of the process includes freezing the chains and polymers of the blend of components obtained in the first step during compounding by reducing the cooling period. The third step of secondary blending of the process includes processing of the compounded product obtained in the second step to achieve predefined morphology in the final sample products by selecting and subjecting a predefined palletizer granule size of 1.5-3.5 mm to injection moulding, wherein the temperature of injection moulding barrel is set at a predefined range of 175°C to 195°C to freeze the molecules and polymer chains followed by annealing the sample in hot water at a predefined temperature of 80 ℃ for a predefined time of four hours to obtain the final canister product. The fourth step of the process includes mechanical testing and analysis of the canisters manufactured. BRIEF DESCRIPTION OF DRAWINGS: The objectives and advantages of the present invention will become apparent from the following description read in accordance with the accompanying drawings wherein, FIG.1A shows a canister for storing oxygen absorber in accordance with the present invention; FIG.1B shows a representative pharmaceutical pill bottle including canister having oxygen absorber in accordance with the present invention; FIG.2 demonstrates the amount of oxygen absorbed by the canister (100) including iron-based oxygen absorber pills in presence of desiccants (silica gel and molecular sieve) in 7 days in accordance with the present invention; FIG.3 demonstrates the amount of oxygen absorbed by the canister including iron free oxygen absorber in presence of desiccants (silica gel and molecular sieve) in 7 days in accordance with the present invention; and FIG.4 shows a process for the preparation of the canister in accordance with the present invention. DESCRIPTION OF THE INVENTION: The present invention relates to a canister for storing an oxygen absorber and a process for preparing the same. The canister enables effective oxygen transmission in the presence or absence of moisture, and with or without desiccants. The canister allows transmission of oxygen from outside to the inside of canister, where oxygen gets absorbed by oxygen absorber present within the canister. References in the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. References in the specification to “preferred embodiment” means that a particular feature, structure, characteristic, or function described in detail thereby omitting known constructions and functions for clear description of the present invention. The foregoing description of specific embodiments of the present invention has been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed and obviously many modifications and variations are possible in light of the above teaching. The present invention discloses a canister for storing oxygen absorber and a method of preparation of the canister. The canister of the present invention is composed of polymers that provides both rigidity and flexibility to the canister. The canister exhibits high oxygen transmission rate (OTR) value (≥500 cc / m² / day) and low moisture vapor transmission rate (MVTR) value (≤0.5 g / m² / day), making it ideal for applications that require selective permeability. These canisters are engineered to absorb oxygen effectively and are self-activated, without requiring moisture for activation. Additionally, the canister ensures leakproof construction that prevents spillage of the oxygen absorbers into the products by secure interlocking lid mechanism. Moreover, the canister includes a scalable and customizable design, making it suitable for applications across pharmaceutical, food, and industrial sectors. The canister of the present invention solves the problems of the prior art that includes moisture dependency for oxygen absorption and leakage of oxygen absorbers in the products. In general aspect, the present invention discloses a canister for storing oxygen absorber. Referring to FIG.1A, a canister for storing oxygen absorber (herein after referred to as “canister 100”) in accordance with the present invention is described. The canister (100) stores oxygen absorbers (105) and has a cylindrical body (110) that is secured by a circular lid (110a). The oxygen absorber (105) is removably placed in the canister (100) and closed by the lid (110a). The oxygen absorber (105) present in the canister (100) for absorbing oxygen is selected from iron-based oxygen absorbers, iron free oxygen absorbers and the like. The dimensions of the canister (100) range from 30–100 mm in height and 20–50 mm in diameter. The dimensions of the canister (100) are customizable based on specific application requirements. The canister (100) is manufactured using an ultrasonic welding process that eliminates micro gaps and ensures a leakproof construction. Further, the canister (100) is non-perforated, including a mono-body molding design and withstands a pressure of 2.5 atm significantly higher than the industry standard of 1.8 atm. The lid (110a) of the canister (100) incorporates an interlock mechanism that prevents the accidental opening of the canister (100). This is achieved by dual stage latch system, wherein the audible click sound upon closure confirms the integrity of the seal. Moreover, the lid (110a) includes a tamper evident strip that provides a clear visual indication of seal breakage. Now, referring to FIG.1B, the canister (100) including the oxygen absorber (105) is further described. The oxygen absorber (105) of the canister (100) is removably placed in the intended product packaging (for example, pharmaceutical pill bottle (115)). The canister (100) allows transmission of oxygen from the bottle (115) to the inside of canister (110), where oxygen gets absorbed by the oxygen absorber (105) present within the canister (110). The canister (100) prevents the spillage of the oxygen absorber (105) in the products such as food, nutraceuticals, pharmaceuticals and the like. The compact active packaging of canister (100) allows absorption of residual oxygen from even the smallest headspace in the pharmaceutical packaging. In one aspect, the present invention discloses a polymeric composition of the canister (100). In another aspect, the present invention discloses a process for preparation of the canister (100). In accordance with the present invention, the polymeric composition of the canister (100) includes: 1. a polymer blend, 2. a copolymer, and 3. an inert filler. In this preferred embodiment, the polymers selected for fabrication of canisters include one or many combinations of low-density polyethylene (LDPE), high-density polyethylene (HDPE), poly styrene (PS), oriented poly styrene (OPS), poly propylene (PP), metalized poly ethylene terephthalate (MPET) and biaxially oriented poly propylene (BOPP) in virgin or mixed compositions. In accordance with this preferred embodiment, the polymeric composition of the canister (100) of the present invention includes: 1. 40 to 60 % by weight of polypropylene (PP), 2. 4 to 26 % by weight of low-density polyethylene (LDPE), 3. 2 to 7 % by weight of high-density polyethylene (HDPE), 4. 1 to 5 % by weight of copolymer, and 5. 1 to 2 % by weight of inert filler. In accordance with this preferred embodiment, the polypropylene is a type of polyolefin polymer having molecular weight in the range of 12-18 KD, that imparts structural rigidity to the canister. The low-density polyethylene (LDPE) and high-density polyethylene (HDPE) are polymers having molecular weight in the range of 200-500 KD and 6000-6700 KD respectively. Low molecular weight polymers exhibit superior optical translucency due to the influence of their polymer chains. Moreover, the location of pendent groups on the backbone chain is crucial during polymerization, as tacticity affects material qualities and structure. The low- density polyethylene (LDPE) enhances MVTR flexibility to the canister, whereas high-density polyethylene (HDPE) act as an internal barrier by improving OTR barrier. In accordance with the preferred embodiment, the copolymer is selected from ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), cyclic olefin copolymers (COCs), chlorotrifluoroethylene (CTFE), and the like. The copolymer acts as an interface modifier and compatibilizer that enhances compatibility and aids in bonding between two polymers resulting into products with high oxygen transmission rate (OTR) values. The copolymers improve sealing performance between two polymers. The inert filler is selected from calcium carbonate, china clay, talc, barium sulphate and the like. This inert filler is responsible for MVTR control and also as a nucleating agent for stiffness. In the present invention, the above composition is selected for preparing canisters to achieve high oxygen transmission rate (OTR) value and low moisture vapor transmission rate (MVTR) value. The unique ratio synergy of components leads to optimized OTR of ≥500 cc / m² / day and MVTR of ≤0.5 g / m² / day. The polymeric blend is formulated based on specific melt flow index (MFI) of 35-42 g / 10 min followed by moulding into canisters of specific wall thickness of 0.86 to 0.92 mm that has near zero MVTR value but excellent OTR value. This specific polymeric blend and inert fillers offer better compliance with pharmaceutical safety standards (e.g., USP, FDA). The canister (100) of the present invention retains 95% efficacy after 12 months at 40°C / 75% RH and 99.8% seal integrity at 120 canisters / minute. In accordance with the present invention, the canister (100) enables efficient oxygen absorption even in the presence of desiccants such as silica gel, molecular sieve, etc. at both low and high relative humidity (RH). Now, a preferred process for preparation of canister (200) (herein after referred to as “process 200”) in accordance with the present invention is disclosed. The process (200) of the present invention includes a plurality of steps including: a. a first step of primary blending of components (205), b. a second step of freezing the chains and molecules (210), c. a third step of secondary blending (215), and d. a fourth step of mechanical testing and analysis of canister prepared (220). In the process, the first step of primary blending (205) includes mixing predefined ratio of components viz. low-density polyethylene (LDPE), High density polyethylene (HDPE) and polypropylene (PP) with a continuous addition of copolymer and inert filler in a biaxial rotating mixer for a predefined time at a predefined temperature. This mixture further undergoes processing in counter-rotating twin screw extruder operated at a low speed to compound each batch at a predefined processing temperature for a predefined time. This is followed by mixing to ensure appropriate physical blending. In the second step of freezing the chains and molecules (210), the blend of components obtained in the first step (205) during compounding are allowed to freeze the chains and molecules before they relax in their own positions by reducing the cooling period. In the third step of secondary blending (215), the compounded product obtained in the second step (210) is processed to achieve predefined morphology in the final sample products. A predefined pelletizer granule size is selected and subjected to injection moulding. Prior to injection moulding, the machine barrels are cleaned to get rid of any residues. The temperature of injection moulding barrel is set at a predefined range in order to freeze the molecules and polymer chains. Using multicavity moulds, canisters of predefined shape and size are prepared by moulding the corresponding samples at low speed and pressure while shortening the cooling period. This is followed by annealing the sample in hot water at a predefined temperature for a predefined time that relaxes the molecules and polymer chains. The processing characteristics namely pressure, speed, and temperature significantly affect injection molding. High processing temperature, pressure, and speed cause the polymeric chain to twist and bend, packing the chains closely during cooling and preventing space between molecules, thus acting as a barrier to heat transmission. In the fourth step of mechanical testing and analysis of canisters (220), the canisters prepared in the third step (215) are subjected to mechanical testing that includes ASTM D 638 for tensile tests, ASTM D 790 for bending tests, and ASTM D 256 for impact tests. Further, analysis includes scanning electron microscopy (SEM), analysis of fractured surfaces and modified differential scanning calorimeter to assess the thermal behaviour. The product obtained is further processed to remove any prior thermal history, by heating the samples at a predefined rate from ambient temperature to a predefined temperature for a predefined time followed by cooling at a predefined rate to a predefined temperature. These samples are rescanned up to a predefined temperature at a predefined heating rate for a predefined time to determine the melt temperature and the heat of fusion. In accordance with the preferred embodiment, in the first step (205), the copolymer is selected from ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), cyclic olefin copolymers (COCs), and chlorotrifluoroethylene (CTFE), and the like and the inert filler is selected from calcium carbonate, china clay, talc, barium sulphate and the like. The components are mixed in a biaxial rotating mixer for the predefined time of five minutes at the predefined temperature of room temperature. This mixture further undergoes processing in counter-rotating twin screw extruder operated at a low speed to compound each batch at the predefined processing temperature of 185°C to 235°C for a predefined time of 60 minutes followed by mixing to ensure appropriate physical blending. In the third step of secondary blending (215), a predefined pelletizer granule size of 1.5-3.5 mm is selected and subjected to injection moulding. The temperature of injection moulding barrel is set in the predefined range of 175°C to 195°C in order to freeze the molecules and polymer chains, whereas the sample is annealed in hot water at the predefined temperature of 80 ℃ for the predefined time of four hours to relax the molecules and polymer chains. In the fourth step of mechanical testing and analysis of canisters (220), the product obtained is processed to remove any prior thermal history, by heating the samples at the predefined rate of 10 K min−1from ambient temperature to the predefined temperature of 220°C for the predefined time of 15 minutes followed by cooling at the predefined rate of 10 K min−1to the predefined temperature of 50°C. These samples are rescanned up to the predefined temperature of 200°C at the predefined heating rate of 10 K min−1for the predefined time of 10 minutes to determine the melt temperature and the heat of fusion. In accordance with the preferred embodiment, the iron free or iron-based oxygen absorber pills are placed in the canisters of the present invention. The oxygen absorbers inside the canisters vary depending on the application. For applications requiring high oxygen absorption capacity, inorganic compositions containing iron-based oxygen absorber pills are used. For applications requiring low oxygen absorption, organic, iron-free oxygen absorber compositions are preferred. In accordance with the present invention, the canisters enable improved oxygen removal from packaging materials such as pouches, pharmaceutical pill bottles, and the like, with or without desiccants, at both low and high relative humidity (RH). This invention also addresses issues related to product-specific moisture. The canister (100) of the present invention is non-perforated, rendering it leakproof. Additionally, the interlock design of the canister (100) prevents the lids from opening easily. The use of specific polymers, their composition and moulding conditions enables strong locking of the caps in the present canisters. These canisters (100) are engineered to absorb oxygen effectively and are self-activated, without requiring moisture for activation. The iron-free absorber pills with redox catalyst are self-activating and requires no H₂O / moisture to trigger for oxygen absorption. The canister (100) aids in 98% O₂ absorption within 24 hrs at 0% RH. The compact active packaging of the canister (100) allows absorption of residual oxygen from even the smallest headspace in the pharmaceutical packaging. Moreover, they function efficiently even in the presence of desiccants such as silica gel, molecular sieve and the like. EXAMPLES: Only a few examples and implementations are disclosed. Variations, modifications, and enhancements to the described examples and implementations and other implementations can be made based on what is disclosed. Examples are set forth herein below and are illustrative of different amounts and types of reactants and reaction conditions that can be utilized in practicing the disclosure. It will be apparent, however, that the disclosure can be practiced with other amounts and types of reactants and reaction conditions than those used in the examples, and the resulting devices various different properties and uses in accordance with the disclosure above and as pointed out hereinafter. EXAMPLE 1 EXAMPLE 1A: PREPARATION OF CANISTER 1. Three different compositions of polypropylene (PP), low-density polyethylene (LDPE) and high-density polyethylene (HDPE) in predefined ratios (PP: LDPE: HDPE viz. 58:45:2, 55:35:10 and 70:25:5) were mixed with EVOH of 72.11 g / mol as a copolymer and different inert fillers in a biaxial rotating mixer for 5 minutes at room temperature. The compositions are given below: A. Composition 1 includes PP: LDPE: HDPE in the ratio 58:45:2. The blend of 50 kg batch in ratio of 58:45:2 for PP: LDPE: HDPE was added with 35 g of EVOH and 120 g of different inert fillers as given in below Table 1. Table 1: Composition 1 for preparing canisters Ingredients Composition Composition Composition Composition 1A 1B 1C 1D Polypropylene (PP) 29 kg 29 kg 29 kg 29 kg LDPE 22.5 kg 22.5 kg 22.5 kg 22.5 kg HDPE 1 kg 1 kg 1 kg 1 kg EVOH 35 g 35 g 35 g 35 g Inert filler Calcium China clay Talc Barium carbonate 120 g 120 g sulphate 120 g 120 g B. Composition 2 includes PP: LDPE: HDPE in the ratio 55:35:10 The blend of 50 kg batch in ratio of 55:35:10 for PP: LDPE: HDPE was added with 35 g of EVOH and 120 g of different inert fillers as given in below Table 2. Table 2: Composition 2 for preparing canisters Ingredients Composition Composition Composition Composition 2A 2B 2C 2D Polypropylene (PP) 27.5 kg 27.5 kg 27.5 kg 27.5 kg LDPE 17.5 kg 17.5 kg 17.5 kg 17.5 kg HDPE 5.0 kg 5.0 kg 5.0 kg 5.0 kg EVOH 35 g 35 g 35 g 35 g Inert filler Calcium China clay Talc Barium carbonate 120 g 120 g sulphate 120 g 120 g C. Composition 3 includes PP: LDPE: HDPE in the ratio 70:25:5 The blend of 50 kg batch in ratio of 70:25:5 for PP: LDPE: HDPE was added with 35 g of EVOH and 120 g of different inert fillers as given in below Table 3. Table 3: Composition 3 for preparing canisters Ingredients Composition Composition Composition Composition 3A 3B 3C 3D Polypropylene 35 kg 35 kg 35 kg 35 kg (PP) LDPE 12.5 kg 12.5 kg 12.5 kg 12.5 kg HDPE 2.5 kg 2.5 kg 2.5 kg 2.5 kg EVOH 35 g 35 g 35 g 35 g Inert filler Calcium China clay Talc Barium carbonate 120 g 120 g sulphate 120 g 120 g D. This mixture or blend was further processed in counter-rotating twin screw extruder for 60 minutes operated at a low speed to compound each batch at a processing temperature of 185°C to 235°C for appropriate physical blending. E. The blend of components obtained were compounded to freeze the chains and molecules before they relax in their own positions by reducing the cooling period from 12 minutes to 7 minutes. F. Further, the compounded product was processed to achieve predefined morphology in the final sample products in secondary blending.1.5-3.5 mm pelletizer proper granule size was selected and subjected to injection moulding. Prior to injection moulding, the machine barrels were cleaned to get rid of any residues, temperature of injection moulding barrel was set in the range of 175°C to 195°C to freeze molecules and polymer chains. G. Using multicavity moulds, canisters of predefined shape and size were prepared by moulding the corresponding samples at low speed and pressure while shortening the cooling period. This was followed by annealing the sample in hot water at 80 ℃ for four hours that relaxed the molecules and polymer chains. H. The canisters prepared were subjected to mechanical testing that includes ASTM D 638 for tensile tests, ASTM D 790 for bending tests, and ASTM D 256 for impact tests and scanning electron microscopy (SEM) analysis of fractured surfaces and modified differential scanning calorimeter to assess the thermal behaviour. I. The product obtained was further processed to remove any prior thermal history, by heating the samples at a rate of 10 K min−1from ambient temperature to 220°C for 15 minutes followed by cooling at a rate of 10 K min−1to 50°C. These samples were rescanned up to 200°C at a heating rate of 10 K min−1for 10 minutes to determine the melt temperature and the heat of fusion. EXAMPLE 1B: OTR AND MVTR STUDIES OF CANISTER The canister for storing oxygen absorber molded using the polymeric composition as described in Example 1 was evaluated for Oxygen Transmission Rate (OTR) and Moisture Vapor Transmission Rate (MVTR) in accordance with ASTM F1927 and ASTM E96 test methods, respectively, at 25°C and 60% relative humidity. Result: The canister exhibited 550 cc / m² / day OTR and 0.4 g / m² / day MVTR. This displayed quantifiable superiority in balanced gas / moisture control, which is critical for dry / humid environments. EXAMPLE 1C: DESIGN OF EXPERIMENTS (DOE) TO DETERMINE VARIOUS RANGES OF POLYMERIC COMPOSITION Design of Experiments (DoE) were conducted to determine various ranges of polymeric composition that shows optimal results of OTR / MVTR balance and rigidity in case of canisters. Various permutations and combinations of the polymeric composition was done. Design of Experiments (DoE) for Polymeric Canister Composition Objective: Determine the optimal polymer blend to achieve: 1. Gas Barrier Balance: Oxygen Transmission Rate (OTR) < 100 cc / m² / day & Moisture Vapor Transmission Rate (MVTR) < 10 g / m² / day. 2. Mechanical Rigidity: Flexural modulus > 1,500 MPa for automated conveyor stability. 1. Experimental Design Factors & Levels Table 4: Study on optimizing polymeric composition Factor Levels Tested Rationale Polypropylene (PP) 45–60% Baseline rigidity & processability LDPE 15–25% Enhances MVTR flexibility HDPE 5–10% Improves OTR barrier EVA Copolymer 0–10% (Fixed 5% in final runs) Balances adhesion / sealability Talc / CaCO₃ 1–3% Nucleating agent for stiffness Table 4: Study on optimizing polymeric composition Factor Levels Tested Rationale Cyclic Olefin Copolymer Ultra-high OTR barrier (niche (COC) 0–5% runs) DoE Matrix • Type: Full factorial design (5 factors, 2 levels). • Total Runs: 32 (including center points for error analysis). • Response Variables: OTR (ASTM D3985), MVTR (ASTM E96), Flexural Modulus (ISO 178). 2. Material Preparation and Testing Step 1: Compounding The polymers / additives were blended using a twin-screw extruder at 180– 220°C and 200 rpm The blend was pelletized and dried at 80°C for 4 hrs to remove the moisture. Step 2: Injection Molding The canister prototypes were molded by injection molding having size 10 cm × 5 cm, 1.5 mm wall thickness The following processing parameters were maintained: Melt temp: 200°C, Mold temp: 40°C. Cooling time: 30 sec (to minimize crystallinity effects). Step 3: Testing Protocol Table 5. Methods for testing OTR, MVTR, Flexural modulus and Impact resistance Property Method Equipment OTR ASTM D3985 MOCON OX-TRAN 2 / 22 MVTR ASTM E96 (Dry cup) MOCON PERMATRAN-W 3 / 33 Flexural Modulus ISO 178 Instron 5967 (50 mm / min) Table 5. Methods for testing OTR, MVTR, Flexural modulus and Impact resistance Property Method Equipment Impact Resistance ASTM D256 (Notched Izod) Ceast Pendulum Impact Tester 3. Results & Optimization Optimized Composition for OTR / MVTR Balance Formula: 55% PP + 20% LDPE + 5% HDPE + 5% EVA + 2% talc. Table 6. Values of OTR, MVTR and Flexural modulus Property Value Industry Benchmark OTR 85 cc / m² / day <100 cc / m² / day (target) MVTR 8.5 g / m² / day <10 g / m² / day (target) Flexural Modulus 1,200 MPa 1,000–1,500 MPa (acceptable) Trade-off Analysis: • LDPE ↑ → MVTR ↑ (desired) but rigidity ↓. • Talc ↑ → OTR ↓ but brittleness ↑ (limited to 2%). Optimized Composition for Rigidity (Automated Lines) Formula: 45% PP + 15% LDPE + 7% HDPE + 3% COC + 1.5% CaCO₃. Table 7. Values of OTR, MVTR and Flexural modulus Property Value Industry Benchmark Flexural Modulus 1,650 MPa >1,500 MPa (target) OTR 110 cc / m² / day Slightly higher (tolerable) MVTR 12 g / m² / day Marginally above target Trade-off Analysis: • COC ↑ → OTR ↓ but cost ↑ (limited to 3%).•CaCO₃ ↑ → Rigidity ↑ without compromising impact strength. 4. Statistical Validation • ANOVA Analysis: PP% and HDPE% were statistically significant (p<0.05) for OTR. COC% and CaCO₃% dominated rigidity (p<0.01). • Desirability Function: Multi-response optimization (Minitab) favored 55% PP blend for balanced properties. 5. Field Performance Data • Automated Line Trials: Rigid blend (45% PP): Zero jams in 10,000-canister run (conveyor speed: 30 cans / min). • Shelf-Life Testing: 55% PP blend: Maintained O2absorption efficacy (>90%) after 6 months in humid climates. Result: 1. The polymeric composition including 55% PP + 20% LDPE + 5% HDPE + 5% EVA copolymer + 2% talc was found to be optimal for OTR / MVTR balance. 2. The polymeric composition including 45% PP + 15% LDPE + 7% HDPE + 3% COC + 1.5% CaCO₃ was found to impart enhanced rigidity for automated lines. EXAMPLE 2: OXYGEN ABSORPTION STUDIES FOR CANISTER INCLUDING IRON-BASED OXYGEN ABSORBER PILLS Experimental study: Oxygen absorption studies were performed using canister prepared by above blend mentioned in Example 1. The experiment was performed by placing iron-based oxygen absorber pills in one canister, iron-based oxygen absorber pills along with silica gel in second canister and iron-based oxygen absorber pills along with molecular sieve in third canister. These canisters were observed for oxygen absorption for 7 days. Result: The oxygen absorption capacity in all the three canisters increased gradually with maximum oxygen absorption of 100 cc (ml) observed on 7thday. FIG. 2 displays gradual increase in oxygen absorbed by canister that includes iron-based oxygen absorber pills and iron-based oxygen absorber pills along with desiccants (silica gel and molecular sieve) in 7 days with maximum absorption capacity of 100cc. The oxygen absorption was similar in all three canisters that remained unaffected in the presence of desiccants such as silica gel and molecular sieve. EXAMPLE 3: OXYGEN ABSORPTION STUDIES FOR CANISTER INCLUDING IRON FREE OXYGEN ABSORBER PILLS Experimental study: Oxygen absorption studies were performed using canister B prepared by above blend mentioned in example 1. The experiment was performed by placing iron free oxygen absorber pills in one canister, iron free oxygen absorber pills along with silica gel in second canister and iron free oxygen absorber pills along with molecular sieve in third canister. These canisters were observed for oxygen absorption for 7 days. Result: The oxygen absorption capacity in all the three canisters increased gradually with maximum oxygen absorption of 20 cc (ml) observed on 7thday. FIG.3 displays gradual increase in oxygen absorbed by canister that includes iron free oxygen absorber pills, iron free oxygen absorber pills along with desiccants (silica gel and molecular sieve) in 7 days with maximum absorption capacity of 20 cc. The oxygen absorption was similar in all three canisters that remained unaffected in presence of desiccants, silica gel and molecular sieve. This is considered a better alternative to oxygen absorbers, in cases where iron-based oxygen absorbers are not preferred. EXAMPLE 4: ACCELERATED AGING The canister for storing oxygen absorption was evaluated for determining its efficacy using accelerated aging study. Experimental study: Accelerated aging study of oxygen-absorbing canister Objective: Evaluate the shelf-life stability and efficacy retention of the oxygen-absorbing canister under accelerated aging conditions (40°C / 75% RH for 12 months). 1. Materials & Methods • Canister was prepared as per composition mentioned in Example 1 and included Iron oxygen absorber tablets / Iron Free Oxygen absorber tablets Accelerated Aging Protocol • Standard Referenced: ASTM F1980 (Accelerated Aging for Medical Devices) adapted for active packaging. • Conditions: Temperature: 40°C (±2°C) Relative Humidity: 75% (±5%) Duration: 0, 3, 6, 9, and 12 months (sampling intervals). • Storage Chamber: Climatic chamber (e.g., Binder KBF-240) with real-time RH / temperature logging. Efficacy Testing At each interval, canisters were tested for oxygen absorption capacity: 1. Test Setup: 1 canister was placed in a 5L airtight chamber (O₂ initially at 20.9%) and the residual O₂ was measured after 24 hrs using an oxygen analyzer (e.g., MOCON Dansensor Checkpoint 3). 2. Efficacy Calculation: % Efficacy Retention = (O₂ absorbed at time T / O₂ absorbed at T=0) × 100. 2. Experimental Data Table 8. Oxygen absorption capacity over time Time (months) O₂ Absorbed (cc) Efficacy Retention (%) 0 (Baseline) 500 cc 100% 3 490 cc 98% 6 485 cc 97% 9 480 cc 96% 12 475 cc 95% 3. Key Observations 1. High Stability: 95% efficacy retention was observed after 12 months at 40°C / 75% RH, that indicates robust performance under tropical conditions. 2. Humidity Impact: Marginal efficacy loss (~5%) was observed that correlates with slight moisture ingress, but filler remains reactive. 4. Statistical Analysis • Regression Model: Linear fit of efficacy vs. time showed degradation rate of 0.42% per month (R²=0.98). • Confidence Interval: 95% CI for 12-month efficacy = 94–96%. 5. Supporting Data Material Characterization • FTIR Analysis: No chemical degradation was observed after aging. • SEM Imaging: Absorber particles were found to retain porosity (>80% vs. fresh sample). Result: The canister was found to retain 95% efficacy after 12 months at 40°C / 75% RH. Conclusions • The canister met ISO 22000 and FDA 21 CFR requirements for long-term oxygen control. • Recommendations: The canisters are suitable to use for high-moisture applications (e.g., seafood, pharmaceuticals) and the canisters shelf-life extends to 2 years at ambient storage. EXAMPLE 5: AUTOMATION COMPATIBILITY The canister for storing oxygen absorption was evaluated for determining seal integrity using automation compatibility study. The canisters were subjected to the friability test to ensure seal integrity and non-spillage of tablets / dust from the canisters. Result: The canister exhibited 99.8% seal integrity at 120 canisters / minute. Advantageously, the canisters of the present invention are self-activated and do not rely on moisture for activation for oxygen absorption. The polymeric composition of the canister of the present invention possesses high oxygen transmission rate (OTR) value (≥500 cc / m² / day) and low moisture vapor transmission rate (MVTR) value (≤0.5 g / m² / day). The polymeric composition of the canister of the present invention ensures rigidity and flexibility to the canisters and withstands pressure compared to the canisters in the prior art. The canisters of the present invention feature a specific interlock design that prevents the lids from opening easily and are non-perforated, making the canisters leakproof. The canister advantageously includes iron free or iron-based oxygen absorber pills based on the requirement that enables enhanced oxygen absorption capacity. Moreover, the canister of the present invention enables oxygen transmission and absorption even in the presence of desiccants such as silica gel, molecular sieve, etc. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others, skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the scope of the present invention.

Claims

CLAIMS:

1. A canister for storing an oxygen absorber (100), comprising a polymeric composition of: a. 40 to 60 % by weight of polypropylene (PP); b. 4 to 26 % by weight of low-density polyethylene (LDPE); c. 2 to 7 % by weight of high-density polyethylene (HDPE); d. 1 to 5 % by weight of copolymer; and e. 1 to 2 % by weight of inert filler.

2. The canister for storing oxygen absorber (100) as claimed in claim 1, wherein the copolymer being selected from ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), cyclic olefin copolymers (COCs), and chlorotrifluoroethylene (CTFE).

3. The canister for storing oxygen absorber (100) as claimed in claim 1, wherein the inert filler being selected from calcium carbonate, china clay, talc and barium sulphate.

4. The canister for storing oxygen absorber (100) as claimed in claim 1, wherein the polypropylene being a polyolefin polymer having molecular weight in the range of 12-18 KD; the low-density polyethylene (LDPE) and high-density polyethylene (HDPE) being polymers having molecular weight in the range of 200-500 KD and 6000-6700 KD respectively.

5. The canister for storing oxygen absorber (100) as claimed in claim 1, wherein the canister (100) including a cylindrical body (110) being secured by a circular lid (110 a) and an oxygen absorber (105) being removably placed in the canister (100), having dimensions ranging from 30–100 mm in height and 20–50 mm in diameter.

6. The canister for storing oxygen absorber (100) as claimed in claim 1, wherein the canister being non-perforated and moisture independent.

7. The canister for storing oxygen absorber (100) as claimed in claims 1 and 5, wherein the lid (110 a) of the canister (100) featuring a dual click interlock mechanism, thereby rendering the canister (100) leakproof.

8. The canister for storing oxygen absorber (100) as claimed in claims 1 and 5, wherein the oxygen absorber (105) being selected from iron-based oxygen absorbers and iron free oxygen absorbers.

9. The canister for storing oxygen absorber (100) as claimed in claim 1, wherein the canister (100) possessing OTR of ≥ 500 cc / m² / day and MVTR of ≤0.5 g / m² / day.

10. The canister for storing oxygen absorber (100) as claimed in claim 1, wherein the canister (100) enabling ≥ 98% oxygen absorption within 24 hours at 0% relative humidity when being used with iron-free oxygen absorbers.

11. The canister for storing oxygen absorber (100) as claimed in claim 1, wherein the canister (100) being manufactured through an ultrasonic welding technique ensuring leakproof construction without micro gaps.

12. The canister for storing oxygen absorber (100) as claimed in claim 1, wherein the canister (100) retaining at least 95% oxygen absorption efficacy after accelerated aging for 12 months at 40°C and 75% relative humidity.

13. The canister for storing oxygen absorber (100) as claimed in claim 1, wherein the canister (100) maintaining 99.8% seal integrity at a processing speed of 120 canisters per minute in automated packaging lines.

14. A process (200) for preparing the canister (100) as claimed in claim 1, including the steps of: a. a first step of primary blending of components (205); b. a second step of freezing the chains and molecules (210); c. a third step of secondary blending (215); and d. a fourth step of mechanical testing and analysis of canisters (220).

15. The process (200) for preparing the canister (100) as claimed in claim 14, wherein the first step of primary blending of components (205) including mixing, predefined ratio of components viz. low-density polyethylene (LDPE), High density polyethylene (HDPE) and polypropylene (PP) with a continuous addition of copolymer and inert fillerin a biaxial rotating mixer for a predefined time of five minutes at a predefined temperature of room temperature; processing, in counter-rotating twin screw extruder being operated at a low speed to compound each batch at a predefined temperature of 185°C to 235°C for a predefined time of 60 minutes followed by mixing, ensuring appropriate physical blending.

16. The process (200) for preparing the canister (100) as claimed in claim 14, wherein the second step of freezing the chains and molecules (210) including freezing the chains and polymers of the blend of components obtained in the first step (205) during compounding by reducing the cooling period.

17. The process (200) for preparing the canister (100) as claimed in claim 14, wherein the third step of secondary blending (215) including processing, of the compounded product obtained in the second step (210) to achieve predefined morphology in the final sample products by selecting and subjecting a predefined palletizer granule size of 1.5-3.5 mm to injection moulding; wherein the temperature of injection moulding barrel is set at a predefined range of 175°C to 195°C to freeze the molecules and polymer chains followed by annealing the sample in hot water at a predefined temperature of 80 ℃ for a predefined time of four hours to obtain the final canister product.

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