Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(Section 10 and Rule 13)

1. TITLE OF THE INVENTION:
BIODEGRADABLE ENCLOSURE AND METHOD OF PREPARATION THEREOF

2. APPLICANT:
Meril Life Sciences Pvt. Ltd., an Indian company, of the address Survey No. 135/139 Bilakhia House, Muktanand Marg, Chala, Vapi-Gujarat 396191

3. The following specification particularly describes the invention and the manner in which it is to be performed:

FIELD OF THE INVENTION
[001] The present disclosure relates to biodegradable medical products. More specifically, the present disclosure relates to a biodegradable enclosure and method of preparation thereof.
BACKGROUND OF THE INVENTION
[002] More often than not, medical products like diagnostic/testing kits are intended for single use, i.e., they are used once and then discarded. Generally, the reason being, most medical products should be sterile for safe use.
[003] Most of the medical products are made from plastic like high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene, petroleum derived plastics, etc. Once these plastic-based medical products are discarded, these medical products take an eternity to naturally degrade. Due to their non-degradable nature, these medical products are accumulated in the environment thereby significantly contributing towards the present-day problem of inefficiency in solid waste management.
[004] Further, recycling these medical products requires treatment methods which are expensive and harmful to the environment as the residual fumes and discharge adulterates the surroundings. This, in turn, discourages recycling of the said medical products.
[005] Thus, there arises a need to provide naturally degradable medical products that can overcome the issues related to conventional medical products.
SUMMARY OF THE INVENTION
[006] The present disclosure relates to a method of preparing a biodegradable enclosure including the steps of preparing a first mixture by homogenously mixing a pre-defined concentration of poly lactic acid (PLA) polymer granules and one or more additives, the first mixture being obtained by homogenously mixing 92% to 96% of the polymer granules and 4% to 8% of the one or more additives; drying the first mixture to reduce a dew point and a moisture level of the first mixture to less than 30°C and 0.1% respectively; and molding the first mixture to a pre-defined shape using a mold at a first pre-defined temperature, a first pre-defined pressure, a first pre-defined time period and a first pre-defined speed.
[007] In another embodiment of the present disclosure, a biodegradable enclosure is disclosed. It includes poly lactic acid (PLA) polymer granules, wherein the PLA polymer granules are present in a concentration ranging from 92% to 96%; and one or more additives in a concentration ranging from 4% to 8%, wherein the one or more additives include a metal salt including titanium dioxide (TiO2) and carrier resins including polypropylene, polystyrene, or polyethylene.
[008] The foregoing features and other features as well as the advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[009] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the apportioned drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.
[0010] Fig. 1 depicts an exemplary biodegradable enclosure 100, in accordance with one or more exemplary embodiments of the present disclosure.
[0011] Fig. 2 depicts an exemplary method 200 to prepare a biodegradable enclosure 100, in accordance with one or more exemplary embodiments of the present disclosure.
[0012] Fig. 3 is a pictorial representation 300 of the biodegradable enclosure 100 subjected to real time in-vitro degradation study, in accordance with one or more exemplary embodiments of the present disclosure.
[0013] Fig. 4 is a graphical representation 400 of percentage biodegradation of the biodegradable enclosure 100 with cellulose as a reference (anaerobic degradation), in accordance with one or more exemplary embodiments of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Prior to describing the invention in detail, definitions of certain words or phrases used throughout this patent document will be defined: the terms "include" and "comprise", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "coupled with" and "associated therewith", as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, or the like; Definitions of certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases.
[0015] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.
[0016] Although the operations of exemplary embodiments of the disclosed method may be described in a particular, sequential order for convenient presentation, it should be understood that the disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment, and may be applied to any embodiment disclosed herein. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed system, method, and apparatus can be used in combination with other systems, methods, and apparatuses.
[0017] Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages of the embodiments will become more fully apparent from the following description and apportioned claims, or may be learned by the practice of embodiments as set forth hereinafter.
[0018] Definitions: Referenced throughout this specification, the term “biodegradable enclosure” refers to an enclosure or housing to be used in medical applications. For example, biodegradable enclosures can be testing cassettes used in diagnostic testing kits including but not limited to antigen assay kits, RT-PCR kits, malaria detection kits, human chorionic gonadotropin (hCG) detection kits, etc. Generally, a diagnostic testing kit is a term coined to describe one time and easy to use biodegradable enclosure deployed to perform quick antigen-antibody screenings. Additionally, or optionally, the biodegradable enclosure and the method thereof described in the present disclosure may be used to prepare various medical products (such as, medical bottles/containers, band-aid containers, a dental floss container, swab containers, syringes, inhalers, droppers, tampons, etc.), food packaging products, films, fibreboards, etc.
[0019] Further, poly lactic acid or PLA is used interchangeably throughout this document. Also, Titanium dioxide or TiO2 is used interchangeably throughout this document.
[0020] In accordance with the present disclosure, a biodegradable enclosure and a method of preparing the same are disclosed. The biodegradable enclosure of the present disclosure is naturally degradable.
[0021] The biodegradable enclosure and the method thereof described in the present disclosure utilizes poly lactic acid (PLA) along with one or more additives as raw materials. PLA is a biodegradable material, which can naturally break down over time. This feature of PLA offers an important advantage for the biodegradable enclosure as it reduces the environmental impact of the waste generated by the biodegradable enclosure. Thus, the biodegradable enclosure of the present disclosure degrades naturally over time and has less environmental impact when compared to biodegradable enclosures derived from non-renewable petroleum sources.
[0022] The biodegradable enclosure of the present disclosure has a higher strength and stiffness than conventional plastics, which makes it a better material for manufacturing testing cassettes, syringes, etc. Further, the biodegradable enclosure has better optical clarity and transparency than enclosures manufactured from conventional plastics, thus making it easier to read test results, quantity, etc. Further, the biodegradable enclosure has a shelf life of around 2-3 years, if stored in a cool, dry place away from direct sunlight.
[0023] Fig. 1 depicts an exemplary biodegradable enclosure 100 of the present disclosure. The biodegradable enclosure 100 is made of polymer granules and one or more additives in pre-defined concentrations. The polymer granules may be made of a biodegradable material selected from a group of poly lactic acid (PLA), poly(e-caprolactone), poly(3-hydroxybutarate), vegetable oil-based polyesters, epoxy and polyurethanes, polycarbonates, etc. 100% compostable injection molding grade PLA polymer granules maybe commercially obtained. The polymer granules may decompose naturally when exposed to environmental conditions, such as sunlight, water, and microorganisms. In an embodiment, the pre-defined concentration of the PLA granules in the biodegradable enclosure 100 ranges from 92% to 96%. In an exemplary embodiment, 94% of the PLA polymer granules are present in the biodegradable enclosure 100.
[0024] In an embodiment, the pre-defined concentration of the one or more additives ranges from 4% to 8%. The one or more additives may include, without limitation, a metal salt, carrier resins, or combinations thereof. The metal salt includes without limitation one of zinc acetate, titanium dioxide (TiO2), etc. Titanium dioxide, as one of the additives, may be present in a concentration ranging from 70% (w/w) to 80% (w/w). In an embodiment, the additive added to the PLA polymer granules includes a mixture of titanium dioxide (TiO2) and a carrier resin. The carrier resin(s) may be one of polypropylene, polystyrene, polyethylene, etc. The carrier resin, as one of the additives, may be present in a concentration ranging from 20% (w/w) to 30% (w/w). In an exemplary embodiment, the additives include a mixture of 70% (w/w) titanium dioxide (TiO2) nanoparticles and 30% (w/w) of polypropylene. In an embodiment, titanium dioxide (TiO2) is present in the form of nanoparticles having a diameter ranging from 50 nanometers to 100 nanometers. In an exemplary embodiment, 6% titanium dioxide (TiO2), is present in the form of nanoparticles with a diameter of 100 nanometers.
[0025] Titanium dioxide (TiO2) provides whiteness and opacity to the biodegradable enclosure 100 while the carrier resin helps the colorant to uniformly spread the white color throughout the PLA polymer granules of the biodegradable enclosure 100. 6% titanium dioxide (TiO2) nanoparticles facilitate the degradation of the biodegradable enclosure 100 via photocatalysis.
[0026] For example, 6% titanium dioxide (TiO2) nanoparticles, due to its chemical properties and its capacity to absorb ultraviolet (UV) light, produce reactive oxygen species. The degradation process of the biodegradable enclosure 100 having a PLA matrix of the polymer granules is accelerated due to TiO2 that functions as a catalyst. Titanium dioxide (TiO2) absorbs UV energy and creates electron-hole pairs when it is subjected to it. The generated oxygen species such as hydroxyl radicals (•OH) and superoxide ions (O2•-), are created when these electron-hole pairs interact with nearby oxygen or water. These oxygen species are highly reactive and further initiate the degradation of the PLA matrix. The reactive oxygen species generated by titanium dioxide (TiO2) photocatalysis attack the polymer chains of PLA, causing chain scission and the formation of smaller fragments. This degradation process breaks down the PLA structure, leading to a reduction in molecular weight and the formation of water-soluble degradation products. The presence of smaller fragments facilitates the subsequent microbial degradation of the biodegradable enclosure 100.
[0027] Additionally, and optionally, the biodegradable enclosure 100 may include one or more plasticizers. The weight percentage of the one or more plasticizers may range from 1% to 10%. The one or more plasticizers may include, without limitation, polyethylene glycol (PEG), lactate esters or combinations thereof. In an embodiment, the plasticizer is polyethylene glycol (PEG). In an exemplary embodiment, the weight percentage of polyethylene glycol (PEG) is 5%. Plasticizers impart flexibility to the rigid biodegradable enclosure 100 as needed as per the application.
[0028] Fig. 2 depicts an exemplary method 200 to prepare a biodegradable enclosure 100 of the present disclosure. The method 200 commences at step 201 by preparing a first mixture. The first mixture may be made by homogenously mixing a polymer and one or more additives. The polymer may be made of biodegradable material selected from a group of poly Lactic Acid (PLA), poly(e-caprolactone), poly(3-hydroxybutarate), vegetable oil-based polyesters, epoxy and polyurethanes, polycarbonates, etc. In an exemplary embodiment, PLA polymer granules are added to the first mixture. The PLA polymer granules may be added to the first mixture in a pre-defined concentration ranging from 92% to 96%. In an exemplary embodiment, 94% of the PLA polymer granules are added to the first mixture.
[0029] The one or more additives may be uniformly added to the first mixture in a pre-defined concentration ranging from 4% to 8%. The one or more additives may include, without limitation, a metal salt (such as zinc acetate, titanium dioxide (TiO2), etc.), carrier resins, or combinations thereof. Titanium dioxide, as one of the additives, may be present in a concentration ranging from 70% (w/w) to 80% (w/w). In an embodiment, the additive added to the PLA polymer granules includes a mixture of titanium dioxide (TiO2) and a carrier resin. The carrier resin(s) may be one of polypropylene, polystyrene, polyethylene, etc. The carrier resin, as one of the additives, may be present in a concentration ranging from 20% (w/w) to 30% (w/w). In an exemplary embodiment, the additives include a mixture of 70% (w/w) titanium dioxide (TiO2) nanoparticles and 30% (w/w) of polypropylene. Titanium dioxide (TiO2) may be present in the form of nanoparticles having a diameter ranging from 50 nanometers to 100 nanometers. In an exemplary embodiment, 6% titanium dioxide (TiO2) in the form of nanoparticles having diameter less than 100 nanometers is present along with carrier resins.
[0030] The homogenous mixing of the first mixture may be carried out by mechanical, solution, melt mixing, etc. In an embodiment, the PLA polymer granules and the one or more additives are homogenously mixed using mechanical mixing. In an exemplary embodiment, the 94% poly lactic acid polymer (PLA) granules and 6% titanium dioxide (TiO2) nanoparticles along with carrier resin are melted and mixed using a twin-screw extruder machine.
[0031] At step 203, the first mixture obtained from step 201 is dried to remove moisture. The first mixture may be dried using without limitation using hot air drying, desiccant dryers, compressed air drying, oven drying, etc. In an exemplary embodiment, after drying the first mixture, the dew point of the first mixture is reduced to lower than 30 °C. In an exemplary embodiment, the moisture level of the first mixture is reduced to less than 0.1% after drying. Removing moisture from the first mixture prevents appearance/occurrence of voids, bubbles and other surface flaws.
[0032] At step 205, the first mixture may be molded to a pre-defined shape depending upon end user requirements. The first mixture may be molded using a technique selected from a group of techniques namely injection molding technique, extrusion technique, blow molding technique, etc.
[0033] The pre-defined shape of the biodegradable enclosure 100 may be set by using a mold. The mold may include a volumetric space corresponding, at least partially, to the shape of the biodegradable enclosure 100. The mold may be made of a material including but not limited to, stainless steel, aluminum, silicone, polypropylene, etc. In an exemplary embodiment, the mold is made of stainless steel.
[0034] In an exemplary embodiment, the first mixture is molded using the injection molding technique. At step 205a, the first mixture is injected inside the mold at a first pre-defined temperature and a first pre-defined pressure in a first pre-defined time period at a first pre-defined speed. The first pre-defined temperature ranges from 170 °C to 210 °C. The first pre-defined temperature ensures optimal flow and filling of the mold by the first mixture. The first pre-defined pressure ranges from 50 MPa to 120 MPa. The first pre-defined pressure helps to achieve desired shape and surface finish of the biodegradable enclosure 100. The first pre-defined time period ranges from 1 second to 5 seconds. The first pre-defined speed ranges from 50 mm/s to 300 mm/s. Alternately, the first pre-defined speed ranges from 50 mm/s to 150 mm/s. Alternatively, the first pre-defined speed may range from 200 mm/s to 300 mm/s. The first pre-defined speed is adjusted to control the filling and packing of the first mixture in the mold, which can affect the strength and dimensional accuracy of the finished biodegradable enclosure 100. In an exemplary embodiment, the first mixture is injected at 190 °C temperature, 85 MPa pressure, 250 mm/s speed for 3 seconds.
[0035] At step 205b, the first mixture is held inside the mold at a second pre-defined temperature and a second pre-defined pressure for a second pre-defined time period at a pre-specified clamping force. The second pre-defined temperature ranges from 30 °C to 60 °C. The second pre-defined pressure ranges from 50 MPa to 100 MPa. The clamping force ranges from 100 to 500 tons. The second pre-defined time period ranges from 5 seconds to 20 seconds. In an exemplary embodiment, the first mixture is held inside the mold at 45°C temperature, 75 MPa pressure, 300 tons of the clamping force for 12 seconds.
[0036] At step 205c, the first mixture is cooled inside the mold at a third pre-defined temperature for a third pre-defined time period to provide the biodegradable enclosure 100. The third pre-defined temperature ranges from 10 °C to 40 °C. The third pre-defined time period ranges from 10 seconds to 30 seconds. Longer cooling time prevents warping and other defects of the biodegradable enclosure 100. In an exemplary embodiment, the first mixture is cooled at 25 °C temperature for 20 seconds.
[0037] At step 205d, the cooled and solidified first mixture shaped as a biodegradable enclosure 100 as per the teachings of the present disclosure may be recovered from the mold.
[0038] At an optional step 207, the biodegradable enclosure 100 is trimmed and checked for quality issues. In an exemplary embodiment, any excess material and/or flash around the biodegradable enclosure 100 is trimmed off. The quality issues that may be inspected in the biodegradable enclosure 100 include but not limited to wrapping, cracks, incomplete parts, etc.
[0039] At an optional step 209, the biodegradable enclosure 100 is cleaned to remove any debris, dust, or other contaminants that may have accumulated.
[0040] At an optional step 211, the biodegradable enclosure 100 is tested for proper functioning. The testing may include testing for leaks, pressure resistance, etc.
[0041] At step 213, the biodegradable enclosure 100 is assembled and packaged with other components as required to protect the biodegradable enclosure 100 from damage and contamination.
[0042] As an exemplary embodiment, the biodegradable enclosure 100 may be assembled as a diagnostic kit to facilitate rapid detection in diagnostic testing applications. This assembly may be stored at a temperature ranging from 20-25 °C, away from heat sources. The assembly should not be exposed to any environment having more than 50% humidity. Storing the kits in a sealed container may yield a shelf life of two to three years, thus, ensuring reliable results in diagnostic testing applications.
[0043] After use, the biodegradable enclosure 100 of the present disclosure may be degraded by at least one of hydrolysis, photolysis, and microbial/enzymatic degradation. The polymer may decompose naturally when exposed to environmental conditions, such as sunlight, water, and microorganisms.
[0044] In hydrolysis, the water molecules break down the ester linkages of the polymer. The hydrolysis rate may be aggravated by increasing or decreasing the pH conditions. In photolysis, the PLA polymer is broken down by UV radiation which is amply available in natural sunlight while in microbial/enzymatic degradation, metabolization of the PLA polymer into carbon dioxide, water and other natural substances takes place. The PLA polymer is broken down by a range of microorganisms including bacteria, fungi and algae. The biodegradation of the biodegradable enclosure 100 of the present disclosure may be effectuated under aerobic or anerobic conditions.
[0045] The biodegradable enclosures 100 produced herein exhibited superior physical properties as described below.
[0046] Rigidity and Strength: The biodegradable enclosures 100 produced as per the teachings of the present disclosure exhibited good rigidity and strength, thus providing structural integrity to the biodegradable enclosures 100 during handling, transportation, and usage. Titanium dioxide (TiO2) nanoparticles improved the tensile strength and stiffness of polymers. The additives reinforced the PLA matrix, enhancing its resistance to deformation and improving mechanical properties such as tensile strength, flexural strength, and impact resistance of the biodegradable enclosure 100.
[0047] Flexibility: Depending upon flexibility needed, by incorporating plasticizers, flexible biodegradable enclosures 100 may be obtained.
[0048] Surface Morphology and Surface Smoothness: The incorporation of TiO2 and other additives influenced the surface morphology of the biodegradable enclosure 100. TiO2 nanoparticles, in particular, due to their high surface area led to improved surface smoothness and uniformity of the biodegradable enclosure 100. The smooth surface finish of the biodegradable enclosure 100 may be important for optimal fluid flow and prevention of sample or reagent retention.
[0049] Superior optical detection properties: TiO2 nanoparticles exhibited high refractive index, opacity and altered the transparency or translucency of the biodegradable enclosure 100. The biodegradable enclosure 100 aided better visual inspection, readability of diagnostic results, and compatibility with optical detection methods.
[0050] Thermal Stability: Biodegradable enclosures 100 exhibited good thermal stability, thus enabling them to withstand the temperatures encountered during storage and use.
[0051] Biodegradability: The biodegradable enclosures 100 when properly disposed in appropriate biodegradation conditions, such as composting facilities or industrial composting sites, underwent biodegradation and demonstrated bioresorbability. During the biodegradation process, microorganisms caused break down of the PLA polymer chains into simpler molecules through enzymatic activity. These simpler molecules were further metabolized by microorganisms, leading to the complete degradation of PLA into carbon dioxide, water, and biomass and allowed for sustainable disposal.
[0052] The present disclosure is further described by reference to the following exemplary embodiments and examples. These exemplary embodiments and examples are provided for purposes of illustration only and are not intended to be limiting unless otherwise specified. Thus, the present disclosure should in no way be construed as being limited to the following exemplary embodiments and examples, but rather, should be construed to encompass any and all variations which become evident as a result of the teaching provided herein.
[0053] Exemplary Embodiments
[0054] Example 1: A biodegradable enclosure 100 made of 94% PLA polymer granules, and 6% TiO2 along with carrier resins when manufactured using the teachings of the present disclosure exhibited the following distinct physical properties:
a. The glass transition temperature of the biodegradable enclosure 100 is 60°C.
b. The density of the biodegradable enclosure 100 is 1.3 grams per cubic centimeter (g/cm³).
c. The tensile strength of the biodegradable enclosure 100 is 50MPa.
d. The flexural strength of the biodegradable enclosure 100 is 80MPa.
e. The impact strength of the biodegradable enclosure 100 is 5 kJ/m² (kilojoules per square meter).
f. The melting temperature of the biodegradable enclosure 100 ranges is 170°C.
[0055] Example 2: In-vitro degradation study of the biodegradable enclosure 100 of Example 1 - For testing degradation outcome, the biodegradable enclosure 100 was fully submerged in a 500mL sealed glass beaker containing 400mL phosphate buffer saline solution (pH 7.2 to 7.4) kept at 37°C ± 3°C. The biodegradable enclosure 100 was visually inspected every alternate day. It was observed that, after 28 days, the biodegradable enclosure 100 shattered into pieces. And, after 70 days, the biodegradable enclosure 100 had degraded into very small pieces (As shown in Fig. 3). Thus, the real-time in-vitro degradation study of the biodegradable enclosure 100 confirmed natural break down of the biodegradable enclosure 100 without any hazardous emissions.
[0056] Example 3: Anaerobic degradation test of the biodegradable enclosure 100 of Example 1 - The biodegradable enclosure was enclosed within a sealed container with 53% methanogenic inoculum from an anaerobic digester. In this experiment, the biodegradable enclosure 100 was made using the exemplary method as described in the present disclosure (Fig.2). The biodegradable enclosure 100 was processed and prepared prior to being subjected to the anaerobic degradation test. The container was incubated at 52±2 °C. The gasses evolving from the container was analyzed for a period of 60 days. After 60 days, it was observed that the percentage biodegradation of the biodegradable enclosure 100 was found to be 75.07% whereas it was 82.83% for cellulose as presented in Table 1 and Fig. 4. Based on the gas production analysis from biodegradation of biodegradable enclosure, the increase in the biogas volume confirmed the trend of conversion of carbon content to gaseous phase indicating increased rate of sample biodegradation over the test period of 60 days. On the basis of these results, it was deduced that if the biodegradable enclosure 100 was continued to be exposed under landfill conditions, the rate of biodegradation would accelerate. The biogas released by the biodegradable enclosure 100 (with cellulose as reference) indicated its biodegradable property.
[0057] Table 1: Cumulative gas production and biodegradation of materials during incubation period of 60 days.
S.No Material Total Vol in mL Methane Content Carbon dioxide Content Theo.C (g) Biodegradation
(%)
% Vol
(mL) % Vol (mL)
1 Methanogenic Innoculum 7100 12.19 865.40 11.30 802.30 - -
2 Cellulose 13310 38.20 5084.40 26.60 3540.40 4.50 82.83
3 Biodegradable enclosure 100 16812 48.40 8137.00 30.70 5161.20 8.30 75.07
[0058] Further, a biofilm formation was observed on the surface of the biodegradable enclosure 100. The said observations were conclusive of the fact that the biodegradable enclosure 100 was readily biodegradable under landfill-like conditions.
[0059] Example 4: A comparative study of bend moment of samples with and without TiO2 was conducted to investigate the impact of TiO2 nanoparticles on material properties especially bending behavior. A bend moment is defined as a controlled bending force or a bending stress applied on a biodegradable enclosure and the response of the biodegradable enclosure to the bending stress. The results are provided in Table 2 below:
Sample 1: Top portion of a biodegradable enclosure without TiO2
Sample 2: Bottom portion of a biodegradable enclosure without TiO2
Sample 3: Top portion of a biodegradable enclosure 100 with TiO2
Sample 4: Bottom portion of a biodegradable enclosure 100 with TiO2
Table 2: A comparative study of bend moment of samples with and without TiO2
Sample # Moment Arm (cm) Yield Load Yield Angle Yield Moment Load @ 30° Load @ 60° Load @ 90° Ultimate Load Ultimate Moment
Sample #1 1 1245 26.24 1245 1330 . . 1455 1455
Sample #2 1 1040 20.2 1040 1190 . . 1275 1275
Sample #3 1 1685 20.32 1685 1940 . . 1995 1995
Sample #4 1 1870 23.2 1870 2085 . . 2245 2245
[0060] It is evident from the table that the load carrying capacity of the biodegradable enclosure 100 of the present disclosure is at least 30-70% more than conventional enclosures.
[0061] The scope of the invention is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. , Claims:WE CLAIM:
1. A method (200) of preparing a biodegradable enclosure (100) comprising:
preparing a first mixture by homogenously mixing a pre-defined concentration of poly lactic acid (PLA) polymer granules and one or more additives, the first mixture being obtained by homogenously mixing 92% to 96% of the polymer granules and 4% to 8% of the one or more additives;
drying the first mixture to reduce a dew point and a moisture level of the first mixture to less than 30°C and 0.1% respectively; and
molding the first mixture to a pre-defined shape using a mold at a first pre-defined temperature, a first pre-defined pressure, a first pre-defined time period and a first pre-defined speed.
2. The method (200) as claimed in claim 1, wherein the molding the first mixture includes:
injecting the first mixture inside the mold at a first pre-defined temperature and a first pre-defined pressure in a first pre-defined time period at a first pre-defined speed;
holding the first mixture inside the mold at a second pre-defined temperature and a second pre-defined pressure for a second pre-defined time period at a pre-specified clamping force;
cooling and solidifying the first mixture inside the mold at a third pre-defined temperature for a third pre-defined time period to provide the biodegradable enclosure (100); and
recovering the biodegradable enclosure (100) from the mold.
3. The method (200) as claimed in claim 2, wherein the first pre-defined temperature ranges from 170 °C to 210 °C, the first pre-defined pressure ranges from 50 MPa to 120 MPa, the first pre-defined time period ranges from 1 second to 5 seconds and the first pre-defined speed ranges from 50 mm/s to 300 mm/s.
4. The method (200) as claimed in claim 2, wherein the second pre-defined temperature ranges from 30 °C to 60 °C, the second pre-defined pressure ranges from 50 MPa to 100 MPa, the second pre-defined time period ranges from 5 seconds to 20 seconds and the pre-specified clamping force ranges from 100 to 500 tons.
5. The method (200) as claimed in claim 2, wherein the third pre-defined temperature ranges from 10 °C to 40 °C and the third pre-defined time period ranges from 10 seconds to 30 seconds.
6. The method (200) as claimed in claim 1, wherein the one or more additives include a combination of a metal salt and carrier resin(s).
7. The method (200) as claimed in claim 6, wherein the metal salt includes one of titanium dioxide (TiO2) or zinc acetate.
8. The method (200) as claimed in claim 6, wherein the carrier resin(s) includes one of polypropylene, polystyrene, or polyethylene.
9. The method (200) as claimed in claim 6, wherein the metal salt ranges from 70% (w/w) to 80% (w/w) and the carrier resin(s) ranges from 20% (w/w) to 30% (w/w).
10. A biodegradable enclosure (100) comprising:
poly lactic acid (PLA) polymer granules, wherein the PLA polymer granules are present in a concentration ranging from 92% to 96%; and
one or more additives in a concentration ranging from 4% to 8%, wherein the one or more additives include a metal salt and carrier resin(s).
11. The biodegradable enclosure (100) as claimed in claim 11, wherein the one or more additives include 70% (w/w) to 80% (w/w) of the metal salt and 20% (w/w) to 30% (w/w) of the carrier resin(s).
12. The biodegradable enclosure (100) as claimed in claim 11, wherein the metal salt includes one of titanium dioxide (TiO2) or zinc acetate.
13. The biodegradable enclosure (100) as claimed in claim 11, wherein the carrier resin(s) includes one of polypropylene, polystyrene, or polyethylene.
14. The biodegradable enclosure (100) as claimed in claim 11, wherein the biodegradable enclosure is degraded within 70 days.
15. The biodegradable enclosure (100) as claimed in claim 11, wherein the biodegradable enclosure is anaerobically degraded within 60 days.