DESC:FIELD OF INVENTION
[0001] The present invention relates to the field of biodegradable polymer chemistry and its applications in medical device engineering and clinical diagnostics. Particularly, the invention relates to a quad polymer biodegradable composition of biodegradable composition comprising Polylactic Acid (PLA), Polybutylene Succinate (PBS), Polyhydroxyalkanoates (PHA), and Polycaprolactone (PCL) for manufacturing single-use medical laboratory consumables and personal protective equipment (PPE). The invention specifically addresses the urgent need for environmentally responsible alternatives to petrochemical-based disposable products used in healthcare settings, offering a sustainable solution that maintains clinical performance.
BACKGROUND OF THE INVENTION
[0002] The medical and diagnostic industry is heavily dependent on single-use plastic materials, particularly in laboratory settings and protective equipment (PPE). These consumables are predominantly fabricated from petrochemical-derived polymers such as polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polystyrene (PS). Despite being categorized as disposable, these materials are neither biodegradable nor recyclable within biomedical waste streams and are typically incinerated, contributing to persistent environmental and toxicological hazards.
[0003] Conventional waste handling practices involving incineration of biomedical plastics can result in the release of harmful compounds including dioxins, furans, and microplastic particles. Furthermore, the lack of biodegradable alternatives in clinical environments limits progress toward sustainable healthcare. Many plastic-based medical devices, including tubes, containers, and PPE, also lack integration with traceability systems such as barcoding or QR codes, which impedes automation and sample management in clinical workflows.
[0004] Although regulatory bodies have proposed restrictions on single-use plastics, medical consumables remain largely exempt due to the absence of suitable biodegradable substitutes that can match the required performance, sterility, and safety standards. The few existing biodegradable options, such as paper or cotton-based materials, are unsuitable for clinical use due to poor fluid resistance and inability to withstand sterilization methods.
[0005] Biodegradable polymers such as polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoates (PHA), and polycaprolactone (PCL) are emerging alternatives due to their compostable and bio-based characteristics. However, each material individually presents critical limitations. PLA is brittle and deforms under thermal stress; PBS lacks mechanical strength; PHA is expensive and challenging to process; and PCL exhibits low melting points and tensile strength. These limitations hinder their application in regulated clinical settings that demand material robustness, chemical compatibility, and sterilization resilience.
[0006] Previous material development efforts have explored single-polymer or binary biopolymer systems. While these provide limited improvements, they fall short of meeting the comprehensive performance requirements for medical-grade consumables, including mechanical durability, dimensional stability post-sterilization, transparency, and chemical compatibility with diagnostic reagents.
[0007] There exists a critical unmet need for a systemically engineered, biodegradable polymer blend that: (a) balances flexibility, mechanical strength, thermal resistance, and degradation rate; (b) supports the fabrication of diverse medical consumables and protective gear; (c) enables compatibility with standard sterilization methods; and
(d) aligns with emerging biomedical waste regulations and sustainability initiatives.
[0008] None of the prior known polymer blend address the core challenge of creating a multi-product, eco-safe solution for hospitals and labs. Thus, there exists a critical unmet need for: A biodegradable quad-polymer formulation that balances flexibility, strength, thermal resistance, and degradation rate, Direct medical applicability across consumables and PPE, Integration of India's agro-waste and starch resources for scalable production, Alignment with both CPCB waste mandates and Make-in-India sustainability goals,
[0009] One of the patent applications US20160053111A1 titled "Biodegradable Polymer Compositions" discloses compositions comprising a blend of a first component including poly (butylene succinate) (PBS) or polybutylene succinate adipate (PBSA), and a second component including a polyhydroxyalkanoate (PHA). The invention focuses on blends where the content of the first component is 50% or greater by weight. While this approach improves certain properties, it fails to address the comprehensive requirements for medical-grade applications, particularly regarding dimensional stability post-sterilization, vacuum integrity, and compatibility with anticoagulants required for blood collection tubes and similar medical devices.
[0010] Another patent application CN102675839A titled "Biodegradable Film and Laminated Material" discloses a biodegradable film primarily comprising PBAT or PBS or a mixture of PBAT and PBS, as well as PLA and other degradable polymers such as PBSA, PCL, PCL-BS and PHA. While this invention addresses certain biodegradability concerns, it is primarily focused on packaging applications rather than medical consumables. It lacks the specific formulations and processing methodologies required for producing medical-grade laboratory consumables that can withstand sterilization processes while maintaining vacuum integrity and biocompatibility.
[0011] Therefore, the present invention aims to resolve these limitations through a novel quad-polymer biodegradable formulation that integrates PLA, PBS, PHA, and PCL into a unified blend. The invention is tailored to produce medical-grade consumables and protective equipment that meet both performance and environmental standards, enabling scalable, eco-friendly solutions for healthcare infrastructure.
OBJECTIVE OF THE INVENTION
[0012] The primary objective of the present invention is to provide a biodegradable, clinically reliable, and mass-producible solution for single-use medical laboratory consumables and personal protective equipment (PPE) through the development of a novel quad-polymer composition comprising Polylactic Acid (PLA), Polybutylene Succinate (PBS), Polyhydroxyalkanoates (PHA), and Polycaprolactone (PCL).
[0013] Another objective of the invention is to overcome the limitations of individual biodegradable polymers by engineering a material that offers a balanced combination of mechanical strength, flexibility, thermal resistance, and biodegradability—suitable for regulated medical applications.
[0014] A further objective is to ensure compatibility of the quad-polymer composition with common sterilization methods including ethylene oxide (EtO), gamma irradiation, hydrogen peroxide plasma, and UV-C exposure, without compromising structural integrity or performance.
[0015] Another objective of the invention is to support the integration of product traceability mechanisms—such as sterilization-resistant QR codes, barcodes, or alphanumeric identifiers—on labware surfaces to enable compatibility with Laboratory Information Systems (LIS), Hospital Information Systems (HIS), and Unique Device Identification (UDI) protocols. This feature is limited to laboratory consumables and is not applied to PPE items.
[0016] Another objective is to enable the manufacture of essential medical laboratory consumables such as blood collection tubes, cryovials, pipette tips, urine and stool containers, centrifuge tubes, and biopsy containers, as well as PPE items such as surgical gloves, face masks, isolation gowns, aprons, caps, and shoe covers. These products are designed to meet clinical requirements including tensile strength, fluid resistance, breathability, vacuum integrity, and skin biocompatibility.
[0017] Another objective of the invention is to facilitate the design of an eco-certified, single-patient phlebotomy kit (Phlebotomy kit) that integrates biodegradable consumables and PPE into a compact unit, optimized for use in public health screening, infection control, and community-based diagnostic programs—especially in resource-limited and rural settings.
[0018] Yet another objective is to promote circular bioeconomy practices by enabling the use of agro-industrial by-products—such as sugarcane bagasse, tapioca starch residue, maize husk, and dairy fermentation effluents—as bio-feedstocks in the sustainable production of PLA and PHA within established biotechnological frameworks.
[0019] Another objective of the present invention is to reduce the environmental burden associated with medical waste by providing a fully compostable, non-toxic material that undergoes complete biodegradation within 6 to 12 months under biomedical waste conditions, including industrial composting, regulated hospital waste processing, and controlled soil burial. The composition degrades without releasing microplastics or toxic residues, eliminating the need for incineration or landfill dependence.
[0020] Yet another objective of the invention is to ensure full regulatory compliance with relevant national and international standards, including ISO 13485 for medical device manufacturing, ISO 10993 for biocompatibility, CE marking requirements, WHO biosafety guidelines, and the Biomedical Waste Management Rules (India, 2016).
[0021] Finally, the invention seeks to remain cost-effective, manufacturing-feasible, and adaptable to existing industrial methods such as injection molding, film extrusion, thermoforming, blow molding, and additive manufacturing. This supports widespread technology transfer to MSMEs, startups, and government healthcare missions under the Make-in-India initiative and aligns with global sustainable procurement frameworks.
[0022] Other objectives and advantages of the present invention will become apparent from the following description taken in connection with the accompanying drawings, wherein, by way of illustration and example, the aspects of the present invention are disclosed.

SUMMARY OF THE INVENTION
[0023] The present invention relates to a biodegradable quad-polymer composition comprising polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoates (PHA), and polycaprolactone (PCL) for manufacturing single-use medical laboratory consumables and personal protective equipment. Each polymer contributes distinct properties—PLA offers rigidity, PBS provides thermal and impact resistance, PHA enhances biocompatibility and biodegradation, while PCL contributes cold flexibility and elasticity. This carefully balanced matrix overcomes the limitations of both traditional plastics and prior bioplastics by achieving high mechanical strength, transparency, processability, and controlled biodegradability—tailored for clinical-grade applications. The quad-polymer composition is engineered to maintain mechanical durability, sterilization resistance, clinical-grade compatibility, regulatory conformity, and environmental degradability. The biodegradable polymer composition comprising polylactic acid (PLA) in a range of 30%–60% by weight, polybutylene succinate (PBS) in a range of 10%–30% by weight, polyhydroxyalkanoates (PHA) in a range of 10%–25% by weight, polycaprolactone (PCL) in a range of 5%–20% by weight; optionally one or more additional biodegradable polymers, and one or more functional additives selected from, the group of, such as but not limited to, biocompatible plasticizers, antimicrobial agents, essential oil-based bioactive, and biocompatible colorants.
[0024] The invention helps in the creation of two optimized composition profiles from the same polymer system: one tuned for laboratory consumables (e.g., test tubes, pipette tips, containers), and another for PPE products (e.g., gloves, gowns, masks). This dual-composition approach enables over 28 medical products to be manufactured with application-specific performance, while maintaining material harmony across the product line. Both blends are compatible with industrial molding techniques and resistant to sterilization methods such as gamma irradiation, ethylene oxide, and hydrogen peroxide plasma—making them suitable for regulated healthcare use. Products such as blood collection tubes can retain EDTA, Heparin, or Sodium Citrate coatings without leaching or degradation, even after sterilization—ensuring diagnostic accuracy and clinical reliability. Additionally, the material offers programmable post-use biodegradation (6–12 months) while maintaining shelf-life stability (24–36 months) under variable storage conditions including cold-chain logistics and high humidity environments. The invention also relates to a method for manufacturing the polymer blend via twin-screw extrusion and subsequent molding techniques. The products are embedded with QR codes or barcodes for traceability and compatibility with Laboratory Information Systems (LIS) or Hospital Information Systems (HIS), and Unique Device Identification (UDI) platforms to enables real-time tracking, sample automation, and inventory control—bridging sustainable material science with digital healthcare workflows. The invention also designed for drop-in compatibility with existing manufacturing infrastructure, avoiding the need for costly retooling. It also aligns with global regulatory and eco-certification standards (ISO 10993, ISO 13485, ASTM D6400, EN 13432), ensuring readiness for clinical deployment and international commercialization. Together, these inventive steps establish a comprehensive, scalable, and environmentally responsible alternative to petroleum-based plastics in healthcare—solving critical problems in waste, safety, and sustainability.

BRIEF DESCRIPTION OF DRAWINGS
[0025] The present invention will be better understood after reading the following detailed description of the presently preferred aspects thereof with reference to the appended drawings, in which the features, other aspects, and advantages of certain exemplary embodiments of the invention will be more apparent from the accompanying drawing.
[0026] FIG. 1 illustrates quad-polymer Blending Interaction (PLA–PBS–PHA–PCL).
[0027] FIG. 2 illustrates morphology cross section of quad-Polymer Blend
[0028] FIG. 3 shows a biopolymer blending process via twin-screw extrusion.
[0029] FIG. 4 DSC thermogram of quad blend
[0030] FIG. 5 illustrates PPE Kit layer comprising a layer of (a) spun bound layer, (b) melt-blown layer, (c) barrier/adhesive layer, and (d) non-woven layer.
[0031] FIG. 6 illustrates biodegradable lab ware articles in accordance with the present invention.
[0032] FIG. 7 illustrates biodegradation curve of Polymer Blends.
[0033] FIG. 8 illustrates tensile Strength vs Polymer Blend Composition.
[0034] FIG. 9 illustrates FTIR Spectrum of Quad-Polymer Biodegradable Blend.
[0035] FIG. 10 illustrates mechanical Strength Retention After Sterilization.
[0036] FIG. 11 illustrates contact angle comparison across materials.
[0037] FIG. 12 illustrates transparency (% Transmission) vs Polymer Blend Type.
[0038] FIG. 13 illustrates barrier strength retention over time (humidity storage).
[0039] FIG. 14 illustrates elongation at break (%) vs Polymer Blend Composition.
[0040] FIG 15 illustrates melt flow index stability of quad blend
[0041] FIG. 16 illustrates water absorption of quad blend over time.
[0042] FIG. 17 illustrates oxygen permeability of quad blend over time.
[0043] FIG. 18 illustrates TGA Curve of quad blend (Thermal Degradation).
[0044] FIG. 19 illustrates barrier strength vs relative humidity.
DETAILED DESCRIPTION OF THE INVENTION

[0045] The following description describes various features and functions of the disclosed apparatus. The illustrative aspects described herein are not meant to be limiting. It may be readily understood that certain aspects of the disclosed apparatus can be arranged and combined in a wide variety of different configurations, all of which are contemplated herein.
[0046] The description of preferred embodiments is not intended to limit the invention to these examples, but to enable any skilled person to practice and apply the invention
[0047] These and other features and advantages of the present invention will become more apparent from the following detailed description
[0048] Variations and modifications are possible without departing from the spirit and scope of the invention.
[0049] Unless defined otherwise, all terms herein are to be given their ordinary meaning as understood by a person skilled in the art
[0050] The singular forms “a,” “an,” and “the” include plural forms unless the context clearly dictates otherwise.
[0051] It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.
[0052] The present invention relates to a biodegradable polymer composition suitable for manufacturing single-use medical articles and personal protective equipment (PPE). The composition comprises a blend of polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoates (PHA), and polycaprolactone (PCL). In certain embodiments, the composition may further comprise one or more additional biodegradable polymers and one or more functional additives. The functional additives may include biocompatible plasticizers, antimicrobial agents, essential oil-derived bioactives, or biocompatible colorants, selected to enhance material performance and application-specific functionality.
[0053] In an embodiment, the present invention provides a quad-polymer biodegradable composition comprising: (a) polylactic acid (PLA), in the range of 30% to 60% by weight, preferably between 35% to 55%, providing structural strength and transparency;(b) polybutylene succinate (PBS), in the range of 10% to 30% by weight, preferably between 15% to 25%, contributing heat resistance and ductility;(c) polyhydroxyalkanoates (PHA), in the range of 10% to 25% by weight, offering biocompatibility and enzymatic degradability; (d) polycaprolactone (PCL), in the range of 5% to 20% by weight, preferably between 5% to 15%, imparting flexibility and low temperature sealing properties, (e) optionally, one or more additional biodegradable polymers in the range of 5% to 30% by weight of the total composition; and (f) optionally, one or more functional additives in the range of 1% to 15% by weight, such as biocompatible plasticizers, antimicrobial agents, bioactive compounds, or colorants.
[0054] In an exemplary embodiment, one or more functional additives are included in the composition, selected from:
(a) biocompatible plasticizers, in the range of 0.1% to 10% by weight, such as acetyl tributyl citrate (ATBC), epoxidized soybean oil, polyethylene glycol esters (PEG), or bio-based succinate esters.
(b) antimicrobial agents, in the range of 0.1% to 2% by weight, selected from silver nanoparticles, zinc oxide, chitosan, or copper oxide.
(c) essential oil-based bioactive compounds, in the range of 0.1% to 1% by weight, selected from tea tree oil, clove oil, eucalyptus oil, or neem oil; (d) biocompatible colorants, in the range of 0.1% to 1% by weight, selected from titanium dioxide, iron oxides, chlorophyllin, or plant-derived anthocyanins.
[0055] In another exemplary embodiment, the composition comprises 5% to 30% by weight of one or more additional biodegradable polymers selected from polybutylene adipate terephthalate (PBAT), thermoplastic starch (TPS), polyhydroxybutyrate (PHB), polyglycolic acid (PGA), polyethylene furanoate (PEF), polyethylene oxide (PEO), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), cellulose acetate, chitosan, gelatin, or alginate. These optional components are incorporated to tailor specific application properties such as flexibility, transparency, processing ease, or functional responsiveness.
[0056] For example, PBAT may be added at 5%–30% to enhance softness, tear resistance, and elasticity; PHBV at 3%–10% to increase rigidity and dimensional accuracy; PEG at 2%–8% to improve hydrophilicity and plasticity; TPS to promote rapid biodegradation at low cost; PGA for fast degradation in single-use products; PEF for oxygen and moisture barrier strength; PEO for water solubility and rapid disintegration; cellulose acetate for stiffness and optical clarity; chitosan for inherent antimicrobial activity; and gelatin or alginate for short-term dissolvability in contact-sensitive applications.
[0057] All supplementary polymers and additives are medical-grade, globally available, and compatible with standard manufacturing processes such as injection molding, extrusion, blow molding, and spunbond/meltblown nonwoven fabrication. The inclusion of these additives does not compromise the sterilization compatibility, composability, or shelf-life stability of the final product. No experimental or proprietary materials are required, ensuring full industrial replicability and regulatory readiness.
[0058] The quad-polymer blend of the present invention is engineered for manufacturing a wide range of single-use medical and laboratory consumables, including but not limited to blood collection tubes, cuvettes, pipette tips, cryovials, urine containers, stool containers, surgical masks, gloves, gowns, and Eppendorf tubes. A particularly advantageous application is in the form of a phlebotomy kit comprising blood collection tubes, gloves, mask, tourniquet, alcohol swabs, cotton swabs, and spot bandages, all designed for single use per patient.
[0059] The composition achieves a synergistic combination of mechanical and functional properties through its semi-miscible matrix structure. Unlike traditional PLA–PBS or PLA–PCL binary blends, the quad-polymer system leverages the compatibilizing properties of PHA and the ductility of PCL, resulting in improved structural uniformity across molded, extruded, and spunbond nonwoven formats.
[0060] In one embodiment, the invention provides a biodegradable personal protective equipment (PPE) article comprising a polymer matrix with PLA in the range of 30–45 wt%, PBS in the range of 20–30 wt%, PHA in the range of 15–25 wt%, and PCL in the range of 10–20 wt%. The PPE article is fabricated as a nonwoven or laminated sheet containing functional layers, including: (a) a spunbond outer layer composed of PLA–PBS composite filaments to provide mechanical strength;(b) a melt-blown barrier layer made of PLA–PCL or PLA–PHA for microbial filtration efficiency; (c) a laminated film layer (serving as the fluid-impermeable barrier layer) to resist liquid penetration and contamination; (d) a microporous membrane (serving as the inner nonwoven comfort layer) to allow breathability and moisture wicking for extended wear comfort.
[0061] In an exemplary embodiment, the PPE article may be selected from gloves, surgical masks, gowns, aprons, shoe covers, or caps. Optionally, the PPE article may be functionalized with antimicrobial, hydrophobic, antiviral, or thermochromic agents.
[0062] The quad-polymer matrix displays a semi-miscible morphology with crystalline PLA–PBS lamellae and amorphous PHA–PCL domains. The overall structure is stabilized through intermolecular interactions such as hydrogen bonding, van der Waals forces, and dipole-dipole attractions, contributing to enhanced durability, thermal stability, and elasticity. As shown in Figure 1, it shows phase interactions in the PLA–PBS–PHA–PCL blend. Most pairs exhibit partial miscibility, while PHA–PCL shows strong hydrogen bonding, enhancing compatibility and mechanical stability.
[0063] In one embodiment, the invention enables traceability through QR codes or barcodes printed, laser-etched, or embedded directly onto the product or packaging. These identifiers are tamper-evident and compatible with high-temperature sterilization processes. The encoded data includes product type, batch ID, composition, sterilization metadata, expiry date, and is scannable by automated analyzers for seamless integration with Laboratory Information Systems (LIS), Hospital Information Systems (HIS), or Unique Device Identification (UDI) platforms. Where digital infrastructure is unavailable, the design permits fallback to manual labeling and data capture without affecting compliance.
[0064] The articles are packaged using multilayer biodegradable films engineered with oxygen and moisture barrier properties to preserve sterility and maintain QR/barcode legibility. The packaging configuration supports a shelf life of 24 to 36 months under ambient storage conditions.
[0065] In an embodiment, the article exhibits =90% weight loss biodegradation within 6–12 months under industrial composting or landfill-simulated conditions, without generating toxic residues or microplastics.
[0066] In an embodiment, the article retains structural and functional integrity after sterilization using ethylene oxide (EtO), gamma radiation (15–25?kGy), hydrogen peroxide plasma, or UV-C (254?nm), without loss of performance or coating integrity.
[0067] In an embodiment, the PPE article or diagnostic consumable may optionally include one or more functional surface coatings to enhance specific performance characteristics. These coatings may comprise:
[0068] Anticoagulant agents, selected from ethylenediaminetetraacetic acid (EDTA), trisodium citrate, or lithium heparin, applied internally in blood-contact surfaces such as collection tubes to prevent clot formation;(b)Antimicrobial agents selected from biocompatible compounds such as chitosan, silver nanoparticles (AgNPs), copper oxide, zinc oxide (ZnO), or natural extracts such as tea tree oil, to inhibit microbial growth on high-contact PPE surfaces; (c)Hydrophobic or barrier-forming agents such as polydimethylsiloxane (PDMS), polyvinyl alcohol (PVA), carnauba wax, or stearic acid, used to increase surface repellency, improve user comfort, and enhance fluid resistance; (d) Indicator agents selected from visual detection compounds such as resazurin (colorimetric metabolic indicator), thermochromic inks (for temperature response), or leuco dyes (for reversible chemical indication), integrated into surfaces or laminate layers for diagnostic or safety alerts.
[0069] These coatings are applied via spray, dip, plasma-assisted deposition, or lamination techniques depending on substrate compatibility and regulatory compliance and are designed to retain their functional properties during storage, sterilization, and intended use.
[0070] In an embodiment, functional surface coatings may be applied to one or more layers of the nonwoven or laminated sheet to enhance the performance of the PPE article. Antimicrobial coatings inhibit microbial growth; hydrophobic coatings increase water repellency and fluid resistance; antiviral coatings provide protection against viral particles; and thermochromic coatings serve as visual indicators of temperature change. Coatings may be applied via dip-coating, plasma activation, or micro-spraying, and are designed to remain adherent and functional post-sterilization.
[0071] Performance-enhancing additives may be incorporated based on the functional requirements of the end-use product. In laboratory consumables such as blood collection tubes, cryovials, pipette tips, and specimen containers, the addition of Polyglycolic Acid (PGA) at 2–5 wt% enhances gas barrier properties and dimensional stability, suitable for vacuum-sealed formats. PLA grafted with Glycidyl Methacrylate (PLA-GMA) at 2–5 wt% acts as a compatibilizer, improving mold uniformity and polymer compatibility. In PPE applications, Thermoplastic Starch (TPS) at 5–10 wt% imparts softness and breathability, particularly in inner linings, while PBAT-based biodegradable elastomers (e.g., Ecoflex®) at 5–15 wt% improve elasticity in components such as glove cuffs and ear loops. Surface coatings may optionally include antimicrobial, hydrophobic, antiviral, or thermochromic agents depending on clinical use.
[0072] In one embodiment, the polymer blend optionally comprises 0.1% to 10% by weight of one or more eco-compatible functional additives selected from a-tocopherol, ascorbic acid, rosemary extract, triethyl citrate, polyethylene glycol (PEG 1000), chitosan, zinc oxide, silver nanoparticles, talc, starch, calcium carbonate, titanium dioxide, iron oxide, or maleic-anhydride–grafted PLA. These additives improve flexibility, processability, or barrier properties without compromising sterilization compatibility or biodegradation efficiency.
[0073] In an embodiment, the invention comprises a scalable manufacturing process compatible with existing industrial polymer-processing equipment, enabling rapid adoption without requiring retooling or equipment overhaul.
[0074] In an embodiment, the article is manufactured using a method comprising: (a) dry-blending the primary polymer composition with optional biodegradable additives; (b) dehumidifying the blend at 60–80?°C to reduce moisture content below 0.2%; (c) extruding the material at 140–190?°C into pellets or sheets; (d) forming the final product via injection molding, blow molding, compression molding, thermoforming, or additive manufacturing; (e) applying optional surface coatings or QR traceability markings; (f) sterilizing using ethylene oxide (EtO), gamma irradiation, plasma sterilization, or UV-C; (g) conducting inline quality control for strength, clarity, and data readability; and (h) reprocessing up to 10% of manufacturing offcuts through grinding and remolding.
[0075] In another embodiment, the method for manufacturing biodegradable PPE articles includes: (a) blending the composition with biodegradable plasticizers and stabilizers; (b) drying the blend to reduce moisture content below 0.2%; (c) extruding the material to produce non-woven or film sheets via spun-bond, melt-blown, or film extrusion; (d) laminating the sheets using thermal bonding, ultrasonic welding, or calendaring; (e) applying functional coatings such as antimicrobial, hydrophobic, or indicator agents using dip-coating, spray-coating, or plasma activation; (f) cutting and forming the PPE into gloves, masks, gowns, aprons, caps, or shoe covers; (g) sterilizing using EtO, gamma irradiation, hydrogen peroxide plasma, or UV-C; (h) packaging in biodegradable barrier-protected pouches; and (i) recycling up to 10% of offcuts without performance loss.
[0076] In this process, a twin-screw extrusion system may be employed to generate a homogeneous quad-polymer blend with tailored properties for medical-grade applications. The blend is processed at barrel temperatures of 140°C to 190°C and shear rates of 80–120 rpm. Following melt blending, the material is cooled, pelletized, and stored for downstream use. Product-specific molding techniques are selected based on the intended application.

Table 1
[0077] In an embodiment, the sterilization method is selected based on the product’s material sensitivity, coating stability, and applicable regulatory requirements. Sterilization techniques include moist heat (steam autoclaving), hydrogen peroxide plasma sterilization (H2O2), ethylene oxide (EtO) gas sterilization, and gamma radiation. Each method is compatible with the quad-polymer blend and preserves coating integrity.
[0078] As illustrated in FIG. 3, it depicts the twin-screw extrusion process used for homogenizing the quad-biopolymer blend into a uniform, medical-grade composite material. The following zones describe the process flow of polymer blending and pellet preparation in the extrusion system:
[0079] Polymer Feed Hoppers (101): Designated feed inlets for PLA (101a), PBS (101b), PHA (101c), and PCL (101d) allow for precise polymer input using automated dosing mechanisms to maintain the intended blend ratio.
[0080] Feeding Zone (102): Twin-screw extruders convey the solid polymer pellets into the barrel where initial mechanical agitation begins the pre-blending process.
[0081] Melting Zone (103) – 140–190?°C: Temperature-controlled heating melts the polymers, initiating molecular-level interactions such as hydrogen bonding and van der Waals forces. The polymers form a semi-molten, partially miscible matrix. Shear and Mixing Zone (104): Controlled shear forces enable distributive and dispersive mixing. This ensures: (i) Uniform distribution of the four polymers; (ii) Breakdown of agglomerates; (iii) Enhanced interfacial adhesion. The resulting blend achieves consistent texture, mechanical stability, and structural uniformity.
[0082] Degassing Zone: Vacuum vents remove residual moisture and volatile compounds, preventing hydrolytic degradation and improving the shelf-life of the final pellets.
[0083] Die Exit and Strand Formation: The homogenized polymer blend is extruded through a die, forming continuous strands that are cooled and prepared for downstream palletization.
[0084] Pelletizing Unit: Cooled strands are chopped into uniform granules (2–4 mm), suitable for forming processes including injection molding, blow molding, or compression molding.
[0085] As shown in FIG. 6, it illustrates Biodegradable lab consumables with QR code traceability, including tubes, containers, pipette tips, cuvette, and biohazard bag for single-use applications. In an exemplary embodiment, the invention encompasses a range of single-use and multi-use biodegradable medical consumables and PPE articles manufactured using the PLA–PBS–PHA–PCL quad-polymer blend. These include, but are not limited to, blood collection tubes, cryovials, pipette tips, petri dishes, gloves, gowns, face masks, aprons, and shoe covers. The products are designed as functional replacements for conventional materials such as PET, PVC, polystyrene, and polyolefins, and are fully compatible with sterilization procedures, clinical workflows, and environmental sustainability requirements.
Table 2A: Biodegradable Blood Collection and Sample Tubes
Product Name Dimension (Standard) Application
EDTA Blood Collection Tube 13×75 mm / 13×100 mm Hematology sample collection
Sodium Citrate Tube 13×75 mm Coagulation studies
Lithium Heparin Tube 13×100 mm Biochemistry tests
SST / Gel Clot Activator Tube 13×100 mm Serum separation and chemistry
ESR Tube 8×120 mm Erythrocyte Sedimentation Rate
Fluoride Oxalate Tube 13×75 mm Blood glucose testing

Table 2A
Table 2B: Biodegradable Body Fluid Collection Containers
Product Name Capacity Use
Urine Collection Container 30 mL / 60 mL / 100 mL Routine urinalysis
Stool Container (with spoon) 30 mL / 60 mL Parasitology and fecal culture
24-Hour Urine Container 2–3 L Volume collection and creatinine clearance
CSF Collection Tube Set 1.5 mL–5 mL Cerebrospinal fluid storage (biocompatible)

Table 2B
Table 2C: Biodegradable Storage and Processing Tubes
Product Size Use
Cryovial Tube 1.8 mL / 2 mL Long-term frozen storage
Conical Centrifuge Tube 15 mL / 50 mL Sample centrifugation
Eppendorf Tube 0.5 mL / 1.5 mL / 2.0 mL Molecular and biochemical assays
Transport Tube with Screw Cap 5–10 mL Specimen referral transport
Table 2C
Table 2D: Biodegradable Personal Protective Equipment (PPE)
Product Size / Description
Examination Gloves Biopolymer-based, latex-free
Surgical Gloves Sterile, powder-free
Face Masks (3-ply & N95-type) Fluid resistant, breathable
Surgical Gowns Full-body coverage with ties
Shoe Covers Slip-resistant, elastic cuff
Surgical Caps Breathable non-woven design
Aprons Disposable splash protection
Table 2D

Table 2E: Eco-Certified Phlebotomy Kit
Kit Component Description
Tubes (EDTA, SST, Fluoride) Biodegradable, QR-coded
1× Alcohol Swab & Spot bandage Individually packed
1× Tourniquet & Needle Plant-based elastic polymer
1× Biodegradable Glove Pair Size S/M/L
1× Sample Label Sticker QR or barcode-enabled
1× Sharps-safe Needle (optional) Biocompatible plastic shell
1× Compostable Outer Pouch Sterile and labeled
Table 2E
[0086] In an embodiment of the present invention, Table 3 provides a comparative analysis of the performance characteristics of the proposed PLA–PBS–PHA–PCL quad-polymer blend relative to commercially available PET-based laboratory consumables. The comparison highlights key functional parameters relevant to clinical and diagnostic applications.
Property PLA–PBS–PHA–PCL Blend (Proposed) PET (Traditional Plastic)
Tensile Strength (MPa) 50–65 55–75
Elongation at Break (%) 15–30 20–50
Glass Transition Temp (°C) 55–65 70–80
Melting Point (°C) 160-180 250–260
Gamma Sterilization Pass (<1% IV drop, no embrittlement) Pass
Biodegradability Yes (compostable within6-12 months) No
Transparency High (90%+) High (85–90%)
Biocompatibility Medical grade compliant Medical grade compliant
Table 3
[0087] Further, as shown in FIG. 8, tensile strength increases from 45?MPa (PLA) to 60?MPa with the quad-blend, showing improved mechanical performance. Another experiment shows that, the mechanical strength retention remains high after EtO (96%) and plasma (95%) sterilization, and slightly lower with gamma radiation (92%).
[0088] As shown in FIG. 11, the contact angle of quad-blend (82°) is higher than PLA (76°) and PPE gloves (74°), indicating better liquid-repellence.
[0089] As shown in FIG. 12, the quad blend transparency (89.5%) is close to PET (90%), exceeding PLA (86%) and PLA PBS (88%).
[0090] As shown in FIG. 13, barrier strength retention after 24 weeks: quad blend (~90%) outperforms PLA (~60%) and approaches PET (~96%).
[0091] As shown in Fig. 14, it illustrates the elongation at break jumps from 6% (PLA) to 300% with the quad blend, showing exceptional flexibility.
[0092] As shown in Fig. 15, it depicts melt flow index remains stable after sterilization and storage, ensuring consistent processability.
[0093] As shown in Fig. 16, it depicts water absorption reaches only ~1.3% after 10 days, indicating low moisture uptake.
[0094] As shown in Fig. 17, it depicts, oxygen permeability rises moderately from 0.50 to 0.70?cc/m²/day over 20 days, maintaining good barrier performance.
[0095] As shown in Fig. 18, it depicts that TGA curve shows major weight loss starting above 250?°C, reaching ~90% at 400?°C, and confirming thermal stability.
[0096] As shown in FIG. 19, it depicts barrier strength retention drops slightly from 98% at 30% RH to 89% at 90% RH, showing good humidity resistance.
[0097] The present invention provides a biodegradable polymer composition comprising a PLA–PBS–PHA–PCL quad-blend, designed to replace conventional medical-grade plastics such as PET, PVC, and polystyrene. While both the proposed blend and traditional materials exhibit high tensile strength, optical clarity, and compliance with medical standards, the PLA–PBS–PHA–PCL formulation uniquely combines biodegradability, sterilization compatibility, and structural performance—rendering it a next-generation alternative for sustainable single-use medical consumables and PPE.
[0098] The resulting polymer matrix is fully compostable under industrial composting conditions in accordance with ISO 17088, with partial home composability achievable depending on additive concentration. The typical degradation window ranges from 6 to 12 months for PPE articles and up to 12 months for laboratory consumables with wall thicknesses around 1 mm. All degradation byproducts are non-toxic, environmentally benign, and compliant with global environmental safety standards.
[0099] In one embodiment, the present invention includes a scalable, industry-compatible manufacturing process for producing biodegradable medical articles using the PLA–PBS–PHA–PCL composition. The process is engineered for compatibility with conventional plastic-processing infrastructure and ensures the preservation of mechanical integrity, sterilization resilience, and regulatory conformity. The manufacturing stages encompass raw material preparation, moisture-controlled blending, twin-screw extrusion, palletization, thermoforming or molding, surface functionalization, and sterilization—tailored for medical-grade performance with minimized environmental footprint.
[0100] In an embodiment, the present invention provides a detailed manufacturing protocol for biodegradable medical and laboratory articles using a PLA–PBS–PHA–PCL polymer blend. The process initiates with the selection of high-purity, medical-grade polymers including polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoates (PHA), and polycaprolactone (PCL). Each polymer is sourced in pellet or granule form compliant with FDA, ISO 10993, USP Class VI, and EU MDR regulations. No phthalates, bisphenol compounds (e.g., BPA), or halogenated additives are included.
[0101] The raw materials are subjected to controlled pre-processing to reduce moisture content below 0.02%, thereby minimizing hydrolysis during melt blending. Dehumidifying ovens or vacuum dryers operate at 40–60°C, with desiccant dryer dew points maintained at –40°C. Pellet size is maintained between 2.5–4 mm, and uniformity is ensured through dry blending at 60–80 RPM for 12–15 minutes. Optional functional additives such as anticoagulants (e.g., EDTA, heparin), natural colorants, or processing aids may be introduced during masterbatch preparation.
[0102] The blended polymers are processed in a twin-screw extruder with zonal temperature control ranging from 140°C to 190°C, depending on polymer melt characteristics. The screws apply shear at 80–120 RPM, promoting uniform dispersion and domain-level compatibilization via hydrogen bonding and van der Waals interactions. Degassing ports eliminate residual volatiles and moisture. Inline additive ports enable real-time incorporation of antioxidants, antimicrobials, biodegradation accelerators, and other optional agents.
[0103] Post-extrusion, the homogenized melt is cooled in a water bath and pelletized into uniform granules of 2–4 mm diameter. These are vacuum-sealed or stored under desiccated conditions to maintain stability. The resulting pellets are shelf-stable for 6–8 months and are suitable for downstream forming processes.
[0104] The final product is formed using standard thermoplastic conversion techniques selected based on application. These include: (a) injection molding for rigid labware such as blood collection tubes, pipette tips, and cuvettes; (b) blow molding or film extrusion for flexible containers such as urine and stool cups; (c) compression molding or blow–fill–seal for PPE components like gloves, gowns, masks, and shoe covers; and (d) optional additive manufacturing (3D printing) for prototypes or low-volume designs.
[0105] In one embodiment, the former articles are compatible with standard sterilization methods including: (a) gamma irradiation (20–25?kGy) with no observable mechanical degradation; (b) ethylene oxide (EtO) with preserved chain integrity; and (c) ultraviolet-C (254?nm) exposure with no yellowing or microcrack formation. Sterilization conditions are selected based on product type, coating sensitivity, and regulatory compliance.
[0106] Mechanical and barrier performance characteristics are validated through standardized testing. Typical values include: tensile strength of 10–28?MPa (ISO 527), elongation at break of 100–700%, Izod impact strength of 5–12?kJ/m² (ISO 180), melt flow index of 1–10?g/10?min (ISO 1133), hydrophobic surface contact angle =90° (ASTM D7334), water vapor transmission rate per ISO 2528, and air permeability of 100–600?L/m²/s (ISO 811). Biodegradation performance shows >90% degradation within 6–12 months under composting conditions.
[0107] Post-molding operations may include: (a) internal anticoagulant or gel coatings via rotary or mist spray techniques; (b) vacuum sealing of tubes or containers; and (c) QR code or barcode labeling using UV or inkjet printing for traceability integration with LIS/HIS systems. Sterilization is the final step, performed using a method appropriate for the specific product and its functional coatings. A comprehensive table of sterilization parameters and associated conditions is included elsewhere in this specification.
Method Temperature Duration Suitable Products Notes

Plasma Sterilization (H2O2) 40–55°C 45–90 min Coated tubes, PPE Safe for temperature-sensitive blends
Ethylene Oxide (EtO) 37–55°C 4–6 hours + degassing Mass batches Common for high-volume sterile production
Gamma Radiation 15–25 kGy ~30 mins Pre-packaged kits Optional and scalable for large batches
Table 4
[0108] In an embodiment, the invention provides a comprehensive evaluation of crystallinity, thermal behavior, and structural integrity of the PLA–PBS–PHA–PCL blend using standardized analytical techniques. As illustrated in FIG. 4 Differential Scanning Calorimetry (DSC) reveals a glass transition temperature (Tg) near 59?°C and melting temperature (Tm 165°C) confirming thermal compatibility and partial miscibility among the polymers. The smooth endothermic transition indicates stable phase blending suitable for precision molding. Fourier Transform Infrared (FTIR) spectroscopy, depicted in Fig.9 demonstrates characteristic ester functional peaks around 1750 cm?¹ (C=O stretching) and 1150 cm?¹ (C–O–C stretching). These signals confirm proper physical entanglement and hydrogen bonding among the polymer chains, without formation of undesirable new peaks, indicating absence of chemical incompatibility or degradation products.
[0109] Biodegradation analysis, illustrated in FIG. 7 shows, biodegradation over 30 weeks in compost: quad-blend (~95%) degrades faster than PLA (~45%), while PET shows negligible degradation. It indicates >90% weight loss within 6–12 months under simulated composting conditions. Initial degradation is accelerated by microbial action on PHA and PCL segments, affirming the blend's compliance with industrial composability norms.
[0110] Scanning Electron Microscopy (SEM) imagery in FIG. 2 reveals a smooth, homogeneous surface morphology at 5?µm resolution. No evidence of phase separation or crack propagation is visible, confirming uniform polymer dispersion, strong interfacial adhesion, and mechanical consistency required for clinical and environmental reliability. SEM morphology showing distinct PCL-rich and PHA-rich phases dispersed within a PLA–PBS matrix, indicating partial miscibility and improved mechanical properties.
[0111] During twin-screw extrusion (140–190°C, 80–120?rpm), molecular-level interactions are optimized as PLA and PBS co-align to establish rigidity, PCL softens the matrix to improve impact resistance, and PHA introduces flexibility and enzymatic degradability. Optional compatibilizers such as maleic anhydride grafted PLA or PBS may enhance inter-domain interaction across immiscible zones.
[0112] In another embodiment, the invention relates to a multi-layered PPE laminate material comprising: FIG. 5 (a) an outer spun bond hydrophobic layer (0.015?mm) composed of PLA–PBS for mechanical strength and fluid resistance; (b) a central melt-blown barrier layer (0.010?mm) made of PLA–PCL or PLA–PHA for high bacterial/viral filtration efficiency (BFE/VFE); (c) an adhesive/barrier layer (0.005 mm) of biodegradable lamination interface using solvent-free or bio-based bonding agents; and (d) an optional inner non-woven layer (0.013?mm) for comfort, moisture absorption, and breathability, composed of soft PLA–PBS blends and optionally infused with soothing agents such as aloe vera or chitosan.
[0113] The total laminate thickness is approximately 0.043?mm. In an embodiment, the product assembly process includes dimensional quality inspection, defect screening (e.g., color, surface), leak testing, cap fit verification, and coating consistency. Final labeling employs QR code/barcode printing for LIS/HIS integration. Optional NFC tags may be embedded for advanced traceability. Assembly is performed in ISO 7 cleanrooms as needed.
[0114] Packaging configurations include single-use units in blister trays or compostable pouches, grouped into batch-labeled cartons with Instructions for Use (IFU). PPE kits may be vacuum-pouched and folded per medical handling norms. Storage conditions are optimized at 18–25?°C with humidity <50%. Cold-chain compatibility is optionally provided for heat-sensitive items.
[0115] In another embodiment, digital traceability features are embedded into each product via QR codes, barcodes, or digital twins printed on surfaces or packaging. These identifiers store or link to metadata including polymer composition, batch number, expiry date, sterilization method, and environmental certification. Integration with LIS/HIS and inventory systems enables seamless traceability from manufacturing to point-of-use.
[0116] This digital infrastructure supports UDI (Unique Device Identification) and Extended Producer Responsibility (EPR) frameworks, facilitating smart labeling, automated recall management, sustainability reporting, and full product lifecycle traceability—from feedstock origin to post-use biodegradation.
[0117] While traditional PET-based diagnostic tubes use standard molding and sterilization processes, this invention adapts those methodologies to a novel, biodegradable quad-polymer matrix. The material and process are optimized to retain vacuum integrity, surface compatibility for coatings, and regulatory sterility, filling an unmet ecological and clinical-grade need.
[0118] The invention provides a high-performance, eco-compatible alternative to conventional plastic laboratory and protective products. The formulation is engineered for biodegradability, thermal resistance, and mechanical durability without compromising sterilization compatibility or product integrity.
[0119] Advantages of the invention include: (a) medical-grade mechanical and thermal performance; (b) biodegradability within 6–12 months under composting conditions; (c) structural stability for 24–36 months in clinical storage; and (d) preservation of coating compatibility and vacuum retention across product lines.
[0120] While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.
,CLAIMS:I Claim:
1. A biodegradable polymer composition suitable for manufacturing medical laboratory consumables, the composition comprising: (a) polylactic acid (PLA) in the range of 30% to 60% by weight; (b) polybutylene succinate (PBS) in the range of 10% to 30% by weight; (c) polyhydroxyalkanoates (PHA) in the range of 10% to 25% by weight; (d) polycaprolactone (PCL) in the range of 5% to 20% by weight; (e) optionally, one or more additional biodegradable polymers; and (f) optionally one or more functional additives selected from the group consisting of biocompatible plasticizers, antimicrobial agents, essential oil-based bioactive, and biocompatible colorants.
2. The composition as claimed in claim 1, wherein the biocompatible plasticizers are selected from acetyl tributyl citrate (ATBC), epoxidized soybean oil, polyethylene glycol esters, bio-based succinate esters, or combinations thereof, and are present in the composition in an amount ranging from 0.1% to 10% by weight.
3. The composition as claimed in claim 1, wherein the antimicrobial agents are selected from silver nanoparticles, zinc oxide, chitosan, copper oxide, or combinations thereof, and are present in the composition in an amount ranging from 0.1% to 2% by weight.
4. The composition as claimed in claim 1, wherein the essential oil-based bioactive are selected from tea tree oil, clove oil, eucalyptus oil, neem oil, or combinations thereof, and are present in an amount ranging from 0.1% to 1% by weight, optionally microencapsulated for controlled release.
5. The composition as claimed in claim 1, wherein the biocompatible colorants are selected from titanium dioxide, iron oxides, chlorophyllin, plant-derived anthocyanins are in a range of 0.1 to 1% by weight.
6. The composition as claimed in claim 1, comprising 5%–30% by weight of additional biodegradable polymers selected from PBAT, TPS, PHB, PGA, or PHBV to improve flexibility, clarity, and processability.
7. The biodegradable polymer composition of claim 1, wherein a QR code is integrated with medical laboratory consumables, selected from, hospital/lab testing tubes including blood collection tubes, blood bank donation tubes, and other cylindrical sample containers, and the QR code/barcode is attached to the laboratory consumables by the method selected from, laser etching, inkjet printing, direct molding, or embedding during additive manufacturing, and remains legible throughout clinical workflows, including automated scanning environments, and the QR code is scannable during sample collection and remains readable by automated diagnostic analyzers for LIS/HIS integration and full sample traceability.
8. The biodegradable polymer composition as claimed in claims 1, wherein the laboratory consumable undergoes =90% weight loss within 6–12 months under industrial composting or simulated landfill conditions, without generating toxic residues or microplastics, and retains structural and functional integrity post-sterilization using ethylene oxide (EtO), gamma radiation (15–25?kGy), hydrogen peroxide plasma, or UV-C (254?nm), without compromising performance or coating stability.
9. A biodegradable personal protective equipment (PPE) article comprising a polymer blend matrix of polylactic acid (PLA) 30–45%, polybutylene succinate (PBS) 20–30%, polyhydroxyalkanoates (PHA) 15–25%, and polycaprolactone (PCL) 10–20% by weight, formed into a multi-layered nonwoven or laminated sheet; and the article comprises: a spunbond outer layer for mechanical durability and hydrophobicity; a melt-blown core layer providing microbial and fluid barrier properties; a laminated barrier/adhesive layer enhancing impermeability to fluids and aerosols; and an inner microporous nonwoven layer designed for breathability and skin comfort.
10. The biodegradable article as claimed in claim 9, wherein the PPE article is selected from gloves, masks, gowns, aprons, shoe covers, or caps, and optionally includes functional coatings comprising antimicrobial, hydrophobic, antiviral, or thermochromic agents.
11.. The biodegradable article as claimed in claims 9, wherein the article undergoes =90% weight loss within 6–12 months under industrial composting or simulated landfill conditions, without generating toxic residues or microplastics, and retains structural and functional integrity post-sterilization using ethylene oxide (EtO), gamma radiation (15–25?kGy), hydrogen peroxide plasma, or UV-C (254?nm), without compromising performance or coating stability.
12 The biodegradable article as claimed in claim 9, wherein the article is integrated with a sterilization-resistant, tamper-evident QR code or barcode for inventory encoding batch ID, polymer composition, expiry date, and sterilization metadata, and is readable by Laboratory Information Systems (LIS), Hospital Information Systems (HIS), and Unique Device Identification (UDI) platforms.
13. The biodegradable article as claimed in claim 9, wherein the article is enclosed in packaging comprising multilayer biodegradable films with integrated oxygen and moisture barrier functionality, configured to preserve sterility and ensure QR code or barcode legibility for a storage duration of 24 to 36 months under ambient conditions.
14. The biodegradable article as claimed in claim 9, wherein the article is optionally coated with: Anticoagulants (for blood preservation): EDTA, trisodium citrate, lithium heparin; Antimicrobials: chitosan, silver nanoparticles, copper oxide, zinc oxide, tea tree oil; Hydrophobic/barrier agents: PDMS, PVA, carnauba wax, stearic acid. Indicators: resazurin, thermochromic ink, leuco dyes;
wherein coatings are applied by dip-coating, plasma activation, or micro-spraying, and remain adherent post-sterilization.
15. The article as claimed in claim 9, wherein it is manufactured by a method comprising: (a) dry blending PLA, PBS, PHA, and PCL with optional biodegradable additives; (b) dehumidifying the blend at 60–80?°C to =0.2% moisture; (c) extruding at 140–190?°C into pellets or sheets; (d) forming articles via injection molding, blow molding, compression molding, thermoforming, or additive manufacturing; (e) applying optional surface coatings and QR/barcode marks; (f) sterilizing using EtO, gamma irradiation, plasma, or UV-C; (g) performing inline quality checks for strength, clarity, and code readability; (h) recycling up to 10% of process offcuts via remolding.
16. The biodegradable PPE article as claimed in claim 9, wherein the polymer blend optionally includes 0.1% to 10% by weight of one or more eco-compatible functional additives selected from a-tocopherol, ascorbic acid, rosemary extract, triethyl citrate, PEG 1000, chitosan, zinc oxide, silver nanoparticles, talc, starch, calcium carbonate, titanium dioxide, iron oxide, or maleic-anhydride–grafted PLA, to enhance flexibility, processability, and barrier performance without compromising sterilization or biodegradability.
17. The biodegradable PPE article as claimed in claim 9, wherein the polymer blend optionally includes 0.1% to 10% by weight of one or more eco-compatible functional additives selected from a-tocopherol, ascorbic acid, rosemary extract, triethyl citrate, PEG 1000, chitosan, zinc oxide, silver nanoparticles, talc, starch, calcium carbonate, titanium dioxide, iron oxide, or maleic-anhydride–grafted PLA, to enhance flexibility, processability, and barrier performance without compromising sterilization or biodegradability.