Comprehensive introduction to pet antibacterial masterbatch: Long-lasting antibacterial property, antibacterial rate of 99.9%
I. Definition and Core Overview
PET antibacterial masterbatch is a functional granular material produced by melting, blending and dispersing the antibacterial functional components (such as inorganic antibacterial agents) with the PET carrier resin, and then extruding and granulating. Its core purpose is to endow PET products with long-lasting antibacterial properties, while also being compatible with the conventional processing methods of PET, ensuring both safety and practicality.
II. Core Components and Structure
(1) Carrier Resin
Base material: Food-grade PET (polyethylene terephthalate), highly compatible with downstream PET products, ensuring the basic mechanical properties and processing adaptability.
Function: As the dispersion medium and carrier of the antibacterial agent, it improves the uniform dispersion of the antibacterial agent in the PET matrix, avoids agglomeration, and does not change the original processing characteristics of PET.
(2) Antibacterial functional components (core)
The mainstream type is inorganic antibacterial agents (organic antibacterial agents are less used due to their poor tolerance to temperature differences and difficulty in migration). They are classified into 3 categories based on their components:
Silver ion series: Highly effective in antibacterial (antibacterial rate ≥ 99% against Escherichia coli, Staphylococcus aureus, etc.), resistant to high temperatures (240 - 300℃), long-lasting and stable, the mainstream choice.
Zinc ion / Silver-zinc composite series: Good transparency, high safety, suitable for transparent PET products (such as packaging, sheets), in line with food contact standards.
Graphene composite series: Equipped with antibacterial, mold-resistant, and anti-virus properties, with an antibacterial rate of 99.99%, and simultaneously enhancing the mechanical strength of the material.
(III) Additives (Auxiliary Components)
Dispersant: Improves the compatibility between the antibacterial agent and PET, prevents agglomeration, and ensures the mechanical properties of the product.
Stabilizer: Enhances the thermal stability of the antibacterial agent, inhibits color change and activity attenuation during high-temperature processing.
Antioxidant: Slows down the aging of the PET matrix, prolongs the service life of the product.
III. Core Performance Features
(1) Broad-spectrum and highly effective antibacterial properties
Inhibitory strains: Bacteria (Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae), fungi (Candida albicans, Aspergillus niger), and some viruses.
Antibacterial effect: Compliant with ISO22196 and QB/T2591 standards, with an antibacterial rate of ≥99%, long-lasting and persistent (the product's antibacterial effect remains unchanged throughout its entire life cycle).
(2) Excellent processing adaptability
Temperature resistance: Compatible with PET processing temperature (280-300℃), antibacterial activity does not diminish and does not change color.
Compatibility: After blending with PET resin, it can be directly injection-molded, blown, extruded, or spun without the need to modify equipment.
Addition amount: Regular 1%-3% (by weight), for transparent products 3%-5%, balancing antibacterial effect with cost and mechanical properties.
(III) Safety and Environmental Protection
Non-toxic and harmless: Compliant with EU ROHS and FDA food contact standards, without skin irritation, suitable for use in the food and medical fields.
No migration: The antibacterial components are stably combined with the PET matrix and do not migrate or leach out, avoiding secondary pollution.
(4) Performance Balance
Mechanical properties: Retain the original tensile strength and impact strength of PET. Partial modification (such as with graphene) can enhance the bending strength and modulus.
Functional compatibility: The transparent version does not affect the transparency of PET, and is suitable for high-transparency packaging and sheet requirements.
IV. Main Production Process
Raw material pretreatment: PET carrier is dried at 80℃ for 2-4 hours. The surface of the antibacterial agent is modified (to improve dispersion).
High-speed blending: Mix PET, antibacterial agent and additives in proportion, and then stir at high speed to achieve uniform mixing.
Melt extrusion: Use a twin-screw extruder to melt at high temperature (280-300℃) and perform shear dispersion to ensure uniform dispersion of the antibacterial agent.
Cooling and granulation: Cool the extruded material strips with water and then air-dry. Cut into cylindrical pellets (typically packaged in 25kg bags).
Testing and screening: Conduct tests for antibacterial rate, thermal stability, and dispersion. If qualified, store in the warehouse.
V. Main Application Areas
(1) Food Packaging
Application scenarios: Fresh produce trays, dairy packaging, beverage bottles, preservation boxes, films.
Value: Reduces microbial growth, extends food shelf life, ensures food safety.
(II) Household Items and Daily Necessities
Application scenarios: Antibacterial tableware, water cups, chopping boards, inner cylinders of washing machines, air conditioner filters, carpets, bedding.
Value: Reduces bacterial growth, improves home hygiene environment, and inhibits odor generation.
(III) Medical and Health Care
Application scenarios: Medical protective clothing, surgical gowns, non-woven fabric for masks, medical equipment shells, medical packaging.
Value: Reduces the risk of cross-infection and meets the requirements of sterile medical environments.
(4) Packaging and Cosmetics
Application scenarios: Cosmetics lotion bottles, cream jars, pharmaceutical packaging, transparent sheets, films.
Value: Prevent microbial contamination of contents, extend product shelf life, meet the requirement of transparent appearance.
(V) Public Facilities
Application scenarios: Antibacterial door handles, elevator buttons, public seats, sanitary fixtures.
Value: Reduces the spread of bacteria in public places and enhances public health security.
VI. Usage Instructions and Precautions
(1) Usage Method
Drying treatment: Before use, perform 2-4 hours of 80℃ forced air/vacuum drying to prevent moisture from affecting the processing and performance.
Blending ratio: Generally add 1%-3%, for transparent/high antibacterial requirements add 3%-5%, and can be adjusted as needed.
Processing conditions: The same as conventional PET (temperature 280-300℃), no need to adjust equipment parameters additionally.
(II) Important Notes
Avoid excessive addition: Exceeding 5% may cause material brittleness, decreased mechanical properties, and increase costs.
Storage requirements: Store in a sealed, dark, cool and dry place. Avoid moisture, high temperature exposure, and keep within the shelf life of 12 months.
Adaptability verification: It is recommended to conduct small-scale trial production for the first use to verify the antibacterial effect, dispersion, and product performance.
