What is the function of adding antibacterial agents to the handle of a toothbrush
Adding antibacterial agents to the handle of a toothbrush can effectively inhibit bacterial growth and improve the hygiene performance of the product. The following is a detailed analysis from aspects such as the types of antibacterial agents, addition methods, application effects and precautions:
I. Selection of Antibacterial Agent Types
Inorganic antibacterial agent
Silver ions/copper ions: Achieve broad-spectrum antibacterial effects by destroying the cell structure of microorganisms and are suitable for plastic handles. When adding, the dosage should be controlled (such as 0.3%-0.8%) to avoid the risk of yellowing or toxicity caused by the precipitation of metal ions.
Nano zinc antibacterial agent: Utilizing nano zinc oxide technology, it is safe, environmentally friendly and has a high antibacterial efficiency. It is suitable for food contact grade materials (such as toothbrush handles) and can inhibit Escherichia coli, Staphylococcus aureus, etc.
Organic antibacterial agent
Antibacterial effects are achieved by interfering with the metabolic processes of microorganisms, but there may be a problem of insufficient durability. The applicability needs to be evaluated in combination with specific usage scenarios.
Ii. Addition Method and Process
Direct addition method
The antibacterial agent (such as silver ion antibacterial powder) is directly mixed into the plastic substrate and evenly dispersed through a twin-screw extruder.
Advantages: Simple operation, controllable concentration of antibacterial agent;
Disadvantage: The dispersion and precipitation of antibacterial agents in the substrate need to be addressed.
Antibacterial masterbatch method
First, the antibacterial agent is mixed with the base material resin to form a high-concentration masterbatch (such as 25 times or 50 times), and then it is mixed with the base material for molding.
Advantages: Better dispersion, reducing dust pollution during the molding process;
Applicable scenarios: High-transparency or high-precision handles (such as made of PP, PE, PET, etc.).
Surface coating method
Spray a coating containing antibacterial agents (such as nano-titanium nitride, silver-copper composite coating) on the surface of the handle to form a protective film.
Advantages: It does not change the properties of the base material and has an intuitive antibacterial effect.
Disadvantages: The wear resistance of the coating needs to be verified, and it may peel off after long-term use.
Iii. Application Effects and Verification
Laboratory verification
The inhibition rate of the antibacterial agent against specific microorganisms (such as Escherichia coli and Staphylococcus aureus) is evaluated through inhibition zone tests, mold culture tests, etc., to ensure that it reaches over 99%.
For example, the handle with the addition of nano-zinc antibacterial agent can significantly reduce the number of bacteria and prevent cross-infection.
Practical application cases
In the medical field: Antibacterial handles are used for surgical instruments to reduce the risk of postoperative infection.
In the field of daily necessities: The antibacterial toothbrush handle combines nano antibacterial bristles to absorb moisture and inhibit bacterial growth, keeping the area dry and clean
Iv. Precautions and Risk Control
Safety assessment
Although silver ion antibacterial agents have long-lasting antibacterial effects, when they are used in imported products, their potential impact on the human body and the environment should be carefully evaluated. It is recommended to give priority to choosing antibacterial agents that have passed food-grade certification.
Process optimization
Control the addition amount of antibacterial agents (such as 0.5%-1%) to avoid excessive amounts leading to a decrease in material transparency or yellowing.
Nano-scale antibacterial agents (such as particle size <100nm) are adopted to enhance dispersibility and antibacterial persistence.
Supporting design
Combined with the anti-slip texture of the handle, detachable structure and other designs, the space for bacteria to hide is reduced;
It is recommended to use a UV sterilizer or air it out regularly to extend the antibacterial effect.
