Textile Knowledge: Antibacterial Finishing Of Textiles

1 the necessity of antibacterial finishing.

Antibacterial finishing of textile materials is very necessary. It can achieve the following objectives:

Avoid cross infection of pathogens.

Control bacterial infection;

Inhibit bacterial metabolism, thereby preventing odor production.

Protect textiles from stain, discoloration and deterioration.

2 requirements for antibacterial finishing

Textile materials, especially garments, are easy to wear. Considering stress strain and thermal and mechanical effects, it is very important to prevent bacteria from finishing the substrate. In order to achieve the best finishing effect, textile antibacterial finishing needs to meet the following requirements:

Washable, dry cleaned and hot pressed.

It has selective activity for harmful microorganisms.

It should not be harmful to manufacturers, users and the environment.

Comply with the laws and regulations of the management organization;

Compatibility of chemical processes;

The application method is simple.

The quality of fabrics will not be reduced.

Resistant to body fluids, sterilizing / sterilizing.

3 antibacterial finishing methods

Antimicrobial agents can be applied to textile substrates by exhaustion, rolling, baking, coating, spraying and foam technology, and antibacterial agents can also be directly added to the fiber spinning solution. It is reported that commercially available antimicrobial agents can be added online during dyeing and finishing operations. The ways to improve durability include:

Reduce the solubility of fiber and surfactant.

Treatment of fibers with resin, curing agent or crosslinking agent;

Antimicrobial agents were added into the fiber matrix.

Coating the fiber surface;

The fibers are chemically modified by forming covalent bonds.

Graft polymers, homopolymers and / or copolymers with fibers.

4 antibacterial mechanism

A negative effect on bacterial activity is commonly called bacteriostasis. Microbial activity is distinguished by terminology sterilization and static state, sterilization means destruction of microorganism, static state means inhibition of microorganism growth without accompanying too much damage.

The substance that affects the activity of bacteria is called antibacterial agent. The bacteria here mainly refer to fungi. Antibacterial substances have different ways of action. In traditional soaking finishing, the antibacterial substance diffuses and destroys bacteria, thereby killing it. This kind of finishing is poor in durability and may cause health problems. Non impregnation or bio oil suppression methods have good durability and will not cause any health problems. Antibacterial finishing of most textiles is achieved through diffusion.

Diffusion rate directly affects the effectiveness of finishing. For example, in the process of ion exchange, the release rate of active substances is slower than that of direct diffusion, so the effect is weaker. Similarly, when the active substance is not released from the surface of the fiber, its antibacterial finishing has little effect on inhibiting the bacteria. Only when active substances are exposed to bacteria will they become active. The new antibacterial technology is based on the study of the principles of medicine, toxicology and ecology.

According to the influence of antibacterial textiles on the activity of microorganisms, it can be divided into 2 categories: passive type and active type. Passive antibacterial textile materials do not contain any active substances, but their surface structure (lotus leaf effect) can have a negative effect on the growth of microorganisms (anti adhesion). Active antibacterial textile materials containing antibacterial substances act on the outside or inside of microbial cells.

5 advantages of antibacterial textiles

At present, there are many kinds of textiles that consumers can benefit from. At first, the main purpose of antibacterial finishing is to protect textiles from bacteria, especially fungi. Therefore, antibacterial agents are used for antibacterial finishing of uniforms, tents, protective textiles and industrial textiles (such as geotextiles). Afterward, antibacterial fabrics were also made for household textiles such as curtains and bathroom mats. At present, the application of antibacterial finishing of textiles has been extended to the field of outdoor, health care, sports and leisure products.

The new technology of antibacterial finishing has been successfully applied in the field of nonwovens, especially in medical textiles. Textile fibers with antibacterial properties can be blended alone or with other fibers to achieve antibacterial effect. Bioactive fiber is an improved form of preparation, which contains chemical drugs in its structure, such as synthetic drugs with bactericidal properties. These fibers can be used not only in the field of medical and health prevention, but also in the manufacture of household textiles and industrial textiles.

The applications of bioactive fibers include sanitary materials, bandage materials, surgical materials, gas and liquid filtration materials, air conditioning and ventilation, building materials, special materials in the food industry, and applications in medicine, footwear, clothing and automobiles.

6 evaluation of antibacterial activity

Various testing methods have been used to test antibacterial activity.

Agar diffusion test;

Challenging testing (Quantitative);

Soil burial test;

Humidity box test;

Pollution testing.

Agar diffusion test is a preparatory test for the detection of diffused antibacterial finishing. It is only applicable to textiles and is not suitable for non diffusion finishing. Through the challenge test, the difference of the actual bacterial counts between unfinished and unfinished materials can provide objective evaluation of antibacterial activity.

A series of antimicrobial activity testing methods can be obtained from AATCC (USA standard), DIN (German standard), JIS (Japanese standard) and SN (Switzerland standard). The antibacterial activity of active substances can be expressed by special antibacterial activity and general antibacterial activity. In the Japanese standard, the general antibacterial activity or bacteriostatic effect is based on the difference between the initial number of bacteria (Ma value) of the unmodified material and the number of modified bacteria (Mc value) after 18 h culture, and the specific antibacterial activity or bacteriostatic effect is evaluated based on the difference between the reference value (Mb value) and the number of bacteria (Mc value) after 18 h culture. Due to the limitations of the existing methods, a new testing method, IS/TC/38/WG23 antibacterial finishing textile product testing method, has been developed by considering the ecological aspects of finishing technology, skin diseases and finishing.

7 evaluation of the effects of fungi and fungi

The following 3 practical testing methods can be used to evaluate the effects of fungi and fungi:

In the growth tests of 5 mixtures of fungi and fungi, the degree of growth of fungi on textiles can be evaluated. The method can be evaluated not only by direct observation, but also by specific strength elongation ratios of materials.

The inhibition zone test can detect the protective effect of finishing agents on textiles, so as to avoid long mildew and mould growth. The evaluation method is to evaluate the growth of fungi on the test materials, and observe the diffusion results of antibacterial agents in the inhibition area around the test samples.

The third test is the humid box test, which can describe the stain of textiles in the wet environment. The evaluation method is to directly observe the degree of mold growth, or to evaluate it by tensile strength test.