Perspective Of Testing Standards For Antibacterial Knitwear

SARS, avian influenza, influenza a H1N1 virus - the tremendous impact of these microbes' invasions and ravages make us familiar with their names, and therefore re recognize and adjust the relationship between microbes and healthy life.

This relationship is not only reflected in the preservation and preservation of food, but also in the prevention and control of infectious diseases and the maintenance of human health.

As one of the functional textiles, antibacterial knitwear has been gradually favored by consumers because of its good antibacterial properties and has become a hot spot in the market.

1 microbiology brief introduction

Microorganism, English is "Microorganism", meaning tiny creature.

Microorganisms are characterized by small size, simple structure, strong metabolic capacity, rapid propagation, wide variety, wide distribution, and easy mutation.

There are tens of thousands of species in the biological world, most of which are good for human beings.

In food, chemistry, medicine, environmental protection and other fields, microbes play an indispensable role.

In the human skin, oral cavity, gastrointestinal tract, respiratory tract and so on, there are different species of microbes in the cavity. The body becomes the external environment of microorganism, and also the host of microorganism, forming symbiotic relationship with each other, so as to achieve a dynamic balance of [1].

However, people associate microbes with diseases and disasters. In fact, it is a mistake in ideological understanding. Only a small part of the large families of microbes can really cause disease.

Pathogenic microorganisms can lead to the spread of infectious diseases.

According to the data released by WHO, the incidence and mortality of infectious diseases occupy the first place among all diseases. The most typical example is influenza caused by influenza virus.

The tested strains in FZ/T73023-2006 antibacterial knitwear have different degrees of pathogenicity, including Escherichia coli, Staphylococcus aureus and Candida albicans.

Escherichia coli (Escherichiacoli) is a major member of the normal flora of human gut.

Under normal circumstances, Escherichia coli is not pathogenic, but also can synthesize vitamin B and vitamin K, producing colibacillin, which is beneficial to the body.

But when the body's resistance drops or the E. coli invades the tissues or organs outside the intestine, it may cause extra intestinal infection.

Escherichia coli is the most common pathogen causing urinary tract infections in humans. Invasion of the urinary system can cause urethritis, cystitis, pyelonephritis and other diseases. It is also a common cause of gram negative bacilli septicemia.

In addition, it can cause cholecystitis, pneumonia, neonatal or infant meningitis, diarrhea and so on.

Staphylococcus aureus (Staphylococcusaureus) is the most resistant pathogen in non spore producing bacteria. It can be killed by heating at 80 C for 30 minutes.

Staphylococcus aureus invades the skin tears, wounds or sweat glands, hair follicle obstacles, can cause folliculitis, carbuncle, pneumonia, tracheitis, abscess otitis media, acute breast cancer and other diseases, invading the blood can cause sepsis [2].

Candida albicans (Candidaalbicans) is commonly found in the oral cavity, upper respiratory tract, and intestines of the normal people. It is generally less in the normal body and harmless to humans. However, when the immune function of the body is reduced or the interaction between the normal bacteria is restricted, it will proliferate and invade cells to cause diseases.

Candida albicans can encroach on many parts of the human body, causing skin candidiasis, mucous candidiasis (thrush, angular stomatitis, Yin Daoyan), visceral and central nervous system candidiasis (gastroenteritis, endocarditis, meningitis, encephalitis).

Due to the pathogenicity of the tested bacteria, the microbiological test personnel must have professional microbiological operation skills, not only to master the basic operations such as sterilization, inoculation, colony count, but also to ensure that they are not infected and ensure personal health through the familiarity with microorganisms, strict compliance with the various protective measures in the asepsis room and the control of the experimental operation.

2 Analysis of testing standards for antibacterial knitwear

Dressing and wearing hats are closely related to people's lives.

People's requirements for clothing are not only satisfied with simple mould proofing, moth proofing and comfortable clothing, but rather that they have health care functions, inhibit or kill the infectious microorganism on the surface of human skin, and maintain human health.

In order to regulate such functional clothing market,

In August 1, 2006, the FZ/T73023-2006 "antibacterial knitwear" standard was formally promulgated.

It is an authoritative standard of China's Knitting Industry Association, the China Center for Disease Control and prevention, and based on the standards of the United States and Japan.

The standard has both qualitative test methods and quantitative test methods. The standard blank sample preparation process, test method, standard detergent formula and washing test method of antibacterial fabric samples are specified in detail. Meanwhile, specific requirements for the internal quality, appearance quality, safety evaluation method, safety evaluation index and evaluation index of antibacterial effect of antibacterial knitwear are specified.

Since the comprehensive implementation of the standard, it has fully reflected its high scientific and operational nature. It is in line with the direction of the development of textile standardization in China. It plays a very important role in standardizing the antibacterial textile market, promoting the scientific and technological progress and healthy development of the antibacterial textile industry, and earnestly protecting the interests of enterprises and consumers.

Of course, compared with the developed countries in the world, the theory and practice of the quality evaluation of antimicrobial fabrics is still in the development stage.

As the first industry standard of antibacterial textiles in China, "antibacterial knitwear" also needs a continuous improvement process, which requires continuous improvement and innovation in combination with specific situations.

This paper discusses and analyzes the standard of FZ/T73023-2006 antibacterial knitwear in the following aspects.

2.1 selection of strains

The selection of tested strains must be scientific and representative.

In the standard FZ/T73023-2006, Escherichia coli, Staphylococcus aureus and Candida albicans were selected as test strains, representing gram negative bacteria, gram positive bacteria and fungi respectively.

However, it is far from enough to represent the antibacterial properties of fabrics only by the antibacterial effect of the three bacteria.

In addition, the standard of antibacterial knitted fabrics tested the inhibition rate of knitted fabrics on three kinds of bacteria, which mostly reflected the function of single strain, but ignored the influence and function of microbes in reality.

Moreover, even if the microorganism belonging to one strain is different, if the source is different, the sensitivity of the antimicrobial agent will also be different, which is bound to affect the accuracy of the test results.

The growth of bacteria has regularity, and the final results will be different when inoculated with different strains at different growth stages.

Therefore, it is of great significance to objectively reflect the antibacterial properties of fabrics by reasonably choosing representative mixed strains for detection.

The standardization of the strains to be tested in the standard should be further improved and perfected.

2.2 culture conditions

It is difficult to simulate the environmental conditions of human skin surface contacting with clothing. In actual detection, the best growth condition of the strain is chosen as the starting point, and the conditions and parameters are appropriately changed to achieve the unification of objectivity and maneuverability.

The main factors affecting the growth of microorganisms were temperature, medium and its pH value, bacteria activity, inoculum concentration and incubation time, [3].

The optimum growth temperature of bacteria is about 37 degrees Celsius. In the oscillating method of FZ/T73023-2006 antibacterial knitwear, the incubation temperature of antibacterial sample and bacteria solution is set at (24 + 1) centigrade, which is different from that of the foreign test method at 37 degrees Celsius.

In addition, when the inoculant solution and concussion contact were diluted 10 times, most of the overseas detection methods used 0.85% ice cold saline as solvent, which is different from the 0.03mol/LPBS buffer used in our industry standard.

2.3 antibacterial properties

In the evaluation of the antibacterial properties of textiles: the third part: oscillating method, the definition of antibacterial property (antibacterialactivity) is that the textile can inhibit the growth and reproduction of bacteria on the fabric.

In fact, there is a certain range of antibacterial activity. The minimum is that the fabric can slow down the rate of microbial growth (the so-called bacteriostatic). If the inhibition rate exceeds the prescribed value, it is considered to be antibacterial.

In the standard, the antibacterial knitted fabrics are divided into grade three, grade AA and grade AAA with [4] according to the number of washing times and the strains tested. The inhibition rates on Escherichia coli, Staphylococcus aureus and Candida albicans reach or exceed 70%, 70% and 60% respectively, which means that they have antibacterial [5].

At present, most of the antibacterial fabrics on the market can only achieve a certain bacteriostatic effect. The products with obvious antibacterial properties are mainly occupied by toxic chemicals, such as disinfectants, detergents, etc.

There are two main types of expression of antibacterial properties: percentage and numerical value.

Although the percentage is commonly used, but because of the geometric growth of bacteria, in the case of only one decimal place after the result is retained, the difference between 99.9% and 99.99% is only 0.09%, but the difference in antibacterial performance is 10 times. The difference in antibacterial performance can be clearly expressed by the pair value, but it is not easy to be understood by [6].

2.4 detection methods

The oscillating method is commonly used in the detection of FZ/T73023-2006 antibacterial knitwear.

The oscillating method is applicable to samples with arbitrary shape. It is a good quantitative test method with good reproducibility.

It has practical significance to prevent microbial growth or sterilization on damp fabrics.

But in real life, the antibacterial fabric can not keep moist like that during the oscillating contact.

The detection of a bamboo fiber fabric by oscillating method showed that the bacteriostatic rates of Escherichia coli and Staphylococcus aureus were 26.5% and 9% respectively, indicating that they had only weak bacteriostatic effect on bacteria and had no antibacterial properties.

In Quin test, the inhibition rates on Escherichia coli and Staphylococcus aureus were 75.1% and 50.1% respectively, which were all higher than those of oscillating method.

The reason may be that microbes are more suitable for growing in warm and humid environment, while bacteria in Quin method grow on dry samples, so the bacteriostatic rate of oscillating method is lower than that of [7].

Therefore, the rationality of the same antibacterial level for different detection methods should be further studied.

3 safety of antibacterial fabrics

3.1 safety for human body

Most of the antibacterial fabrics are directly contacted with the human skin and need to be washed many times. Therefore, a higher requirement is put forward for the unification of the safety and antibacterial durability of the antibacterial fabrics.

Natural sources of antimicrobial agents, such as bamboo charcoal, have become the focus of attention.

At the same time, antibacterial agents need to slowly release their antibacterial effect, otherwise it will stimulate the human skin, and destroy the normal flora of the human body, causing [6] damage to the human body.

To this end, the State stipulated in the "antibacterial knitwear" standard: the antibacterial substances used in antibacterial knitwear must be approved by relevant departments, and have the test reports issued by relevant qualification units. The test reports include testing methods for the chemical content of antibacterial substances, acute oral toxicity, skin irritation, eye irritation, mutagenicity and corresponding test reports. The irritation and allergy of the antibacterial substances used in antibacterial knitwear to skin irritation and allergy need to be tested by human patch test, and the results need to be negative.

All these provide a strong guarantee for the safety of the antibacterial knitwear.

3.2 risk of drug resistance

Few antibacterial fabrics can kill a high proportion of microorganisms in a relatively short period of time (such as 10 minutes). Therefore, the antibacterial fabric is far from reaching the level of prevention and control of infectious diseases.

BerjaminD.Tanner believes that once a bacterium has the ability to resist an antibiotic, it can be quickly amplified and amplified to share its resistance genes with other bacteria.

Long term interactions between low grade antimicrobials and a large number of bacteria that naturally live on the surface of the skin may increase the risk of cross resistance, thereby increasing the risk of [8].

Many manufacturers are selling their own antibacterial fabrics, fabricating and exaggerating their antibacterial properties and misleading ordinary consumers. The final result may not bring the antibacterial effect advertised by the products, but also increase the probability of microbial resistance. The consequences are quite serious.

4 Conclusion

Antibacterial fabric has broad market prospects.

As a supervision and inspection organ, we have the duty to publicize and publicize the knowledge of microbes and antibacterial agents to the public, to enhance people's objective understanding of antimicrobial fabrics. At the same time, we should constantly improve and improve the standards of antibacterial fabrics, standardize the market of antibacterial fabrics, and make them healthier and faster.