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Anti Mosquito Finishing And Testing Standards For Textiles

2010/11/2 10:30:00 59

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　　 mosquito Insecta Diptera mosquitoes, small insects, 0.5cm~1.5cm long, long tentacles, mouthparts form a long beak, female mosquito's beak is generally suitable for pricking blood sucking liquid. Female mosquitoes need to suck blood to spawn and breed eggs. They are sensitive to smell, and are sensitive to volatile substances such as carbon dioxide and lactic acid produced by human respiration and metabolism. They can rush directly to blood sucking objects from 30 m. When the mosquito bites, to prevent blood clotting, it will infuse some human saliva into the wound and infuse some saliva, and the pathogen will spread. Common mosquito borne diseases in China include malaria, filariasis, dengue fever and epidemic encephalitis B. There are also mosquito borne diseases such as yellow fever, West Nile fever, eastern equine encephalitis, western equine encephalitis, Venezuelan equine encephalitis, St. Louis encephalitis and Guinea Kong fever. In Asia, Africa and the Americas, the number of malaria deaths per year is more than 1 million due to mosquito bites. Therefore, mosquito control is of great importance. Significance 。

1. Anti mosquito principle

　　 At present, there are mainly two methods for mosquito control. The first method is to repel or exterminate mosquitoes in the environment, but this method does not last long, and the chemicals released by aerosols will cause some harm to the human body, so it is not suitable for frequent use. The second method is to process and arrange textiles that are often in contact with human body, so as to make them have more durable anti mosquito effect. After a long time of production practice, this method has proved that it has good mosquito repellent effect and is resistant to repeated washing. It is harmless and harmless to human body.

2. Mosquito repellent finishing agent

Mosquito repellent is treated with microcapsules containing various mosquito repellents and insecticides. The microcapsules and fibers are combined to form a mosquito repellent film which is insoluble in water and in general organic solvents. This kind of film can emit the disgust smell such as mosquitoes and flies, so that mosquitoes and others do not want to stay on the fabric containing mosquito repellent and escape. At the same time, when mosquito contact with fabric, it will be knocked down or killed immediately.

2.1 repellent

Mosquito repellents can be classified into natural repellents and synthetic repellents according to their sources.

2.1.1 natural repellent

Natural repellents are mainly plant repellents, which come from roots, stems, leaves and flowers of plants, mostly terpenoid esters, alcohols and ketones. In 1970s, terpenes extracted from plant essential oils had strong repellent activity against mosquitoes. A mosquito repellent was isolated from Eucalyptus eucalyptus oil. Bioassay showed that it had strong repellent activity against Aedes aegypti. In recent years. A lot of researches on natural mosquito repellents have been carried out in the United States, and two kinds of high repellent plants, namely Morus Angus and C. Since twenty-first Century, repellent activity of methanol extracts from seeds of Indus carp has been tested. It is found that it has a strong repellent activity to individuals of Anopheles mosquitoes.

Natural repellents have many advantages, such as low toxicity or non-toxic, no burning sensation to the skin, fresh odor, no drug residue after use, easy degradation, no pollution to the environment, etc., but their efficacy and persistence in mosquito repellency are generally lower than that of synthetic repellents.

2.1.2 Synthetic repellent

Synthetic repellents mainly include organic esters, aromatic alcohols, unsaturated aldehydes, ketones, amines and amides. In 1929, the mosquito repellent oil DMP (two methyl ortho phthalate two) was successfully developed. In 1937, the mosquito repellent was patented. In 1939, the mosquito repellent alcohol (2- ethyl -1, 3- diol) was available. In 1956, a repellent DEET with excellent broad spectrum was discovered in the United States.

At present, there are five kinds of synthetic repellents for skin and fabric treatment:

(1) DEET (N, N-diethyl-m-toluamide, N, N- two ethyl methylformamide) is the Chinese name "diamine", insoluble in water, soluble in alcohols, ethers, isopropanols, chloroform, carbon disulfide, alcohol, benzene, propylene glycol, cottonseed oil, ketones and petroleum extracts and other organic solvents, slightly soluble in petroleum ether and glycerol, its use is 5%~100%. The exact mechanism of DEET is unclear. It may be that it blocks insects' antennae or lubricates their skin. It may also form an isolation layer on the skin, which prevents insect bites or stays. But in recent years, researchers have found that DEET can cause neurological diseases, encephalopathy and skin diseases. Therefore, DEET has been used cautiously, and DEET has been banned in Thailand and Taiwan.

(2) Picaridin (KBR 3023, hydroxyethyl piperidine carboxylic acid isobutyl ester) is colorless liquid, and the vapor pressure at 25 degrees is 5.87 * 10.^Six Pa, boiling point 296 centigrade, melting point -170 centigrade.

(3) Oil of Lemon Eucalyptus (lemon eucalyptus leaf oil) /PMD (paramenthane-3, 8-dio, l pair montane -3, 8- glycol, lemon eucalyptus leaf oil extract) has a strong lemon fragrance, has a citronella oil like grass fragrance, colorless to pale yellow transparent oily liquid.

(4) IR3535 [3- (N-butyl-N-acetyl) -aminopropionic acid-ethylester, the Chinese nickname] is an ester compound. Compared with amide repellents, its aroma is pleasant, and it has no irritation on skin. It has gradually become a research hotspot. The structure of IR3535 is similar to alanine, and its toxicity and environmental harm are less than DEET. It has the advantages of no toxic side effects on skin and mucosa, no allergy and no skin permeability. It is very safe to use. IR3535 has been in Europe for 20 years and listed in the US in 1999. The synthetic repellent used for fabric treatment is two permethrin (Permethrin, also known as permethrin, Chinese name), and two permethrin dissolved in acetone, ethanol, ether and xylene and other organic solvents. The solubility in 25 degree water is (0.07 + 0.02) mg/kg, which is stable to acid medium and light, and can be hydrolyzed in alkaline medium. The relative density is 1.214 (25 C) and the refractive index is 1.5627 (25 C).

(5) cyclodextrins are made from starch degraded by fermentation. The cyclodextrin molecule has a ring configuration and has a hydrophobic inner cavity, as shown in Figure 1. The hydrophobic inner cavity can store gas and non-polar organic substances. Since the lumen of cyclodextrin molecules is nonpolar, non-polar molecules or molecules with non-polar groups can be stored in the base. All known mosquito pheromones involve organic molecules with non-polar parts, so they can form complexes with cyclodextrins. So long lasting cyclodextrin textiles can play a passive role in protecting mosquitoes, and can greatly reduce the total amount of pheromones in the surrounding air.

Figure 1 Beta The structure of cyclodextrin
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2.2 insecticide

Insecticides mainly kill insects by contact, stomach poison or fumigation.

Pyrethrin is one of the two esters extracted from pyrethrum, which can be used as an insecticide. Pyrethroid is a class of nonvolatile hydrocarbon compounds that have developed rapidly in the past forty years. It is a new synthetic insecticide for simulating the chemical structure of pyrethrin. It has the characteristics of fast knockdown, wide insecticidal spectrum and high efficacy. It has repellent effect on insects, low toxicity to human body, easy biodegradation and no toxic residue after biodegradation. However, there are also disadvantages of most species, such as high toxicity to fish, poor selectivity to natural enemies, and no internal absorption.

Pyrethroid compounds, the most suitable for finishing mosquito repellent fabrics, are Tetramethrin. Pure amprothrin is white crystal. It is insoluble in water and soluble in organic solvents. It has a very fast knock down effect on insects and remains unchanged for 3 years at room temperature.

Three Mosquito repellent finishing process

At present, the anti mosquito finishing technology is mainly impregnated and impregnated.

(1) impregnation process: immersion (bath ratio 1:10) to dehydration (with liquid rate of 25% ~30%) to drying (80 ~100, 1 min ~3 min) to baking (120 ~130 ~130, 1 min).

(2) dip rolling process: rolling anti mosquito finishing liquid (rolling rate 70%) to dry (70 ~100, 3 min) to roasting (110 ~120, 30 s).

The dosage of mosquito repellent finishing agent depends on the type of mosquito repellent finishing agent, fabric type and use.

Four Test method of mosquito repellent effect

At present, the domestic testing standard for mosquito repellent finishing fabrics is still a blank. The testing standard of textile anti mosquito finishing effect mainly draws on and refers to the following three standards drafted by the Ministry of agriculture. These standards Only for mosquito repellent finishing agents or raw materials. It is impossible to directly test the fabric directly after mosquito repellent finishing, and there is no test standard for the parameters such as washing fastness and the application performance of the fabric after finishing.

The three test criteria are: GB13917.1 – 1992 "indoor efficacy test method for pesticide insecticides registered in rural areas", "methods for determining the indoor efficacy of spray agents", GB/T 17322.10 – 1998, pesticide repellent for pesticide registration, hygienic insecticides, and GB 13917.3 – 1992, indoor efficacy test method for pesticide registration, hygienic insecticide, small smoke agent and smoke tablets, and table 1 is a comparison of three standard contents.

Table 1 commonly used standards for mosquito control in China

             Project content

             GB13917.1 – 1992


             GB/T17322.10 – 1998


             GB13917.3 – 1992




             Scope of application

When pesticide is registered, sprays are tested for efficacy and efficacy of direct spray and retention contacts for health pests.

The repellent efficacy of repellents on insecticides such as mosquitoes and other harassing insect pests was evaluated when pesticides were registered.

Small aerosol and smoke tablets were used to test the efficacy and efficacy of smoke treatment for flying hygienic pests when pesticides were registered.

             Date of implementation

April 1, 1993

October 1, 1998

April 1, 1993

             Test insect

Mosquitoes: 2~3 days after eclosion, not blood sucking.

Aedes albopictus, not 4~5 days after emergence

Mosquitoes: 2~3 days after eclosion, not blood sucking.

Culex pipiens pallens, Culex pipiens pallens, and Culex pipiens pallens in the southern region.

Female adult of blood.

Culex pipiens pallens, Culex pipiens pallens, and Culex pipiens pallens in the southern region.

             Testing conditions

Temperature (26 + 1), relative humidity (60 + 5)%

             testing procedure

The efficacy of direct spray was determined by a special bell jar device. 20 insect insects were tested, 0.28 mL were tested, and the number of tested insects was recorded at regular intervals. After 20 min, all the tested insects were transferred to a clean cage and fed with 5% sugar water cotton balls, and the number of dead insects tested at 24 h. Test at least three times. At the end of each test, the whole test device must be cleaned. Blank test should be carried out. The knockdown rate and mortality rate of the blank test should be greater than 20%. The whole test must be carried out again.

The efficacy of the remaining spray was measured uniformly on the contact surfaces of the three agents and converted to the grams of effective components per square meter. 20 insect insects were tested and forced to contact the contact surface of the insecticides. After 20 min, all the tested insects were transferred to the clean cage and fed with 5% sugar water cotton balls, and the number of dead insects tested at 24 h. At least three times, the blank test should be carried out. The knockdown rate and mortality rate of the blank test were greater than 20%. The whole experiment was carried out again. After testing, the drug contact surface was stored in a 50 degree thermostat, tested once every other week, and tested for five times.

The attack test must be carried out in human trials. 300 insect species (reduced chance) in the prescribed mosquito cage were exposed to 4 cm * 4 cm skin on the back of the hand, the rest were partially shielded, and the hands were put into the mosquito cage for 2 min. More than 30 of the tested worms were qualified for attack and could be used for repellent test.

In the repellent test, the skin area of 5 cm x 5 cm was painted on the back of the hands of at least 3 qualified persons. One hand was blank control and the other hand was 1.5 mg/cm.^Two (paste) or 1.5 L/cm^Two The dose of the liquid repellent is uniformly applied to the repellent to be tested, exposing 4 cm 4cm skin and tightly covering the rest. 2 h after applying the repellent, put the hand into the cage with 2min of the qualified mosquito. Observe whether any mosquitoes come to suck the blood, and then test it once every hour. As long as 1 mosquitoes come to suck blood, they will be judged as repellent. The effective protection time of repellent was recorded.

The test insects (mosquitoes 40) were put into the glass box, put in a certain amount of smoke agent, began recording, and recorded the number of tested insects at a certain time. After 30 min, all the tested worms were transferred to the clean cage and fed with 5% sugar water cotton balls. The number of dead insects tested was checked at 24 h. The test was repeated at least 3 times. At the same time, the knockdown rate and death rate of the blank samples were tested. If the test was more than 20%, the whole test must be carried out again.

             impact assessment

The three repeated data is calculated according to the machine value method. KT_Fifty (half of the knockdown time) and 24 h mortality; when the mortality rate of the blank test insect was 5% ~20%, the corrected mortality rate of the tested insect must be determined.

The effective protection time is more than 6 h, and the B level is equal to 4 h. Otherwise, it will not be evaluated.

Calculation of three repeated data KT_Fifty (half of the knockdown time) and 24 h mortality. When the mortality of the blank test insect was 5% ~20%, the corrected mortality rate of the insect should be tested.

The applicability of the three test standards varies. GB 13917.1 – 1992 is suitable for the determination of the efficacy of the spray agent. GB/T 17322.10 – 1998 is suitable for the evaluation of the efficacy of the repellent. GB 13917.3 – 1992 is suitable for the evaluation of the efficacy of small smoke and smoke tablets. The difference between the three standards is due to the difference in mosquito species and growth time. At the same time, the methods of testing and evaluation are different.

Five expectation

At present, the mosquito repellent textiles developed in China are cool and ventilated, which can prevent mosquitoes and certain insects from biting. They do not need any drugs to assist, have no allergic reactions to the skin, feel soft and comfortable, and have simple production technology, low cost, and easy to produce in large quantities. It can be made of thermoplastic technology for one-off garments, and can also be made into durable clothing by textile technology. It can be made into suit mosquito repellent clothes, and can also be made into mosquito proof leg sleeves, headsets and cuff sleeves individually. This clothing is of diverse styles, suitable for night workers, field workers, troops, disaster relief and so on. However, at present, there is no testing standard for mosquito repellent finishing fabrics in China, so it is impossible to test the fabric directly after finishing the mosquito repellent. Therefore, making relevant test standards as soon as possible will play an important role in promoting the development of anti mosquito textiles and clothing.