Performance Test of Protective Clothing in Several Simulation Environments

Performance Test of Protective Clothing in Several Simulation Environments

1 Environmental Simulation Test

The technical environment simulation test is an important aspect of the development of test technology. It is a new discipline developed after World War II that studies the influence of the environment on technology products. Its rise has revolutionized the quality and environmental adaptability of technological products. Variety. At present, all advanced countries in the world attach great importance to the application of electrical and electronic products and machinery products, polymer composite materials and products, textile and garment products, labor protection products and protective clothing through specified environmental simulation test conditions. The test provides the user with the experimental basis that is as close as possible to the actual one.

All human activities are carried out under specific environmental conditions. Temperature, humidity, wind and solar radiant heat are the four basic elements that make up the environmental climate. In addition, the weather, physical state of the weather, rain, snow, clouds, etc. The changes are also an important factor in the environmental climate. In the inspection work of labor protection products, people choose to simulate different factors according to different test requirements to ensure the relative reliability of the test. Under normal circumstances, temperature and humidity (constant temperature and humidity) are necessary conditions. Such environmental simulation is the most common minimum requirement, and almost all physical and mechanical performance laboratories must have.

Research and testing institutes from all walks of life abroad have all possessed considerable scale and correspondingly precise environmental laboratories, such as the Army Military Research Institute in Natick, Mass., Massachusetts (renamed Natick's Research and Development Department in 1976). , With Arctic analog laboratory, simulation temperature up to -57e, maximum wind speed of 74 km / h; tropical simulation laboratory, the maximum temperature of 74e; fog and rain simulation laboratory, can simulate the next fog and torrential rain; laser simulation laboratory It can be used as a military clothing dyeing and anti-surveillance research. The flame simulation laboratory can be used to test the combustion resistance of military clothing. There is also a high-altitude simulation laboratory that can simulate an altitude environment test of 13 500 m. The British Military Institute is equipped with a simulation laboratory for hot and cold environments, equipped with a high-light irradiation machine, and a rain simulation laboratory. Toray Japan established an all-weather laboratory at the Putian plant to simulate the use of garments to test textile performance under artificial climate conditions of wind, rain, and snow. The company's product standards are higher than the national JIS standards. A climate-resistant snowfall test device developed by SUGA, with an outer size of 4 m@2.2 m@12 m. The size of the sample rack is approximately 250 mm@1 000 mm. The sample is suspended on a sample rack that is rotated and revolved. Artificial snowfall crystals are equivalent to 5 000 to 3 000 m snowfall. However, the device was expensive to construct. According to the 1986 offer, it was 200 million yen (equivalent to 1.3 million U.S. dollars). The company's solar sun weather tracker, with high-precision solar reflectors and solar tracking devices, concentrates the illuminance of the sun on the sample and is equipped with an automatic rainfall cycle device. It is said that the sun shines on the sun. 20 days is equivalent to 360 days of sunlight.

In the mid-1950s, China began to attach importance to environmental simulation experiments. In the past 10 years, hundreds of departments and laboratories have established research on environmental technology, which has promoted the rapid development of various economic and technical departments. Especially for labor protection safety and health products, military-demand products, should pay attention to and develop environmental simulation test technology, in order to accurately reflect the product's safety, practicality, to improve the current product performance, provide a strong basis for the development of new products.

In daily life, environmental temperature and humidity are critical to human health and work efficiency. According to physiologists' study, high indoor temperature will affect people's body temperature regulation function. Due to poor heat dissipation, the body temperature will increase, the blood vessels will expand, the pulse will increase, and the heart rate will increase. If the temperature is too low, the metabolic function of the human body will be reduced, the pulse and breathing will be slowed down, the subcutaneous blood vessels will be contracted, the skin will be over-stretched, the mucous membrane resistance of the respiratory tract will be weakened, and respiratory diseases will be easily induced. At the same time, the influence of indoor humidity is also very important. If the humidity is too high, it will inhibit the body's heat dissipation, causing irritable and stuffy feeling, and the humidity will be too low, which will cause a large loss of water in the upper respiratory tract mucous membranes, causing dry mouth and even sore throats. , cold, nasal bleeding. The scientists set the minimum temperature of human relative/cold tolerance 0 to 11e, relative humidity 30%, and the upper temperature of the heat tolerance 0 as 32e and relative humidity 80%. Through experiments, the most pleasant temperature in winter is 18~25e, relative humidity 30%~80%, summer 23~28e, relative humidity 40%~60%. Of course, human comfort is not limited to the two meteorological elements of temperature and humidity, but also related to human physique, dress, level of activity, mental state, and other subjective and objective factors. In addition to the safety protection function of the use conditions, the protective clothing series products also need to ensure the wearer's comfort performance as much as possible.

Many countries, including the United States, France, Italy, the Netherlands, Denmark, Hungary, and so on, have special microclimate labs for thermal environments. Among them, the University of Kansas is relatively modern, with a total area of ​​350 m2. The microclimate room of the Hungarian Institute of Building Sciences is approximately 210 m2. The main research contents of the Microclimate Laboratory are state, human activity, air temperature, average radiation temperature, and airflow. Speed, air relative humidity, etc.

The main measures of the wearer's thermal balance; blood pressure, pulse, respiratory rate, skin temperature and dissipated intensity; mental activity status; response time to the acousto-optic signal, tremor level, touch, sensitivity, YYUOH frequency response, skin electrical reactions, EMG and EEG, the ability to work, changes in physical strength, metabolic changes, mental status, memory, concentration, and subjective feelings of clothing and thermal environment. On-site research is mainly about dressing people's thermal balance, their ability to work and their subjective feelings.

Of course, from the viewpoint of labor protection and safety and health, in addition to environmental climate simulation, environmental simulation tests include high and low temperature, alternating damp heat, thermal aging, various corrosive gas effects, anti-virus, dust, vibration, impact, noise, etc. Environmental protection.

2 Dummy Simulation Test Technology

The advanced countries have developed a variety of dummy simulation test systems to simulate real people, replace real-life research and testing for various types of labor protection products, and evaluate and evaluate the practical performance and safety protection of special labor protective clothing and military equipment products. Performance, ergonomics, etc. have a very important role. It is indispensable to provide reliable basis for the design and shaping of various types of protective clothing, production monitoring, and product practicality. China should vigorously develop and use this to narrow the gap with foreign countries.

2.1 warm dummy simulation test device

The warm-body simulator is currently very common in foreign countries. The former Soviet Union began this research in 1946. For example, the former Soviet Union’s Academy of Military Sciences Leningrad began research on the second-generation sweat dummy in the 1950s. Many countries in the United States, Japan, Denmark, Finland, etc. have sweaty manikins. In the early 1950s, the Institute of Military Medical Sciences, the Military Needs Industry Institute, and other units carried out research and experiments on warm body bronzes. The research and application of constant warm body dummy and warm body dummy in the clothing function room of the institute has made continuous in-depth work and achieved remarkable results. Shanghai Feida Down Coat Factory introduced tens of thousands of dollars in the introduction of a warm manikin, but the utilization rate is not high and it is expensive. China still has no sweaty dummies. It is reported that China Spinning University has developed the items, but no research reports have been published.

Clothing often affects people's thermal comfort, and it is important to establish a human/clothing/environment relationship by preventing heat and moisture from spreading from the body to the surrounding environment, through hard work and environmental conditions. By selecting a suitable garment system to reduce the thermal compression stress, the thermal physiological performance of the garment can be evaluated by measuring the physiology of the tester. For this reason, it is recommended that the thermal simulating human quantitative measurement. The textile laboratory of the Finnish Technical Research Center (VTT) joined the Nordic Co-design to develop the Khan Manikin and developed the first sweat-sweepers simulator that can simultaneously measure the heat of clothing or clothes systems by using this dummy. Water vapour permeability, these changes in performance in different parts of the body, and the impact of human motion or wind on performance.

The difference between the sweating warm-up simulator and the earliest thermal simulator is the continuous moisture supply. Especially under hot pressure (stress) conditions, it is extremely important for human body's thermophysiological sweating. The sweat warm-up simulator can be used for quantitative determination of garment designs and is suitable for thermal comfort tests in dynamic environmental conditions.

Taking the example of a sweating warm-body simulator developed by the Finnish Technical Research Center (VTT) as an example, the cross-sectional structure of a simulated human shell and sweat glands is shown in FIG. 1 .

In the figure, (4) is a thin duct through a small hole in a rigid foam layer, (5) a rigid foam molded simulant housing, (6) the outer surface of the housing is wrapped with a heating wire, (7) the heating wire is fixed The insulation film, (8) The metal layer that dissipates heat from the heating wire, (9) The plastic layer that secures the temperature sensor circuitry, (10) It is used to cover the simulated person's press-fit material, which spreads the water from the tube inside to a larger one The area outside is a microporous PTFE membrane that only diffuses water vapor without diffusing liquid water. The simulated human shell surface material is a thin, net-like protective body to prevent the risk of mechanical damage. The wire temperature sensor used to measure and control the surface temperature is below the press-fit material and is connected to an automatic program control cabinet. A microcomputer is used to start the test and print the result.

The simulated person had a total of 187 sweat ducts, the largest surface of the water supply was 120 cm2, and the total sweat area was about 115 m2. The water supply to the sweat duct is a micro-electromagnetically controlled micro-electromagnetic cutting. The maximum water input value was 300 g/m2#h for the simulated person under no-clothing and standard indoor environment conditions.

The size of the simulated person is based on a Swedish study and is equivalent to a person's size C50, which is 172 cm high, 100 cm bust, 88 cm waist, and 50 kg body weight. The body shell is divided into 18 parts. Each part has its own thermal and temperature measurement system. Except for the head, hands and feet, all surfaces can sweat.

2.2 Structural dummy simulation test device

There are many kinds of these types of dummy, which have been widely used in the research and application of labor protection articles, such as the naked cylinder model of the lower limbs of the human body developed by the Japan Fire Research Institute, the trolley for flame exposure test, and the clothing that can be measured. Flame retardancy, the amount of heat conducted in multiple locations, and the time required to reach maximum heat. Foreign countries use lower limb dummy for anti-shock pants, air tightness, lifespan and strength test. Use torso dummy for parachute airdrops, seatbelt strength and other tests. The use of humanoid dummy for protective clothing blowing test, ejection seat system ejection performance test. The British-developed Roberto Humanoid Marine Immersion Manikin (RAMMTM) was used for cold-resistant and anti-impregnated clothing in hazardous and stormy waters for application tests. Using similar dummy for floating life-saving clothing floating test. The Dynamic Air Force Simulator (ADAM) developed by the U.S. Air Force contains 17 active segments for the full and effective testing of high performance protective lifesaving equipment. U.S. North Carolina University's Institute of Textile Manikin Evaluation System, with thermal insulation and sweat board, can not only measure the thermal comfort of the garment, but also has the active joints. It can simulate the artificial leg's artificial leg evaluation system and can predict the wearable human body. Burns escaped from the fire.

2.3 Acting dummy simulation test device

Metabolic dummies simulation test equipment is generally divided into two types. One is a chemical reaction type simulation device that can simulate oxygen consumption, carbon dioxide production, human body chemical reaction water production and heat production in the human generation process, and is generated according to oxidation. Calculate the molar ratio of carbon dioxide (CO2) to oxygen consumption (O2) and obtain a specific respiratory quotient of propionic acid (C2H5COOH) and ethanol (C2H5OH) 5 6 8 10 The mass percentage of the schematic diagram of sweat glands is calculated according to the thermochemical reaction. The test results are similar to those of real people. The other type is an air-suction air-compensation simulator for test personal high-altitude shelter and life support system.

The Canadian dummy evaluation system simulates blood flow under the dummy's artificial skin. It is claimed that the thermal protection performance TPP value (Protective Performance Value) measured by the system is more realistic.

2.4 equivalent radiation dummy simulation test device

People in today's world are surrounded by sky-fired and man-made particles (quantum) radiation and electric radiation (electron fumes). Naturally, there are ultraviolet rays from ionizing radiation produced by the sun, cosmic rays and natural radioactive substances. A, B, C Rays. Man-made nuclear weapons, nuclear reactors and radioisotopes, as well as a variety of sources of electromagnetic radiation and so on.

Electron emission of electromagnetic radiation is mainly microwave radiation. Microwaves are high frequency electromagnetic radiation between radio waves and infrared rays. The electromagnetic spectrum includes multiple waves with wavelengths between 10-12 and 106cm. No single radiation source or single detection mechanism can be applied to the entire electromagnetic spectrum. Therefore, the spectrum is divided into many bands (or spectra) that are not strictly defined. Area). The differentiation of these bands is generally based on the methods used to generate, separate, and detect these emissions.

Particle radiation and microwave radiation damage the human skin, organs and viscera, damage human health, and even cause serious diseases, such as skin cancer, cataract, cardiovascular system, endocrine system, immune system, reproductive system and other functional damage. For particle radiation protection suits and microwave radiation protection suits, corresponding particle radiation dummy and microwave radiation dummy can be used for simulation test evaluation.

2.5 Live Simulation Test

For example, the research and development of flame-retardant garments generally go through five stages, and each phase must be tested accordingly. The first stage is the choice of materials, with emphasis on testing the physical and mechanical properties of the materials. In the second stage, simulation tests were performed using artificial skin prosthesis and dummy, including sweating thermoregulation test of artificial skin, second-degree burn test of prosthesis, and heat-proof test of warm manikin or sweating dummy. Focus on burn performance and comfort testing to provide the basis for apparel design. The third stage is real people's dress simulation activities in a simulated environment. The principle of safe ergonomics is used to test the performance of the overall clothing, focusing on the body's thermal physiology testing to provide a basis for corrective design. The fourth stage is a live simulation of live action at the scene to verify the protective performance and comfort of the garment. The fifth stage is to conduct normal activities for real people's clothing. After a prolonged period of trial evaluation, it tests the changes in durability and collects opinions from all parties to provide the basis for stereotyped protective clothing, formulation of product standards, and production of products.

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