The thermal protection performance of protective clothing is a key test
item for many protective clothing. Because the human body wears this type of clothing and works in dangerous environments, such as fire scenes or rescue moments, and other high-temperature working environments, protective clothing must ensure that the human body Therefore, it is necessary to make a reasonable assessment of the thermal protection performance of protective clothing. Here we use experimental methods to describe the necessity of this type of experiment. Subject content and scope of application This standard specifies the performance requirements and test methods of ordinary protective clothing for firefighters. This standard applies to ordinary protective clothing used by firefighters, and does not apply to other protective clothing such as thermal insulation clothing and fire protection clothing. Reference standard GB 250 Gray sample card for discoloration assessment GB 3918 Fabric trapezoidal method tearing strength test method GB 3923 Woven fabric breaking strength and breaking elongation determination strip method GB 4744 Textile fabric impermeability test method Hydrostatic pressure test method GB 4745 Textile Fabric Surface Moisture Resistance Test Method (Water Test Method) GB 5455 Textile Fabric Flame Retardant Performance Test Method Vertical Method Water Permeability Test Method ①, Classification according to the test method (1) Field test. Field tests are expensive and time-consuming, usually about half a year. During the experiment, regularly test the waterproofness of the fabric after the waterproof and moisture-permeable finishing, so as to know its durability. Although this method has a long cycle and a lot of cost, the data obtained by the test is accurate. (2) Simulation test. The simulation test must have an environmental control room. The chamber is equipped with an artificial rain tower, which can discharge water from a height of 10 m at a flow rate of 450L/m2 ·h to the mannequin like a torrential rain. Water droplets with a diameter of about 5 inln are ejected from the top 2000 holes at a speed of about It is 40 km/h, which is 90% of the maximum raindrop speed in the air. Through adjustment, showers of different degrees can be imitated on an area of u200bu200babout 2m2. The surface of the human body model is filled with sensors, the purpose of which is to determine the time and location of the final water penetration and other indicators. This method of testing is much shorter than the time required for field testing, and can be completed within a few days, but the cost is relatively high. (3) Laboratory testing. Compared with field test and simulation test, laboratory test is less expensive, shorter time, can obtain relative results, and is more practical. The test of the waterproofness of the fabric after the waterproof and moisture-permeable finishing can be divided into three categories. The first category of di is the hydrostatic pressure test, such as the domestic YC312 hydraulic pressure meter, the American standard test method ASTM D-751 and the American federal standard test method FED-STD-191A 5512 used in the Mullen (Mullen) hydraulic pressure tester
. The second type is the spray test, which means that water is continuously dripped or sprayed on the fabric to be tested from a certain height and angle. It can measure the time required for water to penetrate from the side of the fabric to the other side, and it can also measure the elapsed time. Then, the amount of water absorbed by the sample or observe the water stain state of the sample. The domestic ISO 4920 rainproof performance test adopts this principle. ② Classification according to the form of pressure (1) Dynamic method. Continuously increase the water pressure on one side of the fabric, and measure the hydrostatic pressure that the fabric can withstand until a specified number of water droplets appear on the other side of the fabric. (2) Static method. Maintain a certain water pressure on one side of the fabric and measure the time it takes for water to penetrate from one side to the other. ③ Classification according to the size that can withstand the hydrostatic pressure (1) Low pressure test method. Standard test methods include the low-pressure method in the Chinese national standard GB/74744-1997 'Determination of Water Resistance of Textile Fabrics by Hydrostatic Pressure Test'; Chinese industry standard FZ/T01004-1991 'Determination of Water Resistance of Coated Fabrics by Hydrostatic Pressure Test' ; Canadian Standard (CGSB)-4.2No. 26.3-1995 'Determination of Water Resistance of Textile Fabrics by Hydrostatic Pressure Test'; International Standard ISO1420-1987 'Determination of Water Resistance of Rubber and Plastic Coated Fabrics by Hydrostatic Pressure Test'; Japanese Industrial Standard JIS L-1092 ((Textiles) Water Resistance Hydrostatic Pressure Test A'; American Textile Chemists and Dyers Association Standard AATCC 127 (Textile Water Resistance Hydrostatic Pressure Test'; American Standard Testing Method (or American Society for Testing and Materials Standard) ASTM D751-1995 (Coated Fabric Water resistance test B' and other methods. (2) High pressure test method. The standard test method includes the high pressure method in FZ/T 01004-1991 'Water Resistance Test of Coated Fabrics'; ISO 1420-1987 ~ Rubber and Determination of Water Resistance of Plastic Coated Fabrics Hydrostatic Pressure Test'; JIS L-1092 (Textile Water Resistance Hydrostatic Pressure Test B'; ASTM D751-95 'Water Resistance Test Procedure A of Coated Fabrics'; US Federal Standard Test Method FED —STD-191A 5512 and ASTM D3393 ((Standard Specification for Waterproofing of Coated Fabrics) and other methods. Factors affecting the water pressure resistance of fabrics. The level of waterproof and moisture-permeable fabrics' waterproof indicators depends on the following factors. (1) Fabric Tightness. The increase in the distance between the yarns will directly affect the water pressure resistance.
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