CN101736570B - Device and method for testing fabric contact coldness - Google Patents

Abstract

The invention relates to a fabric contact cold feeling test device and a test method, which belong to the field of textile engineering. The test device consists of an outer cover, a test board, a water tank, a fabric splint, and a fabric surface temperature sensor. The test device of the present invention has reasonable structure, convenient use, small volume, low manufacturing cost, and can be produced in a large-scale industrialized manner; the test device of the present invention adopts a platinum resistor with good stability and high precision as a temperature sensor, thereby improving test accuracy. The top of the test platform is provided with a cap made of heat insulating material, which can not only reduce the influence of the surrounding environment on the test, but also reduce the heat loss caused by the thermal radiation of the fabric and improve the reliability of the test; the test device and test The method solves the shortcomings of high technical requirements and high testing costs when evaluating the cold feeling of fabrics by testing the maximum transient heat flow Qmax of fabrics in the past. The fabric contact cold feeling test device and test method of the present invention can be used in the field of fabric contact cold and warm feeling evaluation.

Description

A fabric contact cold feeling test device and test method

technical field

The invention relates to a fabric contact cold feeling test device and a test method, which belong to the field of textile engineering.

Background technique

Along with the raising of living standard, the comfort of clothing is subject to people's great concern. The heat transfer performance of fabric is an important factor affecting the thermal comfort of clothing. The thermal comfort of clothing refers to the heat transfer function of fabrics, so that the human body can obtain a comfortable and satisfactory feeling in a changing environment. After the human body wears clothes, there is always an energy exchange between the body and the environment. The comfort of the human body depends on the balance of energy exchange between the heat generated by the human body itself and the heat emitted to the environment. Clothing made of fabric plays a regulating role in the process of energy exchange through heat transfer. A set of objective indicators for evaluating the thermal comfort of fabrics has been established through in-depth research on the heat transfer performance of textiles and clothing and its influence on comfort. Thermal resistance is one of the important indicators. There are many methods to study thermal resistance, among which the experimental instrument test method is a commonly used research method. Measuring the heat transfer performance of fabrics with instruments and establishing corresponding indicators can quantitatively describe the comfort performance of clothing, and it is not affected by psychological and physiological factors. The test results are comparable, which is beneficial to the production department. Fabric quality control and product design.

The heat transfer performance of fabrics is usually tested by the flat plate method (GB/T11048-2008, ISO11092 and ASTMF1868). The principle is to cover the sample on the constant temperature test plate, so that the heat of the test plate can only be dissipated through the direction of the sample. During the test, the heat retention index of the fabric is calculated by measuring the heating time required for the test plate to maintain the temperature within a certain period of time. Regarding the study of heat transfer performance, although many new technologies such as thermal pulse, thermal wave, photothermal method and photoacoustic method have been applied to thermal performance testing, the application of hot plates and thermocouples is still an effective method for testing the thermal properties of fabrics. Most of the researchers' designs for the test devices are based on hot plates, but the designs for the conditions on both sides of the fabric are different. This test method can only test the thermal performance index of the fabric reaching a steady state, which is different from the actual clothing and the actual situation. It is only suitable for a rough description of the comfort of the fabric and cannot reflect the dynamic heat transfer performance of the fabric.

With the deepening of research, many scholars have begun to notice the important influence of the microclimate in clothing, and have designed different types of microclimate testers to detect the microclimate changes and thermal conditions between the skin and the sample by simulating the external environment. Moisture transfer conditions. That is to detect the whole process of energy exchange and mass exchange between human body heat and sweat vapor through the air layer inside the fabric, the air layer outside the fabric and the fabric and the environment, and use the temperature gradient and humidity gradient method to test the state changes of energy exchange and mass exchange of the fabric. Thus reflecting the fabric's resistance to energy flow and mass flow. The instrument test of this kind of clothing cannot truly reflect the overall performance of the clothing accessories. Scholars at home and abroad have also simultaneously carried out research on dummy testing technology and evaluation methods to more realistically simulate the state of the human body wearing clothing. The thermal manikin method is a relatively advanced experimental method to simulate the heat exchange process between the human body, clothing and the environment under set environmental conditions, and test the overall or partial heat and moisture transfer performance of the clothing. The advantages are high accuracy and repeatability. It has good performance, and can conduct heat and moisture transfer performance tests of clothing under extreme environmental conditions that cannot be tested by real people. However, because the thermal manikin method draws conclusions through a large number of experiments and analyzes under strictly controlled artificial climate conditions, the test time is long and the cost is high.

Cold contact means that when the fabric is in contact with the skin, the temperature of the fabric is lower than that of the human skin, and heat exchange occurs between the human body and the fabric, so that the human body feels cold and warm to the fabric, which is called cold contact. Instantaneous heat transfer occurs when the fabric touches the human body. The fabric at ambient temperature absorbs a large amount of heat from the surface of the human skin, making the human body feel cold. The strength of the cold feeling is related to the heat transfer performance of the fabric. Cold contact is one of the important performances of textile comfort. Due to the heat exchange phenomenon of fabrics, which is a dynamic heat transfer process, the above research methods cannot correctly reflect the cold contact of fabrics. With the improvement of people's living standards, the requirements for comfort in all aspects of textiles are getting higher and higher, and the cold feeling of contact has attracted more and more attention. Especially for textiles used in winter, the contact cold feeling has become an important indicator affecting the thermal comfort performance of fabrics. The traditional evaluation method is to use the precise and rapid thermal physical property measuring device KES-F7 developed by Kawabata, Japan, to evaluate the warm and cold feeling of the fabric by testing the maximum transient heat flow Qmax, but the test equipment is expensive, the technical requirements are high, and the use and maintenance costs are high. .

Contents of the invention

The purpose of the present invention is to propose a new fabric cold feeling test device and test method for evaluating the cold feeling of the fabric in contact with the fabric.

The technical solution adopted by the present invention to solve the technical problem is: a fabric contact cold feeling test device and test method.

The test device is composed of a thermal insulation cap (1), a test board (2), a water tank (3), a fabric splint (4), a heater (5), a fabric surface temperature sensor (6) and the like. A raised platform is arranged on the upper surface of the water tank (3), and the test board (2) is embedded in the raised platform to form a test platform, and a heater (5) and a water inlet pipe (8) are also arranged on the upper surface of the water tank (3). ), the lower end of the heater (5) is set in the water tank (3), the outer wall of the water tank (3) is coated with a heat insulating layer (9), and the heat insulating cap (1) is placed on the upper surface of the water tank (3) .

The test board (2) is copper material or aluminum alloy material.

The water inlet of the water inlet pipe (8) is higher than the height of the test platform.

The liquid medium is distilled water or vegetable oil.

The fabric surface temperature sensor (6) is a platinum resistance temperature sensor.

The test method of the fabric contact cold feeling test device, the test method includes the following steps:

a test preparation

(a) pretreatment of the fabric to be tested (7), that is, placing the fabric to be tested in an artificial climate chamber for 24 hours;

(b) Adjustment of the test device, that is, inject liquid medium from the water inlet pipe (8) into the water tank (3), cover the cap (1) on the test platform, and heat the water in the water tank (3) through the heater (5). The liquid medium is heated to adjust the temperature of the test plate to 35°C;

(c) Paste the fabric surface temperature sensor (6) on the upper surface of the fabric to be tested (7);

(d) The fabric surface temperature sensor (6) is connected with the single-chip microcomputer data acquisition system, and the single-chip microcomputer is connected with the host computer.

two tests

After the temperature of the test board (2) is constant at 35°C, remove the cap (1), spread the fabric to be tested (7) on the test board (2) quickly, then cover the cap (1), press each The data acquisition frequency of 10 times per second starts the test.

Three data processing

The average processing of the data collected by the single chip microcomputer per second, ${\stackrel{\‾}{x}}_i=\underset{j=1}{\overset{10}{\mathrm{\Σ}}}{x}_{\mathrm{ij}}/10,$

Wherein _Xi is the fabric surface temperature average value of the i time period, _{Xij is} the fabric surface temperature collected at the j moment of the i time period, j=1, 2, ..., 10,

After calculating the average value of the fabric surface temperature per second, find the maximum value of the fabric surface temperature heating rate. max|X _i+1 -X _i |{i=1, 2,..., n-1},

Where |X _i+1 -X _i | is the temperature rise rate of the fabric surface in the i second.

The maximum value of the temperature rise rate of the fabric surface is used to evaluate the coolness of the fabric. The greater the temperature difference, the stronger the coolness of the fabric.

Due to the adoption of the above technical scheme, the test device of the present invention has reasonable structure, convenient use, small volume, low manufacturing cost, and can be industrialized on a large scale; the test device of the present invention uses a platinum resistor with good stability and high precision as the temperature sensor. Improved test accuracy. The top of the test platform is provided with a cap made of heat insulating material, which can not only reduce the influence of the surrounding environment on the test, but also reduce the heat loss caused by the thermal radiation of the fabric and improve the reliability of the test; the test device and test The method solves the shortcomings of high technical requirements and high testing costs when evaluating the cold feeling of fabrics by testing the maximum transient heat flow Qmax of fabrics in the past. The fabric contact cold feeling test device and test method of the present invention can be used in the field of fabric contact cold and warm feeling evaluation.

Description of drawings

Fig. 1 is the structural representation of fabric surface temperature testing device of the present invention

Fig. 2 is the test schematic diagram of the test device of the embodiment of the present invention

Fig. 3 is the fabric surface heating rate diagram of the test of the embodiment of the present invention

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing and specific embodiment

see Attachment

The test device is composed of a thermal insulation cap 1, a test board 2, a water tank 3, a fabric splint 4, a heater 5, and a fabric surface temperature sensor 6. The platinum resistor has good stability and accuracy, and the fabric surface temperature sensor 6 adopts a platinum resistor For the temperature sensor, a raised platform is set on the upper surface of the water tank 3. Since the heat conduction of the copper material and the aluminum alloy material is fast, the test board 2 is made of copper material or aluminum alloy material, and the thickness of the material is greater than 8mm, and the test board 2 itself can be increased. heat capacity, improve the accuracy of the test, the test board 2 is embedded in the raised platform to form a test platform, the upper surface of the water tank 3 is also provided with a heater 5 and a water inlet pipe 8, the test board 2 and the liquid medium in the water tank 3 There should be no air bubbles in the middle, uniform contact, the height of the water inlet of the water inlet pipe 8 is higher than the height of the test platform, the lower end of the heater 5 is set in the water tank 3, and the heat insulating layer 9 coated on the outer wall of the water tank 3 can prevent the heat generated during the test. The loss of the test will affect the accuracy of the test. The heat insulating cap 1 is placed on the upper surface of the water tank 3 to prevent heat loss caused by heat radiation. The fabric surface temperature sensor 6 is connected with the single-chip microcomputer data acquisition system, and the signal from the temperature sensor 6 is amplified through the signal amplification circuit, so that it is suitable for the input voltage 0-5V requirement of the analog-to-digital conversion of the single-chip microcomputer. After the signal enters the single-chip microcomputer, it passes through the A/ D Analog-to-digital conversion, the converted data is transmitted to the upper computer through the serial communication port, and the data is processed by the computer.

The test method of the fabric contact cold feeling test device, the test method includes the following steps:

a test preparation

(a) Pretreatment of the fabric 7 to be tested, that is, to place the fabric to be tested in an artificial climate chamber for 24 hours so that the fabric can fully reach the heat and humidity balance. The temperature of the artificial climate chamber is (25±1)°C, and the relative humidity is (50±2)%.

(b) Adjustment of the test device, that is, inject liquid medium from the water inlet pipe 8 into the water tank 3, and the liquid medium can be distilled water or vegetable oil. The use of distilled water can prevent ordinary tap water from generating bubbles during the heating process, thereby forming accumulated bubbles under the test plate 2, changing the contact between the test plate 2 and the liquid medium, and affecting the test accuracy. Vegetable oil will not produce bubbles during the heating process. Plate 2 is evenly heated, which can ensure test accuracy. Cover the cap 1 on the test platform to reduce the heat loss of the test board 2 due to heat radiation. The temperature of the test board 2 is observed with a temperature sensor, and the liquid medium in the water tank 3 is heated by the heater 5 to make the test board 2. Adjust the temperature to 35°C.

(c) Paste the fabric surface temperature sensor 6 on the upper surface of the fabric 7 to be tested.

(d) The fabric surface temperature sensor 6 is connected with the single-chip microcomputer data acquisition system, and the single-chip microcomputer is connected with the host computer through the serial communication port, and starts the data processing program of the single-chip microcomputer and the host computer.

two tests

First use the temperature sensor attached to the test board to test the temperature of the test board 2. After the temperature of the test board 2 is kept at 35°C for more than five minutes, remove the cap 1, and quickly clamp the fabric splint 4 to wait. The test fabric 7 is laid flat on the test board 2, and then the cap 1 is covered to prevent the heat radiation of the test fabric 7 from affecting the test accuracy. The single-chip data acquisition system starts measuring at a data acquisition frequency of 10 times per second, and the The converted data is transmitted to the upper computer in time through the serial communication port, and the collection time is 60 seconds.

Three data processing

The upper computer averages the data collected by the single-chip microcomputer every second, ${\stackrel{\‾}{x}}_i=\underset{j=1}{\overset{10}{\mathrm{\Σ}}}{x}_{\mathrm{ij}}/10,$

Wherein _Xi is the fabric surface temperature average value of the i time period, _{Xij is} the fabric surface temperature collected at the j moment of the i time period, j=1, 2, ..., 10,

After calculating the average value of the fabric surface temperature per second, find the maximum value of the fabric surface temperature heating rate. max|X _i+1 -X _i |{i=1, 2,..., 59}

Where |X _i+1 -X _i | is the temperature rise rate of the fabric surface in the i second.

Use the maximum value max|X _i+1 -X _i |{i=1, 2,...,59} of the maximum temperature rise rate of the fabric surface temperature to evaluate the cold feeling of the fabric. The stronger the cold feeling.

specific embodiment

Use the above test methods to test the temperature of the surface of the three kinds of fabrics with time. The maximum value of the temperature rise rate of the fabric surface is obtained, and the cold feeling of the fabric is evaluated.

Table 1 The average value of the surface temperature of three kinds of fabrics per second (℃)

Table 1

time (seconds) cotton fabric silk fabric wool fabric 0 24.925 25.097 25.030 1 25.035 26.369 25.841 2 26.083 28.148 27.223 3 27.425 29.481 28.307 4 28.432 30.384 29.290 5 29.203 31.085 29.947 6 29.825 31.563 30.484 7 30.366 32.005 30.927 8 30.742 32.286 31.309 9 31.085 32.518 31.568 10 31.339 32.679 31.793 11 31.560 32.824 32.005 12 31.661 32.917 32.173 13 31.820 33.046 32.297 14 31.930 33.104 32.438 15 32.074 33.206 32.536 16 32.137 33.246 32.598 17 32.221 33.286 32.655 18 32.261 33.317 32.686 19 32.279 33.402 32.726 20 32.297 33.451 32.788 twenty one 32.305 33.455 32.811 twenty two 32.368 33.460 32.833 twenty three 32.385 33.477 32.864 twenty four 32.390 33.477 32.895 25 32.394 33.486 32.899 26 32.398 33.504 32.908 27 32.407 33.504 32.913 28 32.434 33.504 32.930 29 32.434 33.513 32.944 30 32.452 33.513 32.975 31 32.465 33.531 32.988 32 32.483 33.540 32.997 33 32.491 33.540 33.015 34 32.522 33.549 33.015 35 32.571 33.558 33.019 36 32.580 33.567 33.024 37 32.580 33.571 33.033 38 32.593 33.580 33.033 39 32.593 33.611 33.059 40 32.602 33.611 33.064 41 32.607 33.625 33.073 42 32.624 33.647 33.073 43 32.629 33.683 33.073 44 32.633 33.687 33.090 45 32.633 33.687 33.090 46 32.633 33.687 33.090 47 32.642 33.687 33.113 48 32.642 33.696 33.113 49 32.664 33.696 33.126 50 32.673 33.700 33.130 51 32.695 33.709 33.135 52 32.704 33.709 33.139 53 32.704 33.709 33.148 54 32.722 33.714 33.161 55 32.753 33.718 33.166 56 32.753 33.718 33.166 57 32.753 33.727 33.175 58 32.775 33.732 33.179 59 32.793 33.732 33.184 60 32.793 33.732 33.201

Table 2 Heating rate (°C/S) of three kinds of fabrics in each time period

Table 2

time (seconds) cotton fabric silk fabric wool fabric 0 0.000 0.000 0.000 1 0.110 1.272 0.811 2 1.048 1.779 1.382 3 1.342 1.333 1.084 4 1.007 0.903 0.983 5 0.771 0.701 0.657 6 0.622 0.479 0.537 7 0.541 0.442 0.443 8 0.376 0.281 0.382 9 0.342 0.232 0.260 10 0.255 0.161 0.225 11 0.220 0.145 0.212 12 0.101 0.093 0.168 13 0.159 0.129 0.124 14 0.110 0.058 0.142 15 0.144 0.102 0.097 16 0.063 0.040 0.062 17 0.084 0.040 0.058 18 0.040 0.031 0.031 19 0.018 0.085 0.040 20 0.018 0.049 0.062 twenty one 0.009 0.004 0.022 twenty two 0.062 0.004 0.022 twenty three 0.018 0.018 0.031 twenty four 0.004 0.000 0.031 25 0.004 0.009 0.004 26 0.004 0.018 0.009 27 0.009 0.000 0.004 28 0.027 0.000 0.018 29 0.000 0.009 0.013 30 0.018 0.000 0.031 31 0.013 0.018 0.013 32 0.018 0.009 0.009 33 0.009 0.000 0.018 34 0.031 0.009 0.000 35 0.049 0.009 0.004 36 0.009 0.009 0.004 37 0.000 0.004 0.009 38 0.013 0.009 0.000 39 0.000 0.031 0.027 40 0.009 0.000 0.004 41 0.004 0.013 0.009 42 0.018 0.022 0.000 43 0.004 0.036 0.000 44 0.004 0.004 0.018 45 0.000 0.000 0.000 46 0.000 0.000 0.000 47 0.009 0.000 0.022 48 0.000 0.009 0.000 49 0.022 0.000 0.013 50 0.009 0.004 0.004 51 0.022 0.009 0.004 52 0.009 0.000 0.004 53 0.000 0.000 0.009 54 0.018 0.004 0.013 55 0.031 0.004 0.004 56 0.000 0.000 0.000 57 0.000 0.009 0.009 58 0.022 0.004 0.004 59 0.018 0.000 0.004 60 0.000 0.000 0.018 maximum value 1.342 1.779 1.382

Cold feeling evaluation basis:

The curve of the surface temperature of the fabric as a function of time is shown in Figure 2. T ₁ and T ₂ are the corresponding temperatures measured by the fabric upper surface temperature sensor at time t ₁ and t ₂ respectively. Within a unit area, a certain temperature T can be considered to correspond to a certain amount of heat q, and if its corresponding coefficient is α, then q=αT, where α varies with different fabrics. As shown in Figure 2, suppose the heat per unit area of the upper surface of the fabric is q ₁ at time t ₁ and q ₂ at time t ₂ . The heat is transferred from one side of the fabric to the other. While the upper surface of the fabric receives the heat q _a transferred from the lower surface of the fabric in contact with the test plate, it also releases a certain amount of heat q _b to the outside, and the heat received is greater than the heat released This heat difference gradually accumulates over time, which is manifested as an increase in the temperature of the upper surface of the fabric macroscopically.

q＝ _qa - _qb (1)

in:

q is the heat per unit area of the upper surface of the fabric at time t (J/m ² h);

q _a is the heat transferred from the lower surface of the fabric in contact with the test plate within the unit area of the upper surface of the fabric at time t (J/m ² h);

q _b is the heat released to the outside in the unit area of the upper surface of the fabric at time t (J/m ² h);

The rate at which the surface temperature of the fabric rises is:

$\frac{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Substitute formula (1) into formula (2)

$\frac{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; a</span>}}}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; b</span>}}}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

Heat is transferred from one side of the fabric to the other, It is the heat transferred from the test board to the upper surface of the fabric per unit area within the time (t ₂ -t ₁ ), which is related to the dynamic heat transfer of the fabric. The greater the heat transferred, the stronger the cold feeling of the fabric.

Let t ₂ -t ₁ =Δt, then (3) becomes

$\frac{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; a</span>}}}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; q</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; b</span>}}}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

能描述织物内部热传递速率的快慢，能反映织物动态热传递性能的优良，升温速率越快，织物传递热量就越快，接触冷感就越强。When Δt is small, in the adiabatic experimental space, the upper surface of the fabric releases less heat to the outside and is relatively stable, so Can be viewed as a constant. It can be seen from formula (4) that the greater the heat (q _2a -q _2b ) instantaneously transferred by the fabric, the faster the temperature of the fabric will rise, so the temperature rise rate is used

It can describe the speed of the internal heat transfer rate of the fabric, and can reflect the excellent dynamic heat transfer performance of the fabric. The faster the heating rate, the faster the heat transfer of the fabric, and the stronger the cold feeling of contact.

Claims (1)

1. the method for testing of a fabric contact coldness testing arrangement; It is characterized in that: testing arrangement comprises adiabatic calotte (1), test board (2), tank (3), fabric clamping plate (4), heater (5), fabric face temperature sensor (6); Tank (3) upper surface is provided with protruding platform, and test board (2) is embedded in the protruding platform and constitutes test platform, also is provided with heater (5) and water inlet pipe (8) at the upper surface of tank (3); The lower end of heater (5) is arranged in the tank (3); Be coated with heat insulation layer (9) on the outer wall of tank (3), adiabatic calotte (1) is seated on the upper surface of tank (3), and method of testing comprises the steps:

One test is prepared

(a) preliminary treatment of fabric to be measured (7) is about to fabric to be measured, is placed on phjytotron 24 hours,

(b) adjustment of testing arrangement; Promptly inject liquid medium from water inlet pipe (8) toward tank (3); Adiabatic calotte (1) is covered on the upper surface of tank (3), make the temperature of test board (2) be adjusted to 35 ℃ Celsius the heating of liquid medium in the tank (3) through heater (5)

(c) fabric face temperature sensor (6) is sticked on the upper surface of fabric to be measured (7),

(d) fabric face temperature sensor (6) links to each other with single-chip data acquisition system, and single-chip microcomputer is connected with host computer,

Two tests

After 35 ℃ of the temperature constant of test plate (panel) to be measured (2), take off adiabatic calotte (1), being tiled on the test board (2), cover adiabatic calotte (1) more rapidly, begin test by the data acquiring frequency of per second 10 times with the good fabric to be measured (7) of fabric clamping plate (4) clamping,

Three data

The data that the single-chip microcomputer per second is collected average processing,

Wherein

Be the i fabric face temperature-averaging value of second, X _IjBe the i fabric face temperature that second, j collected constantly, j=1,2 ..., 10

After calculating

; Obtain the maximum of fabric face temperature heating rate;

{ i=1; 2; ...; N-1}, wherein

is the i fabric face temperature heating rate of second.

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