Original standard number GB 4493-84 HG/T 2489-1993 Test method for hardness of microporous materials for footwear HG/T2489-1993 Standard download decompression password: www.bzxz.net
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Chemical Industry Standard of the People's Republic of China HG / T 2489 —93 Test method for hardness of microporous materials for shoes Published on July 5, 1993 Ministry of Chemical Industry of the People's Republic of China Implementation on December 1, 1994 Chemical Industry Standard of the People's Republic of China Test method for hardness of microporous materials for shoes 1: Main content and specification This standard specifies the method for determining the hardness of microporous materials for shoes using a plastic microporous material hardness tester. HG / T 2489 — This standard is used for the determination of the hardness of microporous materials for shoes when the compression rate is such as %, the stress is above 0.049MPa, and the use of lemon and flame is combined. The plastic contains a foaming agent to make the material hardness of the injection molding machine 2. Application GB / T 2941 Standard degree, intensity and time of environmental conditioning and test of rubber samples 3. Principle The basic principle of hardness test of microporous materials for shoes: A steel hemispherical indenter is pressed into the surface of the sample under the action of the test force. When the pressure surface is tightly bonded to the surface of the sample, the protruding length of the indenter relative to the pressure surface is measured, and a certain number is converted to represent the hardness of the microporous material for shoes. 4 This instrument 4.1 The hardness tester for microporous materials mainly consists of a hardness value display device, a hemispherical pressure needle, a pressure foot and an elastic ball that applies pressure to the pressure needle. The tolerance of the hardness tester is as shown in the following figure. R5 42 The display of the hardness tester should be 100 equal parts, and each division is a hardness unit. The end of the pressure needle is in a free state, that is, the pressure needle is fully extended, and the end is 2.0 meters away from the pressure foot. The hardness tester display should indicate 0. When the end of the pressure needle and the pressure foot are in the middle, the pressure needle end is 2 meters away from the pressure foot. The pressure tester display should indicate 0.0 meters away from the pressure foot. 2489—93 On the plane, when the end of the pressure needle does not extend, the hardness tester display should indicate 0*. 4.3 The stress applied by the pressure spring to the pressure needle has a constant linear relationship with the displacement of the pressure needle extending from the pressure foot. The relationship between its size and the scale indicated by the hardness counter value display device is shown in the following formula: Fw = 0.075H u + 0.350 Wherein: Fw——The force applied by the spring to the pressure needle of the rubber and plastic microporous material hardness tester, N; Hw~The reading of the rubber and plastic microporous material hardness tester, degree 4.4 The pressure foot is the plane where the hardness tester contacts the sample, and its surface area should be greater than 50mm×14mm (700m: When measuring, the plane should contact the sample evenly: 4.3% The auxiliary frame used for measuring hardness is the bracket for fixing the hardness tester. The plane of the auxiliary frame test bench should be flat and smooth: During the test, the hardness tester is vertically installed on the bracket, and a heavy hammer of a specified mass is added along the axis direction of the pressure needle. Make the sample evenly subjected to a total load of 1kg including the pounding meter. 5 Sample 5.1 Remove the skin on both sides of the sample. The thickness should be uniform, the surface should be flat, the micropores should be evenly distributed, and there should be no mechanical damage or impurities.5.2 The thickness of the sample should be 10.0±0.5mm. Use a vernier caliper with a minimum graduation value of 0.02mm to measure. The thickness is not fixed. Three pieces can be overlapped, but the contact surface must be smooth and flat. The total thickness still meets the sample thickness specification. 5.3 The size of the sample should meet the requirement that each measuring point is not too far from the edge of the sample. Less than 15mm, no less than 15 groups of measuring points, no less than three measuring points for each sample. 6 Test steps 61 The sections and test strips of the sample shall be carried out in accordance with the provisions of GB.2941.6.2 Raise the test platform so that the hardness tester, under the action of the fixed weight, has the hardness tester pressure foot in full contact with the test platform. At this time, the value display should indicate "100±1". When the pressure needle completely leaves the test platform, it should indicate "0±1". 6.3 Place the sample on the test platform so that the pressure needle head is at least 15m away from the edge of the sample. Slowly raise the platform and steadily and without impact, allow the hardness tester to Under the action of the specified heavy hammer, press the sample. When the pressure foot is in full contact with the sample, read the value within 1 second. 6.4 Each measuring point is only allowed to be measured once. There should be no less than three measuring points at different locations on the same sample that are more than 15 mm apart. 7 Result Representation 7.1 The number read on the display device of the hardness tester is the hardness value of the measured material. The symbol Hw is used to represent the hardness in degrees. 7.2 The median value of the measured value is taken to represent the hardness of the material. 8 Test Report The test report should include the following contents: Table: Material name, specification and manufacturer; b. Test temperature, humidity and adjustment time Median value of hardness; d. Test date. Test personnel: Additional instructions: HG / T 2489—93 This standard was proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of the Shanghai Rubber Shoes Research Institute. This standard was drafted by the Shanghai Rubber Shoes Research Institute. The main drafters of this standard were Ni Weigou, Yan Lizhi and Xu Cajia. After the release and implementation of this standard, the original national standard GB4493-84 "Test method for hardness of microporous materials of rubber and plastic shoes" will be abolished. HG/T People's Republic of China Chemical Industry Standardbzxz.net Hardness Test Method for Microporous Materials for Footwear HG/ T 2489 - 93 Editor: Chemical Industry Standard Editorial Department (Institute of Standardization, Ministry of Chemical Industry) Postal Code: 100013 Printer: Institute of Standardization, Ministry of Chemical Industry Copyright reserved. No reproduction allowed Format: 880×[2301 / 16 Sheet: 6 characters 5000 First edition in October 1993 First printing in October 1993 Number of copies [—500 Cost: RMB 1.30 Tip: This standard content only shows part of the intercepted content of the complete standard. 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