GB/T 3687-1989 Determination of interlayer bonding strength of V-belts GB/T3687-1989 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Method for Determination of Ply Adhesion Strength of V-Belts
V-belts-Determination of ply adhesionGB 3687-89
Replaces GB3687-83
This standard refers to and adopts the international standard ISO36-1985 "Determination of adhesion strength between vulcanized rubber and fabric". 1 Subject content and scope of application
This standard specifies the method for determining the adhesion strength between the tensile layers of V-belts and the adhesion strength between the covering layers by the peeling method. This standard is applicable to V-belts of C, D, E and other similar cord structures. 2 Reference standards
GB2941 Standard temperature, humidity and time for parking and testing of rubber specimens 3 Definitions
Peel force: The force required to peel off two adjacent layers of the specimen in the peel test. a.
b. Interlayer adhesion strength: The ratio of the peel force to the width of the specimen. Peak point: The position of each maximum value on the recording curve. c.
d. Complete curve: record the part from the first peak to the last peak on the curve. 4 Test principle
On the tensile testing machine, peel a certain length between the adhesive layers of the sample at a certain speed, and calculate the interlayer bonding strength using the automatically recorded peeling force curve.
5 Test instrument
This test uses a tensile testing machine that meets the following requirements: a. The working speed of the dynamic clamp should be 50±10mm/min, and the movement speed should be basically constant; b. With a drawing device that automatically records the peeling force; c. The measurement error is not greater than 1% of the range
α. The force measuring part should be non-inertial (such as electronic). When using an inertial testing machine, the measured force should be within the range of 15% to 85% of the range.
6 Test specimens and their preparation
6.1 Size and quantitybZxz.net
6.1.1 The test specimens shall be rectangular, with a width of 10±0.2mm and a length that can provide a peeling length of not less than 100mm. 6.1.2 Take two test specimens between each test layer. Take one test specimen between four layers or less, and take two test specimens between five layers or more.
6.2 Preparation
6.2.1 Cut the test sample into sections according to the length requirements of Article 6.1.1. 6.2.2 Cut off the top and bottom rubber of each section, but the first and last two layers shall be attached with a rubber layer or wrapping cloth equivalent to the thickness of one layer of cloth. 6.2.3 Cut into rectangular specimens according to the width requirements of 6.1.1. For three-layer cords, take the first layer, for four-layer cords, take the middle layer, for five-layer cords or more, take the first layer and the two adjacent layers between the first layer and the last layer, and peel off the middle layer in groups of four layers. 6.2.4 Cut the working cloth specimens according to the length and width requirements of 6.1.1. 6.2.5 Pre-peel a 30mm long opening between the test layers at one end of the specimen, and this end will be used as the clamping end. 6.2.6 If the displacement of the cord layers exceeds two lines or other conditions that cannot be cut occur, the specimen shall be invalid and another specimen shall be taken. 6.2.7 Mark the fabric layer number on each specimen, and the fabric layer close to the base rubber is the last layer. 7 Test conditions
The sample parking conditions, test temperature and relative humidity shall be in accordance with GB2941. 8 Test procedures
8.1 Clamp the two clamping ends of the sample in the upper and lower clamps respectively. The center lines of the upper and lower ends should coincide and be consistent with the direction of the force.
Start the test machine and continuously peel the sample to obtain a peeling force curve representing a peeling length of 100mm. 8.2
9 Test results
9.1 Calculation of results
9.1.1 Determination of average peeling force
9.1.1.1 Method A
Mark 9 straight lines perpendicular to the time axis on the recording curve, which divide the projection of the complete curve on the axis (the AB line segment in Figure 1) into 10 equal parts. Mark the 9 peak points closest to these 9 straight lines. According to the height of the peak point position, find the median of the 9 peak values ​​as the average peeling force.
When the curve near one of the above 9 straight lines is relatively flat, so that the distance from the straight line to the nearest peak point is also greater than half of the distance between the adjacent straight lines, the ordinate corresponding to the intersection of the straight line and the curve is taken as one of the 9 peak points for finding the median (see figure). 9.1.1.2 Method B
Draw a straight line parallel to the time axis on the peeling force recording curve chart. It and the peeling force curve of the sample together form two closed curves. Use visual inspection to make the difference between the closed curve areas on both sides of the straight line within 10%. The ordinate of the straight line is taken as the average peeling force. In arbitration, evaluation and appraisal, the calculation method A should be used. 9.1.2 Calculation of interlayer bonding strength
The interlayer bonding strength is calculated according to the following formula:
Where: α interlayer bonding strength, N/mm, F
—average peeling force, N,
-sample width, mm.
Results
The test results include
GB 3687--89
The average value of the interlayer bonding strength of the two test samples between the test layers. The lowest value of the average value of the interlayer bonding strength of the two test samples between the test layers. Test report
The test report includes the following contents:
The type, specification, batch number and manufacturer name of the test tape, the temperature and relative humidity of the test room,
Test results;
Parking time,
Test date,
Tester.
Additional remarks:
This standard is under the jurisdiction of Qingdao Rubber Industry Research Institute. This standard was drafted by Qingdao Rubber Industry Research Institute. The main drafters of this standard are Zhang Xiuxiang, Gao Qun and Han Deshen. 32
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