This standard specifies a method for determining the edge compression strength of corrugated board parallel to the flute. This standard applies to single-wall (double-sided), double-wall and triple-wall corrugated board. This standard does not apply to wax-coated and curtain-coated corrugated board. GB/T 2679.17-1997 Determination of edge compression strength of corrugated board (edge ​​reinforcement method) GB/T2679.17-1997 Standard download decompression password: www.bzxz.net

GB/T 2679.17—1997
This standard is equivalent to ISO/CD13821.
Based on ISO/CD13821, this standard supplements the precision requirements of the test in accordance with the provisions of Tappi (Technical Association of the Pulp and Paper Industry) T811-88.
This standard is a method for determining the edge compression strength of corrugated board dipped in wax, while GB6546-86 is a method for determining the edge compression strength of corrugated board without wax dip.
This standard is proposed by China Light Industry General Association.
This standard is under the jurisdiction of the National Technical Committee for Standardization of Paper Industry. The drafting units of this standard are China Pulp and Paper Industry Research Institute and Nanjing Forestry University. The main drafters of this standard are Li Lanfen and Zhang Shaoling. This standard is published for the first time.
National Standard of the People's Republic of China
Determination of edgewise crush resistance of corrugated fiberboard
(Edge reinforced method)
GB/T 2679.17—1997
Corrugated fibreboard--Determination of edgewise crush resistance(Edge reinforced method)
1 Scope
This standard specifies a method for determining the edge crush resistance of corrugated fiberboard parallel to the flute. This standard is applicable to single-wall (double-wall), double-wall and triple-wall corrugated fiberboard. This standard does not apply to wax-coated and curtain-coated corrugated fiberboard.
2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB450—89 Paper and paperboard specimens
GB6546—86 Determination of edge compression strength of corrugated paperboard GB10739—89 Standard atmosphere for handling and testing of pulp, paper and paperboard specimens 3 Principle
A rectangular corrugated paperboard specimen is placed between the two pressing plates of the compression tester, with the edges of the specimen perpendicular to the pressing plates. A compressive force is then applied until the specimen is crushed. To prevent premature damage to the edges of the specimen when the load is applied, the stress-bearing edges of the specimen are reinforced. The maximum pressure that each specimen can withstand is measured. 4 Apparatus and materials
Compression tester driven by an electric motor 4.1
The pressing plate must be large enough to support the specimen of the selected size (see 7.1) and the guide block (4.3) will not protrude outside the pressing plate. The pressing plate should also meet the following requirements:
Parallelism is not greater than 1:1000;
The lateral movement does not exceed 0.05 mm.
The tester must have a tool for measuring and indicating the maximum load that the specimen can withstand. 4.1.1. The relative speed of the platen movement shall be in a constant range of (12.5 ± 2.5) mm/min. 4.1.2 If the tester operates on the principle of beam deflection, the deflection of the specimen at the moment of collapse shall be within 20% to 80% of the deflection range that the instrument can measure.
When the platen contacts the test piece, the platen shall apply pressure at a rate of (110 ± 23) N/s. 4.2 The cutting device shall be capable of cutting the test piece in accordance with the requirements specified in 7.1. Approved by the State Administration of Technical Supervision on June 26, 1997 and implemented on December 1, 1997
GB/T 2679.17—1997
Test pieces may be prepared using a band saw or a knife cutting fixture, which can produce test pieces with cut edges that are not damaged, straight and perpendicular to the surface of the paperboard.
4.2.1 Band saws are circular in shape and have sharp, endless (preferably in the form of a circle or circular band) blades. Ensure that the blades are at a 90° angle to the surface on which the specimen is supported.
4.2.2 Motor-driven double-blade cutters have flat, straight, parallel, freshly sharpened blades approximately 0.5 mm thick, sharpened on one side, with the bevels increasing by approximately 3 mm so that the flat sides of the blades face each other. The blades of this cutter must be kept in a straight line. It is recommended that this type of cutter be used no more than 50 times. 4.2.3 Other: Other types of specimen cutters, such as hand cutters, may be used with standard specimens to provide specimens that meet the requirements of 7.1.
4.3 Guide blocks: Two rectangular, smooth-ground metal (or wood) blocks measuring 40 mm × 20 mm. At least 40 mm long are used to support the specimen to keep it perpendicular to the platen. The guide block is cut off 2mm from the back, as shown in Figure 1, to avoid contact with the wax-immersed area of ​​the sample. 4o
4.4 Paraffin
Paraffin with a melting point of approximately 52°C should be used. 5 Sampling
Figure 1 Guide block
Sampling should be carried out in accordance with GB450. A test piece without any mechanical scratches should be produced on the sample. 6 Temperature and humidity treatmentwww.bzxz.net
The sample is subjected to temperature and humidity treatment in accordance with GB10739. 7 Preparation of test pieces
7.1 Cutting of test pieces
Use a saw or a sharp blade and a standard template to ensure parallel cutting. Cut rectangular test pieces perpendicular to the width direction of the corrugated board or to the stress-bearing edge (within 10mm) from the sample (unless agreed by both parties, at least 10 pieces shall be cut). Its size is as follows: For A flute and double and triple flute paperboard: (50.8 ± 0.8) mm × (50.8 ± 0.8) mm; For C flute: Height (38.1 ± 0.8) mm × Width (50.8 ± 0.8) mm; For B flute: Height 32.0 ± 0.8) mm × Width (50.8 ± 0.8) mm Note: A cutting device with a maximum width and height of 50 mm can be used. The stress edges should be parallel to each other and perpendicular to the direction of the corrugation. The stress edges should be cut cleanly and straight, and the inspected test pieces should be confirmed to have no damage or obvious fiber looseness. It should be possible to place a sample vertically without support on one stress edge, and then gently press on its top edge with a finger. At this time, no light should be able to penetrate under the bottom cut edge. Turn the sample over and check it in the same way. Indentations, printing and damage from processing machinery should be avoided in the corrugation and test area of ​​the test piece. 7.2 Wax Immersion
Immerse each stress-bearing edge (length edge) in molten paraffin to a depth of 6 mm and maintain this depth, visually inspecting until the absorbed wax exceeds the 6 mm wax immersion line and then remove it. Generally, immersing in molten paraffin at (69-74) °C for 3 seconds is sufficient. If it is removed too quickly, the temperature of the molten paraffin will be lowered. Immediately after wax immersion, dry the stress-bearing edge of the specimen with a paper towel that has been preheated on a hot plate at (77-~82) °C. Then subject the specimen to temperature and humidity treatment for 2 hours until equilibrium is reached. Note
1 It is also acceptable to immerse the stress-bearing edge of the specimen with paraffin in the following manner. Place the stress-bearing edge on a pad saturated with paraffin, such as a paper towel that has been heated on a hot plate at (77-82) °C, until the paraffin has penetrated the specimen to a depth of 6 mm. This method is generally slower than the wax immersion method and thus allows for better control of the depth of wax penetration into the specimen, since the movement of the wax in the specimen is rapid. 2 Waxed or curtain-coated specimens should not be edge-waxed. 8 Test Procedure
The test should be conducted under the same atmospheric conditions as the temperature and humidity treated specimens. After the test compression apparatus is separated, place the wax-impregnated edge of a specimen in the center of the lower platen. Place a guide block on each side of the specimen on the lower platen with the larger side of the guide block facing upward so that its end contacts the unwaxed portion of the specimen surface. In this way, the specimen can be held perpendicular to the platen surface. The zero point of the measuring instrument should be adjusted with the guide blocks. Apply pressure to the specimen at the specified pressure rate. When the load applied to the specimen reaches 50N and the platen movement speed has not changed, carefully remove the guide blocks from the side of the specimen without removing them from the platen. Continue to operate the test apparatus until the specimen is crushed. Alternatively, if the guide blocks are not in place on the platen, adjust the zero point of the specimen. In this case, the guide block should be removed from the platen as soon as the specimen is firmly supported (the guide block is removed from the platen). Record the maximum pressure in Newton (N). If the deflection has been measured from the pressure, read the deflection to the nearest 0.01 mm. Repeat the above steps to test the remaining specimens.
9 Calculation
The edge compressive strength R is expressed in kN/m and is calculated according to formula (1): F
W—the width of the stress-bearing edge of the specimen, mm. 10 Precision
(1)
The variation between two tests of the same specimen depends mainly on the structure of the corrugated board. The following data can be used as a reference for the precision of this method.
Between instruments in the same laboratory—test repeatability 10.1
A certain amount of corrugated cardboard is tested simultaneously by four different testers in parallel. The coefficient of variation of the test results (four average values ​​of 10 tests) is generally less than 5%.
10.2 Reproducibility of the test between different laboratories
The coefficient of variation of the same type of corrugated cardboard tested by 10 laboratories is less than 12%. 11 Test report
The test report shall include the following items;
a) the number of this standard;
b) the date and place of the test;
c) the characteristics and description of the tested product;
d) the conditions of the temperature and humidity treatment used;
e) the size of the cutting tool and the test piece used;f) the number of repeated tests;
GB/T2679.17--1997
g) the arithmetic mean of all repeated test results, expressed in kN/m, with three significant figures;h) the standard deviation and coefficient of variation of the repeated test results, kN/m, accurate to 0.05;i) any deviation from the procedures specified in this standard or factors that may affect the results. 360
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