Strength test and analysis of corrugated paper and

2022-10-16
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Technology: strength test and analysis of corrugated paper and carton

release date: Source: carton

corrugated paper is the main material for manufacturing all kinds of cartons and packaging. The quality and strength of corrugated paper will directly affect the quality of cartons or packaging. On the one hand, the quality and strength of corrugated paper are affected and limited by the production process and operation, on the other hand, they are required by the products to be packaged and the use

therefore, the strict determination of all aspects of the strength index of corrugated paper is a very important link in packaging, printing and production, which is of great significance to ensure product quality and 5g network performance

I. strength test and analysis of corrugated board

sampling is the first step to accurately measure corrugated board. Sampling should be able to represent the characteristics of the whole batch of products to the greatest extent, but should be as few as possible. In China, the standard is 3% - 5%, and sampling can also be carried out according to the specific production scale and situation

after sampling, the paper should be processed so that the measured data can be obtained under a specific condition, so that the data can be compared under the same conditions. The humidity and temperature of the air have a great influence on the physical and mechanical properties of paper and paperboard. It is necessary to do proper humidity control before measurement

below we introduce the strength index and test method of corrugated paper

01. Ring crush strength of corrugated board and carton board

it is difficult to measure the compressive strength of base paper or paperboard along the width direction (i.e. perpendicular to the thickness of the paper). Because the thickness of paper or paperboard is very small, it is difficult to apply pressure on a flat paper in the direction perpendicular to its thickness, and to maintain the shape stability of the base paper or paperboard. If paper or paperboard is enclosed in a ring, its shape stability is much better when pressure is applied. Therefore, surround the base paper or paperboard into a ring, and then measure its compressive strength, which is the ring compressive strength of the base paper or paperboard. The measurement is carried out on a small pressure testing machine

02. Flat compression strength of corrugated core

the main function of corrugated core is to maintain a certain thickness of corrugated board when it is compressed and deformed, so as to obtain a large moment of inertia for the board in the past two years. The function of corrugated paper is closely related to its reliable performance in single-sided machine. The corrugated paper core should be able to bear the effects of stress and strain, form uniform contour corrugated when it starts at high speed, and firmly adhere to the face paper

this effect of corrugated core can be measured by the flat compression strength of grooved corrugated core. The flat pressing strength of the corrugated core is measured by pressing the corrugated base paper into corrugated with a certain shape with a grooving tester at a certain temperature and pressure. Then do the flat compression test on the small testing machine to measure its bearing capacity, which is expressed in kn (KGF)

03. Flat compression strength of corrugated paperboard

an inherent characteristic of corrugated paperboard is that it has a larger moment of inertia than ordinary paperboard. When the corrugated board is subjected to the action of high pressure moment of inertia, maintaining its original thickness is a prerequisite to maintain its inherent characteristics. Therefore, the ability of corrugated board to withstand flat compression load without crushing is an important strength index of corrugated board. This index is particularly important for the elasticity of corrugated board in use and for maintaining the original thickness of the board in all processing processes of making cartons

the flat compression strength of corrugated board is expressed by the force acting vertically on the unit area of the board, and the unit is kPa. The flat compression strength of corrugated board can be measured with a small pressure testing machine, using a circular sample with a diameter of 5.13cm

04. The edge pressing strength of corrugated cardboard

corrugated boxes are different from paper bags in that they are used as rigid containers and must maintain a certain shape when used. One of the main forms of corrugated box damage is crushing and loss of rigidity. A lot of research work has shown that an indicator of the rigidity of cartons is the compressive strength of cartons, which is directly related to the edge compressive strength of corrugated cardboard

the edge compression strength of corrugated paperboard refers to the ability of the paperboard to bear the compression load along the corrugated direction, expressed in force per unit length, with the unit of n/m. This index can be used to compare the quality of products produced under similar conditions, but not the same batch of products; It can also be used to compare the edge pressing strength of corrugated board produced from different materials

small pressure testing machine can be used to measure the edge pressure strength. The area of the upper and lower pressing plates is 100mm*100mm, and the other requirements are the same as those for measuring the flat compression strength. In addition, two rectangular metal guide plates with a length of 100mm and a cross section of 20mm*20mm are required to hold the sample

05, burst resistance

burst resistance has always been considered as an important quality index of corrugated board and its components (core paper, face paper and lining paper). In the early days, even all quality specifications of corrugated board were mainly based on bursting strength. Although the current specifications have paid attention to indicators such as edge pressure, the fixture used in the tensile testing machine has no fixed mode in structure. According to different samples and experimental forces, the structure is very different, and the determination of bursting resistance is still of great significance. Because the paperboard will be subjected to stress similar to that in the determination of bursting strength during use. Burst resistance is the load of paper or paperboard when it is not broken. It indicates the ability of paper or paperboard to withstand external pressure when it is not broken. The bursting strength is measured with a bursting strength measuring instrument

06, puncture strength

puncture strength can be used to measure the resistance of corrugated board when it is damaged by sharp objects. It is a comprehensive index. Recent studies have shown that the tear strength of the face paper in both vertical and horizontal directions is related to the corrugated core paper, and the flat compression strength of the corrugated core paper has an important impact on the strength of the corrugated board. Puncture strength has become more and more important recently, and many countries have included this index in the quality specification of corrugated paper

the puncture strength is measured by the puncture strength tester. The tester uses a pendulum equipped with a puncture head to measure the resistance of the paperboard to puncture by the change of potential energy before and after it punctures the paperboard, and converts the change of potential energy into kinetic energy to puncture and tear the paperboard, so as to express the puncture strength of the paper or paperboard

07, adhesive strength

adhesive strength refers to the bonding strength between corrugated paper and face paper or lining paper. Apply an outward pull perpendicular to the surface of the face paper or corrugated core paper until they are separated. The maximum load that the interface of adhesive or bonded fiber can bear before separation is the bonding strength of the sample, also known as peel strength, in n

the adhesive strength can be measured by a small pressure testing machine. The tension applied to the face paper and corrugated core paper is generated by inserting the upper and lower groups of corrugated rods, so this test is also called the pin gluing strength test

the model of the test bar depends on the model of the corrugated board being tested. A long set of test bars is inserted under the corrugated core paper, and a short set of test bars is inserted under the corrugated core paper. Then pull up the upper side and pull down the lower side to measure the bonding strength of the weaker of the two bonding surfaces of the two authorized utility model patents. When a long group of test bars are inserted into the upper or lower side of the core paper at intervals, and a short group of test bars are also inserted into the same side of the core paper at intervals, the bonding strength of the side connected with the test bar can be measured

II. Performance test of cartons

corrugated cartons can largely replace wooden cases, but the main reasons why they cannot completely replace wooden cases are as follows: 1 Water resistance and moisture resistance are not as good as wooden cases; 2. It is easy to be punctured by sharp hard objects; 3. The compressive strength is not as good as that of wooden cases. Especially the last point. Therefore, it is of great significance to study how to improve the compressive strength of corrugated boxes

corrugated boxes belong to packaging containers, and their tests can be carried out according to the requirements of packaging containers. The main test items are:

01, carton pressure test

carton pressure test is the compression test, which is the most basic test for carton performance. Through this test, the compressive capacity of cartons in different states can be determined

the equipment used for carton pressure test is a special pressure testing machine for cartons. The pressurized area of the bench of this testing machine is relatively large. Generally, the area of the upper and lower pressing plates is 1.5m*1.5m or 1m*1m respectively. One of the two pressing plates is a support plate, whose position can be adjusted according to the size of the sample to make it have a suitable height, and then fasten it; The other is a pressing plate, which can slide along the guide rod to apply pressure to the sample

02. Drop test of carton

drop test is a commonly used test for general commodity packaging, and it is also used for corrugated cartons. Through the drop test, the physical strength of the contents can be detected under different drop conditions. At the same time, the performance of the carton and the cushioning effect of the carton structure can also be determined through the test

The drop test is a simple and applicable test. It is suitable for packaging with a total weight of less than 150kg or a small volume. The equipment used by the testing machine is relatively simple, which can be used as hook drop testing machine or support plate testing machine

03, oblique impact performance

for packages with large weight or volume, such as large packages weighing more than 150kg, oblique impact test can be used to detect the impact resistance of packages and contents

the inclined plane impact test can simulate the strong impact load caused by the starting, braking and downhill of trains and cars. In addition, this test can also provide similar experiments for various impact loads caused by the transfer process (such as goods passing through the transport belt, lifting, unloading and other links). The test device is a collision testing machine composed of slide, pulley and baffle

04, hexagonal drum test

hexagonal drum test is a comprehensive test that simulates the cartons with internal items under various external loads during transportation. This test can imitate the case that cartons enter warehouses, machine silos, carriages by transportation belts, or cartons are transported from one floor to another by transportation belts. The tumbling and falling of the carton in the testing machine is random, and there is no certain law. This natural fall of the carton can fall on the baffle of the drum, or on all corners, sides and sides of the drum, providing various load tests for the carton

two purposes can be achieved through this test: simulate the impact and vibration that the carton may encounter during transportation, and measure the resistance of the carton to these impacts and vibrations; Determine the protective ability of cartons, inner packaging and shockproof materials against the contents. In addition, this test is also useful for determining the reliability of carton joints and closures. This test is measured on a hexagonal drum testing machine

05, vibration and anti vibration performance test

cartons will undergo vibration of different frequencies and amplitudes during transportation, which will affect cartons and their contents, such as carton deformation and cracking, surface wear, ink stains, etc. through the vibration test, the general vibration in the transportation process can be simulated, and the accidental vibration of some known parameters can also be carried out. Due to the wide range of vibration frequencies during transportation, the test includes two aspects: first, put the carton loosely on the shaking table to test the ability of the carton to withstand fatigue and high-frequency vibration caused by repeated vibration; The other is to tie the carton tightly on the shaking table and check whether the low-frequency vibration will cause the carton to be loaded

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