Test method for adhesive strength of edge-sealing of portable paper bags

Paper bags are often used as clothing paper bags, gift bags, food bags, wine bags, shopping bags, etc. Most of them are made of paper and kraft paper of better quality and higher grade. During the use of the paper bag, the bottom or side sealing edge of the bag often cracks, which seriously affects the service life of the paper bag and the weight or quantity of the contents, and causes a waste of resources.

Portable paper bags

The cracking of the edge of the paper bag is mainly related to the adhesive effect of the edge. Most of the edge of the paper bag is sealed by an adhesive. If the adhesive has poor durability, is more sensitive to temperature and humidity, and has poor adhesion on the surface of the paper bag, the paper bag is prone to sealing cracks during use.

Therefore, by selecting suitable adhesives, improving the sealing process (such as needle holes in the edge sealing), etc., to improve the adhesive effect of the edge of the paper bag, and strengthen the test of its adhesive strength, it is an effective means to reduce the probability of cracking of the edge of the portable paper bag and improve its load-bearing capacity.

For the test of the adhesive strength of the edge sealing of paper bag, refer to QB/T 4379-2012 "Portable paper bags". In this standard, the evaluation index of the adhesive effect of the edge is the sealing adhesive strength. The test process is carried out according to the constant speed stretching method in GB/T 12914-2008 "Determination of Tensile Strength of Paper and Paperboard". The equipment adopts the adhesive strength testing machine (Auto Tensile Tester) TST-02H developed and produced by HORIZON TESTER. The equipment integrates dozens of independent test procedures such as stretching, peeling, and tearing, and provides users with a variety of test item options.

Adhesive strength testing machine

Test Principle:

The bond strength test is the force value required to peel off a certain width of sealing edge. Adhesive strength testing machine is equipped with upper and lower fixtures. The upper fixture can move up and down. It is a movable grip and equipped with a force sensor. The lower fixture remains stationary. During the test, the two free ends of the sample are clamped in the upper and lower clamps, and then peeling failure or tensile failure occurs with the separation of the two clamps. The force sensor records the failure of the sample in real time during the test. The resulting force value, thereby obtaining the adhesive strength of the sample. In addition, the device is equipped with a displacement sensor, which can be used to monitor the displacement of the sample during the test in real time to obtain indicators such as deformation rate and elongation.

Test Procedure:

1. Cut 5 specimens with a width of 15 ± 0.1 mm from the side sealing edge of the handbag sample, and the length should be at least 300 mm, and the adhesive part of the side sealing edge is located in the middle of the sample.

2. Open the Adhesive strength testing machine and set the parameter information: the test speed is 50 mm/min, the sample width is 15 mm, and the number of samples is 5.

3. Adjust the initial distance of the clamp to 250 mm, take one of the samples, and clamp the two ends of the sample in the upper and lower fixtures of the equipment respectively, so that the long axis of the sample is parallel to the center line of the two fixtures.

4. Click the test option, the test starts, the upper clamp moves upwards at the set speed, the device displays the force curve generated during the test in real time, and automatically calculates and displays the test result of the tested sample's bond strength after the sample is over.

5. Repeat operations (3) and (4) until all 5 samples have been tested

The adhesive strength of the edge sealing of the paper bag is an important factor that determines whether it cracks during use, and to a certain extent determines the quality of the paper bag. HORIZON TESTER is committed to testing services for various packaging materials. For more information, please visit www.horizontester.com