The unsealing force of corrugated cartons should be controlled within a certain range to facilitate unpacking. There are two methods of opening corrugated boxes: the tearing method with tape as the medium and the pull-seal opening method. The tearing method is more laborious when unpacking, and is prone to damage during circulation. In order to solve these problems, it is necessary to test the unsealing force of the tear part, and then obtain an appropriate shape of the pull seal to improve the gap width, etc. Figure 2-66 shows the principle of the test method for the unsealing force of the torn part of the corrugated box.
Figure 2-66 Principle of unsealing force test method
1-fixed part; 2-corrugated box; 3-load Detector; 4-lock block
At least 3 corrugated boxes are required for each test. Before the test, each part of the carton sample should be marked according to GB 3538, a temperature and humidity condition should be selected according to GB4857.2, and the temperature and humidity pretreatment should be carried out on the sample for more than 24 hours. Then, place the corrugated box on the base surface, and adjust the horizontal position of the corrugated box by means of the lock block and the fixed part. The vertical stop installed on the lock block can adjust and control the vertical position of the corrugated box, and the connecting part will load the Detector Attached to the tape on the top of the corrugated box. During the test, a tensile force is applied to the corrugated box along the direction of the load Detector until the top of the sample box is separated from the tape, and the tensile value is recorded, and the average value of the tensile values of all sample boxes is taken as the unsealing force of the corrugated box.
