Analysis of the test principles of the bursting strength tester's ball bursting
The bursting strength tester is used to test the bursting strength performance of textiles. It is a test equipment independently developed and produced by our company Shanghai Qianshi Precision Electromechanical Technology Co., Ltd. Welcome to call for inquiries.
The pin bursting method and the elastic diaphragm method are commonly used test methods for bursting strength testers. In this article, the Standard Group R&D technical engineer describes the test principles of these two methods.
Pin bursting method:
The pin bursting strength tester uses a pair of brackets to replace the upper and lower clamps of the electronic fabric strength tester. The upper bracket and the lower bracket can move relatively to fix the sample in the cloth clamping ring. When the lower bracket descends at a certain speed, the pin on the top rod pushes vertically to the sample until the sample bursts. The instrument automatically displays the bursting strength and bursting elongation values.
Elastic diaphragm method:
A certain area of fabric sample is placed between the pressure box and the air pressure box. A rubber pad (elastic diaphragm) of appropriate thickness and good toughness is placed under the sample and clamped with a ring clamp of a specified size. Turn on the liquid inlet switch and increase the fluid pressure smoothly under the diaphragm until the sample breaks. Read the bursting strength value from the hydraulic gauge, and read the bursting elongation of the sample at the time of rupture on the extensometer.
Test operation:
1. Pin bursting method
①. Preheat the machine for 30 minutes, and select the bursting function in the reset state. Set the margin and positioning displacement (margin is the distance from the outer circle of the ejector to the inner circle of the clamp, and positioning displacement is to collect the strength value at the set elongation, for geotextile).
②. Press the "experiment" key, insert the sample into the cloth clamp ring, tighten it, and then place it flat on the cloth clamp (push the cloth clamp to the bottom).
③. Press the "stretch" key to start the test. After the sample is completely burst, the lower clamp automatically returns to the initial position, and the display screen displays various data.
④. Repeat the above steps to measure 5 samples.
If the sample is not clamped tightly, it will slip out of the ring, or the bursting deformation of the sample is too large, and the sample will not break. At this time, the test result is invalid, and another sample should be replaced and tested again.
⑤. After completing the test, the instrument automatically records and counts all the data.
⑥. Clear the data and prepare for the next test.
2. Elastic diaphragm method
①. Check and calibrate the instrument: Check whether all parts of the instrument are normal; if necessary, the comprehensive performance of the instrument can be verified with a standard diaphragm; the elastic diaphragm must be replaced when it is significantly deformed (in the absence of a sample, expand the diaphragm to a certain height and observe the shape of the diaphragm. If there is a significant difference from the normal spherical crown shape, the diaphragm should be replaced).
②. Clamp the sample: Cover the sample on the diaphragm in a flat and tension-free state, and then clamp the sample with a ring clamp. Prevent the sample from being damaged by the clamp when pressurizing.
③. Pre-test: Before the test, two additional pre-test samples should be used for pre-testing to observe whether it is completed within the specified time range under the gradually increasing hydraulic pressure until the rupture occurs (general fabrics are specified as 30s±10s; wool fabrics are specified as 15s±10s). If not, the pressurization rate can be adjusted to make the average bursting time within the specified range.
④. Formal test: Test the samples one by one at the adjusted pressurization rate and record their bursting strength and bursting expansion. If the sample breaks at the edge of the clamp ring, another sample should be taken and redone.
⑤. Diaphragm correction number: Use the same liquid speed as the above test, clamp the diaphragm with a clamp without a sample, and the pressure required to expand the diaphragm to the average bursting expansion of the above sample is the diaphragm correction number.