Tensile testing machines, also called universal material testing machines, are testing machines that test the…
Concept of Tearing Strength
Local yarns in fabrics tear in residual rent due to concentrated loads, which is called tearing phenomenon of fabrics. For example, when the fabrics are caught by objects, local yarns will be forced to tear in rent; or the parts of the fabrics are held and torn in half. In general, tearing properties are used to assess the durability of textiles, such as resins-treated cotton and woolen chemical fabrics.
Several Ways of Evaluating Tearing Strength of Fabrics:
B: Trousers Type Method (including single tongue method and double tongue method)
D: Airfoil Method
Various Tearing Methods of Tearing Mechanism
A: Tearing Strength of Pendulum Method
As shown below, the two sides of marked P are where the sample is clamped by the sample clamp. When the heavy hammer drops instantaneously, the sample will tear from the first yarn in the torn triangle until the whole sample is torn.
A triangular area forms between the first broken longitudinal yarn and the two cut transverse yarns. This area is called tearing triangle area.
B: Tearing Strength of Trousers Type Method
The tearing strength of the principle of trousers method is the same as that of pendulum method in that the tearing speed is different; the pendulum is a fast tearing, while the single tongue is a slow and uniform tearing.
C: Tearing Strength of Trapezoidal Method
As shown below, there are trapezoidal samples and camped samples.
We can see, from the two figures above, that trapezoidal method is completely different from pendulum and sing tongue method. If the pendulum method is to tear a single yarn in battle, then the single tongue method is at least two or several yarns in battle, while the trapezoidal method is a group of yarns in battle, forward and follow-up, until the sample is complete. Like the figure below Figure of Tearing Strength of Trapezoidal Method)
We can see, from the picture of tearing mechanism, that trapezoidal tearing begins with the first red-marked yarn and ends with the nth unstretched yarn. This group of yarns resists the pull from the vertical direction. So trapezoidal tearing is not so much tearing as stretching strength of some yarns.
D: Tearing Strength of Airfoil Method
The tearing strength of airfoil method is basically the same as that of the trapezoidal method, but with different angles. Different angles represent a different number of yarns participating in resistance to tension, so trapezoidal method and airfoil method can not only be the same type of test, and the test results cannot be compared with each other.
Comparisons of tearing results of various types only take a plain cotton cloth as an example, because the fabric of other organizational structures is affected by the particularity of organizational structure, and the tearing situation is more complex. Here, taking a plain cloth as an example, the purpose is to give you a general understanding of tearing data of various types.
Conclusion: The tearing strength: Pendulum Method < Single Tongue Method< Double Tongue Method < Airfoil Method < Trapezoidal Method
Auto Elmendorf Tear Tester, which is used to determine the ballistic tearing strength of various common materials and was naturally adopted for all materials in the form of sheet or films, cardboards cloth, knitted fabrics, plastic films, aluminum foil, non-woven fabrics, complex flexible packaging, etc.
The model is the only one that covers the most completed test range from 0cN to 12800cN.
The machine can be controlled by the large graphic touch panel without computer and software.
Automatic specimen clamping and notching.
Repeatable, pneumatic specimen gripping system guarantees sufficient clamping pressure to avoid all slipping phenomena, thus ensuring perfect reproducibility of the experimental conditions.
How to test the tear strength? Through this article, I think you might have got some information. If you want to know more, please contact us. As a professional supplier of textile instruments, we are committed to continually improve the user experience, TESTEX Textile Testing Equipment is a reliable choice for testing textile quality.