Comparing Mullen and Elmendorf Burst Testing for Paper and Fabric

As a user investigating burst strength tester paper fabric, you might encounter different testing principles and equipment. Two prominent methods for assessing the burst strength of sheet materials like paper and fabric are the Mullen burst test and the Elmendorf tear test (while not strictly "burst," it's often considered alongside burst strength as a measure of material failure resistance). This article clarifies the fundamental differences between these two material strength testing techniques to help you understand which method is most appropriate for evaluating your specific materials.
 

The most significant difference lies in the type of force applied and the mode of failure. You might ask: "How does each test stress the material?"

Mullen Burst Test (using a traditional Burst Strength Tester Paper Fabric): This test applies a hydrostatic pressure to a clamped circular area of the material until it ruptures. The force is applied uniformly over the test area from one side, causing the material to bulge and eventually burst. The result is a measure of the material's resistance to pressure applied over a defined area. Standards like TAPPI T 403 and ASTM D3786 describe the Mullen burst test.
 

Elmendorf Tear Test (typically using a separate Tear Strength Tester): This test measures the force required to propagate an existing tear through a defined length of the material. A pendulum with a sharp blade initiates a tear in a clamped specimen, and the energy lost by the pendulum as it swings through the tear is used to calculate the tear strength. The result indicates the material's resistance to tearing once a tear has started. Standards like ASTM D1424 (for textiles) and TAPPI T 414 (for paper) detail the Elmendorf tear test.
 

You might also be curious about: "What material properties does each test primarily evaluate?"

Mullen Burst Test: Primarily assesses the tensile strength and extensibility of the material under multi-directional stress. It indicates the material's ability to withstand forces that could cause it to rupture or burst. This is particularly relevant for packaging materials that need to contain internal pressure or resist puncture.
 

Elmendorf Tear Test: Primarily evaluates the tear resistance of the material. It indicates how easily a tear, once initiated, will propagate through the material. This is important for materials that might be subjected to tearing forces in their end use, such as bags, clothing, and paper that needs to resist tearing during handling.
 

Another key difference lies in the sample preparation and the nature of the test. You might ask: "How are the samples prepared and what does the test involve?"

Mullen Burst Test: Requires a relatively small, circular specimen that is securely clamped. The test is dynamic, with pressure increasing until the material bursts.
 

Elmendorf Tear Test: Requires a specifically shaped specimen with a pre-cut slit. The test involves a single, dynamic tear propagation under the force of a swinging pendulum.
 

The results are also reported differently. You might wonder: "What units are used for each test?"

Mullen Burst Test: Results are typically reported in units of pressure, such as kilopascals (kPa) or pounds per square inch (psi).
 

Elmendorf Tear Test: Results are reported as the tearing force in units such as millinewtons (mN) or grams-force (gf).

Finally, the applications of each test differ based on the material and its intended use.

Mullen Burst Test: Widely used for evaluating the strength of paperboard and corrugated materials for packaging, as well as some textiles that need to resist bursting.
 

Elmendorf Tear Test: More commonly used for evaluating the tear resistance of paper, textiles, and plastic films, where resistance to tearing is a critical performance factor.
 

In conclusion, while both the Mullen burst test and the Elmendorf tear test provide valuable information about the strength of paper and fabric, they assess different material properties under different types of stress. The Mullen test measures resistance to bursting under pressure, while the Elmendorf test measures resistance to tear propagation. Understanding these fundamental differences is crucial for selecting the appropriate material strength testing technique to ensure the quality and suitability of your materials for their specific applications.