Sealing Plug Compression Fatigue Testing - Solving Early Fatigue Failure with Superior Material Performance

Photo: Customer's headache - sealing plug fatigue failure that required our support to resolve.

For rubber seals and sealing plugs that endure repeated compression over long periods, static sealing performance is only the first step. What truly determines a product's long-term reliability is whether the rubber material can maintain its elasticity, structural integrity, and stable sealing function under sustained cyclic loading.

Recently, a customer of Tianjin TGE has faced a problem: their sealing plug products showed multiple cases of early fatigue failure during end-user operation, and their original supplier was unable to resolve it. Fortunately, the customer turned to TGE. We quickly prepared a premium rubber compound suitable for frequent loading and unloading cycles, and produced samples using the customer's existing mold. We then conducted a dedicated Compression Fatigue Test on the new product.

Test results showed that under test conditions of 3 mm compression, a cycling frequency of 5–7 Hz, and a cumulative 100,000 compression cycles, the sealing plugs displayed no significant deformation, cracking, flaking, or crushing after the test. The overall product structure remained intact, and the customer's equipment continued to maintain good sealing function in use.

This successful project not only validated the excellent compression fatigue performance of the new NBR compound solution, but also demonstrated TGE's integrated technical capability across rubber compound design, vulcanization process, and performance verification. The customer's procurement team leveraged TGE's high-performance yet cost-effective material and product solution to resolve their product failure issue, avoid the risk of large-scale product failure and recall, and ultimately deliver long-term, reliable functional assurance to their end users.

Test Conditions & Key Results at a Glance

1. From "Product Failure" to Re-Validation: What the Customer Really Needed

For rubber sealing plugs, seals, and rubber-metal composite components, sealing properly at initial assembly does not mean the product will work reliably over the long term.

During repeated compression and release cycles, the rubber material continuously deforms. If the material's fatigue resistance is insufficient, prolonged cycling can lead to:

• Surface cracking of the rubber
• Edge tearing or peeling
• Localized crushing
• Permanent deformation
• Loss of elastic recovery
• Ultimately, degraded sealing performance

Photos of the customer's original products showed varying degrees of rubber deformation, surface damage, and local structural failure. These problems are usually not a matter of "were the product dimensions correct," but require analysis from the perspective of rubber material, compound system, hardness, and elastic recovery.

In this project, TGE therefore manufactured products with a new NBR compound solution using the customer's existing mold, and went on to conduct compression fatigue testing.

This means TGE cares not only about "Can the product be installed?" but also "Will the product still work after long-term repeated compression?" - and that is exactly the value TGE provides. Procurement departments should prioritize not only price, but also the product's service life and reliability.

2. Why Compression Fatigue Performance Matters So Much for Sealing Plugs

In actual service, sealing plugs rely on the elastic deformation of the rubber material to form a seal or maintain a certain contact pressure.

Unlike one-time static compression, real working conditions involve a large number of repeated cycles. Put simply:

Compression → Release → Recovery → Re-compression → Re-release

This process continuously challenges the rubber material's:

• Elasticity
• Fatigue Resistance
• Compression Recovery
• Tear Resistance

If the rubber gradually loses elasticity through cycling, a situation can arise where "everything seems fine at first, but performance drops sharply and unexpectedly after a period of use." For end users, this can lead to catastrophic consequences with no warning.

Drawing on the customer's actual working conditions, TGE gave full consideration to compound design, vulcanization process, and many other aspects, and significantly improved the customer's early fatigue failure problem with outstanding NBR material performance - providing long-term, reliable functional assurance.

3. What Happened to the Product After 100,000 Compressions?

This is the most important result of the entire test.

After completing the 100,000-cycle compression fatigue test, the products underwent appearance and condition inspection. The test report recorded:

• No abnormality in compound color
• No significant abnormality in outer diameter dimensions
• Complete product structure
• No cracks, no flaking, no crushing

The final test conclusion: TGE sealing plugs successfully passed the compression fatigue test at 3 mm compression and 100,000 cycles.

In other words, simulating the customer's working conditions, the NBR rubber sealing plugs produced by TGE maintained excellent overall condition after a cumulative 100,000 compression fatigue cycles.

For the customer, this material performance delivers tangible value: more stable sealing function, better long-term elastic retention, lower risk of early failure, and ultimately a longer service life.

4. From "Material Performance" to "Customer Value": Why Fatigue Resistance Matters

For industrial customers, choosing a more consistent rubber supplier is not about saving a few cents per unit. What really matters is the total cost over the product's entire life cycle.

If a sealing plug fails prematurely from fatigue during long-term use, the customer may bear:

• Equipment downtime costs
• Labor and repair costs
• Replacement part costs
• On-site service costs
• Customer complaint and quality management costs
• - and in critical equipment, reduced reliability of the entire machine

Therefore, although the fatigue resistance of rubber parts is a material-level indicator, what it ultimately impacts is the customer's Long-Term Functional Reliability. And that is precisely the important difference between high-reliability rubber seals and ordinary rubber parts.

5. TGE Provides More Than Rubber Parts: Matching "Material + Product + Working Conditions"

This project had another important feature: the tests used a mold provided by the customer.

In other words, we did not simply change the product dimensions. We manufactured and validated products on the basis of the customer's existing design, using TGE's compound solution.

This is essential in rubber product development, because the final fatigue performance of a rubber product is never determined by a single factor. It is typically influenced by:

• Compound formulation
• Product structure
• Compression amount
• Mating dimensions
• Working frequency and working temperature
• Media environment

That is why we prefer to start from the real application scenario and select the most appropriate material and product solution for each customer.

6. Testing Capability: An Important Tool for Solving Customer Problems

For a rubber product supplier, true technical capability is more than "being able to produce."

More importantly, it is the ability to:

Define the problem → Establish the validation method → Execute the test → Analyze the results → Continuously optimize

The sealing plug project is a typical example: from the customer's original fatigue deficiency, to re-validation of a new material solution, to the 100,000-cycle compression fatigue test, and finally to verified product condition and test data.

This allows customers to understand intuitively how the product performs under long-term cyclic loading.

7. 100,000 Cycles Is Not Just a Number

For procurement professionals, "100,000 cycles" may look like nothing more than a test count.

But for product engineers, this number represents:

• 100,000 repeated deformations
• 100,000 elastic recoveries of the material
• 100,000 interactions between the rubber and its mating structures

When a product remains fully intact after cycling at this magnitude, the value of the test goes far beyond proving "the product didn't break."

More importantly, it provides customers with direct experimental evidence for product design validation, supplier qualification, material selection, life assessment, and reliability analysis.

Conclusion: Validate Materials with Real Testing - Make Reliability a Provable Performance

For customers, this means TGE provides not just an NBR rubber sealing plug, but a complete NBR material and product solution verified through actual testing.

From NBR compound formulation, to product vulcanization and manufacturing, to fatigue performance verification, we help customers turn "the rubber part looks fine" into "the rubber part is proven to withstand long-term use." That is the value we pursue at TGE.

TGE - Rubber Material Expertise, Reliable Performance, Verified by Testing.

Sealing Plug Compression Fatigue Testing - Frequently Asked Questions

TGE - Rubber Material Expertise, Reliable Performance, Verified by Testing.
Professional rubber material technology, reliable product performance, and data validation based on real testing.