DIN 53572 Testing of Flexible Cellular Materials - Determination of Compressive Permanent Deformation After Constant Stress

The standard “DIN 53572 Testing of flexible cellular materials - Determination of compressive deformation after constant stress”, published by the German Institute for Standardization (DIN), describes a test method for determining the compressive deformation of flexible cellular (foam) materials such as polyurethane foams, polyethylene foams, rubber foams, and other elastomeric cellular products.

Compressive permanent deformation measures how well a material recovers its original thickness after being compressed under constant stress (constant percentage of deformation) for a specific period of time. This process is typically performed at room temperature or at high temperatures. A lower compressive permanent deformation value indicates better elastic recovery and long-term performance, which is critical for applications such as:

• Seating and upholstery foams
• Sealing tapes and gaskets
• Acoustic and thermal insulation
• Packaging and cushioning materials
• Automotive interior components

This test method evaluates a material's resistance to permanent deformation (shape change) when used under compressed conditions over time.

The basic test principles of this standard are as follows:

• Compression levels: Typically 20%, 25%, 50%, or other specified percentages of the original thickness.
• Duration: Typically 22 hours, 24 hours, 48 ​​hours, 72 hours, or 100 hours.
• Temperatures: Room temperature (23 degrees) or high temperature (e.g., 70 degrees).
• Recovery time: Typically measured 30 minutes (half an hour) after decompression.
• Calculation: Calculated according to the formula given in the standard.

Values ​​typically range from a maximum of 5 percent (excellent recovery) to 10-30 percent or higher, depending on the foam type and conditions.

This method involves compressing standardized test specimens between parallel plates to a constant tension, holding them for a specified time and temperature, releasing the compression, allowing for recovery, and measuring the remaining thickness difference.

Today, the DIN 53572 standard has been replaced by the “DIN EN ISO 1856 Flexible cellular polymeric materials - Determination of permanent compression deformation” standard. However, in technical data sheets for foams (e.g., polyethylene, PVC, or recycled rubber foams), one frequently encounters expressions such as “Permanent compression deformation - DIN 53572 standard” specifying particular test conditions. This helps engineers and buyers compare flexibility and durability.

In short, DIN 53572 is a German industry standard that specifies methods for determining the tear propagation resistance of rubber materials. This property measures how well a rubber sample resists the growth of an existing cut or crack under mechanical stress. It is particularly critical in applications where rubber components are subjected to repeated loading, deformation, or harsh environments.

The primary aim of the DIN 53572 standard is to provide a uniform and repeatable method for evaluating tear resistance. Unlike simple tensile tests, this standard focuses on how cracks form and propagate, providing a more realistic representation of real-world failure modes.

The described test method generally includes the following:

• To prepare a rubber sample with a predefined notch or cut.
• Applying tensile force using a testing machine.
• Measuring the force required to spread the tear.

Tear resistance is calculated based on the maximum force applied and the sample thickness.

The DIN 53572 standard typically defines different sample shapes, which include:

• Samples in the form of trousers
• Angular test pieces
• Notched Graves type specimens

Each sample type is designed to simulate different stress distributions and crack propagation behaviors.

To ensure consistency, the standard specifies the following:

• Test speed (e.g., constant crosshead speed)
• Temperature conditions (typically standard laboratory climate)
• Sample preparation guidelines
• Conditioning period before the test

The DIN 53572 standard is widely used in the following sectors:

• Automotive (sealing elements, gaskets, tires)
• Aviation (flexible components)
• Construction (membranes, insulation materials)
• Consumer goods (footwear, rubber products)

The DIN 53572 standard is considered important for the following reasons:

• It predicts real-world failures: Rubber materials often fail due to crack growth rather than simple fracture. This test helps simulate these conditions.
• Quality control: Manufacturers use this to ensure consistent material performance across production batches.
• Material comparison: Allows engineers to compare different rubber compounds and select the most suitable one.
• Safety and reliability: High tear resistance is crucial for components subjected to dynamic stress, increasing product lifespan and safety.

The main advantages of this standard are:

• Realistic simulation of crack propagation.
• Applicable to a wide range of rubber materials.
• Standardized and widely accepted

However, this standard has some limitations:

• Results may vary depending on the sample type.
• It is sensitive to test conditions and sample preparation.
• It is not a complete indicator of overall mechanical strength.

In conclusion, the DIN 53572 standard plays a crucial role in evaluating the durability and reliability of rubber materials by focusing on tear propagation behavior. It complements other mechanical tests and is indispensable for industries where material failure due to tearing can lead to significant safety or performance issues.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services in accordance with the DIN 53572 standard.