I. What Is the Schober Abrasion Tester?

The Schober abrasion tester, also known as a rotary abrasion tester, is a testing device specifically designed to evaluate the abrasion resistance of flexible materials such as textiles, automotive interior materials, and leather. This instrument simulates the wear and tear a material experiences during actual use through rotational friction, thereby assessing its durability.

Compared to the Martindale abrasion tester, the Schober abrasion tester uses larger test specimens (approximately 100 mm in diameter, with a test area of about 50 cm²) and silicon carbide sandpaper as the abrasive. This results in more concentrated friction stress and higher testing efficiency, making it particularly suitable for testing materials with stringent abrasion resistance requirements, such as automotive interior materials.

II. Operating Principle

The core operating principle of the Schopper Abrasion Tester is based on rotational tangential friction. During the test, a circular specimen is mounted on a rotating test head and secured using an obtuse-angle conical fixture. The specimen rotates at a set speed (typically 75 revolutions per minute) while maintaining linear contact with the abrasive material (silicon carbide sandpaper) located below it, generating friction in the tangential direction.

A key design feature is that after every 100 friction rotations, the instrument automatically stops and prompts the operator to reverse the rotation direction (alternating between clockwise and counterclockwise). This design ensures a more uniform wear distribution across the specimen’s surface, prevents localized excessive wear caused by unidirectional friction, and makes the test results more representative.

When mounted, the test specimen is given a certain degree of camber (typically 58 mm). This curvature creates a slight oscillating effect during rotation, ensuring that every point within the test area of approximately 50 cm² is subjected to uniform, periodic friction.

III. Applicable Standards and Fields of Application

The test method of the Schopper Abrasion Tester has been adopted by numerous international and industry standards, primarily including:

Core Standard: DIN 53863 Part 2, “Testing the Abrasion Resistance of Textile Surfaces (Rotary Abrasion Test),” serves as the foundational standard for this method. Additionally, GME Standard 60345, GMW Standard 3283, and the Volkswagen/Audi PV 3908 standard also widely adopt this testing method.

Main Application Areas:

- Automotive interior materials: Seat fabrics, headliner fabrics, door panel coverings, etc. These materials must withstand prolonged friction and wear, making the Schober Abrasion Tester a core piece of equipment for quality control at automotive OEMs.

- Apparel fabrics: Particularly workwear and outdoor clothing that require high abrasion resistance.

- Footwear materials and leather: Evaluation of the abrasion resistance of sole materials and leather goods.

- Industrial textiles: Durability testing of conveyor belts, filter materials, and similar products.

IV. Detailed Experimental Procedure

1. Sample Preparation

First, cut a circular sample with a diameter of approximately 100 mm from the specimen to be tested. The sample must undergo standard temperature and humidity conditioning (typically acclimation for at least 4 hours in an environment with a temperature of 21±1°C and a relative humidity of 65±2%) to eliminate the interference of environmental factors on the test results.

2. Sample Installation

Use the dedicated fixture provided with the instrument to mount the sample onto the rotating test head. During installation, note the following: Adjust the sample’s protrusion height using the camber measurement device, generally maintaining it within 58 mm. The camber setting directly affects the contact between the sample and the abrasive and is a key parameter for ensuring test consistency.

3. Installing the Abrasive

Securely attach silicon carbide sandpaper (commonly 280# or 400# grit) to the underside of the pressure plate using the friction material clamp, ensuring it lies flat. As the sandpaper is a single-use consumable, ensure it is installed flat and free of wrinkles. Replace it with a new sheet after each test to maintain consistent abrasive conditions.

4. Setting the Load Pressure

Select the appropriate load weight based on the specimen’s weight per unit area. Generally, the following principles apply: apply 1.0 N for specimen weights ≤ 100 g/m²; 2.0 N for 100–150 g/m²; 5.0 N for 150–300 g/m²; and 10.0 N for weights exceeding 300 g/m². The instrument’s standard weight set includes 50 g, 100 g, 250 g, 500 g, 1000 g, and 1500 g weights, enabling a pressure adjustment range from 0.5 N to 25 N.

5. Starting the Test

Set the total number of rotations and the number of rotations in a single direction via the touchscreen interface, select either manual or automatic mode, and then start the instrument. During the test, the instrument automatically records the number of rotations, pauses automatically every 100 rotations, and prompts the user to reverse direction.

6. Result Evaluation

After the test is complete, remove the test specimen for result evaluation. The Schober abrasion test typically employs the following evaluation methods:

- Mass Loss Method: Weigh the specimen before and after the test, then calculate the mass loss rate; this is the most objective quantitative indicator.

- Hole Formation Method: Record the number of rotations at which holes appear in the specimen to evaluate its ultimate abrasion resistance.

- Visual Inspection Method: Evaluate the specimen’s surface for fuzzing, pilling, and changes in gloss through visual inspection or instrument analysis.

V. Comparison of the Schober Method and the Martindale Method

In the field of textile abrasion testing, the Schober method and the Martindale method are the two most commonly used methods, each with its own specific applications:

The Schober method offers the advantages of concentrated friction stress and high testing efficiency; large test specimens (50 cm² test area) can reach the failure point more quickly. It uses mass loss as the primary evaluation metric, providing objective and quantifiable results; The standard system is centered on German DIN standards and automotive industry specifications, giving it an irreplaceable status in the automotive interior sector.

The Martindale method, on the other hand, is the more universally accepted “gold standard” internationally. It is suitable for the apparel and home textiles sectors, and the testing process more closely mimics the multidimensional friction conditions encountered in actual use.

The two methods are not simply interchangeable but rather specialized tools designed for different application scenarios. For automotive interior and industrial material testing, the Schober method is preferred due to its efficiency and objectivity; whereas for apparel and home textiles, the Martindale method offers advantages in terms of international applicability and realism.

VI. Conclusion

With its unique rotating tangential friction principle, high testing efficiency, and objective quantitative evaluation method, the Schober abrasion tester plays an irreplaceable role in abrasion resistance testing for automotive interiors, industrial textiles, and other fields.

For textile testing laboratories and manufacturing enterprises, gaining a deep understanding of the Schober abrasion tester’s experimental principles and operational key points, and establishing standardized testing procedures, is the foundation for ensuring product quality and meeting customer requirements.

If you have any questions about the Schober Abrasion Tester or textile abrasion testing, please feel free to contact the UTSTESTER technical team; we will provide you with professional testing solutions.

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