What is a penetrometer and why is the dynamic water resistance test important for leather materials?

What is a Penetrometer? Dynamic Water Resistance Testing in Leather Materials

A penetrometer is a precision testing device primarily used to determine the dynamic water permeability characteristics of flexible leather and upper shoe leathers. The device is designed to evaluate whether leather samples allow water to pass through when subjected to specific test conditions over a period of time. In the leather industry, it plays a vital role in quality control processes, directly impacting product durability and customer satisfaction.

Application of the Penetrometer on Leather

Leather products—especially upper shoe leathers—must be water-resistant due to their flexible structure and direct exposure to outdoor elements. The penetrometer test is used to assess the performance of such leathers. Prior to testing, leather specimens are cut to specified dimensions and placed in the penetrometer. The device applies dynamic pressure while exposing the samples to water, simulating real-world conditions.

During the test, the specimen is mounted on a rotating drum that intermittently immerses the leather into water. The time taken for water to penetrate the inner surface and the resistance shown during this period determine the outcome. The test evaluates not only water resistance but also the structural integrity and susceptibility to leakage at seam lines.

Applicable Standards for the Test

Penetrometer tests are carried out in accordance with internationally recognized standards, ensuring that results are reliable, repeatable, and comparable across laboratories.

TS EN ISO 5403-1 / EN ISO 5403-1

This standard defines the dynamic water resistance test method for leather. The sample is subjected to movement while in contact with water, and water absorption and penetration time are measured. This standard is published by ISO (International Organization for Standardization) and is adopted as EN in Europe and TS in Turkey.

TS EN ISO 20344 / ISO 20344

This broader standard outlines the testing methods for various components of footwear such as soles and uppers. The penetrometer test here specifically evaluates water resistance in upper leather components.

Importance of Penetrometer Testing for Leather

For leather manufacturers, penetrometer testing is a critical step in enhancing product quality and minimizing customer complaints. High water permeability leads to early product degradation. Especially in outdoor footwear and premium leather goods, this test determines whether the product can perform under real-life conditions. For exporters, it is often a requirement to meet international quality standards.

Device Specifications and Testing Process

A typical penetrometer includes a specimen mounting section, water reservoir, and rotating drum system. It operates by exposing the leather sample to moving water under fixed pressure and temperature. The standard test duration is 60 minutes, during which water penetration is recorded. Advanced models provide digital reports upon test completion.

Test conditions:

• Water temperature: 20 ± 2 °C

• Test duration: 60 minutes

• Sample size: 80 mm x 80 mm (may vary by standard)

Applications in the Leather Industry

Penetrometer testing is commonly applied to the following leather products:

• Upper shoe leathers

• Boot and high-shaft footwear leather

• Outerwear leather garments (jackets, coats)

• Leather bags and outdoor accessories

With this test, manufacturers can objectively assess their product’s fitness for real-life use scenarios.

Frequently Asked Questions (FAQ)

1. How does the penetrometer test evaluate leather quality?
It measures the water resistance of leather, revealing its durability under wet conditions.

2. Why is the TS EN ISO 5403-1 standard important?
It ensures globally accepted and consistent test procedures for leather water resistance.

3. What types of leather are suitable for this test?
Flexible, upper, and both natural and synthetic leathers used in footwear are suitable.

4. Is penetrometer testing mandatory?
While not always mandatory, it is widely used for quality assurance and product certification.

5. Under what conditions is water permeability tested in leather?
Under 20 ± 2 °C water temperature, fixed pressure, and dynamic immersion conditions.