Water Barrier Property Test Methods for Rubber Materials

Rubber's elasticity and ability to recover from deformation make it ideal for sealing and protecting various products. However, its water barrier property, which refers to its resistance to water vapor and liquid water permeation, is crucial for its effectiveness. This report examines the test methods used to evaluate this property.

There's no single standardized test method specifically designed for water barrier property of rubber materials. Consequently, relevant methods from other materials, such as plastics, are adapted.

Desiccant method (GB/T 1037) measures the amount of water vapor permeating through a rubber sample under specific temperature, humidity, and pressure differentials. A desiccant is used to capture the permeated vapor, and the weight change is measured to calculate the Water Vapor Transmission Rate (WVTR). While relatively simple, achieving a good seal with wax and maintaining a constant high humidity can be challenging.

The ASTM E96 (Desiccant and Water Methods) standard offers two methods: desiccant and water method. The water method uses liquid water on one side of the sample to create a high humidity environment. The WVTR is calculated based on the weight change of the test dish. Notably, the two methods yield different results and should be chosen based on the application's specific environment.

 

Labthink C360H Water Vapor Transmission Rate Test System, is designed and manufactured based on the gravimetric determination method and conforms to the requirements of ASTM E96. This instrument can be used to measure the water vapor transmission rate of barrier materials with high moisture barrier properties. C360H is applicable to determination of water vapor permeability of plastic films, sheeting, paper, packages and other packaging materials in food, pharmaceutical, medical apparatus, building materials and consumer goods, etc.

Hydrostatic Pressure method (ISO 1420) focuses on liquid water barrier property. It utilizes a pressurized container to assess the sample's ability to withstand water leakage under pressure. The test determines if the material leaks or the maximum pressure it can endure before leakage.

Water barrier property testing helps ensure rubber materials meet the required specifications for sealing applications. By comparing the WVTR or hydrostatic pressure results of different rubber types, manufacturers can select the most suitable material for a specific application's moisture sensitivity. Test results can guide the development and improvement of rubber compounds with enhanced water barrier properties.

While there's no single standardized test method for water barrier property of rubber materials, adapting methods from other materials like plastics offers valuable insights. Selecting the appropriate test method (desiccant, water, or hydrostatic pressure) depends on the intended use of the rubber and the type of water barrier property being evaluated (vapor or liquid). These tests play a vital role in quality control, material selection, and product performance improvement for rubber sealing and protection applications.

As the demand for functional packaging materials grows, testing methods are evolving to ensure a more comprehensive evaluation of packaging films. Labthink encourages collaboration with packaging industry companies for quality control! Visit the website www.labthink.com to learn more!