Water Vapor Transmission Rate | A Key Factor in Packaging Performance

Water Vapor Transmission Rate (WVTR) is a crucial measure in packaging, especially for moisture-sensitive products. It quantifies the rate at which water vapor permeates a material, with lower WVTR values indicating superior moisture barrier properties. WVTR is vital for maintaining product quality, as moisture can degrade texture, taste, efficacy, and shelf life in items like pharmaceuticals, electronics, and food. Furthermore, high WVTR can compromise packaging integrity, leading to leaks, spoilage, and damage. Effectively controlling moisture through appropriate WVTR levels minimizes waste and safeguards valuable goods throughout the supply chain.

Several factors influence WVTR, including the type of material used, its thickness, and the surrounding temperature and humidity. For instance, OPP films are known for their excellent WVTR. Thicker materials generally offer better barrier properties, while higher temperatures and humidity accelerate moisture transmission. Even the manufacturing and conversion processes can impact a material's WVTR.

Understanding and controlling WVTR is essential across diverse industries. In the food sector, it preserves freshness and prevents spoilage. For pharmaceuticals, it safeguards drug stability and efficacy. Electronics manufacturers rely on low WVTR packaging to protect sensitive components from moisture damage. Even the construction industry utilizes WVTR principles to ensure building materials remain dry and perform as intended.

To measure and control WVTR, standardized tests are employed under controlled conditions. Packaging engineers meticulously select materials and optimize designs to achieve the required WVTR for specific applications. Looking ahead, innovations in materials science, such as new polymers, coatings, and laminates, promise even better moisture barrier properties.

Watch this video for a visual representation of the process :