Outgassing Characteristics and Diffusion Model Fitting of Vacuum Insulation Panels at Different Temperatures

The thermal insulation performance of vacuum insulation panels (VIPs) relies on the high vacuum environment inside them, which is primarily composed of a core material, barrier film, getter, and desiccant. In practical applications, the outgassing behavior of the core material and barrier film can lead to a decline in vacuum level, thereby affecting their long-term stability. Temperature is a key factor influencing the outgassing characteristics of materials. In this study, the outgassing behavior of VIPs at different temperatures （−15°C to 70°C） was experimentally tested. The gas composition was analyzed using mass spectrometry, and the outgassing rate was calculated. Based on a composite material diffusion outgassing model, experimental data were fitted to establish a mathematical expression for the relationship between the outgassing rate of VIPs and time. The experimental results demonstrate that a rise in temperature can remarkably accelerate the outgassing process, whereas temperature exerts a negligible influence on the composition of gases released from the VIPs. Water vapor （H₂O） and nitrogen （N₂） are the main gases released. At low temperatures, the outgassing rate is lower, but slow release still occurs over time. The results offer a theoretical foundation for the optimization of desiccants in vacuum insulation panels (VIPs) and the prediction of their service life, while also providing guidance for their application in diverse temperature environments.