Study On Technology Of Measuring Water Vapor Permeability Of Film Encapsulation Material By Weighing Method

With the development of flexible film packaging technology in various fields,the research of film barrier is becoming more and more important for industry related industries.Weighing measurement has many advantages such as easy realization,mature technology,good repeatability and multi-parameter measurement.However,the traditional weighing method has disadvantages such as low measurement sensitivity multiple kinds of gases,so it needs to be further optimized specifically.In this paper,while optimizing the traditional weighing method,the penetration behavior of water in the film was studied by using the weighing method.On the one hand,the barrier performance of the barrier film was evaluated,and on the other hand,the basis was provided for the design of the barrier film with higher performance.The main work included the following aspects:(1)The weighing method penetration measuring device was designed and built,and the measurement methods of weighing method adsorption and weighing method penetration were studied and compared.Weighing method was used to measure the permeation behavior of water in the film under different temperature,humidity and thickness.The influence of different conditions on Water Vapor Transmission Rate(WVTR),diffusion coefficient,solubility and other parameters of the film was studied.The permeation mechanism of water molecules in the films was further analyzed by measuring the kinetic parameters of diffusion activation energy and dissolution heat of the films.(2)Using Quartz Crystal Microbalance(QCM),the traditional weighing method is optimized to achieve the accuracy range of nano level and improve the measurement sensitivity of weighing method;The permeation behavior of water molecules in monolayer and laminated films was measured,and the coupling relationship between water flux in laminated films and water flux in monolayer was studied.In addition,infrared spectroscopy was used to measure the permeation behavior of water in the film to further analyze and understand the permeation process of water molecules in the film.