Engineering Properties of Commercially Available Hermetic Storage Bag Liners

Abstract

Highlights Fundamental engineering properties of hermetic bag liners were identified and measured to establish specifications for a new ASABE X657 standard for measurement and rating the performance of gas barrier liners in hermetic storage bags. Results showed strong evidence of differences in properties among six types of commercially available hermetic bag gas barrier liners (P<0.05). Critical gas barrier properties (OTR and WVTR) were measured to assess their ability to maintain initial conditions (“hermeticity”). Critical mechanical properties, such as impact failure weight, penetration resistance, and tear strength, were measured to determine their durability during handling and storage. Abstract. The impacts of hermetic storage bag technology on food security are well established. However, understanding the hermetic bag liner's mechanical and barrier properties with its useful life and efficacy are needed to ensure the continued successful adoption of this critically important storage technology to control biological activity. The goals of this study were to identify and quantify fundamental engineering properties as a basis for establishing an American Society of Agricultural and Biological Engineers (ASABE) engineering standard for testing and rating the hermeticity of gas barrier liners in storage bags for smallholder farmers. Six commercially available hermetic storage bag liners (AgroZ, Elite, PICS, GrainPro, Storezo, Zerofly) were evaluated for mechanical properties (tensile, impact, tear, penetration resistance) and barrier properties (oxygen transmission rate and water-vapor transmission rate) following American Society for Testing and Materials (ASTM) test methods. Results indicate significant differences (P< 0.05) in material properties among brands of storage bag liners. Values for oxygen and water vapor transmission rates were determined to ensure hermetic conditions can be achieved. Values for mechanical properties (yield and tensile strength, elongation, and toughness, tear strength, penetration resistance and impact failure weight) of gas barrier liners were quantified to ensure acceptable performance of hermetic storage bags. Keywords: Elongation, Hermetic storage, Hermetic storage bags, Impact failure weight, Oxygen Transmission Rates (OTR), Penetration resistance, Tear strength, Tensile strength, Toughness, Water Vapor Transmission Rate (WVTR), Yield strength.