The Cushion Packaging Material Imitating The Peel Of Grapefruit

The development of technology has brought growing pressure to the environment, whichcaused the shortage of natural resources and serious energy and climate problems. It’s becomingmore and more important for people to pay attention to the exploitation of new energy sourcesand protection of natural environment, as well as the development of global economy. Cushionpackaging materials used currently are either non-degradable or based on petroleum, which isharmful to the environment or exacerbate the consumption of non-renewable resources. It’s veryessential for the study of new eco-friendly cushion packaging materials to completely replace theconventional ones.Inspired by the good cushion properties of mesocarp of grapefruit, a biomimetic model wasdesigned with the bionics method and design principles of cushion materials. Biodegradablematerials with similar composition were chosen to prepare the packaging materials with goodcushion properties. The results were as followed.1. It was turned out that the mesocarp of grapefruit held a porous structure with sizegradient from outside to inside. In the static compression tests, as the stress-strain curvesshowed, the sample had a very small modulus at the beginning and followed by a relatively largerise, indicating that a large amount of energy was needed to be absorbed during the process.Packaging materials with this property could perform better as cushion to protect the cargoesinside.2. According to the structure and properties of the grapefruit mesocarp, biomimeticstructure model was designed with the bionics method and design principles of cushionmaterials.3. Pulp fibers were used as substrate, carboxymethyl cellulose as adhesives, azobis-methylamide as the blowing agent, a biomimetic cushion packaging material was prepared. Theeffects of adhesive and blowing agent content on the mechanical properties were characterized,as well as the relationship between blowing agent content and the pore size. The results showedthat the optimal content for adhesive was20%. The blowing agent concentration was1%,1.5%or2%. 4. Multilayer of slurries were foamed simultaneously to achieve the grapefruit mesocarp-likefoam packaging materials. The static mechanic performance of materials were tested andanalyzed. The results showed that the bionic cushioning material had a good cushioning effect inthe packaging of small items.5. The stress-strain relations of single-layer cushioning materials with different dosages ofblowing agent were formula fitted and the theoretical stress-strain curves of the multilayercomposites were drawn, holding a high similarity with the actual curves of composites, whichindicated the gas permeation during the preparation process.