A multilayer composite film and its application in packaging with braille

Abstract

The application discloses a multilayer composite film and application thereof in packaging with Braille, and relates to the field of high polymer composite materials and special packaging technology. The composite film comprises at least a surface layer, a core support layer and a bottom layer, wherein the core support layer comprises the following components in parts by mass: 55-75 parts of polyvinyl chloride resin, 15-25 parts of plasticizer, 1.5-4 parts of heat stabilizer, 0.5-2 parts of lubricant and 5-15 parts of structure modified sepiolite fiber; the structure modified sepiolite fiber is an oleophilic fiber which is subjected to acid microchannel reaming and surface modification by ultrasonic in-situ intercalation of pyrophosphate type titanate coupling agent. The composite film forms a compact interface transition layer through uniform dispersion of the modified fiber in the matrix, effectively dissipates forming stress and internally interweaves to form a rigid microskeleton network, can significantly inhibit the creep collapse under continuous pressure and prevent the generation of microcracks at the edges of convex points during stamping, and makes the packaging film have excellent Braille pressure-resistant shape-retaining effect and good toughness.