Study On Properties And Processing Of Starch-Fiber Sheet For Degradable Packaging

This paper studies a kind of packaging material for lower hydrous merchandise. The packaging material is composed of starch and vegetable fiber mainly, and added by degradable resin, plasticizer, crosslinking agent and inorganic filler. It is molded by compression molding and the abandoned material could be biodegraded in the environment in short period. By this way we explore the solution of environmental pollution brought out by the abandoned packages.Study the result enunciation, tensile strength and stiffness of the starch-fiber sheet increases gradually with the increase of starch content. When the content arrives at 40 percent, the stiffness of the sheet increases continuously, but the tensile strength of the sheet decreases. Varieties of starch and the rate of starch gelatinization also have direct effects on mechanical properties of the sheet. The tensile strength of the sheet increases remarkably with the increase of fiber content, but changes little beyond 15 phr. The mixing uniformity of the raw materials gets worse with higher content of fiber, which influences mechanical properties and external appearance of the sheet. Varieties of fiber affect the mechanical properties of the sheet obviously. The mixing uniformity of the raw materials gets worse with decrease of the poly(vinyl alcohol) content. The mixture of raw materials is softer with higher content of poly(vinyl alcohol), which has negative effects on mechanical properties of the sheet. The tensile strength of the sheet increases gradually with the increase of the poly(vinyl alcohol) content, but decreases slowly beyond 15 phr. Glycol and glycerol are better plasticizers of the sheet. The tensile strength of the sheet increases gradually with the increase of glycerol content, and stiffness of the sheet decrease gradually. As crosslinking agent of the sheet, salts of calcium and zirconium could improve waterproof property in a certain extent. From 0 to 2 phr of the calcium salt, waterproofness improves obviously, but no change beyond 2 phr. Stiffness of the sheet increases by added inorganic filler, and costs of production reduced. But the addition affects tensile strength and extension at break of the sheet obviously. The rate of weight lose of the sheet arrives beyond 90 percent after two months, so the sheet has excellent biodegradability.Compared with current packaging materials, the processing of this starch-fiber sheet is simple and the raw materials are abundant and cheap. The sheet has good mechanical properties, innocuity, waterproofness, degradability, and shows wide application prospects in packaging field.