| 摘要 |
<p>PURPOSE:To obtain a packing material which has an excellent retaining function of freshness and which can adjust the water vapour permeability, oxygen permeability, and carbon dioxide permeability in accordance with purposes and prevents merchandise value of fruit and vegetables from decreasing, by using a packing material composed of a vinyl alcohol polymer and starch and provided with a specified weight ratio thereof. CONSTITUTION:A packing material is composed of a vinyl alcohol polymer and starch at a weight ratio of the materials ranging 5:95-90:10. The water vapour permeability, oxygen permeability, and carbon dioxide permeability can be set at an aimed value by the adjustment of the weight ratio of vinyl alcohol polymer and starch within the composition range. When starch exceeds 95wt.%, or vinyl alcohol polymer is short less than 5wt.%, the thermoplasticity of the composite material is lost and the melt molding becomes impossible. On the other hand, when starch is short less than 10wt.% or vinyl alcohol polymer exceeds 90wt.%, the water vapor permeability, oxygen permeability, and carbon dioxide permeability can not set at a target value.</p> |
