涂膜工艺和硅橡胶气调窗膜性能关系的研究

STUDY ON THE CORRELATION BETWEEN MEMBRANE-FORMING TECHNIQUE AND PROPERTIES OF SILICONE RUBBER MEMBRANE FOR CONTROLLED ATMOSPHERE STORAGE OF FRUITS AND VEGETABLES

以棉布为底材,采用热熟化加成型硅橡胶涂覆工艺,批量生产了水果蔬菜保鲜用气调窗膜。其胶浆配方(质量份)为:甲基乙烯基硅橡胶100,甲基(氢)聚硅氧烷4.0,烃类溶剂200,硫化催化剂SAC-1 铂络合物0.015。SAC-1 铂络合物能使胶浆的室温适用期大于 10h,在 130℃×80 s的条件下硫化,能满足连续化生产的要求。膜透气量由上胶量控制。在适当的浓度和刀距下,胶浆涂覆三次,膜总上胶量为 55—60 g/m^2。该膜对 CO_2 的透过量为 0.82—1.07 mL/(m^2·h·Pa),透比(Q_(CO_2)/Q_(O_2))≥4。

Membrane for controlled atmosphere storage of fruits and vegetables was commercially made by coating silicone rubber onto matrix of cotton textile. The composition of polysiloxane coating latex was as follows ( mass ratio ) : polymethyl-vinylsiloxane 100, polymethyl-H-siloxane 4.0, hydrocarbons solvent 200, SAC-1 ( Pt-complex catalyst ) 0.015. SAC-1 for crosslinking was of excellent properties and could meet the requirements for continuous production of membrane.The latex could be kept at room temprature for 10 h without apparent crosslinking and cured rapidly to form membrane at 130℃ within 80 s.The gas permeability of membrane formed was mainly dependent on the weight of silicone rubber coated on unit area of textile substrate. The CO2 permeation of the membrane was 0.82-1.07 mL/ ( m2 ?h ?Pa ) and permeation ratio ( Qco2/Qo2 )≥4 when the weight of silicon rubber coated was 55-60 g/m2,which was controlled by coating with latex of proper concentration for three times and using proper distances between coating blades.