The Application of Starch - Sodium Alginate Composite Coating on Transparent Paper for Food Packaging

Fluorocarbons were added into the mixture of modified starch and sodium alginate to get uniform coating solution, and the solution was then coated on the surface of transparent paper. The color as well as grease barrier property of paper at different coating weight were studied. The results showed that color under different coating weights were not significantly different from base paper. The scanning electron microscopy (SEM) diagram showed the surface of paper became smoother and more homogeneous as the coating weight increased. The grease barrier property of coated papers were significantly improved compared with base paper according to Tappi-559 kit test. A highest grease rating number of 12 was obtained when the coating weight became 3.3 g/m2. The dynamic changes in contact angle studies revealed that the contact angle of the base paper was continuously decreased from 29.41 °minutes to 23.46 °within 20, the contact angles of coated papers were significantly increased, and reaching a steady state within 2min with the maximum rate of contact angle change was of merely 0.06 ° / min.