THE RESEARCH ON DYEING PERFORMANCE OF MELIORATED PULP WITH CHITOSAN FOR PRODUCING COLOR MOLDED PULP PRODUCTS PACKAGING FOOD

摘要

The color Molded pulp products packaging food which are favourable to protect the environment are generally acceptable, but the color fastness and the security are burning questions. In order to assure the security, we selected artificial food colorant to dyeing, and meliorated bleached pulp with chitosan to endue it with dyeing possibility. In this paper, effects of different molecular weight and deacetylation degree, the amount of chitosan, modified time, modified temperature, pH on dyeing property of pulp. The results showed that after meliorated with chitosan, the dye uptake to food colorant including tartrazine, erythrosine, etc. will heighten from below 1% to above 80%. The desirable meliorating condition is that the dosage of chitosan is 7% (to dry pulp quality), the temperature is 20 and the time is °C 5 min. The dye uptake to tartrazine, erythrosine and brilliant blue will exceed 80%, the fade rate will below 3.5%, and average chromatism will be less than 1.5. The suitable dosage of colorant is 0.6%(compared with even dry pulp quality), and the pH of dye bath is 3.5. Dyed color pulp can be used for color pulp mold production and sale food packaging.