Dyeing Of Natural Food Packaging-material And Research Of Its Additives Migrant Behavior

The dyeing methods of various colored paper packaging production are commonlyadsorptive dyeing, which are relatively simple. The usual synthetic dye, including direct dye,reactive dye etc., often produce a large amount of residual dye in dyeing wastes because oflow dyeing rate. The dyeing wastes contain multiple persistent organic substances that willpose a threat to water quality. Moreover, lots of neutral electrolyte like salts which are addedto raise the dye rate, will increase the wastewater’s COD value when discharging with the dyewastes. That would cause great contamination of enviroment.This paper has done a fairly meticulous research on the dyeing of natural food packagingmaterials. The migration behavior of materials safety is studied as well. There are three parts:the study of pulp dyeing properties by using food colorant, preliminary study of the pulpdyeing craft industrialization and the migrant behavior study of additives to food in coloredpulp products.Aspects of chitosan to pulp fiber modification properities: the chitosan （viscosity is475mPa·s,deacetylation degree is85.6%） is choosen for the modifying agent. The preferredcrocess condition of chitosan modifying pulp fiber（wood and reed pulp） is attained byorthogonal experiments: chitosan dosage3%owf, modifying bath pH value5.5, modifyingtemperature20℃and modifying time3min. In this condition, repeatibilty dyeing rate oflemon yellow to wood pulp fiber is92.66%, fade rate is3.71%, repeatibilty dyeing rate oflemon yellow to reed pulp fiber is92.23%, fade rate is4.54%.Dyeing properities of food colorant to modified fiber: regression equation of dyeing oflemon yellow to reed pulp is attained by response surface method:Y=4.54333+0.17000X₁+0.07750X₂-0.25500X₃+0.19333X₁X₁+0.14833X₂X₂+0.25833X₃X₃+0.14000X₁X3+0.07500X₂X₃In the equation, R²=94.83%, Y is fade rate%, X1is dye dosage, owf%、X₂is dyeing bath pHvalue、X₃is dyeing time, min. The optimum condition is: dye dosage0.54owf%, dyeing bathpH value3.83, dyeing time2.1min, dyeing tempreture room tempreture. Under this condition,repeatibilty dyeing rate of lemon yellow to reed pulp fiber is95.24%, fade rate is4.51%.Dyed handsheet has a better color uniformity, the total color difference is less than1.5. Aspects of preliminary study of the pulp dyeing craft industrialization: cyclic utilizitionof modified filter liquor, cyclic utilizition of dyeing residual liquor, waterproof properities ofdyed pulp molded products and color match&dye of edible dye are studied. In addition,reasonable process and parameter are designed on basis of the formor condition.Aspects of migrant behavior study of additives to food in colored pulp products:3simulacrum are choosen:10%ethanol,50%ethanol,95%ethanol,3migrant temperature arechoosen:20℃、40℃、60℃. Under the condition, migrant experiment data is significantly lessthan the largest usage of lemon yellow that can be used in food prescribed by <use andhygienic standard for food additives>. That proves using the materials studied in thisexperiment packaging aquosity foods, acid foods, alcohol foods/fatty foods are quite safe.