Experimental Study On Water-based Colorant Formulation And Gravure Process

This project mainly researched on the formulation of the water-based colorants for cigarette paper produced.Most of the water-based colorants used by most companies before were purchased from manufacturers.These purchased universal water-based colorants are not only expensive but also occasionally incompatible with paint.Hence the prepared coating cannot be adapted for high speed packaging machine.Therefore,this thesis has optimized the water-based colorant formulation to improve its packaging adaptability.At the same time,in order to increase the production efficiency and reduce the production cost,this work has explored the studied gravure process of the optimized colorant on the new gravure machine.In the screening process of the pigment,the parameters such as the leveling property of the pigment,the curing characteristics,and the anti-scaling rate of the coating film were mainly compared.In the selection of fillers,the effect of the type of filler on the viscosity of the entire system was examined by adding same amount of filler.In the selection of wetting and dispersing agent,a demand curve method was used.The density method and defoaming durability testing were adoptedd in the selection of defoamers.For the selection of bactericidal and fungicidal agents,a simple bactericidal effect experiment was designed.The determination of the optimum formulation of the coating:Firstly,a large number of pigments,additives for the initial screening were selected based on the actual needs of production;Secondly,The selected pigments,additives were secondarily screened through the experiment;Finally,the optimum concentration of the pigment was determined according to the relationship between the concentration and the viscosity in the pigment by stoke formula.And the pigment base formula is employedd to design the formulation of the coating.This thesis has also improved the gravure printing process by adjusting the parameters of the new machine:Firstly,the single-factor control variable controlling approach was used to narrow the process parameters;After obtaining a relatively better range of process parameters,the orthogonal experiment method was adapted to establish L_25?5?6Type of orthogonal table;Additionally,through the orthogonal table,25 sets of experimental samples were obtained,and each set of samples was tested;Finally according to former results,the optimal process parameters were determined based on analysis performed by SPSS software.The results of the experiments showed that:for pigments,iron oxide yellow,CI Pigment Red 254,and carbon black were superior to other alternative pigments;fumed silica and natural calcium carbonate mixed at ratio of 3:2 was selected as filler;Defoamer 122 was used as the defoamer in this research;BIOCIDE D7 was chosen as the bactericide;the maximum concentration of yellow pigment,red pigment,dark red pigment,and black pigment were 51%,21%,31%,and 34%,respectively.On the basis of above determined parameters,a specific formulation of four color water-based colorants would be obtained.According to the ratio of the pigment to the base,the four coating formulations were determined.The products printed by the colorants and paint in this thesis could meet the production standards.In the aspect of gravure,a range of process parameters has been obtained by the single factor control variable method:Printing pressure is 0.2-0.35MPa;Scraping blade Angle is 45°⁵5°;The drying temperature is of 95¹05?;Printing speed is90¹10m/min;Net hole depth is 40⁴5um.The test results obtained by further orthogonal tests showed that the optimum parameters for the new machine are as follows:the printing pressure is 0.31MPa,the Angle of the scraping knife is 51°,the drying temperature is 97?,the printing speed is 105 m/min,and the hole depth is 42um.</sub>