Study On Coating Process And Mechanism Of Calcium Carbonate/Polymer Resin Blend Printing Material

With the development of social economy and the increasing awareness of environment and resources,China paper industry has to face the problem of environmental pollution and resources deficiency.Calcium carbonate/polymer resin blend printing material is a new non fibrous material,which can be manufacutured by cleaning process that cannot pollute environment.However,the rough surface and the porous structure of calcium carbonate/polymer resin blend printing material results in low smoothness and low pick resistance.Additionally,the uneven oil absorbency and illegible writing put the materials at the poor application status that they can not satisfy the printing demand.Therefore the objective of this work focus on how to improve the properties,including smoothness,pick resistance,oil absorbency.The pigment types and ratio were selected based on the consideration of optimal properties of the printing material.Diatomaceous silica and synthetic plastic pigment was used as the pigment on account of its low density and higher surface properties.Furthermore,the printing material has optimum properties while the ratio of diatomaceous silica and synthetic plastic pigment was set at 70:30.Since the surface properties are principally depended on the adhesive which are applied,the effects of adhesive types,content and ratio on the surface properties of printing material were studied,the results showed that the printing material has the optimum properties when the adhesive content and the ratio(polyvinyl alcohol,polyvinyl acetate and XSBRL)was 40%and 5:1:4 respectively.The SEM and FTIR results indicated that the surface strength was probably improved by the means of bonding between coating and printing material.The coatings penerate into the printing material and then form a stable wedge structure which can enhance the pick resistance.Besides,the chemical reaction between XSBRL and calcium carbonate/polymer resin blend printing material would also enhance the pick resistance.Additionally,the influence of water proofing agent content and lubricant content on the surface properties of printing material were studied based on the selected process,the results show that the opitimum properties occured when the water proofing agent content was set at 0.4%and lubricant content was set at 1.5%.While the coating amount and process would essentially impact the end properties of the printing materials,the effect of coating addition,dring temperature and time on the surface properties of printing material were studied.The results showed that higher coating level would result in smoother coating layer and higher surface strength.Moreover,the dring temperature would significantly affect the wetting performace of the printing materials,that is to say,raising temperature would decrease the contact angle and oil absorbency.In the all,dring temperature 100℃ and coating number 2 was selected as the optimum process based on the consideration of surface properties of the printing materials.