| In our country,the production history of the decorative base paper is only 40 years,and it is still a new type of paper.As people are increasingly diversified in the decoration style,it is necessary to improve the properties of the decorative base paper to meet the requirements of post-processing.The decorative base paper has strict requirements for brightness and other optical properties,and the price of titanium dioxide is expensive.So it is very important to find a kind of filler which is close to titanium dioxide in properties and replace titanium dioxide.In this paper,it was studied the effects of the quality ratio of softwood pulp and hardwood pulp,beating degree,the dosage of PAE,the content of titanium dioxide and the dosage of CPAM on the physical properties of decorative base paper.Titanium dioxide/titanium dioxide composite fillers were prepared by mechanochemical method.Also,the effects of different drying methods and different types of fillers on the physical properties of decorative base paper were studied.It was studied the making process of the decorative base paper.The results showed that the quality ratio between softwood pulp and hardwood pulp was 6:4;the mixed beating degree of softwood pulp and hardwood pulp was 33°SR;the dosage of additive of PAE was 2%;the dosage of additives of titanium dioxide and CPAM were 30%and 0.06%respectively.Under these conditions,the requirements of the decorative base paper for strength,air permeability,absorbability and optical properties can be met.Four factors such as the dosage of dispersant,the quality ratio of titanium dioxide and kaolin,the reaction time and the grinding concentration were selected for the preparation of the composite filler of titanium dioxide/kaolin.The suitable composite conditions were obtained by orthogonal experiment.We could obtain that the optimum technical conditions:the dosage of dispersant was 0.3%,m(titanium dioxide):m(kaolin)was 5:5,the grinding time was 0.5h and the grinding concentration was 45%.Under these conditions,the composite product had good performance;the brightness and hiding power were 92.5%ISO and 30.33g/m2 respectively.The composite fillers were evaluated by SEM,FTIR and XRD.SEM can be used to visualized intuitively the combination of titanium dioxide and kaolin.According to FTIR and XRD,it showed that the cladding of kaolin with titanium dioxide was not a simple physical reaction,but a chemical reaction.The Si-O-Ti and Al-O-Ti chemical bonds were formed between titanium dioxide and kaolin.So the composite filler’s crystal structure changed,and the cladding effect was great.Besides,titanium dioxide/kaolin composite filler and the mixed filler were added in the decorative base paper;The effects of press+ vacuum drying,vacuum drying,press + flat drying and flat drying on the properties of decorative base paper were compared.Among them,the first three drying methods were more favorable for the strength of the decorative base paper,but the air permeability and absorbency obtained by press+ vacuum drying were little worse than those of vacuum drying.The vacuum drying and press+ flat drying were not very effective,but the press technology will increase the cost.The strength of the decorative base paper was poor;its air permeability and absorbency were good;it could not meet the needs of production,when using flat drying.The four drying methods little affected the optical properties of the decorative base paper,and they could not become a standard to distinguish the optical properties of the decorative base paper.Therefore,the effect of vacuum drying and press+ flat drying was more suitable.Kaolin,titanium dioxide,titanium dioxide/kaolin composite filler and the mixed filler were added to the paper,but there was small difference on the brightness and opacity.It was good that the properties of the strength,air permeability and capillary imbibition height of the decorative base paper,and they are close to titanium dioxide. |
