High Pressure Laminates(HPL)panels consist of stacks of self-gluing paper sheets soaked with phenol-formaldehyde(PF)resins.An important requirement for such PFs is that they must rapidly penetrate and saturate the pa...High Pressure Laminates(HPL)panels consist of stacks of self-gluing paper sheets soaked with phenol-formaldehyde(PF)resins.An important requirement for such PFs is that they must rapidly penetrate and saturate the paper pores.Partially substituting phenol with bio-based phenolic chemicals like lignin changes the physico-chemical properties of the resin and affects its ability to penetrate the paper.In this study,PF formulations containing different proportions of lignosulfonate and kraft lignin were used to prepare paper-based laminates.The penetration of a Kraft paper sheet was characterized by a recently introduced,new device measuring the conductivity between both sides of the paper sheet after a drop of resin was placed on the surface and allowed to penetrate the sheet.The main target value measured was the time required for a specific resin to completely penetrate the defined paper sample(“penetration time”).This penetration time generally depends on the molecular weight distribution,the flow behavior and the polarity of the resin which in turn are dependent on the manufacturing conditions of the resin.In the present study,the influences of the three process factors:(1)type of lignin material used for substitution,(2)lignin modification by phenolation and(3)degree of phenol substitution on the penetration times of various lignin-phenolic hybrid impregnation resins were studied using a complete twolevel three-factorial experimental design.Thin laminates made with the resins diluted in methanol were mechanically tested in terms of tensile and flexural strains,and their cross-sections were studied by light microscopy.展开更多
Printing quality evaluation is an important means to check whether prints are qualfied.However,the urrent printing quality evaluation system for gravure decorative paper is not perfect.In order to solve this problem,a...Printing quality evaluation is an important means to check whether prints are qualfied.However,the urrent printing quality evaluation system for gravure decorative paper is not perfect.In order to solve this problem,a method for evaluating quality of decorative paper based on analytical hierarchy process(AHP)and the entropy weight method(EWM)model is proposed in this paper.So as to verify the proposed model,decorative paper of different grades was selected as the experimental objects.Firstly,the data about five indices eflecting printing quality were measured.Secondly,the evaluation model was used to assign weights to the indices,and scores in each index were calculated according to scoring tables.Finally,the evalua tion scores were statistically analyzed.The results of data analysis showed that the 95% confidence intervals and coefficients of variation were small.The average error of the evaluation system was 0.2061.It indicates that the model can stably distinguish decorative paper of diferent grades,accuracy of which is high.The research in this paper can provide reference to the quality improvement of decorative paper and the printing quality evaluation of other paper.展开更多
基金This work was carried out within the COMET program funded by the Austrian FFG,project number 844608.
文摘High Pressure Laminates(HPL)panels consist of stacks of self-gluing paper sheets soaked with phenol-formaldehyde(PF)resins.An important requirement for such PFs is that they must rapidly penetrate and saturate the paper pores.Partially substituting phenol with bio-based phenolic chemicals like lignin changes the physico-chemical properties of the resin and affects its ability to penetrate the paper.In this study,PF formulations containing different proportions of lignosulfonate and kraft lignin were used to prepare paper-based laminates.The penetration of a Kraft paper sheet was characterized by a recently introduced,new device measuring the conductivity between both sides of the paper sheet after a drop of resin was placed on the surface and allowed to penetrate the sheet.The main target value measured was the time required for a specific resin to completely penetrate the defined paper sample(“penetration time”).This penetration time generally depends on the molecular weight distribution,the flow behavior and the polarity of the resin which in turn are dependent on the manufacturing conditions of the resin.In the present study,the influences of the three process factors:(1)type of lignin material used for substitution,(2)lignin modification by phenolation and(3)degree of phenol substitution on the penetration times of various lignin-phenolic hybrid impregnation resins were studied using a complete twolevel three-factorial experimental design.Thin laminates made with the resins diluted in methanol were mechanically tested in terms of tensile and flexural strains,and their cross-sections were studied by light microscopy.
基金This work was supported in part by the National Natural Science Foundation of China under Grant 62076199the Opening Foundation of State Key Laboratory of Power System of Tractor under Grant SKT2022004+2 种基金Humanities and Social Sciences Research Planning Project of the Ministry of Education under Grant 17YJC760007in part by Doctoral Scientific Research Foundation of Xi’an University of Technology under Grant 108-451121001Shaanxi Collaborative Innovation Center of Green Intelligent Printing and Packaging.
文摘Printing quality evaluation is an important means to check whether prints are qualfied.However,the urrent printing quality evaluation system for gravure decorative paper is not perfect.In order to solve this problem,a method for evaluating quality of decorative paper based on analytical hierarchy process(AHP)and the entropy weight method(EWM)model is proposed in this paper.So as to verify the proposed model,decorative paper of different grades was selected as the experimental objects.Firstly,the data about five indices eflecting printing quality were measured.Secondly,the evaluation model was used to assign weights to the indices,and scores in each index were calculated according to scoring tables.Finally,the evalua tion scores were statistically analyzed.The results of data analysis showed that the 95% confidence intervals and coefficients of variation were small.The average error of the evaluation system was 0.2061.It indicates that the model can stably distinguish decorative paper of diferent grades,accuracy of which is high.The research in this paper can provide reference to the quality improvement of decorative paper and the printing quality evaluation of other paper.
