Study On Modification Of Chopped Polyester Fiber And Its Effect On The Performance Of Lining Paper

In recent years,with the improvement of people's quality and level of life,the demand for various special papers has also been increasing.It has been widely used and developed rapidly in different fields such as building materials,industrial filtration,and biochemical cutting-edge technology.Liner paper,as one of the special papers that play the role of liner and material spacing,is also constantly being developed and applied.At present,there is a large domestic demand for high-performance interleaving paper,but the research and production started late,and the variety of interleaving paper is single and most of the processes are similar.Therefore,how to enrich and expand the application of high-performance interleaving paper and obtain high-end interleaving paper with excellent performance comparable to those outside the United States is our goal.In this paper,firstly,pure wood pulp fibers are optimized and papermaking aids and forming processes are optimized to obtain ordinary glass liner paper with excellent properties.Secondly,in order to obtain liner paper with better performance and wider application,polyester staple fiber was introduced and modified with green and affinity to improve its hydrophilic dispersibility.Then the modified polyester staple fiber was applied to the liquid crystal glass liner paper and the high-temperature liner paper respectively,and the two paper forming processes were optimized,their performances were evaluated,and their mechanisms were analyzed.Finally,high-performance liner papers with different properties and different uses are obtained.Firstly,by changing the beating degree of softwood pulp and hardwood pulp and the ratio of softwood pulp and hardwood pulp,and the above parameters are optimized by orthogonal experiment,the fiber morphology of the optimized raw material is analyzed.Through single factor experiments,the influence of pressing pressure,pressing time,conductivity of papermaking water,dosage of pH regulator,and dosage of wet strength agent on the performance of liner paper was discussed.The results show that: in hardwood pulp:softwood pulp=8:2,softwood pulp beating degree is 32°SR,hardwood pulp beating degree is24°SR,pressing pressure 4MPa,pressing time 3min,papermaking water conductivity 21?s Under the test conditions of 1.5% pH adjuster and 0.3% wet strength agent(both relative to the absolute dry pulp),the physical properties of ordinary glass liner paper are excellent,the conductivity of the paper is small,and the pore size distribution is uniform.In order to improve the air permeability of the liner paper and obtain a more widely used liner paper,chemical fiber polyester staple fiber is introduced,but due to its smooth surface and fewer hydrophilic groups,it has extremely low hydrophilicity and poor performance.For dispersibility,it needs to be hydrophilically modified first.In alkaline tris(Tris)buffer,gallic acid and ethylenediamine are co-deposited on the surface of polyester chopped fibers through Michael addition or Schiff base reaction,and the modification process is carried out.Hand in test optimization.The dynamic contact angle of polyester chopped fiber before and after modification was measured,the morphology of the fiber was observed by SEM,and the change of fiber surface structure was characterized by FTIR and XPS.Finally,the polyester chopped fiber before and after modification and a certain degree of beating were measured.The hardwood pulp was used for papermaking,the combination of polyester staple fiber and hardwood pulp fiber before and after modification was observed,the pore size distribution change and air permeability of the paper were measured,and the physical properties of the paper were tested.The results show that there are a large number of hydroxyl groups on the surface of the polyester chopped fiber after co-deposition modification,nitrogen elements are generated on the surface of the fiber,and the surface roughness is improved.Compared with the unmodified polyester chopped fiber,the thermal stability is not changed.After the modification,the contact angle of polyester chopped fiber and deionized water is reduced by57.2°,which significantly improves the hydrophilicity of the fiber;compared with unmodified fiber paper,the strength performance is improved,and the air permeability is increased by11.1 %,the pore size increases by 23%?29% within the same pore size range,and the fiber dispersion is significantly improved.The obtained modified polyester staple fiber with good hydrophilic dispersion was mixed with hardwood pulp and softwood pulp to make liquid crystal glass liner paper,and the effect of adding modified polyester staple fiber in different proportions on the performance of liquid crystal glass liner paper was studied.At the same time,the papermaking process of liner paper is adopted and optimized.The results show that: when hardwood pulp: hydrophilic polyester staple fiber=8:2,hardwood pulp beating degree is 24°SR,the conductivity of papermaking water is 21?s/cm,the amount of boric acid is 1.5%,and the amount of wet strength agent is 0.6%,When the amount of antibacterial agent is 0.3%(all relative to the absolute dry pulp),the self-made liquid crystal glass liner paper can meet the requirements of wet strength,air permeability and anti-mildew and antibacterial properties.Among them,the self-made liquid crystal glass liner paper has excellent air permeability,and the advantages of higher porosity and larger pore size can use modified polyester staple fiber as an effective reinforcement material for high air permeability paper.Because the self-made modified polyester staple fiber has good thermal stability,and the paper-made base paper has a higher porosity and a larger pore size,it is conducive to the retention of high-temperature additives on the fiber and the curing in the pore size,which can make the impregnated coating The high temperature resistant liner paper achieves a good high temperature resistant effect.The inorganic high temperature resistant auxiliary agent is added into the pulp,and the organic high temperature resistant auxiliary agent is impregnated and cured at a certain temperature to obtain a high temperature resistant liner paper with excellent performance.