Research On Interlayer Adding Filling Technology And Mechanism Of Papermaking

White mineral pigment and synthetic filling were joined in the pulpsuspension system in the process of internal filling. Through this method, itcould improve paper quantity, satisfy the use requirement and save fiber rawmaterial, so as to reducing the cost of product. But the quantity of filling was toomuch, not only reduce the physical strength of paper, make the paper linting anddusting, also to adversing effect of the wet environment of paper machine. In theprocess of papermaking, because the particle size of filler was smaller than thefiber, the majority of fillers were in white-water system through the wire section.Therefore, it lead to the concentration of white water was increased. At the sametime, the filler has certain solubility in the water, adding can cause the solublesalt concentration and pH were changed, accelerating the scaling andsedimentary of the system of paper machine. Using the new technology ofinterlayer filling, the filler was added between two wet sheets. And use theadhesive laminating it. In this way, fillers were all kept in the paper and forminga kind of multilayer structure of paper which was similar to"sandwich". It can beincreasing the retention of filler greatly and reducing the content of fines in thewhite water, what is more, optimizing the wet end chemistry of paper machine.The talc and calcium carbonate as filler, cationic starch, polyvinyl alcohol,styrene-acrylic emulsion and carboxylated styrene-butadiene rubber latex asadhesive respectively. The strength properties of paper was effect of the packingproperty, bonding properties and compound proportion of adhesive in the processof interlayer filling. The objective was to ensure the strength properties of paperwhen the fillers were all retention in the paper. At the same time, reduce thecontent of fines in the system of white water, improve the system of white waterclosure cycle and raise the utilization ratio of resource. Achieve the effectivecombination paper industry production economic benefits and environmentalbenefits. Effect of the different kinds and sizes of fillers on the strength properties ofpaper were analyzed. We found that all the fillers were kept in the paper but thetensile strength, ring crush strength, tearing strength as well as internal bondstrength were lower than the paper of internal filling when the talc as filler in theinterlayer filling. The advantage of interlayer filling was not found. Throughcomparing two different sizes of calcium carbonate,It was found that when thelarge size of calcium carbonate as filler, the tensile strength, ring crush strengthand tearing strength of paper were greatly improved comparing with internalfilling. And the range of the increased was larger than the small size of calciumcarbonate （1.34μm）. So the size of calcium carbonate （7.14μm） was moresuitable for the technology of interlayer filling in the production of corrugatedpaper.The physical property of paper was influenced by kind and dosage ofadhesive. In this paper, the two different degree of substitution of cationic starch,polyvinyl alcohol, styrene-acrylic emulsion as well as carboxylatedstyrene-butadiene rubber latex as research object, comparing the strengthperformance of paper was influenced by different adhesives. The effect ofadhesives as follow： carboxylated styrene-butadiene rubber latex＞styrene-acrylic emulsion＞polyvinyl alcohol＞low degree of substitutioncationic starch＞cationic starch with high degree of substitution. Compared withinternal filling, the tensile strength of paper was22.18N·m·g^-1increased by27.25%, the ring crush strength was4.80N·m·g^-1increased by5.73%, tearingstrength was7.25mN·m²·g^-1increased by28.09%. When the loading volume ofcalcium carbonate reached25.0%, the dosage of carboxylated styrene-butadienerubber latex was2.0%. Thus, it was illustrated that the interlayer filling wassuperiority.In order to reduce the production cost and considering the bond behavior ofdifferent adhesives, the polyvinyl alcohol and styrene-acrylic emulsion,styrene-acrylic emulsion and cationic starch, carboxylated styrene-butadienerubber latex and cationic starch was composite stabilizer as adhesive respectivelyused in the interlayer filling. The compound proportion was4:1,3:2,1:1,2:3,1:4.The effect of carboxylated styrene-butadiene rubber latex/cationic starch wasbest. When the compound proportion was1:4, the strength properties of paper was improved compared with using the carboxylated styrene-butadiene rubberlatex alone. The internal bond strength and ring crush strength of paper wasincreased by5.83%and63.36%respectively. In addition, the internal bondstrength and ring crush strength of paper was increased by128.05%and25.74%respectively compared with using the low degree of substitution cationic starchalone.