| As a non-wood raw material, the fiber properties of bamboo fiber may be a partialsubstitute for wood pulp to make quality cultural paper due to its property between soft woodand hardwood pulp, significantly better than wheat straw, reed, grass fibers, with low cost andhigh quality advantages.The paper use DQP bleached bamboo pulp as raw material, workingon bamboo beating features and the adsorption characteristics of wet chemicals, so thatprovide a reliable theoretical basis and data support for the application ofenvironment-friendly DQP bleached bamboo pulp.In the present experiments it show that, the total charge of the fiber remained unchangedunder the different beating degree of pulp. However, the surface charge and the charge ratioincreases. Besides,the adsorbed amount of polymer also increased significantly. As it is wellknown, beating promote the amount of fiber surface charge and adsorption of the polymerwhich can improve the strength of the paper, but also the inevitable emergence of fines, whichare sure to bring about a series of negative issues, this paper attempts to find a method thatcan replace or reduce the level of beating.Because of the high crystallinity and the highly oriented structure of bamboo fiber,paper strength made of bamboo pulp can not be comparable to the wood fibers. In the pulpand paper industry, dry strength agents can improve sheet strength and compensate forstrength loss due to the use of filler. Therefore, it is very important for us to have afundamental understanding of the mechanism of dry strength agent and fiber we can use avariety of dry strength effectively.This paper aimed to improve the paper dry strength by adding the proper amount of wetend chemicals.The adsorption properties of polymers on fiber is studied by using severalcommon dry strength agents for the model compounds.The study try to determinethe chemical optimum dosage of the monolayer adsorption and the multilayer adsorption(PEM, polyelectrolyte Multilayers).The results showed that, according to several differentkinds of dry strength agent of the adsorption curve, in the mono-layer adsorption process theadsorption effect of polyacrylamide (CPAM) on the fiber better than the cationic starch andcarboxymethyl cellulose sodium (CMC); Compared to the same amount of low charge densityof starch，high charge density cationic starch obtained paper strength increase toa greaterdegree.when treating the beating3000r long bamboo fiber without fines by PEM3(polyelectrolyte Multilayers)，it is founded that paper tensile strength, the tensile index rise d from43.5Nm/g to69.8Nm/g;The sheet tensile index made of the fiber without beating byPEM3processing46.7Nm/g, sheet strength of beating6000r without polymer treatment47.4Nm/g; that is，thestrength of both is considerable. This implies that: the combination ofbeating and PEM processing may be an effective way to improve the sheet strength.The light scattering coefficient of paper made of fiber treated by PEM decrease to someextent, however, formation and density did not change significantly.Then different amounts ofuntreated fines are added to the PEM-treated long fiber before the paper is prepared. Theresults is compared with the pulp without fines adding. It is found that:the increase of thetensile index for sheet made from PEM–treated long fiber without a subsequent finesaddition,however,was much lager.The possible explaination is that: because the fines coverthe surface of the long fiber processed by PEM and hinder the mutual penetration andestablish an effective connection between the PEM layer. |
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