Research On Modified Short Fiber Used As Paper Strengthening Agent

Pulp raw material contains a large number of pulp fines. These fines will have systemic effects on paper properties. If the lost fibers are reused to produce the value-added products with high performance, it will be helpful to environmental protection and raw material saving. In this paper, fine fibers of the pulp, used as the raw material, were processed by carboxymethylation and hydrogen peroxide oxidation to obtain two kinds of paper strengthening agents. Then modified fibre and cationic starch or PAE were compounded with different concentrations of carboxymethylated fines and fines oxide to study the influence of modified fibers on the physical properties of handsheets and recycled handsheets and make an initial research on the strengthening mechanism of modified fibers on handsheets. SEM, FTIR were used to analysis the modified fibers and handsheets.The results proved that the content of carboxy group and carbonyl group of fibers air flotation rejects were increased via H2O2 oxidation and carboxymethyl groups were connected to the surface of carboxymethylated fibers by carboxymetheylation.Two kinds of modification can increase the oxygen content in the pulp short fiber.Add carboxymethylated short fibers in the paper can improve the physical properties of handsheets and recycled handsheets.The tightness,tensile index, burst index,folding index and folding endurance of handsheets with 1.0% carboxymethylated time of 120 minutes fibres increased by 17.0%,33.0%,15.3%,23.5%, 371.4% respectively compared to the contract sample.Add H2O2 oxidation short fibers in paper can improve the physical properties of handsheets and recycled handsheets.The tightness,burst index,tensile index, folding index and folding endurance of handsheets with 1.0% H2O2 oxidation time of 75 minutes fibres increased by 15.625%,2.26%,23.97%,28.9%,133.33%.The tightness,tensile index, folding index and folding endurance of recycled handsheets increased by 2.62%、32.73%、157.4%.300% compared to the paper without strengthening agents.The dosage of carboxymethylated or H2O2 oxidation short fibers,PH value of pulp, the increment of strengthening agents and aluminum sulfate also can affect the performance of paper.SEM analysis showed that the strengthening agents increases the bonding strength between the fibers and more thin.AFM analysis proved carboxymethylation staple fibers are nanoscale, indicating that enhancement and nano-effect relationship.PAE and cationic starch or carboxymethylated or oxidized staple fibers compounded use, high-properties paper than the single use of cationic starch or paper PAE performance,and cationic starch and carboxymethylated short fiber compound can improve the physical properties of recycled paper.The innovation is the modification of short fiber pulp preparation into efficient paper strengthening agent,used to improve the strength of the paper and recycled paper, also improve the added value of the short fiber pulp.