Performance Improvement And Application Of Agricultural Straw High Yield Pulp

The implementation of the policy of prohibiting the entry of foreign waste has led to a shortage of domestic recycled fiber resources.In order to alleviate this issues,making full use of the huge amount of agricultural straw resources is one of the effective solutions.On the basis of studying the properties of high yield pulp from agricultural straw by hydrothermal method,the effects of p H value and fines on the properties of the pulp were discussed.At the same time,in order to improve the performance of high yield pulp of straw and solve the problem of shortage of raw materials,and realize the high value application of agricultural straw resources,this paper studied the effect of blending agricultural straw high yield pulp with OCC waste pulp or softwood kraft pulp.The cell structure of corn stover is complex,and the content of non-fibrous cells is high.Compared with other parts,stem bark is more suitable for papermaking.The parenchyma cells in the stem pulp are more likely to be mechanically broken,which will adversely affect the dewatering performance of the pulp.In addition to a small amount of fiber,there are more epidermal cells with serrated edge.The leaf sheath contains more fiber than the leaf,and is mainly composed of non-fibrous cells.It is one of the ways to improve the yield and properties of pulp by adding proper amount of sodium hydroxide during hydrothermal pretreatment.The sieving method was used to remove the fines and found that it not only improved the strength of the paper but also solved the problem of poor dewatering performance of the pulp.When the fines sieving rate is small,the broken filamentous fines play a major role in reducing the beating degree,while the fines sieving rate is large,the original square and rod-shaped non-fibrous cells play a major role in reducing the beating degree.The study found that when the sieving rate of fines is 17.8%,the tensile strength,burst index and ring crush index of the pulp are the best,and the dewatering performance is improved.The study also showed that adding an appropriate amount of cationic polyacrylamide(CPAM)to the high-yield agricultural straw pulp has a positive impact on the pulp strength performance while improving the pulp retention and drainage performance.After surface sizing,the strength of the fiber component increased most obviously,tensile index,burst index and ring crush index increased by 55.19%,131.76% and 47.94%,respectively.The results of studying the high-yield pulp of corn stover,rice straw or wheat straw with domestic OCC pulp respectively showed that high-yield agricultural straw pulp can effectively improve the mechanical strength of OCC pulp,and is an excellent substitute for domestic OCC pulp.Among them,high-yield wheat straw pulp has the best effect.When the addition amount of rice straw or wheat straw high yield pulp is greater than 40%,surface sizing will not significantly improve the paper strength performance,and even has a negative impact.When the ratio of straw high yield pulp to OCC recycled pulp is more than 60%,its strength is higher than that of pure 100%waste pulp after surface sizing.The results of mixing high-yield corn stover,rice straw or wheat straw pulp with softwood kraft pulp show that the high-yield wheat straw pulp has the best effect.When wheat straw high yield pulp is blended with softwood kraft pulp,it has the potential to make food packaging paper by adding appropriate amount of water and oil repellent chemicals.