The Endo-cellulase Influence On The Pulp's Property

In recent years, the way of using Eucalyptus for pulping has developed rapidly. The species has a short growth cycle and its pulp has a wide range of applications, but it is difficult to break during the normal beating process because the pipe is large and hard, so it will bring some adverse effect to paper properties and its print performance. Furthermore,in grasses raw material the mixed fiber content is high, the fiber fines is many, the semi-cellulose content is high, the fiber is short and thin, thus, in the process of beating, the stock is very easy to become sticky and the beating degree rises quickly ,as a result of low drainage property and so on. Based on the use of the cellulose enzyme and the characteristics of the pulping and paper making during this research. We treated the bleaching chemicals Eucalyptus pulp and bleaching wheat straw pulp with single endo-cellulase enzyme to observe the effects of beating performance and drainage property brought about by the endo-cellulase enzyme. As a result, we were able to provide a basic theory in the paper industry.The research results were shown as the following:1. Through the experiments the superior craft condition is: in 50℃, adding buffer solution at PH=7.5, and the dosage of endo-cellulase is 3.0 IU/g, concentration of pulp is 3%, 2 hours reaction. Finally, while reaching the same beating-degree(41±1°SR), the application of endo-cellulase reduced the energy consumption in beating over 30% and lifted up six beating-degrees after using the same rotating speed(25,000 r).2. By investigating the sieving of bleaching Eucalyptus pulp, we can see that the inverse proportion of long fiber of the treated pulp is less than the untreated pulp's, which is in accord with the decline of avulsion index of the treated pulp. And the degree of crystallinity improved a little through electron microscope.3. Deal with the pulp in different conditions and synthesize the factors of beating degree,water retention value (WRV) and polymerization degree of cellulose, results showed that the suitable conditions for enzyme treatment of bleached wheat pulp are :at the temperature 50℃, enzyme dosage (0.6-1.0)IU/g, the pulp's pH value 7.5, pulp consistency 3%. The improvement of pulp drainage mostly happened at the beginning 60 minutes of the enzyme treatment, there are small effects on the change of beating degree later. 4. By investigating the sieving, we can see that the inverse proportion of long fiber of the treated pulp is less than the untreated pulp's, and it proved that the physical strength of the paper made by treated pulp changed. The broken index, the avulsion index and the tensile strength of the paper which is made from the treated pulp are invariable. But filtered water performance of the treated pulp has improved, and it is propitious to the dehydration of the papermaking forming department and improvement of the machine speed. The degree of crystallinity of the pulp treated by the cellulose has improved.