Summary of the experiment of the hottest sodium ca

Summary of the test of sodium carboxymethyl starch in kraft paper (Part 2)

5.1 the bursting index of the finished paper is greatly improved

as can be seen from table 1; Whether we produce 65g/m2 kraft paper (referred to as 65g/m2 kraft paper, the same below) or 80g/m2 ordinary kraft paper (referred to as 80g/m2 kraft paper, the same below), we believe that this is the special purpose kraft paper with enhanced performance that the composite material market is most interested in and has been looking for. After adding additives, the bursting index of the finished paper has been improved by the new concept of "industry 4.0" proposed by the German Federal Ministry of education and research and the Federal Ministry of economy and technology in 2013, Its range is 21.85% at the highest and 6.23% at the lowest, but it has little impact on other physical inspection indicators

5.2 the proportion of bamboo pulp has been greatly increased

it can be seen from table 1 that because the physical inspection standard of 65g/m2 kraft paper is relatively low, it can meet the standard requirements without additives and the pulp ratio is bamboo: wood =70:30, so no additives can be added in the production of 65g/m2 kraft paper. However, in the production of 80g/m2 kraft paper, due to the relatively high physical inspection standards, in the past, the slurry ratio can meet the requirements when bamboo: wood =30:70, while when the slurry ratio is bamboo: wood =60:40, if no additives are added, the bursting index index index can not meet the requirements, and if additives are added 1.5%, the bursting index index index can meet the requirements

5.3 when producing 80g/m2 kraft paper, with the same amount of additives added, the optimization of the proportion of pulp

due to the fact that bamboo pulp and wood pulp cannot be completely separated in the chemical pulp process, the proportion of bamboo and wood fluctuates greatly in the production process. For this reason, we tracked the influence of the change of bamboo wood ratio on the bursting index under the condition that the addition amount of additives was 1.5%, and obtained the curve as follows:

5.3.1 when the proportion of bamboo pulp was less than 50%, the lowest proportion of bursting index exceeding the standard line of physical inspection was 7.62%, and the highest was 21.3%. This surplus is contributed by the use of too much wood pulp, which also provides a basis for us to reduce wood pulp and increase the proportion of bamboo pulp

5.3.2 when the proportion of bamboo pulp is 50% - 70%, the change of bursting index is small and relatively stable, and the proportion exceeding the physical inspection standard is 4.44% - 7.62%

5.3.3 due to the short time of this test and the specified bamboo wood ratio of 60:40, the proportion of bamboo pulp in actual production has not exceeded 70%, so the maximum limit of the proportion of bamboo pulp has not been found, which needs to be solved in the next test

the corresponding relationship between the proportion of bamboo pulp and burst resistance (the amount of additives added is 1.5%)

6 economic effect analysis

6.1 unit cost estimate

unit price of bamboo pulp: 2.60 yuan/kg, unit price of wood pulp: 3.50 yuan/kg, unit price of sodium carboxymethyl starch: 6.50 yuan/kg

will also bring errors to the equipment. In the past, when kraft paper was produced without additives, the ratio of bamboo to wood was bamboo pulp: wood pulp =30:70

during the test of producing 80g/m2 kraft paper, the average test value of bamboo wood ratio is bamboo pulp: wood pulp =52.07 ∶ 47.93, 575kg of sodium hydroxymethyl starch is shared, 39t of 80g/m2 kraft paper is produced, and the actual dosage of sodium carboxymethyl starch is 0.575/39 × 100%＝1.47%。

the cost of size without additives is 1. Some products with high scientific and technological content: 1000 × 30% × 2.6+1000 × 70% × 3.5=3230 (yuan/ton of paper)

after adding additives, the slurry cost is: 1000 × 52.07% × 2.6+1000 × 47.93% × 3.5=3031.37 (yuan/ton of paper), the increased auxiliary cost per ton of paper is: 1.47% × one thousand × 6.5=95.55 (yuan/ton of paper)

6.2 economic benefit analysis

the cost savings of tons of paper pulp are: 55=103.08 (yuan/ton of paper)

the return on investment of sodium hydroxymethyl starch is 103.08/95.55 × 100% =107.88%

4 paper machine produces 400 tons of ordinary kraft paper every month, and the monthly cost savings is 103.08 × 400=41232 (yuan)

7 conclusion

7.1 when producing kraft paper with a high proportion of bamboo pulp, the addition of sodium carboxymethyl starch additive can significantly improve the bursting index of the paper, making this index meet the requirements

7.2 under the condition of basically unchanged production conditions, it is appropriate to use 1.5% sodium carboxymethyl starch in the production of kraft paper and increase the proportion of bamboo pulp from the past 30% to about 65%

7.3 improve economic benefits: the application of sodium carboxymethyl starch in the production of kraft paper can increase the amount of bamboo pulp, reduce production costs, and ensure product quality. The return on investment is 107.88%, which has good economic benefits

7.4 it should be noted that the test time in mass production is relatively short, and the maximum proportion of chemical bamboo pulp is not found, which needs to be solved in the next test