نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 دانشگاه تهران
2 عضو هیأت علمی مؤسسه تحقیقات جنگلها و مراتع کشور
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objectives
Paper recycling currently is considered one of the most important solutions for the environmental and sustainable production of paper products. In addition to reducing the consumption of various resources such as water, energy, and virgin fibers using this process, the paper recycling rate is continuously increasing in different countries due to less pollution. Most of the recycled paper is usually used to produce packaging paper and board. Paper and paperboard should not only possess dry-strength, but also must be able to provide the required strength at wet condition for the packaging of products that need to be kept in the cold and freezer condition. For this purpose, different procedures such as refining and additives can be used. This research investigates the independent effect of each factor as well their interaction effect in order to improve the characteristics of office deinked pulp (DIP) for producing packaging paperboard.
Materials and Methods
DIP was obtained from Latif Paper Company. After refining the pulp to SR = 30, additives including cationic corn starch (at the levels of 1, 1.4, 2, and 3w%), wet strength resin (at the levels of 1, 2, and 3w%), and AKD (at the levels of 1, 2, and 3w%) were separately added to the pulp suspension based on the dry weight of pulp in order to manufacture handsheets with the basic weight of 120 g/m2. In order to compare and determine the effect of optimum treatment of the additives on the treated pulp, tests i.e. water absorption, tensile strength, burst and tear strength of the handsheets, as well as wet strength retention and absolute wet strength retention were measured. The relative retention strength was measured after determining the independent effect of each treatment on the tensile strength, burst, and tear strength of handsheets in both wet and dry conditions. The effect of optimal combination treatment on the characteristics of handsheets was investigated and compared, when the optimal values of each independent treatment were determined.
Results
The independent effect of refining on the strength of handsheets made from DIP is statistically significant in the dry conditions. The results indicated that using 2w% cationic corn starch in the refined pulp could induce better performance in the term of increasing the strength of handsheets in dry conditions, specifically the tear strength, compared to the independent refining factor. Using wet strength resin and AKD also represented a significant increase in the strength of handsheets in the wet conditions and also a significant decrease in the water absorption compared to the control sample, respectively. Using of refining and optimal combination treatment of additives including 2w% cationic corn starch, 3w% wet strength resin, and 1w% AKD simultaneously caused a significant improvement in the wet and dry strength, and water absorption of handsheets.
Conclusions
All the properties of the handsheets were improved with the applying of optimal combination treatment including the refining of DIP and adding additives at the same time compared to the control sample, so it could be used for the packaging of products that should be stored in the refrigerator and freezer. The strengths of handsheets in the dry conditions are superior compared to the standard strength of bleached kraft paper according to the Iran national standard no. 2875 except for tear strength. The measurement of absolute relative retention wet strength demonstrated that the performance of the combination treatment is very suitable compared to other previous research reports. The combination treatment significantly has reduced the paper water absorption by 22 g/m2, which is suitable for paper storage in the freezer.
کلیدواژهها [English]
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