Gift bags should be strictly controlled for drying temperature

Process adjustment of Dalian gift bag coated base paper: Bleached chemical wood pulp is used in all the pulp fibers of base paper, and the amount of pulp is increased, and the coverage of lining mechanical pulp is strengthened. The neutral alkaline sizing process was adopted to reduce the amount of aluminium sulfate in the pulp and increase the 13H value of the base paper.

The experiment proves that the pH value of base paper surface layer is better between 6.5 and 8.0. In the process of papermaking, the drying temperature should be strictly controlled to ensure the drying of cardboard. The drying temperature should be lowered as far as possible, and the cold cylinders of base paper and coated paper should be used well. Choose liquid whitening agent with better quality.

Experiments show that the application of liquid whitening agent can reduce the yellowing degree of coated products. The effect on yellowing is obviously lower than that of powder whitening agent while ensuring the improvement of product self-control. The liquid whitening agent with better quality must have higher purity. The liquid whitening agent with poor purity will not only cause unnecessary waste, but also easily form yellowing phenomenon. In addition, fluorescent whitening agent should be used well in paint formulation, and the application of whitening agent carrier (auxiliary adhesives) should also be paid attention to.

Reasonable application of toner pigments: The use of toner pigments is to maximize whiteness, reduce the amount of fluorescent whitening agent, and balance different chemical raw materials to achieve the required color. In order to reduce yellowing of coated white board paper, the selection of toner pigments requires not only easy operation, good affinity, but also high light resistance. Therefore, the selection of high-quality organic pigments, its various aspects of performance is relatively ideal. More attention should be paid to the dosage of toner pigments, because too high or too low dosage can not achieve the purpose of toner. Excessive yellowing will aggravate the yellowing degree of coated white board, while too low will not achieve the desired whiteness.