(1) The influence of fiber raw materials and ratio

Commonly used domestic flour pulp is unbleached KP softwood pulp or non-wood fiber semi-chemical pulp. The pulp produced by different varieties, different production areas, and different process methods have color differences. The stability of the raw material ratio is also a factor that affects the dyeing effect. Generally, it is necessary to achieve a stable supply of raw materials and a stable raw material ratio in production. It is also a normal phenomenon if raw material changes occur, but it is necessary to plan in advance so that The amount of dye can be adjusted in time when changing.

(2) The influence of beating degree
The slurry has a high beating degree, a high degree of fibrillation of the fiber, and a large specific surface area. These slurries have a strong ability to absorb dyes, thereby increasing the retention rate of dyes, and increasing the tightness and light transmittance of the formed paper sheet, reducing the reflection of light, increasing the proportion of colored light, and deepening the paper Hue. In ensuring the other physical properties and papermaking conditions of kraft paper, the beating degree must be considered comprehensively. The beating degree control should be stable and the fluctuation should be small, generally between 32~36 bSR.

(3) The influence of temperature
The influence of temperature includes two aspects: dyeing temperature and drying temperature. Temperature has a great influence on the dyeing effect. Increasing the dyeing temperature of pulp can usually increase the coloring effect, especially for anionic direct dyes. However, due to the different thermal stability of the dyes, the dye migration phenomenon will occur due to the improper control of the drying curve during the heating process of the formed paper. The result of the migration will produce a color difference between the left and the right. Therefore, the dryer dyeing process parameters should be tested regularly.

(4) Impact of water quality
Water quality has a certain effect on dyeing, and production water with high hardness and high suspended solids content has a negative effect on dyeing. The treatment of production water should be strengthened, and the impurities in the pulp should be removed as much as possible.

(5) The influence of system pH
Various dyes have their suitable pH range, and strict control of pH is an important aspect to achieve uniform dyeing. Generally, the pH is controlled between 4.5 and 5.5, and its retention rate is the largest, and the coloring effect is the best. Decreasing the pH below 4.5 is unfavorable for basic dyes; while the retention rate of acid dyes will decrease significantly when the pH exceeds 5.0.

(6) The influence of the sizing process
The commonly used rosin gum acid sizing can help the coloring of the pulp, but the situation is not exactly the same for different dyes. For acid dyes and direct dyes, rosin gum and alumina (alumina) can both act as mordants, but they will cause the direct dyes to have dim hue and poor light resistance. Rosin gum and a small amount of alumina can also promote the coloring of basic dyes, but too much alumina, once the pH drops below 4.5, it is not conducive to the use of basic dyes. Adding alumina at the end during sizing and dyeing can better ensure the sizing and dyeing effect.

(7) The influence of dyes
Dyes color matching affects, because the mixing of two or more dyes will produce a wide range of color changes, resulting in differences in the upper dyeing luster. The change in dyeing concentration affects the shade of the pulp. Stable dyeing concentration is a necessary guarantee to reduce the color difference of pulp. Dyeing time, to make the dye in the fiber reach the dyeing balance, there should be enough reaction time.

As professoinal paper dyes manufacturer, our factory not only provide reliable quality paper pulp dyes including solid paper dyes and liquid paper dyes, but also we can give instructions for dyeing paper pulp. Welcome your inquiry.

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