Paper Dyeing

Paper dyeing is a crucial part of the paper making process. Through the dyeing process, the paper can present various colors to meet different usage requirements. According to the type and purpose of the paper, it is particularly important to choose the right dye and dyeing method. This article will explore in depth the dyeing methods of different types of paper, the selection of dyes, and the influencing factors and precautions of pulp dyeing.

Dyeing methods and dye selection of different types of paper

1. Ordinary paper such as document paper, printing paper, and book paper

Dye type: direct dye

Features: Direct dyes can provide a rich selection of colors and are suitable for the dyeing needs of ordinary paper.

2. Wrapping paper, gift wrapping paper and other packaging paper

Dye type: direct dye, acid dye

Features: Direct dyes provide a rich selection of colors and are suitable for dyeing colored wrapping paper; acid dyes have good dyeing fastness and are suitable for wrapping paper that needs to be stored for a long time.

3. Special purpose paper such as colored art paper and colored printing paper

Dye type: direct dye, dye ink

Features: Direct dyes are suitable for various types of colored paper and provide a rich selection of colors; dye inks are often used in the printing process of special purpose paper such as digital printing and inkjet printing.

4. Special paper (such as anti-counterfeiting paper, fluorescent paper, etc.)

Dye type: special dye, special pigment

Features: It is necessary to select the corresponding special dye or pigment according to special needs to achieve special effects, such as anti-counterfeiting, fluorescence, etc.

5. Paper for certain specific purposes

Dye type: basic dye, direct dye

Features: basic dye is suitable for dyeing egg trays, religious paper, Joss paper dyes, firecracker paper dyes, etc.

Classification and application of paper making dyes

Paper dyes are mainly divided into pulp dyeing and surface dyeing. The commonly used dyes for pulp dyeing are mainly direct dyes and basic dyes, while surface dyeing mainly uses direct dyes. The following details the influencing factors, precautions in the pulp dyeing process, and the characteristics of direct dyes and basic dyes on dyed paper.

Precautions for pulp dyeing

1. Dye selection and ratio: Select the appropriate dye according to the final use of the paper and the required color, and reasonably control the amount of dye. Different dyes have different dyeing effects, light resistance, water resistance and other properties. Choosing the right dye is the key.

2. Even stirring: During the dyeing process, ensure that the dye is evenly distributed in the pulp to avoid color difference. Even stirring is an important step to ensure dyeing consistency.

3. Control pH: According to the type of dye used, adjust the pH value of the pulp to achieve the best dyeing effect. The pH value of the pulp will affect the adsorption and binding of the dye. Proper adjustment of the pH value can improve the dyeing effect.

4. Dyeing temperature and time: According to the characteristics of the dye, set the appropriate dyeing temperature and time to ensure that the dye is fully adsorbed on the fiber. The dyeing temperature affects the solubility and diffusion rate of the dye, and the length of time will directly affect the degree of adhesion of the dye on the fiber.

5. Use dyeing auxiliaries and fixing agents: Adding dyeing auxiliaries and fixing agents in appropriate amounts can improve the dyeing effect and fastness. Chemical substances such as dyeing auxiliaries and fixing agents can improve the dyeing effect and ensure that the color is more stable and lasting.

6. Cleaning and treatment: After dyeing, proper cleaning and treatment are carried out to remove unadsorbed dyes and prevent color migration. The cleaning and treatment steps are key links to ensure dyeing quality and stability.

7. Properties of pulp: The type of pulp, fiber length, chemical composition, etc. will affect the dyeing effect. Choosing the right type of pulp and controlling its properties are crucial to the dyeing effect.

In the paper making process, pulp dyeing and surface dyeing each have their own applicable dyes and process characteristics. Direct dyes are suitable for dyeing various papers, and the operation is simple Basic dyes are suitable for paper for specific purposes. Choosing the right dye and dyeing process can ensure that the paper has the required color, quality and performance, and provide high-quality colored paper for various applications.

To learn more about paper dyeing, please visit our official website or contact our team of experts. We are committed to providing you with the best dyeing solutions to meet your various needs.