Analyzing the Application Methods of Organic Pigment Dispersion in Papermaking

Analyzing the Application Methods of Organic Pigment Dispersion in Papermaking

There are various application methods for organic pigment dispersion in papermaking, and below is a brief introduction to several common approaches:

01 Whitening

Blue and yellow are complementary colors. Based on this principle, reducing yellow light reflection or increasing blue light reflection can both achieve a whitening effect. Most paper mills use either blue-violet pigment dispersion whitening or fluorescent whitening to enhance paper brightness, which is suitable for papers with specific brightness requirements.

02 Internal Staining

Applicable to all colored papers, the principle is the same as that of white coating color paste. Commonly used in colored cultural papers, food-grade papers, noodle paper, kraft paper, etc., it features high costs, low retention rates, and difficult wastewater treatment. The manufacturer's production process must be fully considered, especially the addition amount and position of retention aids and fillers, as they significantly affect pigment retention.

03 Coating

A relatively common method for coloring paper involves coating production. Common coating techniques include: roll coating, metering bar coating, and air knife coating. Color paste products must be compatible with the client's paint formulation system. For applications requiring high pigment loading, the impact of the pigment paste on the paint properties (pH, viscosity, water resistance) must be considered.

04 Gum dipping

Commonly used in the production of decorative paper, the characteristics of the pigment paste include: the prepared adhesive has good compatibility, fewer bubbles, strong affinity with decorative base paper, strong adhesion, excellent and uniform coating quantity, stable viscosity, and pH value.

05 Pre-impregnation and Dyeing

A relatively challenging coloring method, commonly used in the production of cultural paper, aims to better control production costs.

Does the paper mill need to use pigment dispersion?

Yes, the paper mill needs to use pigment dispersion.

1. The Uses and Importance of Pigment dispersion( Pigment paste)
Pigment dispersion refers to a concentrated suspension formed by mixing pigments and fillers. In the papermaking process, it is used to dye the paper and enhance its surface texture. Specifically, pigment paste serves the following purposes:
1. Dyeing: pigment paste can be used for dyeing, enabling industrial paper to achieve various colors such as white, gray, and brown in appearance.
2. Enhancing the glossiness of the paper surface: Color paste can improve the gloss and texture of the paper surface, making it more visually appealing.
3. Enhancing Paper Printing Quality: Most colored printing papers on the market contain not only pigments but also various fillers, such as precipitated calcium with high brightness and reflectivity, finely textured talc, lightweight talc, and ink leveling agents. These fillers must be properly formulated with color paste to achieve better printing results.

From the three aforementioned uses, it can be seen that pigment dispersion plays a crucial role in the papermaking process. It not only enhances the quality of the paper but also improves printing quality, thereby meeting customer demands.

II. How to Select the Appropriate pigment dispersion
Selecting the appropriate color paste is crucial for the production quality of paper. Below are some factors to consider when choosing a pigment paste:

1. Color: The color of the pigment dispersion should meet the customer's requirements and also be compatible with other pigment pastes.

2. Stability: The stability of the pigment paste needs to meet certain requirements, otherwise it will lead to uneven dyeing.
3. Usability: The pigment dispersion should be easy to use, blend and add to paper.
4. Repeatability: For large-scale production, the quality of pigment paste should be able to maintain consistency.
5. Price: For paper mills, the price of pigment paste is also an important consideration factor.

In short, choosing the appropriate pigment dispersion is an indispensable part of paper production, as it can affect the quality of the paper and customer satisfaction.