What is the core process for producing three proof thermal paper?

The core process of producing three proof thermal paper mainly includes the following steps:

1、 Raw paper preparation

Choosing high-quality paper with a certain thickness and strength as the substrate is the foundation for ensuring the stability and durability of the paper during the printing process. The quality of the base paper has a significant impact on the adhesion of subsequent coatings and the performance of the final product.

2、 Coating configuration and coating

Thermal sensitive coating configuration:

Thermal sensitive coatings are mainly composed of various chemical substances such as colorless dyes, color developing agents, sensitizers, stabilizers, adhesives, etc. These components can undergo chemical reactions under heating conditions, releasing colors and forming printed content.

When preparing a thermosensitive coating coating solution, it is necessary to mix these chemical components in a certain proportion and evenly disperse them through processes such as stirring.

Three proof coating configuration:

Three proof coatings usually contain special chemical materials such as waterproofing agents, oil repellent agents, etc., which can endow paper with waterproof, oil repellent, anti fouling (or PVC resistant) and other properties.

When configuring the three proof coating coating liquid, it is also necessary to mix these chemical components in a certain proportion and achieve the desired coating viscosity through specific processes.

Coating process:

Add the pre configured thermosensitive coating and three proof coating coating liquids into the coating machine material tank separately.

Apply the coating evenly onto the surface of the base paper using a coating machine. The coating method can be metering rod coating, film transfer coating, etc.

After the coating is completed, it needs to be dried and cured to ensure that the coating firmly adheres to the paper and achieves the best printing effect.

3、 Post processing and detection

Post processing:

After coating, drying, and curing are completed, further processing such as calendering and slitting of the paper is required to meet different market demands.

Pressing can improve the glossiness and flatness of paper, while slitting can cut large sheets of paper into the desired small sheet size.

Quality inspection:

Strict quality inspection is required for raw materials, semi-finished products, and finished products throughout the entire production process.

The testing content includes the flatness of the paper, the uniformity of the coating, the printing effect, and durability. These tests can ensure that the quality of thermal paper meets the standards and customer requirements.

4、 Special processes (such as isolation layer, top coating, etc.)

In the production process of some three proof thermal paper, special process layers such as isolation layer and top coating are also added.

Isolation layer:

The isolation layer is usually located between the thermosensitive coating and the three proof coating, and its main function is to prevent other substances such as oil from penetrating into the thermosensitive coating, thereby protecting the printed content from damage.

The configuration and coating process of the isolation layer are similar to those of thermal sensitive coatings and three proof coatings, but the chemical composition and process parameters used may differ.

Top coating:

The top coating is usually located on top of the three proof coating, and its main function is to further enhance the wear resistance, waterproofness, and glossiness of the paper.

The configuration and coating process of the top coating also need to be strictly controlled to ensure that it can meet the required performance requirements.

In summary, the core process of producing three proof thermal paper includes multiple steps such as raw paper preparation, coating configuration and application, post-processing and testing, and special processes (such as isolation layer, top coating, etc.). These steps collectively determine the performance and quality of the three proof thermal paper.