How is the protective layer of long-lasting three proof thermal paper made?

The production of the protective layer for long-lasting three proof thermal paper is a relatively complex process that typically involves multiple steps and specific material selection. The following is a detailed analysis of the production process of the protective layer:

1、 Material selection

Basic materials: The protective layer of long-lasting three proof thermal paper is usually made of materials with excellent wear resistance, chemical stability, and lubricity, such as polyethylene wax micro particles, VAE latex, etc. These materials can form a tough and uniform protective layer, improving the scratch resistance and ink absorption of thermal paper.

Additives: In order to enhance the performance of the protective layer, some special additives will be added, such as dispersant, inorganic pigment, zinc stearate lotion, polyvinyl alcohol glue, etc. These additives can improve the dispersibility, glossiness, and processability of materials.

2、 Production process

Preparation of coating solution: Firstly, mix the selected base materials and additives in a certain proportion, and add an appropriate amount of water for stirring. During the stirring process, it is necessary to control the stirring speed and time to ensure that the material is fully dispersed and mixed evenly.

Coating: Apply the prepared coating solution evenly onto the base paper (i.e. the bottom layer of the thermal paper) through a coating machine. The coating amount needs to be adjusted according to the thickness, density, and required protective layer thickness of the paper. Common coating methods include metering rod coating and film transfer coating.

Drying and curing: After coating is completed, the paper is sent to a drying equipment for drying and curing. The purpose of this step is to remove moisture from the surface of the paper, allowing the protective layer material to fully solidify and adhere tightly to the paper. The control of drying temperature and time is crucial for the performance of the protective layer.

Calendering and slitting: After drying and curing, the paper also needs to be calendered to improve its glossiness and flatness. Finally, cut the paper into the desired size and shape to obtain the finished long-lasting three proof thermal paper.

3、 Performance optimization

Wear resistance improvement: By adjusting the amount and particle size distribution of polyethylene wax micro particles, the wear resistance of the protective layer can be significantly improved.

Ink absorption enhancement: The addition of VAE latex can increase the porosity of the protective layer, thereby improving the ink absorption and drying speed.

Glossiness improvement: The addition of materials such as polyvinyl alcohol can improve the glossiness of the protective layer, making the thermal paper more beautiful.

In summary, the production of the protective layer for long-lasting three proof thermal paper is a complex process involving material selection, production process, and performance optimization. By reasonable material ratio and process control, a protective layer with excellent wear resistance, ink absorption, and glossiness can be prepared to meet the needs of various application scenarios.