What is the production process of the three heat-resistant label paper?

The production process of heat-sensitive label paper is a complex and fine process, which combines traditional papermaking technology with modern coating technology. The following is a detailed analysis of the production process:

First, paper-based selection

Raw material preparation: The bottom layer of the heat-resistant label paper is the paper base, and paper with a certain thickness and strength is usually selected as the base material. In order to prepare the fiber compact, stable quality of the three heat sensitive base paper, the raw material often contains 18% ~ 22% coniferous wood pulp and 78% ~ 82% hardwood pulp.

Beating and mixing: the coniferous wood pulp and hardwood pulp are beaten respectively to obtain the coniferous wood pulp and hardwood pulp. Beating concentration and freeness should be strictly controlled to ensure pulp quality.

Second, paper-based manufacturing

Sizing, forming, pressing, drying: after sizing, the pulp enters the sizing system of the paper machine and is evenly distributed in the web to form a wet web. Subsequently, the wet web passes through the press to remove excess water, and then enters the drying part to further dry, forming a paper substrate with a certain strength.

Sizing and calender: In order to improve the surface properties and printability of the paper, it is usually necessary to size the paper after drying. After sizing, the paper also needs to be calender to improve its gloss and flatness.

Third, heat sensitive coating

Composition of thermal coatings: Thermal coatings are mainly composed of thermal pigments (such as colorless dyes, phenols or other acidic substances), polymers and other additives. Thermal pigment is a key part of thermal paper, it can be heated under the condition of biochemical reaction, release heat and change color.

Coating process: Use a roller or other coating equipment to evenly coat the heat-sensitive coating on the paper substrate. During the coating process, the thickness and uniformity of the coating need to be strictly controlled to ensure the print quality.

Fourth, dry and protective coating

Drying treatment: After the heat sensitive coating is applied, it needs to be dried to remove moisture from the coating. There are a variety of drying methods, including air drying at low temperatures and rapid drying using ultraviolet lamps. The drying process not only helps to remove moisture, but also ensures the gloss and flatness of the coating.

Protective coating: In order to improve the durability and adhesion of thermal label paper, a protective layer is sometimes covered on the thermal coating. The protective layer can absorb some of the light that causes the chemical reaction of the thermal coating, slowing the deterioration of the printing paper, while protecting the thermal components of the printer from damage. The coating and drying method of the protective layer is similar to that of the heat-sensitive coating.

Fifth, post-processing and packaging

Cutting: Cut the coated and dried thermal label paper according to the required specifications to form a single sheet or roll label paper.

Packaging: Package the cut heat-sensitive label paper to prevent moisture, contamination and damage. The packaging material is usually moisture-proof paper or plastic film, and the relevant information and instructions of the product are marked.

Sixth, quality inspection

In the entire production process, it is necessary to carry out strict quality testing on raw materials, semi-finished products and finished products to ensure that the quality of thermal label paper meets the standards and customer requirements. The test content includes the flatness of the paper, the uniformity of the coating, the printing effect and the durability.

In summary, the production process of thermal label paper is a highly integrated and automated process, which combines the essence of papermaking technology and modern coating technology, and produces thermal label paper products with excellent performance and wide application prospects through fine process control and strict quality inspection.