What is the production process of BOPP thermal synthetic paper?

The production process of BOPP thermosensitive synthetic paper is a complex and fine process, mainly involving raw material preparation, coating, stretch forming, heat treatment and coiling and cutting. The following is a detailed description of the production process:

First, raw material preparation

Base film selection:

BOPP thermal synthetic paper is based on BOPP (Biaxially stretched polypropylene) film. This film has good physical properties, chemical stability and processing properties, and is an ideal substrate for making heat-sensitive synthetic paper.

Raw material purchase and inspection:

Procurement of high quality polypropylene resin as raw material to ensure that the raw material has a high molecular weight, narrow molecular weight distribution and good processing properties. At the same time, the quality of raw materials is inspected to ensure that it meets the production requirements.

Additive:

Additives such as antioxidants, antistatic agents and smoothing agents are added as needed to improve the properties of the film. These additives should be mixed evenly with the polypropylene resin in a certain proportion.

Second, coating

Coating solution preparation:

The coating solution of base coating, hair color layer and protective layer was prepared respectively. These coatings contain specific chemicals that give BOPP films their heat-sensitive properties.

Coating operation:

Each layer of coating liquid is separately poured into the feed tank of the coating machine, and the base coating, hair color layer and protective layer are successively applied on the BOPP base film by using the metering rod coating method or other suitable coating method. The amount and speed of coating need to be precisely controlled during the coating process to ensure uniform coating and consistent thickness.

Three, stretch forming

Melt extrusion:

The coated BOPP base film is sent to the extruder for melting extrusion. By controlling the temperature, pressure and speed of the extruder, the polypropylene resin is fully melted and evenly distributed on the base film.

Bidirectional stretching:

The molten extruded sheet is subjected to bidirectional stretching treatment. This step stretches the sheet lengthwise and laterally to increase the strength and toughness of the film. The stretching process needs to be carried out at a certain temperature and tension to ensure the quality and performance of the film.

4. Heat Treatment

The stretched film is sent to the heat treatment furnace for heat treatment. Heat treatment can eliminate the internal stress of the film, improve the dimensional stability of the film and the sensitivity of the thermal sensitive coating. At the same time, the heat treatment process requires precise control of temperature and time to avoid deformation or aging of the film.

Five, winding and cutting

Roll up:

The film after heat treatment is rewound to form a rolled product of a certain width and length. During the winding process, the winding speed and tension need to be controlled to ensure the quality of the film coil.

Divide:

According to the need, the large roll of film is cut into smaller rolls of different specifications. The cutting process needs to maintain the consistency of the sharpness of the tool and the cutting speed to ensure that the edge of the film after cutting is smooth and the size is accurate.

6. Quality control and testing

In the entire production process, the process parameters and quality standards need to be strictly controlled. The appearance test, physical property test and chemical property test of the produced BOPP thermal synthetic paper are carried out to ensure that it meets the quality requirements. At the same time, establish a sound inspection record and quality traceability system in order to find and solve problems in time.

In summary, the production process of BOPP thermal synthetic paper is a process involving multiple links and complex operations. By strictly controlling the key factors such as raw material quality, coating accuracy, stretch forming conditions and heat treatment parameters, high quality and high performance BOPP thermal sensitive synthetic paper products can be produced.