The production and manufacturing process of BOPP thermal sensitive synthetic paper

The production and manufacturing process of BOPP thermal sensitive synthetic paper is a relatively complex and delicate process, involving multiple steps and precise proportioning of raw materials. The following are the main steps of the process:

1、 Raw material preparation

Main raw materials: Polypropylene (PP) resin, especially isotactic polypropylene, is mainly used, and its content needs to reach a high standard (such as 95%~97%) to ensure the tensile strength and physical properties of the film.

Functional fillers: Add functional fillers such as pigments, dyes, etc. as needed to give paper specific colors and functional properties.

Additives: including antioxidants, lubricants, fluorescent whitening agents, titanium dioxide, etc., to improve the processing performance of paper and the performance of the final product.

2、 Raw material mixing

Mix polypropylene resin, functional fillers, and various additives evenly in a certain proportion. The mixing process requires strict control of the proportion of raw materials and mixing quality to ensure the performance of the final product.

3、 Plasticization and Extrusion

Plasticization: Feed the mixed raw materials into an extruder for plasticization. The processing temperature of the extruder is generally around 250 ℃, and the specific temperature is adjusted according to the temperature resistance of the raw materials and the performance of the extruder.

Extrusion: During the plasticization process, the raw materials are melted into a uniform melt through high temperature and high pressure in the extruder, and then extruded into thick sheets through the die.

4、 Casting and Cooling

After extruding the melted polypropylene melt into thick sheets through a die, it is rapidly cooled into regular thick sheets. The cooling process usually uses chilled rollers and a water tank, with a temperature controlled between 30~45 ℃.

5、 Stretching treatment

Longitudinal stretching: The casting sheet is subjected to longitudinal stretching treatment, with a stretching ratio generally between 4.5 and 5.5. During the stretching process, it is necessary to control the temperature of the preheating zone, stretching zone, and shaping zone to ensure the uniformity and tensile strength of the film.

Lateral stretching: The casting sheet is subjected to lateral stretching treatment, with a stretching ratio generally between 9 and 10. Horizontal stretching also requires controlling the temperature and stretching speed of the preheating zone, stretching zone, and shaping zone to achieve bi-directional stretching of the film.

6、 Surface treatment

Perform corona treatment or other surface treatments on the stretched film as needed to improve the surface tension of the film and enhance the adhesion of the coating layer.

7、 Coating

Coat the surface of the film with a thermosensitive coating, a base coating, and a protective layer. The coating process requires strict control of the composition, concentration, and coating amount of the coating liquid to ensure the performance of the final product. Thermal sensitive coating is formed by coating chemical substances such as latent dyes and color developing agents on the surface of BOPP film through a special process. This coating remains stable at room temperature and does not undergo color development reactions.

8、 Roll up and slitting

Roll up: Roll up the coated film into a uniform large roll. During the winding process, it is necessary to control the tension of the contact roller and pressure roller to maintain the flatness and tightness of the large film roll.

Slitting: Cut large film rolls into appropriate sizes according to customer requirements. The slitting process requires strict control of slitting accuracy and edge quality.

9、 Timeliness processing and quality inspection

Aging treatment: The sliced film is subjected to aging treatment, usually completed within 24-48 hours, to improve the physical properties and stability of the film.

Quality inspection: Conduct quality inspection on the aged film, including appearance quality, physical properties, printing effect, etc., to ensure that the final product meets relevant standards and customer requirements.

In summary, the production and manufacturing process of BOPP thermal sensitive synthetic paper involves multiple fine process steps and precise proportioning of raw materials. These steps together ensure the quality and performance of the final product, enabling it to meet a wide range of application needs in fields such as e-commerce.