What is the production process of BOPP colored synthetic paper?

The production process of BOPP color synthetic paper (especially BOPP color thermosensitive synthetic paper) usually includes the following key steps:

1、 Raw material preparation and mixing

Main raw material selection: High quality 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 and additives: Add functional fillers such as pigments and dyes, as well as antioxidants, lubricants, fluorescent whitening agents, titanium dioxide and other additives as needed to improve the processing performance of paper and the performance of the final product.

Mixing: Mix polypropylene resin, functional fillers, and various additives evenly in a certain proportion, and strictly control the proportion and quality of the raw materials during the mixing process.

2、 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 through the die.

3、 Casting and Cooling

Casting: extruding molten polypropylene into thick sheets through a die.

Cooling: Quickly cool the cast piece to make it form a regular shape. The cooling process usually uses chilled rollers and a water tank, with a temperature controlled between 30~45 ℃.

4、 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.

5、 Surface treatment

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

6、 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. For BOPP color thermal sensitive synthetic paper, the application of thermal sensitive coating is particularly crucial, as it determines the thermal printing effect of the paper.

7、 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.

8、 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. Aging treatment helps to release the internal stress of the film and improve its thermal stability.

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

9、 Packaging and Delivery

Packaging: After passing the quality inspection, the film is carefully packaged to ensure that the product is not damaged during transportation.

Delivery: Deliver according to the agreed time, location, and method. At the same time, we provide a comprehensive after-sales service system, including product usage guidance, problem solving, etc.

In summary, the production process of BOPP color synthetic paper is a complex and delicate process, involving multiple key steps and strict quality control. Each step has a significant impact on the performance and quality of the final product.