What are the steps involved in the process of manufacturing colored thermosensitive synthetic paper?

The process of manufacturing colored thermosensitive synthetic paper involves multiple steps, and the following are the main process flows:

1、 Raw material preparation

Main raw materials: Select high-quality polypropylene (PP) resin, especially isotactic polypropylene, whose content usually needs to reach 95%~97%, to ensure the tensile strength and physical properties of the film.

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

Additives: Adding 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, it is rapidly cooled to form 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 treatment

Preparation of coating solution: Prepare coating solutions such as thermosensitive coating, primer, and protective layer, strictly control the composition, concentration, and coating amount of the coating solution.

Coating: Apply thermal sensitive coating, base coating, protective layer, etc. on the surface of the film. The coating process needs to ensure the uniformity and adhesion of the coating.

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 process of manufacturing colored thermosensitive synthetic paper involves multiple steps, including raw material preparation, raw material mixing, plasticization and extrusion, casting and cooling, stretching treatment, surface treatment, coating treatment, winding and slitting, as well as aging treatment and quality inspection. The precise control and optimization of these steps are crucial for obtaining high-quality color thermosensitive synthetic paper.