What is the coating process of colored thermosensitive synthetic paper?

The coating process of colored thermosensitive synthetic paper is a critical step that determines the final performance and printing effect of the paper. The following is a detailed explanation of the process:

1、 Preparation before coating

Raw material mixing:

Mix polypropylene resin, functional fillers (such as pigments and dyes), additives (such as antioxidants, lubricants, fluorescent whitening agents, titanium dioxide, etc.), and thermosensitive coating materials (such as latent dyes, color developing agents, etc.) uniformly 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.

Substrate preparation:

BOPP (biaxially oriented polypropylene) film is usually used as the substrate.

The substrate needs to have a certain thickness and strength to ensure stability and durability during the printing process.

2、 Coating process

Preparation of coating solution:

Mix the thermosensitive coating material, solvent (such as water or organic solvent), and other necessary additives evenly to prepare a coating solution.

The composition, concentration, and viscosity of the coating liquid need to be adjusted according to specific product and process requirements.

Coating operation:

Use a coating machine to evenly apply the coating liquid onto the surface of BOPP film.

The coating methods may include scraper coating, air knife coating, roller coating, etc., and the specific selection needs to be determined according to the properties of the coating liquid and process requirements.

During the coating process, it is necessary to strictly control the coating amount, coating speed, and coating uniformity to ensure the performance and quality of the final product.

Drying and curing:

After coating, the paper needs to be dried and cured to ensure that the coating adheres firmly to the paper and achieves the best printing effect.

Drying methods may include air flow drying under low temperature conditions, rapid drying using ultraviolet lamps, etc.

The curing process may involve reactions such as heating or chemical cross-linking to enhance the adhesion and durability of the coating.

3、 Subsequent processing

Surface treatment:

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

Roll up and slitting:

Roll the coated and dried cured film into a uniform large roll.

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

Timeliness processing:

Perform aging treatment on the sliced film to further improve its physical properties and stability.

The processing time for timeliness is usually completed within 24-48 hours.

quality testing:

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.

In summary, the coating process of colored thermosensitive synthetic paper involves multiple key steps and detailed control. By precisely controlling the process parameters such as raw material ratio, coating liquid preparation, coating operation, drying and curing, color thermosensitive synthetic paper with excellent performance and printing effect can be produced.