What factors affect the color uniformity in the production of BOPP color synthetic paper?

There are many factors that affect the color uniformity in the production process of BOPP color synthetic paper, and the following are some of the main factors:

1. Selection and ratio of raw materials

Pigment quality: The quality of the pigment directly affects the brightness, stability and uniformity of the color. The use of high-quality, well-dispersed pigments helps to ensure color uniformity.

Raw material ratio: The ratio of polypropylene resins, pigments and auxiliaries needs to be precisely controlled to ensure color consistency and uniformity. Any deviation in the ratio can result in uneven color.

2. Ingredients mixing process

Mixing uniformity: The mixing uniformity of raw materials in the high-speed mixer directly affects the color uniformity of the final product. If the mixture is not uniform, the distribution of pigment particles in the resin will be uneven, resulting in color differences in the product color.

3. Extrusion casting process

Extrusion temperature: The control of extrusion temperature is crucial to the uniformity of color. Too high or too low a temperature may affect the dispersion and stability of the pigment, thus affecting the uniformity of the color.

Extrusion speed: The stability and consistency of the extrusion speed is also an important factor affecting the color uniformity. Velocity fluctuations may result in uneven distribution of thickness and color of extruded sheets.

4. Bidirectional stretching process

Drawing conditions: Conditions such as temperature, tension and speed during the drawing process need to be precisely controlled to ensure a uniform color distribution of the film during the drawing process. Improper stretching conditions may result in different local color shades of the film.

5. Heat treatment and cooling process

Heat treatment temperature and time: Temperature and time control during heat treatment is essential to eliminate internal stress and improve color stability. Too high temperature or too long time may cause color change or uneven color.

Cooling conditions: Cooling speed and uniformity also affect the final performance of the color. Uneven cooling may lead to local shrinkage or deformation of the film, which will affect the uniformity of color.

6. Equipment and process conditions

Equipment accuracy: The accuracy and stability of the production equipment directly affect the color uniformity of the product. Uneven colors can result from equipment wear, reduced accuracy, or improper operation.

Process control: The process control in the entire production process needs to be strictly controlled, including the process parameter setting and adjustment of various links such as raw material preparation, mixing of ingredients, extrusion casting, bidirectional drawing, heat treatment and cooling. Any link out of control can lead to uneven color.

7. Environmental factors

Temperature and humidity: Temperature and humidity changes in the production workshop may also have an impact on color uniformity. Temperature and humidity fluctuations may lead to changes in raw material properties or decrease in equipment accuracy, thereby affecting color uniformity.

To sum up, in order to ensure the color uniformity in the production process of BOPP color synthetic paper, it is necessary to carry out comprehensive control and management from many aspects, such as raw material selection and ratio, mixing process, extrusion casting process, bidirectional tensile process, heat treatment and cooling process, equipment and process conditions, and environmental factors.