How to control the quality of BOPP color synthetic paper?

Controlling the quality of BOPP color synthetic paper is a comprehensive process that involves multiple aspects such as raw material selection, production technology, equipment control, subsequent processing, and quality inspection. Here are some key quality control measures:

1、 Raw material selection and proportioning

Main raw materials: Select high-quality polypropylene (PP) resin, especially isotactic polypropylene, with a content that meets high standards (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. The types and amounts of these fillers need to be strictly controlled to ensure that the final product has bright, uniform colors and meets customer requirements.

Additives: including antioxidants, lubricants, fluorescent whitening agents, titanium dioxide, etc., to improve the processing performance of paper and the performance of the final product. The selection and ratio of additives need to be adjusted according to specific production needs.

2、 Production process control

Plasticization process: Send the mixed raw materials into an extruder for plasticization. The processing temperature of the extruder needs to be strictly controlled, generally around 250 ℃, and the specific temperature should be adjusted according to the temperature resistance of the raw materials and the performance of the extruder. During the plasticization process, the raw materials undergo high temperature and high pressure in the extruder, melting into a uniform melt.

Casting and cooling: The molten polypropylene is extruded into thick sheets through a die and rapidly cooled into regular thick sheets. The cooling process usually uses chilled rollers and a water tank, with a temperature controlled between 30~45 ℃. The cooling rate and temperature need to be uniform and consistent to ensure the thickness uniformity and surface quality of the casting.

Bi directional stretching: The casting sheet is subjected to longitudinal and transverse stretching treatment, and the stretching ratio needs to be adjusted according to specific production requirements. During the stretching process, it is necessary to control the temperature and stretching speed of the preheating zone, stretching zone, and shaping zone to achieve bi-directional stretching and uniformity of the film.

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. The effect of surface treatment needs to be strictly inspected to ensure a strong bond between the coating and the substrate.

3、 Equipment control and automated production

Intelligent control system: Adopting advanced intelligent control system, real-time monitoring of various parameters in the production process, such as temperature, pressure, speed, etc., and automatic adjustment according to preset process requirements. This can ensure the stability of the production process and consistency of product quality.

Automated production line: Introducing automated production lines to reduce manual intervention, improve production efficiency and product accuracy. The application of technologies such as automatic roll changing, automatic film bonding, and automatic detection makes the production process more efficient and continuous.

Efficient extruder and energy-saving drying system: Adopting new high-efficiency extruders and energy-saving drying systems to improve melting efficiency and extrusion speed, and reduce production costs. Meanwhile, optimizing the drying system through technologies such as infrared preheating and hot air circulation can improve drying efficiency and reduce energy consumption.

4、 Subsequent processing and quality inspection

Coating and winding: Coating the surface of the film with thermosensitive coating, primer, and protective layer. The coating process requires strict control of the composition, concentration, and coating amount of the coating liquid. 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.

Aging treatment: The sliced film is subjected to aging treatment to improve its physical properties and stability. The time for timely processing needs to be adjusted according to specific production requirements.

Quality inspection: Conduct quality inspection on the aged film, including appearance quality, physical properties (such as tensile strength, elongation at break, etc.), optical properties (such as transmittance, haze, etc.), and printing effect. Ensure that the final product meets relevant standards and customer requirements.

In summary, controlling the quality of BOPP color synthetic paper requires starting from multiple aspects such as raw material selection, production process, equipment control, subsequent processing, and quality inspection. By strictly controlling the quality and process parameters of each link, it is possible to ensure that the quality and performance of the final product meet customer requirements.