Solution for flexographic printing on BOPP plastic film

The printing plate used in flexographic printing is made of rubber or resin, which has the characteristics of softness and flexibility, and has good ink transfer performance.
Flexographic printing generally uses water-based ink for printing, which uses water as a solvent and has significant environmental advantages compared to traditional solvent based inks.
Flexographic printing uses a mesh roller for ink transfer, with a simple structure, high printing accuracy, and fast printing speed. Combined with quick drying water-based ink, the printing speed can reach 1.5 to 2 times that of offset and gravure printing machines, achieving high-speed multi-color printing.

Flexographic printing is suitable for a variety of substrates, including plastic films, paper products, aluminum foil, non-woven fabrics, etc. It has a wide range of applications in packaging printing, label printing, and other fields.

BOPP film is widely used as various packaging materials due to its high transparency, good glossiness, and excellent mechanical properties. It can be made into various packaging bags, such as food packaging bags, candy packaging, clothing packaging, daily chemical product packaging, etc

The high barrier properties and excellent heat sealing performance of BOPP film make it an ideal choice for cigarette packaging film. BOPP film can also be compounded with other materials such as PET, aluminum foil, PE, etc. to make composite films. Widely used in fields such as food packaging, pharmaceutical packaging, pesticide packaging, etc.
BOPP film has a smooth surface and low surface tension of approximately 40 dynes, requiring high adhesion to ink.

1. Adhesion problem
The insufficient adhesion between water-based ink and BOPP film can easily lead to ink peeling, blurring, and other phenomena during the use of printed materials. This requires us to perform appropriate surface treatment on BOPP film before printing, such as corona treatment, to increase its surface tension; At the same time, it is necessary to optimize the water-based ink formula and select resins and additives that are compatible with BOPP film.
2. Drying speed issue
The drying speed of water-based ink needs to match the speed of the printing machine. When high-speed printing is required, it is necessary to improve the drying system, increase the wind speed and air volume, and accelerate the drying process. Otherwise, not only will it affect production efficiency, but it may also cause problems such as deformation and adhesion of printed materials.
3. Printing quality issues
During the printing process, quality issues such as uneven ink color, pinholes, and scratches may also be encountered. This requires us to ensure accuracy and adaptability when selecting flexographic printing sleeves and mesh rollers; At the same time, it is necessary to adjust the printing process parameters, such as printing pressure, speed, etc., to achieve the best printing effect.

1. Improve adhesion
Surface treatment: Using methods such as corona treatment to increase the surface tension of BOPP film and enhance the adhesion of ink.
Ink formula optimization: Select resins and additives that are compatible with BOPP film, such as adding adhesion promoters, to improve the adhesion of the ink.
• Additive use: Introduce leveling agents and other additives to improve the spreading of ink on BOPP film, making the ink layer more uniform and smooth.

2. Accelerate drying speed
• Improve the drying system: Redesign the heating device and the angle of hot air inlet and outlet to improve drying efficiency; Increase wind speed and volume to accelerate the evaporation rate of moisture.

3. Improve printing quality
Equipment selection and adjustment: Choose high-precision and adaptable flexographic printing sleeves and mesh rollers; Adjust printing process parameters to ensure even ink transfer and stable printing effect.
Strengthen equipment maintenance: Regularly maintain and upkeep printing equipment to ensure it is in optimal working condition.

 

There is a candy manufacturer that has won the love of consumers with its unique taste and exquisite packaging. With the increasingly fierce market competition, the brand has decided to upgrade its candy packaging bags to further enhance its brand image and market competitiveness. After careful consideration, they chose BOPP film as the new packaging material and decided to use flexographic printing technology to achieve their exquisite design vision.

Product Description:
This candy packaging bag is made of highly transparent BOPP film, designed to showcase the enticing colors and texture of the candy itself. The design of the packaging bag combines modern simplicity and retro elements, with gold and white as the main colors, matched with exquisite patterns and delicate textures, creating a high-end and elegant visual effect.

Printing Challenge:
Color reproduction: Due to the rich and diverse colors of candy itself, ensuring accurate reproduction of colors on packaging bags has become a major challenge in the printing process.
Pattern precision: The pattern design on the packaging bag is complex, including delicate lines and tiny text, requiring printing technology to achieve extremely high precision.
Environmental requirements: As food packaging materials, BOPP film and printing ink must comply with food safety standards to ensure non-toxic and harmless properties.

Printing scheme:
Material selection: Select highly transparent and weather resistant BOPP film as the substrate to ensure the texture and durability of the packaging bag.
Ink selection: Environmentally friendly water-based ink is used, and strict testing is conducted to ensure compliance with food safety standards. At the same time, precise colors are adjusted according to design requirements to ensure the color reproduction of printed materials.

Pre press preparation: During the pre press design phase, work closely with the designer to carefully review and adjust the design draft. Utilize advanced color management systems for color correction to ensure color consistency between design drafts and printed materials.

Printing process: High precision flexographic printing machine is used for printing. During the printing process, the speed, pressure, and tension parameters of the printing machine are strictly controlled to ensure the precision and stability of the pattern. At the same time, real-time monitoring of printing quality is achieved through an online detection system to promptly identify and resolve issues.
Post processing: After printing is completed, the packaging bag undergoes post-processing processes such as cutting, folding, and heat sealing. During the heat sealing process, special attention should be paid to controlling the temperature and time to ensure that the seal is firm and does not affect the aesthetics of the packaging bag.