Container Screen Printing Knowledge
Introduction: Screen printing uses a silk screen as a base and a photosensitive platemaking process to create a screen printing plate with images and text. Screen printing consists of five key elements: the screen printing plate, squeegee, ink, printing table, and substrate. The image and text portion of the screen printing plate can be transferred through the ink mesh to various packaging materials, enhancing the packaging's appearance and conveying information.
Applications of Screen Printing in Cosmetic Packaging: It is used on bottles made of plastics such as PET and PP to print brand names, logos, ingredient lists, barcodes, and other information. Multiple overprints are possible to ensure vibrant colors and distinct layers. It is used on bottle caps made of materials such as ABS and acrylic to print logos and simple designs. Matte, pearlescent, or 3D gravure effects can be achieved, enhancing the visual and tactile quality of the packaging.
Process Flow
1. Design and Plate Making: A screen template is created based on the packaging design. 2. Equipment Adjustment: Secure the module to the screen printer and adjust the squeegee pressure and printing speed.
3. Printing: Print on the bottle or cap, ensuring even ink coverage.
4. Curing: Use LED or UV curing to ensure secure ink adhesion.
5. Inspection and Post-Processing: Check the printing results and perform surface coating if necessary.
Technical Points
1. Screen Printing: Use polyester or metal screen as the base material, manufactured according to the design.
2. Printing Parameter Control:
① Maintain the squeegee angle between 60-75 degrees to ensure even ink transfer and adapt to the surface tension of different substrates.
② Printing Pressure: Adjust according to the substrate thickness and ink characteristics to maintain clear images and text.
③ Screen Printing Mesh Count: Selecting the screen mesh count requires a comprehensive consideration of the design fidelity, slurry particle size, and process parameters. A higher mesh count results in denser threads, smaller pores, and higher-definition patterns. A lower mesh count results in larger pores, allowing the slurry to penetrate more easily, but also resulting in rougher pattern details. Therefore, the slurry particle diameter must be much smaller than the mesh diameter, otherwise it can easily clog the pores or prevent the pattern from printing.
Key Factors in Bottle Screen Printing Process
1. Bottle Surface Tension: The surface tension of the bottle affects the ink's durability after printing. Generally, the surface tension of the material should reach 50 dyn/cm to ensure that the ink does not readily rub off. If surface treatments such as corona treatment or flame treatment are not desired, products with a higher polarity can be printed directly or with an appropriate ink.
2. Ink Selection: To ensure ink durability on the bottle, select the appropriate ink for the bottle material. Different types and colors of inks have different adhesion to different bottle surfaces. If ink adhesion is critical, we can also try adding a curing agent or other auxiliary solvent to the ink to achieve the desired finish after printing.
3. UV Lamp: The key equipment for ink curing is the UV lamp. The choice of UV lamp specifications varies depending on the ink's composition, color, and thickness. To ensure that the ink adheres firmly to the product surface, the UV lamp can be selected to achieve the desired effect. Generally speaking, in actual product processing, different plastic materials and inks will encounter different problems during the screen printing process, and specific issues require specific analysis.
PS ：If you have any needs for plastic bottles and plastic jars, please contact us to place an order. Guangdong Hongyuan, as a plastic bottle and lotion pump manufacturer, is committed to providing customers with high-quality products and excellent service.
