Polyvinylidene Chloride (PVDC) inner printing film is a versatile and widely used material in the packaging industry. Its excellent barrier properties against oxygen, moisture, and odors, along with good mechanical strength and printability, make it a popular choice for various food and non – food packaging applications. As a supplier of PVDC inner printing film, I understand the importance of achieving clear and high – quality prints on this film. In this blog post, I will share some practical tips and considerations on how to print clear images on PVDC inner printing film. Polyvinylidene Chloride Inner Printing Film
Understanding the Characteristics of PVDC Inner Printing Film
Before diving into the printing process, it’s crucial to understand the unique characteristics of PVDC inner printing film. PVDC has a relatively low surface energy, which means that inks may not adhere to it as easily as they do to some other materials. This can lead to issues such as ink adhesion failure, poor print definition, and smudging. Additionally, PVDC film can be sensitive to temperature and humidity changes during printing and storage, which can affect the final print quality.
Surface Treatment
One of the first steps to ensure clear printing on PVDC inner printing film is to properly treat the film surface. Surface treatment increases the surface energy of the film, allowing the inks to wet and adhere better. Corona treatment is the most commonly used method for treating PVDC film surfaces.
Corona treatment works by using high – voltage electricity to create a corona discharge in the air above the film surface. This discharge breaks the molecular bonds on the film surface, creating free radicals that can react with the ink, improving adhesion. It’s important to monitor the corona treatment level regularly using a surface tension test pen. The recommended surface tension for PVDC film after corona treatment is typically around 38 – 42 dynes/cm. If the surface tension is too low, the ink may not spread evenly, resulting in poor print quality; if it’s too high, the film surface may be over – treated, leading to film degradation and reduced barrier properties.
Ink Selection
Choosing the right ink is essential for achieving clear images on PVDC inner printing film. There are several factors to consider when selecting inks:
- Adhesion: The ink must have good adhesion to the PVDC film. Solvent – based inks are often a popular choice for PVDC printing because they can provide better adhesion compared to water – based inks. However, solvent – based inks also have some environmental and safety concerns. Water – based inks are becoming more popular due to their lower VOC emissions, but they require careful formulation and may need additional additives to improve adhesion to PVDC.
- Colorfastness: The ink should have good colorfastness to ensure that the printed images do not fade or change color over time. This is especially important for products that will be exposed to light, heat, or other environmental factors during storage and transportation.
- Viscosity: The viscosity of the ink affects its flow and transfer properties during the printing process. Inks with the right viscosity will flow smoothly through the printing press and transfer evenly onto the film, resulting in clear and sharp prints.
Printing Press Setup
Proper setup of the printing press is crucial for clear image printing on PVDC inner printing film. Here are some key aspects to consider:
- Printing Plate Preparation: The printing plates should be clean, free of scratches, and properly mounted on the printing press. Any defects on the printing plates can be transferred to the film, resulting in poor print quality. The plate’s surface roughness and cell depth also need to be optimized according to the type of ink and the desired print effect.
- Ink Delivery System: The ink delivery system, including the ink fountain, anilox roller, and doctor blade, needs to be adjusted correctly. The anilox roller should have the appropriate line count and cell volume to transfer the right amount of ink onto the printing plate. The doctor blade should be properly installed and adjusted to ensure a uniform ink layer on the anilox roller.
- Registration: Accurate registration is essential for multi – color printing. The printing press should be calibrated regularly to ensure that each color is printed in the correct position on the film. Any misregistration can lead to blurred or overlapping images.
Printing Process Control
During the printing process, it’s important to closely control various parameters to ensure clear image printing:
- Temperature and Humidity: As mentioned earlier, PVDC film is sensitive to temperature and humidity changes. The printing environment should be maintained at a stable temperature and humidity level. Generally, a temperature range of 20 – 25°C and a relative humidity of 40 – 60% are recommended. Fluctuations in temperature and humidity can cause the film to expand or contract, leading to registration problems and poor ink adhesion.
- Printing Speed: The printing speed should be optimized according to the type of ink, printing press, and film. If the printing speed is too fast, the ink may not have enough time to dry properly, resulting in smudging and poor print quality. On the other hand, if the speed is too slow, it can reduce production efficiency.
- Drying Conditions: Proper drying is crucial to ensure that the ink adheres firmly to the film and does not transfer or smudge. Different types of inks require different drying methods and conditions. Solvent – based inks usually require forced hot – air drying, while UV – curable inks are dried using ultraviolet light. The drying temperature and time should be carefully controlled to avoid over – drying or under – drying the film.
Quality Inspection
After printing, a thorough quality inspection should be carried out to ensure that the printed images are clear and meet the required standards. This can include visual inspection for defects such as scratches, ink stains, misregistration, and poor adhesion. Additionally, more quantitative tests such as ink adhesion tests (using tape tests), colorimetry tests to measure color accuracy, and print durability tests can be performed.
Troubleshooting
Even with careful process control, some printing problems may still occur. Here are some common issues and their possible solutions:
- Ink Adhesion Problems: If the ink does not adhere well to the film, check the surface treatment level of the film. If the surface tension is too low, re – treat the film. Also, make sure that the ink is compatible with the PVDC film and that the drying conditions are appropriate.
- Poor Print Definition: Poor print definition can be caused by issues such as dirty printing plates, incorrect anilox roller selection, or improper ink viscosity. Clean the printing plates regularly, choose the right anilox roller, and adjust the ink viscosity as needed.
- Smudging: Smudging can be a result of insufficient drying or over – printing pressure. Increase the drying temperature or time, and adjust the printing pressure to ensure a uniform transfer of ink.
Conclusion
Printing clear images on PVDC inner printing film requires a comprehensive understanding of the film’s properties, proper surface treatment, ink selection, printing press setup, process control, and quality inspection. By following the tips and considerations outlined in this blog post, you can significantly improve the print quality of your PVDC inner printing film.
Coextruded Film As a supplier of PVDC inner printing film, I am committed to providing high – quality products and technical support to help you achieve the best printing results. If you are interested in our PVDC inner printing film or have any questions about printing on this material, please feel free to contact us for further discussion and potential procurement opportunities. We look forward to working with you to create outstanding packaging solutions.
References
- Packaging Technology and Science Journal, various issues on PVDC film properties and printing
- Printing Industry Handbook, chapters on flexible packaging printing
- Manufacturer’s technical data sheets on PVDC films and printing inks
Sinosealed Packaging Solutions Limited
With a professional production team, we are one of the most experienced polyvinylidene chloride inner printing film manufacturers and suppliers in China. Please rest assured to buy high quality polyvinylidene chloride inner printing film for sale here from our factory. For price consultation, contact us.
Address: Luohe City, Henan Province, China
E-mail: contact@barrierpackage.com
WebSite: https://www.barrierpackage.com/
