Ensuring print durability on rollstock films is a critical aspect of our business as a rollstock films supplier. In this blog, I’ll share insights and strategies that we’ve developed over the years to guarantee long – lasting prints on our rollstock films. Rollstock Films
Understanding the Basics of Rollstock Films
Rollstock films are a type of flexible packaging material that come in long rolls. They are widely used in various industries, including food, pharmaceuticals, and consumer goods, for packaging products. The films can be made from different materials such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). Each material has its own unique properties, and these properties can significantly affect print durability.
For example, PE is a very flexible and cost – effective material. However, it has a relatively low surface energy, which can make it difficult for inks to adhere properly. On the other hand, PET has a higher surface energy, providing better ink adhesion, but it is more rigid and may be more expensive.
Factors Affecting Print Durability
1. Film Surface Treatment
One of the most important factors in ensuring print durability is the surface treatment of the rollstock film. Surface treatment is necessary to increase the surface energy of the film, allowing the ink to adhere more effectively. Common surface treatment methods include corona treatment and plasma treatment.
Corona treatment involves exposing the film surface to a high – voltage electrical discharge. This process creates free radicals on the film surface, which react with oxygen in the air to form polar groups. These polar groups increase the surface energy of the film, making it more receptive to ink. Plasma treatment, on the other hand, uses a low – temperature plasma to modify the film surface. It can be more precise and effective than corona treatment, especially for films with complex surface structures.
We always recommend that our customers ensure proper surface treatment before printing on our rollstock films. Our technical team can provide detailed guidelines on the appropriate surface treatment parameters based on the type of film and the printing method.
2. Ink Selection
The choice of ink is also crucial for print durability. There are different types of inks available, such as solvent – based inks, water – based inks, and UV – curable inks.
Solvent – based inks have been widely used in the past due to their good adhesion and fast drying properties. However, they contain volatile organic compounds (VOCs), which can be harmful to the environment and human health. Water – based inks are a more environmentally friendly alternative. They have lower VOC emissions and are suitable for many applications. But they may require longer drying times and may not adhere as well to some types of films.
UV – curable inks are becoming increasingly popular because they offer excellent print durability. When exposed to UV light, the inks cure almost instantly, forming a hard and durable film. They have good resistance to abrasion, chemicals, and fading. We work closely with ink suppliers to ensure that the inks we recommend are compatible with our rollstock films and can provide long – lasting prints.
3. Printing Process
The printing process itself can have a significant impact on print durability. There are several printing methods commonly used for rollstock films, including flexography, gravure printing, and digital printing.
Flexography is a widely used printing method for rollstock films. It uses a flexible relief plate to transfer ink onto the film. The key to achieving good print durability in flexography is to ensure proper ink transfer and pressure control. If the pressure is too high, it can damage the film surface, while if the pressure is too low, the ink may not adhere properly.
Gravure printing uses engraved cylinders to transfer ink onto the film. It can produce high – quality prints with excellent detail and color accuracy. However, it requires a more complex setup and may be more expensive for short – run jobs. To ensure print durability in gravure printing, it is important to control the ink viscosity and drying conditions.
Digital printing is a relatively new technology that offers more flexibility and shorter turnaround times. It uses inkjet or laser technology to print directly onto the film. Digital printing can be a great option for small – scale production or customized prints. To ensure print durability in digital printing, we recommend using high – quality inks and proper curing methods.
Testing and Quality Control
To ensure the print durability of our rollstock films, we have a comprehensive testing and quality control system in place.
1. Adhesion Testing
Adhesion testing is one of the most important tests for print durability. We use methods such as the cross – hatch test and the tape test to evaluate the adhesion of the ink to the film surface. In the cross – hatch test, a grid of cuts is made on the printed film, and then a piece of tape is applied and removed. The amount of ink that is removed with the tape is used to assess the adhesion strength.
2. Abrasion Testing
Abrasion testing is used to evaluate the resistance of the print to wear and tear. We use equipment such as the Taber abraser to simulate the abrasion that the printed film may encounter during handling, transportation, and storage. The print is subjected to a certain number of abrasion cycles, and then the appearance and quality of the print are evaluated.
3. Chemical Resistance Testing
Chemical resistance testing is important, especially for films used in packaging products that may come into contact with chemicals. We expose the printed film to various chemicals, such as acids, alkalis, and solvents, and then evaluate the effect on the print. This helps us to ensure that the print will not be damaged by the chemicals in the packaged product.
Post – Printing Treatments
In addition to the above factors, post – printing treatments can also enhance print durability.
1. Lamination
Lamination involves applying a protective layer of film over the printed surface. This can provide additional protection against abrasion, moisture, and UV light. There are different types of lamination films available, such as clear polyester films and polyethylene films. The choice of lamination film depends on the specific requirements of the application.
2. Coating
Coating is another post – printing treatment that can improve print durability. Coatings can be applied to the printed film to provide a hard, protective layer. There are different types of coatings available, such as acrylic coatings and polyurethane coatings. The coating can also enhance the appearance of the print, giving it a glossier or matte finish.
Conclusion
Ensuring print durability on rollstock films is a complex process that involves understanding the properties of the film, selecting the right ink and printing method, and implementing proper testing and quality control measures. As a rollstock films supplier, we are committed to providing our customers with high – quality films and technical support to ensure that their prints are long – lasting and of the highest quality.
Self-adhesive Labels If you are interested in our rollstock films and want to discuss your specific printing requirements, we invite you to reach out to us for a procurement discussion. Our team of experts is ready to assist you in finding the best solutions for your business.
References
- "Flexible Packaging: Technology and Innovation" by J. Hanlon, R. Kelsey, and F. Forcinio
- "Printing Technology Handbook" by J. D. Godwin
- "Plastics Packaging: Properties, Processing, Applications, and Regulations" by R. J. Crawford
Nanjing Green Label Printing Co., Ltd.
We are one of the most professional rollstock films manufacturers and suppliers in China, also support customized service. We warmly welcome you to wholesale high quality rollstock films at competitive price from our factory. For pricelist and quotation, contact us now.
Address: No. 116-3 Suyuan Avenue, Jiangning District, Nanjing
E-mail: greenlabel@126.com
WebSite: https://www.chinalabelprint.com/
