A Printing on plastic film substrates presents some unique challenges. Unlike paper or cardboard, plastic films have a non-porous surface that can make it difficult for ink to adhere. In addition, many plastic films are flexible, which can affect the accuracy of the printing process. To overcome these challenges, it is important to use the right combination of ink, substrate, and printing technique.
Substrate Selection
The first step in printing on plastic film substrates is to select the right substrate. There are many different types of
plastic films available, each with its own unique properties. Some of the most common types of plastic films used in flexo printing include:
Polyethylene (PE)
PE is a popular substrate for flexo printing due to its low cost and excellent printability. It is commonly used for food packaging, shopping bags, and other applications.
Polypropylene (PP)
PP is another popular substrate for flexo printing. It is more rigid than PE, making it a good choice for applications where stiffness is important.
Polyester (PET)
PET is a high-strength substrate that is commonly used for label and packaging applications. It has excellent printability and is resistant to moisture and chemicals.
Polyvinyl Chloride (PVC)
PVC is a rigid substrate that is commonly used for credit cards, gift cards, and other applications. It has good printability and can be made in a variety of colors.
When selecting a substrate, it is important to consider factors such as print quality, durability, and cost.
Ink Selection
The next step in printing on plastic film substrates is to select the right ink. There are many different types of inks available, each with its own unique properties. Some of the most common types of inks used in flexo printing include:
Water-Based Inks
Water-based inks are a popular choice for flexo printing on plastic film substrates. They are environmentally friendly and offer good print quality.
Solvent-Based Inks
Solvent-based inks are another popular choice for flexo printing. They offer excellent adhesion and are resistant to water and chemicals.
UV-Curable Inks
UV-curable inks are a newer type of ink that are becoming increasingly popular in flexo printing. They offer fast drying times and excellent adhesion.
When selecting an ink, it is important to consider factors such as adhesion, print quality, and environmental impact.
Printing Process
Once the substrate and ink have been selected, it is time to begin the printing process. The following steps outline the basic process for printing on plastic film substrates with flexo printing:
Step 1: Pre-Press
The first step in the printing process is pre-press. This involves preparing the artwork and creating the printing plates. The printing plates are typically made of photopolymer and are used to transfer the ink to the substrate.
Step 2: Ink Preparation
The next step is to prepare the ink. This involves mixing the ink to the desired color and viscosity.
Step 3: Printing
Once the ink has been prepared, it is time to begin printing. The printing press is set up with the substrate and the printing plates. The ink is transferred from the printing plates to the substrate, creating the desired image.
Step 4: Drying and Finishing
After the ink has been transferred to the substrate, it is important to allow it to dry. This can be done using a variety of methods, including air-drying, heat-drying, or UV-curing. Once the ink is dry, the finished product can be cut, folded, or otherwise finished as needed.
Best Practices for Printing on Plastic Film Substrates
To ensure the best possible results when printing on
plastic film substrates with flexo printing, it is important to follow some best practices:
Use the Right Combination of Substrate and Ink
As discussed earlier, selecting the right combination of substrate and ink is key to achieving good print quality and adhesion.
Consider the Printing Environment
The printing environment can have a significant impact on the quality of the printed product. Factors such as temperature, humidity, and air flow should be carefully controlled to ensure consistent results.
Optimize the Printing Process
The printing process itself should be carefully optimized to ensure the best possible results. This includes factors such as press speed, ink viscosity, and anilox roll selection.
Conclusion
Printing on plastic film substrates with
flexo printing can be challenging, but by selecting the right substrate, ink, and printing process, it is possible to achieve excellent results. Whether you are printing labels, packaging, or other plastic film products, following best practices and optimizing your process can help you achieve the highest quality and most consistent results possible.
