
Dual Cure vs. Pure Photopolymer Emulsion: A Comprehensive Guide

Choosing between dual cure emulsions and pure photopolymer emulsions for screen printing depends on the specific needs and conditions of the printing job. This decision can impact the quality of your prints, the efficiency of your process, and even your bottom line.
In this blog post we delve into the differences between these two types of emulsions, debunk some common misconceptions, and highlight where our Chromaline emulsions fit into the picture. For a more comprehensive emulsion guide, check out our Textile Emulsion Selection Chart.
What Does Dual Cure Emulsion Mean?
A common misconception in our industry is that "dual cure" emulsions are resistant to both solvent and water-based inks. While it's true that many dual cure emulsions exhibit resistance to both ink types, the term "dual cure" actually refers to the emulsion's chemical composition.
Specifically, it means that the emulsion uses two sensitizers. One sensitizer is already present in the emulsion before mixing, and the other, usually a diazo compound, is added by the user. For example, our MagnaCure UDC-HV dual cure emulsion is not recommended for water-based inks, but our CP Tex is suitable for both water-based and plastisol inks, and our MagnaCure UDC-ACE is suitable for water-based, plastisol, and solvent inks.
Advantages of Dual Cure Emulsions
Dual cure emulsions offer several benefits that can make them the preferred choice for many screen printers:
1. Ease of Use:
For beginners, dual cure emulsions are generally easier to handle. They have longer exposure times, providing a larger margin for error during the exposure process. This forgiving nature can be a significant advantage for those still learning the intricacies of screen printing.
2. Versatility:
Dual cure emulsions are versatile and compatible with a wide range of inks, including water-based and plastisol inks. They are also more adaptable to varying environmental conditions such as temperature and humidity.
3. Durability:
Once properly exposed and processed, dual cure emulsions are durable and resistant to the chemicals used in the screen printing process. They also exhibit good resistance to mechanical wear and tear during printing.
4. Tonal Range:
Dual cure emulsions often provide a better tonal range, making them ideal for fine detail work and halftone printing. This quality is critical for achieving high-quality prints with intricate designs.
Situations Where Dual Cure Emulsions Are Preferred
1. Newcomers to Screen Printing:
Due to their forgiving nature during the exposure process, dual cure emulsions are perfect for beginners who are still mastering the craft.
2. Varied Environmental Conditions:
In settings where temperature and humidity fluctuate, dual cure emulsions can be more reliable compared to photopolymer emulsions, which are more sensitive to environmental changes.
Drawbacks of Dual Cure Emulsions
Despite their advantages, dual cure emulsions do have some drawbacks:
1. Longer Exposure Times:
Dual cure emulsions require longer exposure times compared to pure photopolymer emulsions. This can slow down the production process, especially for high-volume jobs.
2. Shelf Life:
Mixed diazo emulsions have a shorter shelf life, usually around 4-6 weeks, compared to photopolymer emulsions which can last several months. This necessitates more frequent mixing and can lead to waste if not used promptly.
What Does Pure Photopolymer Emulsion Mean?
Pure photopolymer emulsion refers to a type of screen printing emulsion that is ready to use right out of the container, without the need for any additional sensitizers like diazo. This type of emulsion is created using a 100% photopolymer formula, which makes it highly sensitive to UV light and results in faster exposure times compared to other emulsions. Advanced pure photopolymer formulations, often referred to as 'hybrid photopolymers' can produce fine details and crisp edges typically only found in dual cure products.
Additionally, pure photopolymer emulsions have a long shelf life and provide consistent, reliable performance, making them a preferred choice for many professional screen printers. Chromaline offers a wide selection of pure photopolymer emulsions, including ChromaBlue, ChromaLime and Hydro-X.
Advantages of Pure Photopolymer Emulsions
Pure photopolymer emulsions offer several distinct advantages that make them a compelling choice for many screen printers:
1. Faster Exposure Times:
One of the most significant benefits of pure photopolymer emulsions is their rapid exposure times. This allows for quicker screen preparation, increasing overall production efficiency and reducing downtime. For high-volume printing operations, this can lead to substantial time savings.
2. High Resolution and Detail:
Pure photopolymer emulsions are known for their ability to capture fine details and produce high-resolution prints. This makes them ideal for intricate designs, halftone printing, and any application requiring precise detail and sharp edges.
3. Extended Shelf Life:
Unlike diazo-based emulsions, pure photopolymer emulsions typically have a longer shelf life. They do not require mixing with diazo sensitizers, which can degrade over time, allowing them to maintain their performance characteristics for several months when stored correctly.
4. Consistency and Stability:
Pure photopolymer emulsions offer excellent consistency and stability. They are less sensitive to environmental changes such as temperature and humidity, which can affect the performance of diazo-based emulsions. This stability ensures more reliable and predictable results.
5. Chemical Resistance:
Hybrid versions exhibit strong resistance to chemicals, including water and solvent-based inks. This makes them suitable for a wide range of applications, providing versatility without compromising on durability.
Situations Where Pure Photopolymer Emulsions Are Preferred
1. High-Volume Production:
For screen printers dealing with high-volume production, the faster exposure times of pure photopolymer emulsions can significantly enhance workflow efficiency and reduce turnaround times.
2. Fine Detail and High Resolution:
When print jobs require capturing intricate details or achieving high-resolution outputs, pure photopolymer emulsions are the preferred choice due to their superior detail reproduction capabilities.
3. Long-Term Storage and Consistency:
For operations that need emulsions with a long shelf life and consistent performance over time, pure photopolymer emulsions provide a reliable solution.
Drawbacks of Pure Photopolymer Emulsions
Despite their advantages, pure photopolymer emulsions also have some limitations:
1. Less Forgiving Exposure Process:
The rapid exposure times of pure photopolymer emulsions can leave less room for error during the exposure process. This requires more precise control and experience to achieve optimal results.
The Bottom Line: Know Your Shop's Needs
Choosing between dual cure emulsions and pure photopolymer emulsions often comes down to balancing cost, ease of use, and the specific requirements of the print job. While photopolymer emulsions offer faster exposure times and greater precision, diazo emulsions remain a popular choice due to their affordability, versatility, and forgiving nature. By understanding the strengths and limitations of each type of emulsion, you can make an informed decision that best suits your screen printing needs.
Are you still not sure which emulsion is right for your shop? Contact Chromaline's Technical Specialists to help you find the optimum stencil system for your screen printing shop.