Positioning Solvent, Water-Wash, Thermal & Liquid Flexographic Printing Plate Processors

No matter the size of your printing operation, one photopolymer plate processor cannot cover the needs of every printer.

Printers need different types of processing equipment to efficiently design and print a variety of packaging materials. During the printing process, many types of substrates are used, with each being unique in its own way. To achieve the highest quality out of every material, operators must understand the differences between the four types of photopolymer processors: water-wash, thermal, solvent and liquid.

What follows is a guide on all four types of processors that highlights their distinguishing qualities, who should use them, and the best solutions for each process.

Water-Wash

If you’re a narrow web printer looking for an eco-friendly solution that yields high-quality imaging and plates, then water-wash offers a great solution.

Water-wash photopolymer processors are one of the most environmentally friendly ways to create plates in the industry because they are solvent-free and reduce VOC emissions during the entire printing process. Water-wash photopolymers utilize tap water instead of the typical solvent, allowing the water used during the washout process to be recycled and recirculated back into the system for reuse.

This type of processor is most suitable for printers who want to print their plates without potentially damaging the environment with toxic washout chemicals and solvents. Plates can be completed with a much shorter drying time because of the solvent-free process, which helps printers boost productivity and improve cost savings.

Toyobo, for example, has been leading letterpress printing as the pioneer of water-wash, photo-sensitive, nylon printing plates and has been around for more than 25 years. Water-wash processing solutions:

• Offer the latest computer-to-plate (CTP) technology
• Create clear reproduction of screen dots and letters, and improve productivity
• Produce a water-wash plate that is also durable to water-based ink
• Achieve rich ink transfer with consistent printability on a wide range of substrates
• Provide consistent plate quality
• Are toxic-free for the operator

Thermal

Thermal photopolymer plate processing is one of the most widely used methods of plate processing in the flexographic industry thanks to its ease of use and quick turnaround times. Thermal processors involve no water, liquids or chemistry, which is a major advantage for many printers, since they won’t have to deal with solvent chemistry or maintain water and polymer reclamation.

Additionally, not only does thermal plate processing require little to no processing, it also offers better print quality through enhanced edge definition and improved print consistency across repeated printruns.

XSYS, for example, is a leader in thermal photopolymer plate processing, with its nyloflex Xpress Thermal Processing System. Printers utilizing thermal plate processing can simplify the plate making process, enhance user experience, and reduce cost and maintenance. Designed to provide a solvent-like product but in a thermal world, the processing system saves printers a lot of time during its workflow process by:

• Establishing a short-wave IR heating assembly
• Allowing for precise control of heat distribution and very low vapor generation
• Offering a zoned pre-heating system for maximum energy efficiency at any width
• Promoting energy conservation and lower impacts on the environment
• Providing lightning-fast turnaround times with quick processing and no drying required

Solvent

In the flexographic printing industry, solvent plate processing systems have been around for the longest amount of time. The reason for their popularity is derived from low upkeep and maintenance compared to all other types of photopolymer plate processing. Such systems make use of chemical solvents during the washout process and provide a high level of productivity for users.

Although solvent plate processing is less environmentally friendly than other types of processing, such as water-wash and thermal, there have been many recent developments of environmentally friendly and non-hazardous washout solvents. These new solvents offer lower odors, HAPs and VOC alternatives to those of the past, which significantly reduces environmental and operator harm.

Again, XSYS is known in the global flexographic printing industry for its commitment to supporting customers by providing high-quality solvent plate processing equipment, with an extensive nyloflex selection. Solvent processors offer enhanced productivity thanks to:

• Digital layer separations
• Faster washout speeds
• Improved process control
• Effective solvent usage
• Temperature control of washout solution
• Touchscreen operations

Liquid

If you’re a corrugator printing pizza boxes, grocery boxes, food packaging and want a high-quality product that is economical and efficient to run, liquid plate processing is the best solution for you.

The process of liquid plate making makes use of equipment that has an exposure unit, UV lights and a washout system. To create liquid photopolymer plates, printers need to place the image negative on the exposure unit and cover it with a transparent sheet. A liquid photopolymer resin is then spread and rolled evenly on top of the transparent sheet. After two rounds of exposure to UV light, the exposed plate is then washed out to remove the unhardened photopolymer.

Having been a leader in the flexographic industry for more than 50 years, Anderson & Vreeland knows what is needed to meet the demands of printers in the packaging industry. It offers an extensive selection of AVantage Liquid Photopolymers for improved print quality and consistency. It manufactures AVantage Liquid Photopolymer resins in-house. Liquid photopolymer solutions:

• Reduce environmental impact and control costs
• Deliver optimum elasticity, resilience, hardness and ink transfer
• Couple with the best film solutions
• Work with every type of application
• Come in formulations specific to each marketplace: bag, corrugated, stamp, cap, master and star inkjet film