Cutting-edge LED Curation saves time, money and mitigates health risks. 

By John Freismuth, President, Empire Screen Printing

Sustainability and Screen Printing

Screen printing is a notoriously polluting industry, and there’s mixed information on how the process can be made more sustainable. As it stands, most screen printers utilize time and labor-intensive processes. The sheer number of manual steps makes mistakes all too common, resulting in massive amounts of material waste. By and large, using solvent inks and heat to cure (or “set”) ink into the substrates is the process's least sustainable and inefficient part. This traditional curation method requires a lot of time and is incredibly toxic to the environment and employees. The process releases hazardous byproducts, including  Methanol, Ethanol, Butanol, Acetone, Propyl Acetate, Propylene Oxide, Isopropyl Alcohol Ethyl Acetate, and more.

Many of these byproducts are carcinogenic or otherwise toxic to humans. Prolonged exposure can have lasting health implications on employees who must be around these materials. When the resulting toxic fumes are released into the atmosphere, they produce pollution and smog.

Using LED technology to cure UV-based inks drives efficiency and boosts sustainability through every aspect of the screen printing business. LED curation is an example of how sustainability can increase without increasing costs. LED technology significantly decreases overall costs—from material usage to energy and utilities.

While utilizing LED technology hasn’t received a lot of traction in the screen printing industry, Empire wants to change the narrative around how much this switch can impact business and customers alike. Empire is a leader in the industry—one of the only screen printing businesses using UV inks and LED curation.

Benefits of LED Processing

Switching to LED curation has a multiplying effect on efficiency. It is more energy and time efficient, and the process has less environmental impact. From a financial standpoint, the increase in workflow speed is probably the biggest draw. As screen printers know, it must be cured after the ink is printed onto the material. Solvent technology requires a combination of heat, which consumes energy, and time, typically twenty-four to forty-eight hours before printers can move on to the next step. With traditional screen printing processes, each color is printed one at a time. 40-60% of solvent ink evaporates during each curation cycle. With LED technology, 100% of the ink remains on the material. The combination of UV and LED in manufacturing doesn’t produce ozone emissions or harmful volatile organic compounds (VOCs), eliminating the need for workplace ventilation systems. Another benefit is the UV LED process is 98% more energy efficient than traditional UV mercury curing.

With LED curation, there’s more material efficiency throughout the screen printing process. It requires less time and is more energy and cost-efficient, all while increasing business output. These benefits are explained in further depth below.

Increased Workflow Efficiency

While traditional curation processes take 24-48 hours for each layer of ink (a new layer for each color), LED processing enables printers to print up to 12 colors simultaneously and cure the ink in less than 15 seconds. Businesses can go from raw material to finished product in less than 20 minutes, compared to a multi-week, sometimes multi-month process for a single project.

Empire has completely reoriented workflows to enable single-piece flow—the ability to make a finished product in one process, minimizing the back-and-forth between manufacturing entities. At Empire, the entire manufacturing process required an 8-week lead before the company moved to the UV LED workflow.

Quality Control and Material Efficiency

The LED-based workflow recognizes real-time problem identification during manufacturing. If there’s an error in the middle of the process, Empire can identify and correct it. Before using LED curation, Empire would have to re-run the entire process again. The impact of this change is evident in waste reduction and quality control processes.

Previously, Empire had an inspection area at the end of the manufacturing workflow staffed with forty-two employees. They were tasked with quality control but had no control over the printing or manufacturing process. Today, quality control is part of the printing process instead of waiting until the end. Rather than having a dedicated team to point out errors after it’s too late, each employee has control over quality. There’s no one else to pass the problem to, which allows Empire to take the risk out of the process.

Automation has also significantly increased efficiency, quality, and price. With less mundane labor, two people work in a cell versus seven. Empire automation systems are 4x more accurate than manual systems, allowing for a more specialized and efficient workforce. It’s been shown that automation can make work more meaningful. Fewer people doing more interesting, higher-value jobs impacts individual career growth and the development of specialized skill sets. Companies can retain employees longer in more engaging, higher-value positions.

Increased quality control within the manufacturing process has enabled Empire to reduce material waste to just under 1% waste for the entire year, almost eliminating risk from our manufacturing process. The print method uses 98% less energy when compared to Mercury Vapor curation. LED curing reduces heat waste and prevents chemical toxins from being released into the air.

Resistance in the Industry

Within the printing industry, many players have shifted to LED. From flexible to digital inks, businesses use LED as a regular mainstay. However, there’s been more resistance to screen printing due to a lack of understanding—people not knowing how to make LED work within their current processes. The question should be, how can the process be built around LED technology?

Empire redesigned the entire manufacturing process based on LED curation. As intimidating as it may seem to make such a shift when workflows are already in place, understanding that companies utilizing UV-based inks can cure with either LED or Mercury Vapor within the same process. However, there are no off-the-shelf LED curing units for screen printing. Empire developed its own curing units. As companies are developing LED technology, they could run Mercury Vapor to keep workflows moving.

“LED processing is sustainability in action. And from what we’ve learned about sustainability, it needs to be who you are, not just a light you have for curing. The multiplying effects of a switch like this opens a world of possibilities for your business,” says Jennifer Schloesser,  Creative Director and Sustainable Coordinator at Empire Screen Printing. The massive decrease in necessary labor, energy costs, materials costs, and turnaround time increases overall costs and production capacity. In today’s shifting economy, companies using LED processing have a more secure labor force of specialized workers and the assurance that they can take on more capacity in response to changing demand.

“Because of the efficiencies, we’ve been able to capitalize and leverage this technology to meet the client's expectations. We’ve also invested in automation and additional equipment, combining these investments with LED technology ensures our capacity is scalable—meaning we can grow quite a bit within our current structure,” Alexis Marsh - VP of Operations at Empire Screen Printing, explains. “Empire’s willingness to share technology and information makes us a standout in the industry. Empire currently sources 30% of our jobs from other screen printers that don’t have the capacity to print high-risk jobs (like jobs with multiple colors).”

LED curation is the future for sustainability and business growth potential within the industry. More than 75% of millennials and younger generations make decision purchases based on ESG factors.^[1] Luckily, screen printing is an industry where making sustainable choices saves time and money, increasing profits and keeping employees safe. Not many industries can say the same. There’s a clear leader here, and it’s time the industry takes note of LED’s potential for change.

^[1] Business News Daily. “Most Consumers Want Sustainable Products and Packaging”. 2023.