by Industrial Print Magazine Staff
Maintaining a proper relative humidity in a print environment is important, especially with materials like paper or corrugated board. Since corrugated board absorbs moisture easily, imlpementing a humification system is essential to avoid warped or damaged material, which could also ruin a press.
Importance Restated
As mentioned, maintaining the correct humidity is important. Ideal indoor relative humidity ranges between 40 to 60 percent in a print environment.
According to David Baird, senior application engineer, DriSteem, managing humidity “is essential for preserving material integrity, ensuring high print quality, preventing static electricity build-up, maintaining machine performance, and enhancing operational efficiency.”
Corrugated board presents a particular challenge. “Corrugated board is sensitive to moisture levels, which affects its structural integrity. Low humidity dries out the material, making it brittle, while high humidity can cause swelling and warping. Both scenarios weaken the board’s ability to protect and cushion products during shipping and handling,” explains Baird.
An optimal humidity level assures the corrugated board maintains its proper moisture content and remains dimensionally stable. “This stability means there is less risk of warping, curling, or other forms of deformation that can compromise the quality of the printed product and cause operational issues in the printing process,” says Baird.
“Humidification is important, yet often overlooked in printing. Proper humidification will have a positive impact on print quality. If the humidity level is too low, then paper tends to shrink and curl; and misfeed. Additionally, inks may not properly transfer to surfaces including corrugated cardboard,” agrees Bud Thomas, manager, Hydrofogger, LLC.
Benefits of a Real System
Implementing a humidification system assures better quality prints, increases productivity, and minimizes downtime. There are other benefits as well.
Controlling humidity allows for even ink absorption, precise color reproduction, and sharp images, lists Baird. If humidity is too low, ink can dry too quickly, which results in smearing and bleeding. When humidity is too high, dry times extend, smudging occurs, as do print defects like mottling and color inconsistency.
“When humidity is at the correct level, inks adhere more uniformly to the printing substrate, preventing problems such as smearing, bleeding, or blotching. Uniform adhesion results in sharp, clear images and text with vibrant colors true to the original design,” says Baird.
Maintaining the right humidity level in a print shop also helps manage static electricity. “When the humidity level falls in a pressroom, static electricity can build up. This can obviously cause not only printing problems and decreased productivity but damage to equipment as well,” shares Thomas.
“Low humidity levels cause static electricity to build up, causing paper and other substrates to stick together or repel each other, which leads to feeding problems. Misfeeds, double feeds, and paper jams are common consequences, disrupting the printing process and reducing productivity. Excessive static build-up can affect the electronic components of digital printing equipment. This can lead to malfunctions, errors, and potential damage to sensitive printer parts, increasing maintenance costs and downtime,” continues Baird.
Changes Over the Years
Humification systems have changed significantly over the years. They are more advanced in regards to controls and sensors, as well as more efficient.
Today’s humidification systems are easier to install, maintain, and operate. “There are several affordable options on the market that make it easy for any size printer to have adequate humidification. Also consider power consumption of your humidifier. There is a wide span of power usage for different types of humidifiers with steam basically being the most expensive to operate and adiabatic costing the least to produce,” says Thomas.
“Commercial humidification systems have changed significantly over the years. Many now use advanced controls and sensors to optimize performance and reduce both energy and water consumption, which has improved efficiency compared to older systems. Additionally, today’s humidification systems offer precise control, ensuring consistent environmental conditions with minimal fluctuations. This level of control is crucial for maintaining optimal conditions in print environments, to ensure print quality and machine performance,” shares Baird.
Get the Correct One
For corrugated printing environments in particular, it’s important to get a handle on what exactly to look for in a humification system.
According to Baird, there are several factors. “The system should maintain consistent humidity levels to prevent issues such as paper curling or static electricity build up, which affect print quality. The chosen system should adapt to specific environmental conditions of the printing facility, considering factors such as temperature fluctuations and varying production levels.”
Energy saving features are also something to consider. “Look for systems that offer energy saving features to reduce operational costs. Choose systems that are easy to maintain and have a reputation for reliability and longevity. Finally, consider how the system will integrate with your existing equipment and building automation systems to ensure seamless operation and compatibility,” adds Baird.
Adiabatic or evaporative, ultrasonic, and steam humidifiers are the three different types of humidifiers to consider in a corrugated print space. “Each has its own features and benefits. Be sure to understand the full scope of cost, installation, equipment lifetime, and maintenance when considering your humidifier,” stresses Thomas.
When it comes to a specific system, Baird suggests evaporative humidifiers for print shops. “They use the heat already present in the air to evaporate evenly distributed water droplets dispersed by the system. As atomized water droplets are absorbed, the evaporation causes air temperature to drop, saving on energy costs and reducing the cooling load. This provides significant energy savings when both cooling and humidifying are required. This energy efficiency translates to lower operational costs, which is particularly beneficial for print shops that require continuous operation.”
Look Into It
When the right humidification system is chosen, the long-term benefits are apparent. In corrugated printing environments a humidification system provides press operators with a certain level of confidence that their prints won’t bleed or smear, with inks adhering uniformly thanks to an optimum humidity level.
Sep2024, Industrial Print Magazine
