The printing industry employs multiple complex processes to ensure the production of high-quality paper products; several of these processes center on maintaining a conducive printing environment, as this sector faces several unique technical challenges, including the optimization of resource and energy utilization.
Therefore, maintaining optimal air quality and controlling humidity levels are critical for ensuring smooth, efficient operations.
The need to control humidity by either adding or removing moisture, stems primarily from the hygroscopic nature of paper.
Put simply, paper absorbs water, and the amount of water absorbed varies depending on ambient temperature. So, without proper humidity control, paper will expand or contract leading to registry problems, between images, which will compromise quality.
To help control air quality, print shops introduce outdoor make up air to the space which can add unwanted moisture during the warm months or extremely dry air during the cold months. Each has to be dealt separately with HVAC systems.
The Effects of Uncontrolled Humidity
Although paper is shipped in moisture-resistant containers with a certain moisture content, it can still absorb atmospheric moisture while being stored at a printing facility that is not humidity controlled.
As previously mentioned, uncontrolled humidity causes water to be absorbed by paper, thus causing registry problems. Paper with the wrong moisture content cannot be used for printing and therefore counts as unused raw material.
Plus, even minor quantities of moisture in paper can result in weak, low-quality stenciling and poor imaging; the compromised paper interferes with the absorption of printing dye, making images less crisp and less precise.
The dye-drying process is also more time-consuming when working with moist paper, as the excess absorbed water must be accounted for.
Moisture weakens the lattice of paper as well, resulting in surface pinholing. And paper with excess moisture is unsuitable for printing photographs, as the final products may turn out sticky.
Moisture absorption can hamper all of the most common printing technologies. For example, moisture affects the toner adhesion in digital printing, and deformed paper often results in more frequent paper jams.
In offset printing, high moisture levels affect the interaction between ink, press, and paper. If inkjet printing is employed, excess moisture results in smudging, delayed drying, and ink spreading.
Excess humidity can also have a negative effect on other stages of printing. For example, platemaking requires a constant dry-bulb temperature (DBT) and relative humidity.
On the other hand, very low humidity levels can also have an adverse effect, making paper dry and brittle. These scenarios are common in cold climates with untreated outdoor make up air.
The Importance of Dehumidification in Printing Processes
A quality dehumidifying system can spell the difference between a successful printing operation and a failed one. Ensuring proper moisture control is especially important in small operations lacking high-end storage facilities.
Dehumidifiers remove excess water vapor from the air, allowing a constant indoor humidity irrespective of outside weather conditions. These systems can account for both daily and seasonal variations in atmospheric humidity.
Two types of dehumidifiers can be considered, one being a 100% outdoor make-up air dehumidifier that removes moisture in the make-up air before it enters the building. The second type is a recirculating dehumidifier that deals with any excessive moisture that is produced in the building or printing process.
Many times, both systems are needed for effective humidity control. Dehumidifiers can also be equipped to not only dehumidify but also to add room heating and cooling as needed.
These systems can also be configured to add humidity to the space when needed. Evaporative technology can also reduce indoor temperatures; this can be a key advantage, as lower temperatures help prevent printers from overheating, effectively extending their life span.
Allowing for better product quality, minimizing raw material waste, and even assisting in reducing indoor temperature, dehumidifiers play a key role in all types of paper printing processes. But to ensure optimal performance, it’s critical to choose the right dehumidifier for the specific application at hand.
Dehumidifier Corporation of America (DCA) is proud to provide top-quality dehumidification equipment for the commercial and industrial printing sectors; we offer both horizontal and vertical dehumidifiers, and supply types that run on a range of different fuels and employ various cooling methods.
Our team of specialists has the expertise necessary to help you select the perfect dehumidifier for your unique printing needs. Reach out to the team today to learn more.