According to Ilisna O’Reilly, Sales Manager Southern Africa at NUtec Digital Ink, environmental conditions play a critical role in the performance and stability of digital inkjet inks. Poorly controlled operating environments can lead to inconsistent print quality, nozzle failures, and ultimately production downtime.
These factors are often underestimated, yet they can significantly affect output and efficiency across many printing companies.
How do operating conditions impact digital print quality, and what are some of the common defects found in many printing companies? Below are some of the key ambient factors and the typical defects they may cause in your print room.
Humidity
As humidity rises at a constant temperature, the vapour pressure increases. The vapour pressure of the water suppresses the ink from drying. The force applied on the solvent by the water vapours prevents the solvent vapour from leaving the liquid phase. At high humidity, you will have trouble drying the solvent on the media. Low humidity will result in fast drying of the solvent that can lead to nozzle drying. If ignored for a long time without proper maintenance, this could lead to nozzle blockage, eventually leading to permanent nozzle loss.
Temperature
High temperature will have a similar influence on the drying rate, but it will also affect the viscosity of the ink. Inks are designed with a specific viscosity range to ensure optimum performance. If the temperature increases outside of the prescribed operating range, it will lead to firing instability. If temperature decreases below the prescribed operating range, this will lead to nozzle starvation. Both these conditions could lead to permanent blockages if maintenance is not done to recover the nozzles within a reasonable timeframe. As temperature increases, the drying rate of the inks increases by encouraging the molecules from the liquid phase to the gas phase.
Sunlight And UV
As we learnt in primary school, all matter absorbs energy. Energy is converted to a chemical reaction (usually oxidation) or physical reaction (electron transition) which breaks down the previous molecule to a new one with different physical and optical properties. Printers positioned in a print room in direct sunlight or possibly the cartridges, bottles or pouches being affected by direct sunlight, can produce problems with stability of the inks. Dyes are more susceptible to light and UV than pigments, which would result in dyes fading faster than pigments.
Airborne Contaminants And Dust
Fibres, dust and static can lead to droplet deflection and misfiring nozzles. Ensure the print room is a controlled environment away from routers, cutters and other equipment that can create airborne contaminants. When using PVC or other media types, ensure that the edges are free from fibres that could potentially enter the printhead nozzles.
Key Steps
As digital printing technologies evolve, so too must our awareness of the environmental variables that impact the performance. Invest in proper climate control and maintenance to ensure that your printheads are safeguarded and not at risk. Understand your ink’s behaviour in different conditions. Ink formulations are engineered for stability and their performance is directly influenced by the environment in which they operate. Talk to the ink manufacturer or distributor for advice.
Being aware of how ambient conditions affect ink performance can make all the difference to maintaining consistent, high-quality graphics. Taking small proactive steps by investing in a humidifier and a temperature and humidity clock can assist you to prevent many common problems before they start.
C1W Initiative
Change One Woman (C1W) aims to empower women in the branding, print and signage industries. As part of this initiative, Sign Africa would like to spotlight women-authored content like this piece. If you have any trend/business articles related to the signage, branding and printing industries, please email content to: meggan@practicalpublishing.co.za. Follow C1W on Facebook and LinkedIn.
NUTEC DIGITAL INK
https://nutecdigital.com
