After what seemed like a long winter, and a brief glimpse of spring, the warm summer weather
seems to making its first appearance of 2015. For many people, this means trips to the beach, days spent by the pool, and maybe even a mojito or two. For those of us in the printing industry, however, hot temperatures and high humidity mean paying extra attention to the weather in order to take proper care of our inks.
For instance, in the colder months, you may have noticed that your pad wasn’t picking the image out of the cliche as easily. If the pad is in good condition and does not require replacement, this could very likely be a result of the weather. On a dry, winter day, when the relative humidity is almost non-existent, this solvent flashes quickly resulting in the inability of the transfer pad to pull the image from the cliché. The ink has dried in the etch.
Just like weather, pad printing goes through its own set of “seasons.” Fundamentally, pad printing is a process that transfers a layer of ink from a printing plate to a designated print surface. This “transfer” is dependent upon the ink becoming “tacky” from the moment the image is doctored clean until it is placed onto the part. “Tack” is created through the evaporation of solvent, which is designed to evaporate upon contact with air. This solvent (thinner) is added to the ink at the time of manufacturing, as well as during set up.
But now it’s summer. As the heat and humidity slowly rise, you will likely notice that the solvent flashes slowly, causing a delayed reaction in the creation of the “tack.” You can determine if this is happening by checking the transfer pad at the end of a print cycle; if there is ink left on the transfer pad, warm weather is likely the cause.
What can you do to accommodate the seasons?
The general rule of thumb is to add thinner in the winter, utilize the standard in spring and fall, and use less in the summer.