The Perfect Temperature to Minimize Blanket Piling
Take a look at the graph above. It reveals countless hours of testing to find the optimum press temperature for minimizing blanket piling. Yes, the temperature of your press can and does effect how quickly your blanket piling happens. I've written before about how to prevent blanket piling, but this time I want to hone in on one particular variable that contributes to blanket piling - temperature.
What The Graph Reveals About Piling
The above graph reveals two things. First, an ink and water balance window that shrinks as temperature increases. You can get the formula for calculating this here. The yellow line represents the lowest point you can set your water without scumming at a particular temperature as measured at the oscillating or vibrator roller in the printing unit. The pink line represents the highest water setting possible at the limit of emulsifying your ink. As you can see, the gap between the two naturally narrows as temperature (as indicated at the bottom) increases.
What is most interesting though, is the blanket piling that takes place at those temperatures. It is difficult to measure piling of course, but it can be measured by carefully monitoring how many hours it takes before you begin to lose image quality. Yes, a test like this takes a long time to perform.
What You Need to Know
What I would like to share with you all is the magic window that appears at about 27-28 degrees celcius (80-82 Farenheit). Blanket piling is at it's minimum and then more dramatically increases after this. This indicates that if your press runs higher than this, you will have more blanket piling.
This window of 27-28 degrees celcius (80-82 Farenheit) is measured on the vibrator or oscillating rollers, but can apply to any point in the ink train. The reason it is measured in the ink train is that ink temperature greatly effects viscosity. In fact 1 degree difference can be a 9% difference in viscosity. That difference in viscosity will definitely effect piling. So this is an additional cause of blanket piling to ones that I have mentioned before.
You're probably thinking, I wish I had an infrared thermometer to read my ink train temperature. They're not expensive and worth every penny. My next article will tell you why.
I have not found any other research on this subject, but I would love to hear the results from anyone else who has done research on this. Leave me a message, subscribe by email, or like me on Facebook to get updates on this research. Thanks for looking.
Related Articles:
How We Greatly Reduced Blanket Piling
Troubleshooting Piling Problems
