Test #6: Trend Analysis
What Are We Testing?
For this test, we are comparing the weight of blank sheets of paper to ones that have been printed on over the course of an hour. This is done by weighing the same amount of plain and printed papers and then continuing to weigh the printed sheets in 5 minute intervals over the course of an hour to monitor how it’s weight fluctuates. The data is then entered into an Excel document and made into a scatter diagram to plot the points and determine a trend.
Theory Behind the Test
By comparing the weight of paper when it’s blank, printed on, and then given an hour in the open air, we are able to get a general idea ...view middle of the document...
For instance, knowing that laser printer paper is typically very dry, and that absorbing moisture would cause it to “boil unevenly and create wrinkles” (Prime Image, 2014) as well as the toner not sticking would encourage those planning to use that method to store it in a way that would avoid exposure to humidity. In this case, that would be storing it off the ground and in an area that is a similar temperature to where the printer of choice is being kept (Glatfelter, 2005). Storing any kind of paper in their original wrapper or one that’s specifically meant for blocking moisture is also a good idea if the substrate that’s being used is known to be absorbent.
Expected Outcomes and Educational Gains
Considering what we’ve already learnt about how ink and humidity affects paper through past instrumentations, we had a few expected outcomes that we knew would be correct. Printed paper always weighs more than blank paper, because it’s had to absorb the ink used to print the image. This is especially true for uncoated paper, because it’s the most absorbent. Also, after being taught about the Xerox this semester, we were aware that as the sheets are printed, they would lose some moisture, which would most likely be gained back once it was able to sit in the open. After completing the test, we learned that our estimations had been correct, but also thought that it would have been interesting to continue the test to see how long it would take for the paper weight to plateau.
Significance of This Test and End Use Applications
This test is significant for a few different reasons. Firstly, before running a job, it’s helpful to know how much weight and moisture your substrate will gain, not just for when it goes through the press, but also when considering storage and shipping. Knowing that “paper dimensions increase with higher moisture content and decrease with lower moisture content” (Glatfelter, 2005), running this test on the paper you’re planning to use will help to determine where it should be stored, if it needs to be protected between processing steps, or if it will need time to sit and adjust to room temperature before use.
Before printing, without letting them adjust to room temperature - cold papers absorb moisture which could lead to them becoming wavy and having issues with ink drying, where hot papers may tighten and also become wavy (Glatfelter, 2005). Paper waviness can cause paper jams, which in turn costs time and money.
After printing, humidity can have an effect on the drying process as well as general ink preservation (Torraspapel, 2008). Also, having a general idea of how much weight or size your substrate of choice tends to gain when printed on and exposed to humidity will help plan and determine shipping costs.
Denver Instruments Analytical Scale
Xerox 700 Digital Colour Press
Husky Copy Uncoated, 92 White
1. Cut 30 blank sheets to 2.7”x 2.7” squares