Quote:
Originally Posted by ReynoldsSlumber
Responding to your ancient thread! In the interest of making flying models, I took International Paper's data, noting that stiffness goes with thickness cubed, and made a "stiffness lightness score" by dividing the relative stiffness by the density (area basis). The higher the score, the more stiffness per unit weight you get. (Click then zoom in to see the figures.)
Attachment 497713
That said, the relative stiffness figures in this table rest on an assumption of identical paper stiffness per unit volume throughout. Your finding that stiffness varies a lot by brand (and by paper type?) means there's another variable that's not accounted for in this particular table. Also if the longevity of tag cardstock is bad, that strikes out a lot of these options.
It may be that weight (density) is the primary concern for paper airplanes, but after that, looking at papers of comparable weights with different stiffness could be helpful for choosing. |
Thank you! Never thought of using Math to find the stiffness.
The same time I created this chart, I did one on testing certain blanks from a swatch book of cardstock manufacturers.
I cut each piece exactly the same size, clamped the blanks to a table, picture a swimming pool dive board.
Marls were placed on each end to make piece was clamped to the same spot. The other end had another mark to make sure my test weight was placed at the same location.
Then I placed a 5-gal bucket under the diving board and placed single staples on the extended end. Once the staples fell, I weighed them using a Dillion Re-Loading digital scale. This test was done three different times, then the weight was averaged for my final score.
Math would have been easier.........
Here are the mentioned PDF (old stuff but gives an idea-limited to certain cardstock I was using at the time: Now I use Cover cardstock due to its smoothness and how well ink prints on it.)
4 Testing Results For Card Stock Stiffness.pdf
3 Cardstock Laminates.pdf
Mike