2023-01-23 Environmental resource science experiment I (applied physics) “Paper manufacturing and physical property evaluation of paper”
Following on from last week, here is a look at the "Environmental Resources Science Experiment I (Applied Physics)" class for second-year students in the Department Department of Environmental and Natural Resource Sciences Faculty of Agriculture.
Today, Associate Professor Kose Ryota will be introducing "Papermaking and Evaluation of Paper Physical Properties."
Paper is something that is very familiar to us, but how long has it been made?
The oldest paper ever found dates back to the 2nd century BC!
Although it has been used for 2,000 years, the process of making paper has actually been the same since ancient times: dispersing pulp fibers, the material of paper, in water, dehydrating them, and drying them.
What the students are looking at in the first and second photos is a machine used to make paper.
One that measures the water in which pulp fibers are dispersed, puts it into the machine, and drains the water.
Dewatering takes time if you just dry it, so modern paper making uses a method of pressing to drive out the water.
In this experiment, a heavy metal tool like a rolling pin is used for pressing.
As shown in the third photo, the dog is being rolled around to dehydrate it.
The finished paper is still wet, so it is sandwiched between filter papers and pressed to remove more water.
Those are the 4th and 5th photos.
Finally, dry it and it's done.
When you think of handmade paper, it's easy to think of something like Japanese paper, but the paper that was made was actually the kind of paper used for notebooks.
The 6th photo shows pulp dispersion, which is the raw material for paper, and the 7th photo shows Professor Kose giving a lecture.
After this, there will be an experiment to compare the properties of the ordinary paper we made this time and the recycled paper.
The way to make recycled paper is to first make regular paper, disperse it in water, and make it into paper again.
I feel like if you just disperse it in water and make it into paper again, the properties won't change, but what's the difference?
When recycled, the surface tension of the water during the drying process changes the structure of the pulp fibers, causing them to deteriorate.
Recycled paper looks the same, but its properties are different from the paper before recycling.
Recycling weakens paper, but papermaking involves processes that make paper stronger.
The reason why paper is made by sticking together loose pulp fibers even without any adhesive is because the stacked pulp fibers are connected by hydrogen bonds where they touch each other.
By grinding the pulp fibers before dispersing the pulp in water, the pulp fibers become softer, increasing the area of contact between the fibers and increasing the area of hydrogen bonds.
That way, paper with the same amount of pulp will be stronger.
Paper making is a very profound thing.
One that made me want to know more!
Next week, Wan will introduce the noise and dust measurement experiments.
looking forward to!
Department Department of Environmental and Natural Resource Sciences Instagram @tuat_en
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Related Links
- 2023-01-20 Environmental resource science experiment I (applied physics) "Synthesis of adhesives, production of wood materials, and evaluation of physical properties"
- 2023-01-27 Environmental resource science experiment I (applied physics) “Wood machining and safety education, wood drying, environmental measurement”
- Faculty of Agriculture Department of Environmental and Natural Resource Sciences
- Faculty of Agriculture Department of Environmental and Natural Resource Sciences Ryota Kose Researcher Information Associate Professor
- Tokyo University of Agriculture and Technology Official Instagram (@tuat_hakkenkoken)
