Brains On! Episode Summary: "How is Paper Made?"
Podcast Information:
- Title: Brains On! Science podcast for kids
- Host/Author: American Public Media
- Description: Brains On!® is a science podcast for curious kids and adults from American Public Media. Each week, a different kid co-host joins Molly Bloom to find answers to fascinating questions about the world sent in by listeners.
- Episode: How is paper made?
- Release Date: January 7, 2025
Guest Hosting and Introduction
In this special episode of Brains On!, Rosie Dupont takes the helm as a guest host alongside Aria from Acton, Massachusetts. Molly Bloom, the regular host, is away, but Rosie ensures that the episode remains as engaging and informative as usual.
Rosie Dupont:
"Hi, Aria. So today's episode is about how paper is made. We've gotten a lot of questions about it over the years." (02:02)
Understanding Paper: Materials and Sources
Aria begins the discussion by highlighting the ubiquity of paper in our daily lives.
Aria:
"There’s printer paper and pizza boxes, toilet paper, wrapping paper, sandpaper, diapers, books, wallpaper, receipts, and even money, honey." (02:33)
The conversation quickly shifts to the fundamental component of paper—cellulose.
Aria:
"It's made from plants. Cellulose, to be exact. The stuff that makes plants stiff and strong." (05:08)
Dr. Sanford Smith (Sandy), a teaching professor in forestry at Penn State University, provides an in-depth explanation of cellulose and its role in plants.
Dr. Sandy:
"And there's thousands upon thousands of them, millions of them in any stem of a tree or branch. And they're all stuck together with a special kind of glue called lignin." (07:37)
While the United States primarily uses wood from trees to produce paper, the episode explores alternative sources utilized globally due to varying availability.
Aria:
"In other parts of the world, when they don't have a lot of trees, they use the plants they do have a lot of." (15:07)
Sri Ramaswamy, a professor in bioproducts and biosystems engineering at the University of Minnesota, elaborates on these alternatives.
Sri Ramaswamy:
"Bamboo is a resource that is available in some parts of the world. So places in Asia, it is an option. The alternative are similar to bamboo. In South America, they actually use sugarcane bagasse, which is a residue after you take out the sugar from sugar cane, and that can be also used in making paper." (15:30)
Notable Quote:
"What's cool about that sugarcane paper is that it's made from materials leftover after you turn sugar cane into sugar crystals. So it's stuff that otherwise would have been trash or burned for energy, but instead it's paper." (15:55)
The Paper-Making Process
Dr. Sandy takes listeners through the intricate journey of turning trees into paper.
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Cutting and Debarking:
- Trees are cut down, and their branches are removed.
- The trunks are loaded onto trucks heading to paper mills.
- Aria:
"Debarking is when you rub the bark off the tree trunk in a tumbling machine." (08:33)
-
Chipping and Digestion:
- The trunks are chopped into wood chips and placed into a digester.
- The digester uses chemicals and steam to soften the chips.
- Dr. Sandy:
"The digester has lots of chemicals in it, and it's heated up with steam to very high temperatures. And those chips break down and get very soft." (08:48)
-
Separation of Lignin:
- Lignin is separated from cellulose during the cooking process.
- The lignin is often burned to create energy for the mill.
- Dr. Sandy:
"Cells and that lignin is dissolved and taken away. And most of that lignin goes into the power plant of the mill. They burn that to create energy." (09:08)
-
Pulp Formation:
- The remaining cellulose breaks down into fine fibers, creating a pulpy liquid.
- Aria:
"What you're left with is a soupy liquid called pulp, which is made of liquid and lots of little cellulose fibers." (09:31)
-
Paper Production:
- The pulp is spread onto large screens at high speeds within paper machines.
- The fibers are dried and pressed into flat sheets of paper.
- Dr. Sandy:
"At the paper mill, the magic is turning old paper into new." (20:00)
Notable Quote:
"The whole process is going so fast. And these rolls of paper come out at the end and they're huge. They're huge. They're several tons thick." (09:51)
Recycling: Giving Paper a New Life
The episode delves into the importance and process of recycling paper, emphasizing environmental sustainability.
Aria:
"In the US we recycle over 60% of all paper and around 90% of all cardboard." (17:02)
Dr. Sandy personifies recycled paper as "Crumplestiltskin," sharing the journey of recycled fibers.
Dr. Sandy (Crumplestiltskin):
"You see, when you drop that paper in a bin with all your other recyclables, it sets off on a journey that is both long and winding... At the paper mill, the magic is turning old paper into new." (19:20)
Recycling Process:
-
Collection:
- Used paper is collected and taken to a materials recovery facility.
- Dr. Sandy:
"We get to ride this fun little conveyor belt and plastic and paper and metals all get sorted by machines." (19:01)
-
Processing:
- Paper is shredded and mixed with water and chemicals to form pulp.
- Contaminants like staples and plastic are removed.
- Dr. Sandy:
"First, we're shredded into little pieces. Then they dump water and chemicals on those pieces to turn them into soupy pulp." (20:08)
-
Reforming:
- The clean pulp is spread into sheets, flattened, and dried to create new paper products.
- Dr. Sandy:
"And once you have your pulp, all you have to do is make it into a sheet, flatten it and dry it." (20:25)
Sustainability Insights: Sri Ramaswamy highlights the environmental benefits of paper compared to plastics.
Sri Ramaswamy:
"Paper is actually coming from a renewable resource and it is recyclable. It's reusable. So from that point of view, I don't think one has to feel that, oh, I'm using paper, I'm actually affecting the environment in a negative way. Right. At least in the U.S." (16:11)
Notable Quote:
"It's not that. It's just at some point, the fibers and recycled paper are just too worn out to be reused. And my fibers are old. Most paper can be recycled five to seven times." (21:06)
Interactive Segments and Fun Facts
Throughout the episode, Rosie and Aria engage listeners with interactive segments, including the Mystery Sound game and encouraging creative participation.
Mystery Sound Highlight:
- Rosie introduces the segment where listeners guess sounds related to the episode's theme.
- Notable Guess:
"I think it might be someone stapling something amazing." (11:55)
Fun Fact: Rosie:
"Of course, in the United States, we recycle over 60% of all paper and around 90% of all cardboard." (17:00)
Conclusion and Key Takeaways
The episode wraps up with a recap of the paper-making and recycling processes, emphasizing the significance of sustainability and the versatile uses of paper.
Molly Bloom:
"We learned that paper is made out of cellulose, the stuff that makes plants stiff and strong." (14:52)
Aria:
"We turn the plants into pulp and then machines dry it and make paper." (15:01)
Final Thought:
- Molly Bloom:
"When we recycle a piece of paper, it's turned back into pulp and made into paper again." (21:48)
Through engaging dialogue, expert insights, and interactive elements, this episode of Brains On! effectively demystifies the complex process of paper production and recycling, fostering a deeper appreciation for the materials we often take for granted.
Notable Quotes with Timestamps:
-
Rosie Dupont:
"How is paper made? How is paper made from trees?... " (02:09)
-
Dr. Sandy:
"The trunk of a tree is actually millions upon millions of tiny little pipelines going up to make paper." (07:46)
-
Sri Ramaswamy:
"Paper is actually coming from a renewable resource and it is recyclable." (16:11)
-
Dr. Sandy (Crumplestiltskin):
"At the paper mill, the magic is turning old paper into new." (19:20)
This comprehensive summary encapsulates the key discussions, insights, and educational content delivered in the "How is Paper Made?" episode of Brains On!, providing listeners with a clear understanding of paper production and recycling.