Paper Towels Information Questions & Answers

What makes up a paper towel?

Paper towels are made up of cellulose fibers, which also make up cotton, wood, and most other plants. These cellulose fibers are actually giant molecules that consist of many small molecules linked together.

 


How many trees are in a paper towel?

To make one ton of paper towels 17 trees and 20,000 gallons of water are polluted. In the U.S. we currently use more than 13 billion pounds of paper towels each year and that number is growing steadily. This equals more than 3,000 tons of paper towel waste in the U.S. alone.

 

Who makes Bounty paper towels?

Bounty is a paper towel product manufactured by Procter & Gamble (P&G) in the United States. It was introduced in 1965.  It is used in households nationwide and is the preferred brand of most tattooers.

 

How many paper towels are used in a year?

13 billion pounds of paper towels are used each year. That’s over 45 pounds of paper towels per person, per year. Talk about wasteful! If every American reduced the number of paper towels they use by just one per day, we would divert 571,230,000 pounds of paper waste each year.

 

What is the Bounty paper towel made out of?

This brand is made out of wood pulp, Resin, paper sheets, fibers and the trees that are mainly pine and spruce types. This brand is only made out of one substance which is just pulpwood.

 

What chemicals are used in making paper towels?

Paper towels are sometimes bleached with elemental chlorine (chlorine gas), which causes the release of chlorinated compounds, such as dioxins and furans, which are powerful carcinogens and mutagens.

Chlorine and its derivatives such as hypochlorite and chlorine dioxide should not be used to make recycled paper.

 


Who made the first paper towel?

In 1907 Scott Paper introduced Sani-Towels paper towel, the first paper towel in America. Sanitowel was designed to be used in Philadelphia schools to help promote good hygiene in the classroom.

Scott Paper Company First Paper Towel History

In 1879 brothers Clarence and E. Irvin Scott founded the Scott Paper Company in Philadelphia. Arthur Scott, son of Irvin, joined the company in 1896.

During a cold epidemic in 1907, a Philadelphia teacher blamed the spread of germs on the student use of the same cloth towel. She cut heavy copy paper into squares and used them as individual towels.

Arthur Scott heard about it and had some heavier than normal tissue made into rolls and perforated into individual 13″ X 18″ sheets. They were originally called “Sani-Towels”, but were later renamed “ScotTissue Towels”.

In 1930, Scott was the first to introduce paper napkins.
In 1995, Kimberly-Clark Corporation acquired Scott Paper Company.

 

How do paper towels absorb water?

Paper towels absorb water via capillary action. This principle originates from the observation that when a thin glass tube (a capillary) is inserted into a liquid, it draws up liquid (independent of air pressure) to a height inversely proportional to the radius of the tube.

This happens because of competing tendencies of inter-molecular forces (the liquid wants to stick to the tube and to itself, aka surface tension) to draw the liquid up and gravity to pull it down.

In a paper towel, there are no tubes, but the liquid has a tendency to adhere to the thin plant fibers, and it is drawn up through the voids between the fibers just the same.

Sketch of capillary action in thin tubes. Source: Surface Tension
http://hyperphysics.phy-astr.gsu.edu/hbase/surten2.html

Capillary action in a paper towel. Surface tension overcomes gravity and the liquid is drawn up into the paper towel. Source: How Greywater moves through soil (capillary effect)
http://www.thegreywaterguide.com/how-greywater-moves-through-soil-capillary-effect.html

 

Why do paper towels absorb oil, as oil is hydrophobic and cellulose is hydrophilic?

Capillary action is not an explanation because that is an effect, not a cause. It just means that work can be done from the surface free energy effects, and lift the bulk liquid against gravity. Indeed the oil is lifted, but this leaves us no wiser as to where this energy came from. Anyway, capillary action is the wrong answer.

Oils also may contain some dissolved water and polar impurities or functional groups which will assist wetting. Cellulosic absorbents can also be treated to enhance their affinity for oil which as you would expect, increases absorbency. But this is not convincing enough, I agree. What have we overlooked?

Contrary to popular belief and poorly worded explanations in chemistry books and tutorials, hydrophobic it is not a repulsive force.

Hydrophobic means a low affinity for water, as opposed to hydrophilic meaning a high affinity, through polar forces and hydrogen bonding.

Oil and water do not form two layers because the molecules repel each other. They exclude each other because like attracts like more strongly than like attracts unlike.

Wettability as a definition cuts off at a contact angle of 90 degrees, but there are always attractive or adhesive forces between a liquid and a solid at that interface, at all angles.

Even at high contact angle, there is some attraction, some adhesive force. But there are also cohesive forces within a liquid that act in opposition. Is the cohesion-adhesion difference the whole story?

Sorbency is a net free energy effect, not just energy per se, but also entropy, because you are immobilizing liquid molecules at a surface, and removing degrees of freedom, as well as creating and destroying surfaces. This seems to be worse than we thought. Entropy is not helping.

Aha! We must consider the gas molecule interfaces as well. Surface tension measures free energy per area so even though the paper towel has low attraction it has a very large surface area and provides a matrix where the oil can fill the pores without creating oil-air surfaces.

In fact, it can reduce the oil-air interface, and the cellulose-air interface, so a sponging action has this mechanical – thermodynamical aspect.

So we can put it more cutely like this:

Cellulose does have some affinity for oil, but the sponging action is due to the replacement of a large non-sticking interface with the air for both substances, and replacing it with a large partly sticking, which offsets the entropy cost of immobilizing the oil and the loss of cohesion in the oil.

 

 

Why are paper towels more effective for cleaning up water compared to cooking oil?

Why? Polarity. It is the same reason oil floats on water. Water and paper towel cellulose are both polar molecules. Meaning they have a slightly negative and slightly positive pole. Therefore they attract one another.

Cellulose – http://en.wikipedia.org/wiki/Cellulose
Water – http://en.wikipedia.org/wiki/Image:Water_molecule_dimensions.svg

If you look at those two sites you’ll notice that both of those items have oxygen bound to hydrogen. These groups can actively form Hydrogen bonds.

Oil is a very stable molecule with very few chances to form hydrogen bonds.
Compare the image below with the two from above. You’ll notice way fewer OH groups that might form Hydrogen bonds.

Common lipids.png
http://en.wikipedia.org/wiki/Image:Common_lipids.png

Basically OH, FH and NH groups form hydrogen bonds because those molecules are polar. Oil is deficient in OH bonds, therefore, it is not interested in forming hydrogen bonds with water and or paper towel cellulose.

 

Why do paper towels not burn in the microwave?

The microwave works by exciting water molecules, this means that if you ever stick something in the microwave with absolutely zero water molecules, which isn’t realistic at all, the microwave won’t actually heat it up to generate heat, which means there is no combustion going on.

Sparks and fires come when you stick something with a lot of moveable electrons into the microwave like metal, electrons will jump back and forth from prong to prong, causing sparks, and if there happens to be something flammable near the sparks, a fire may start.

A paper towel is indeed flammable, however, microwaves don’t heat directly. They cause water molecules to vibrate producing heat that way. A dry paper towel doesn’t have anything that would vibrate, so it doesn’t heat up much.

As long as the food don’t splatter oil or fat onto the paper towel, and there is not thin wire, metal shavings, etc. present to create sparks and ignite the towel, you are safe.

 

What paper towels are made of and what makes them absorb?

Paper towels are made up of small coagulated fibers that are sourced from plant material.

The pores in the paper towel between fibers are what makes them absorb, although partial credit is to be given to the surface tension which exerts a “minimum surface area” force that causes the capillary action you see as water makes its way up the towel against gravity.

There is a limit to absorbency, the towel cannot hold much more liquid than it has in pore space, although it does expand and increase this space when there is fluid in it.

The towel will start to drip when the bonds between liquid molecules absorbed in the towel and those being held outside the towel are overcome. This can happen when liquid droplets outside have enough mass that the force of gravity is greater than the cohesive force of the liquid itself.

The absorbance of a liquid is somewhat proportional to its viscosity. Therefore, low viscosity liquids will require more paper towel to soak them up then high viscosity or “stickier” liquids, for the same reason I gave for the absorbancy limit above.

 

Substances that paper towel can, and can not absorb?

Substances that paper towel can absorb

Paper towels should be good at absorbing any low viscosity liquid, like water or water-based solutions (water, juice, light sauces etc) or fat suspensions in water (milk, yogurt, creamy sauces etc).

They could also absorb some organic solvents (methanol, ethanol etc). You really should be wearing gloves for this. Dumping sand/sawdust on them would be a better method of cleanup, though. Please remember to avoid lit cigarettes and naked flames!

To a lesser degree, they also absorb some lighter liquid fats (cooking oil, lubricating oil etc) but not as efficiently.

Beyond this, they can be useful for cleaning up most other household spills, but mainly as a means of scooping them up, not absorbing them as such.

There are other substances that are liquid at room temperature. I’d advise you not to mess with these at all, let alone to see how well paper towels absorb them.

Substances that paper towel can not absorb

paper towel can’t absorb anything solid or extremely viscous, mercury, roadmenders’ tar, lava, wet cement (loose water, but not the cement) and chlorine trifluoride, though it would be quite dramatic to watch.

They do a poor job on quite a few other things, including molasses (Thick dark syrup produced by boiling down juice from sugar cane; especially during sugar refining).

 

Why use paper towels when you can use hand towels?

Here are some reasons:

Germs. Those hand towels are usually pretty infested with some gross germs, consequently, they are spread onto food and food surfaces.

Hand towels, while re-usable, do require that you clean them frequently, which means using water.

The paper towel, while seeming like a waste, is no more wasteful than having to wash a bunch of hand towels in hot water, which means something needs to be burned to produce the hot water, again anti-environment, not to mention the soap that then gets into the environment.

Nothing is ever easy or as clear cut as one may think.

 

Is it ok to put a paper towel in the microwave?

Yes. Though for best results one shouldn’t microwave pastry products, inevitably they do get microwaved from time to time. I have found that placing a Cornish pasty, mince pie or other pastry covered food lightly on top of scrunched up paper towel preserves at least some of the crispness.

Pastry really doesn’t microwave well. You can’t cook it in the microwave and it’s usually greatly inferior when reheated in the microwave compared to a conventional oven, at least makes the reheated product edible.

 

How to keep the paper towel from sticking to microwave cooked bacon?

Spray a nice thin layer of cooking spray (like Pam) over the paper towel.

 

Why paper towel catch fire in a microwave?

It takes heat, fuel, and air to make a fire. Remove any one item and the fire is gone.

The paper is certainly a burnable material as it is made of cellulose fibers. You have plenty of air inside the microwave and the heat of the microwave that would not ordinarily spark a fire on paper alone. However, oil can get hot enough to burn in a microwave.

So, if what you are cooking splatter oil or fat onto the paper towel, that could start it burning.

 

What makes paper towels absorb liquids?

All paper will absorb liquid in one way or another, the fact that the paper of a paper towel has lots of air spaces in it, instead of being very compact and slick like a magazine page, is part of what makes it pull liquid away from a more solid surface.

 

Why are Bounty paper towels so absorbent?

They have thicker sheets than most paper towels.

 

Why do paper towels clog the toilet

Paper towels will dissolve, but not as fast as toilet paper. Being a larger size piece they can get caught on more joints in the drain no matter how large it is. Any elbow is a place where things can get stuck.

Just for fun, put two bowls of water on the counter. Put toilet paper in one and paper towel in the other. See how long it takes to disintegrate.

Do an experiment just for fun. Get two bowls of water. Put toilet paper in one and paper towel in the other. See how long it takes to disintegrate, and why paper towel can clog toilets.

The drain pipe may be large, but the water going down isn’t deep in the pipe. It can’t wash away things that don’t dissolve or turn into very small pieces when exposed to water.

 

 

Paper Towels Information: Tips and Facts

 

Cover food with a wet paper towel when reheating in a microwave

Your microwave will stay much cleaner, your food won’t be dried out and will heat more evenly. This also works for cooking whole baked potatoes in a pinch too. Wrap raw potato in a wet paper towel and microwave for 2-5 minutes per potato…not quite the same as from the oven but, it beats waiting an hour for them to cook.

If you have something like a sauce or cheese on top of the dish you’re trying to reheat, break a few toothpicks in half and prop up the wet paper towel to prevent it from taking the goods with it.

 

Want to cool beverage fast?

Wrap the wet paper towel around your beverage and put it in the freezer. In about 15 minutes it will be almost completely ice cold.

Does it work and why?

Yes, this does work, the two primary causes are evaporation of the water and more surface area for heat transfer.

Water has a huge latent heat (of vaporization) requirement (the heat required for it to go from the liquid to the gas phase), and when you put a damp paper towel inside a dry, cold environment the water will start to cool, but it will also equilibrate in the air of the freezer, causing rapid evaporation and thus rapid cooling.

The second effect is surface area related, the paper towel has probably 2 orders of magnitude more surface area than the outside of the can due to it’s being made out of cellulose fibers. All that surface area (covered in evaporating water, remember) acts as a highly efficient set of cooling fins (like you would see on a heatsink for a CPU).

What does “equilibrate” mean in this context, and why a cool environment causes evaporation at an elevated pace?

Equilibrate in this context means “the system moves towards agreement with Raoult’s law”
Raoult’s law states that the mole fraction of a vapor at the interface of a gas and a liquid is equal to the vapor pressure of that liquid over the pressure of the system.

Because of something called Le Chatelier’s Principle since the water vapor is constantly being removed and frozen to the evaporator coil of the freezer, the liquid water will continue to evaporate (again, in order to establish equilibrium) until it is depleted from the towel.

From all of that, you can see that it’s more that it’s a dry environment than because it’s a cool one. If you had a warm environment with the same relative humidity as a freezer (say, a dessert) it would evaporate faster than it would in the freezer.

How is it that the water evaporates at such a low temperature?

The paper towel has a large surface area and relatively small mass so it would cool very rapidly. Having the cold paper towel right next to the warm beverage would allow more rapid heat exchange than not having the paper towel because air is a poor conductor.

The beverage undergoes an endothermic process more rapidly because the paper towel effectively acts as a “heat exchanger”. Similar to the air conditioning in an abstract way.

Evaporation still takes effect. The freezer is dry and pulls moister out of the air and it freezes to the walls of the freezer, so the dry air will pull moisture out of the paper towel, and that causes it to cool slightly faster. (probably non-perceptively faster, but faster none the less)

What if you put it into a sealed bag with water in it? (a small amount of water, of course) Would that be better or worse?

Probably worse, since if it’s in a bag and water sinks to the bottom you would have a large mass of water at the bottom and air at the top.

The point of the paper towel is that you’re getting the regular (radiative) cooling plus evaporation cooling. Putting it in a sealed bag merely increases the liquid volume you need to cool, without the benefit of evaporation.

Would salting the wet towel to extend the liquid phase help speed the cooling at all?

In evaporative cooling? No, salt only helps by forcing solid ice to become liquid water, forcing additional latent heat to be absorbed from the environment. Salt has a small effect on evaporation rates, but nothing that would make a difference.

If you wanted to add something to the water to improve evaporative performance I would suggest a low flashpoint organic solvent, like Acetone or Isopropyl Alcohol.
What about at the freezing point depression keeping the water liquid longer to facilitate better heat transfer from the can than a frozen towel would provide? As the towel is usually frozen solid by the time the beverage is cooled without the addition of salt.

Yes if you had enough water on the towel that it froze before it was dry the salt would help.

How does water on a paper towel evaporate when it cools in a freezer?

It’s a concept known as Raoult’s law it tells you how a given liquid mixture will behave at a certain vapor pressure with a certain volume of air. Water at any temperature above absolute zero has a non-zero vapor pressure and will evaporate with sufficient airflow (or a vacuum, which is how freeze drying works).

 

Feeling dehydrated and not cool water available?

Take 2 bottles of water, wrap one in a sock, wet the sock with the second bottle and swing it around. The water evaporation will cool the bottle in the sock enough so that you can drink it.

 

Bacteria on your hands?

Drying your hands with a paper towel will reduce the bacterial count by 45 – 60% on your hands. However, using a hand dryer will increase the bacteria in your hands by up to 255% because it blows out bacteria already living in the conveniently warm moist environment.

 

Why does paper have brittle texture after it has been wet and dried?

In the paper making process, the pulp is strained to create the initial textured/brittle paper, but the process doesn’t end there. The textured paper must be put through high pressured steam rollers to create the smooth paper you’ve come to know.

This setting process causes all the fibers to be pressed flat and packed together evenly on the surface. When paper gets wet, it “upsets” itself, breaking up the tension that held the fibers together, again causing the uneven texture it initially had.

Water disrupts the hydrogen bonds that once held the calendered and pressed/stacked paper together. Also, it has the added effect of disrupting the “filler” that gives paper its optical qualities. This roughens the paper and decreases the amount of strength that the paper once had. A lower amount of force is needed to burst or tear it.

 

Putting paper towels with lettuce keep it from turning brown

Spread two paper towels (still connected) on the counter and pile the dry lettuce in the middle. Wrap the paper towels around the lettuce and slide into a gallon-size zippered plastic bag. Squeeze the air out and close the bag.

The lettuce can now be stored in the fridge and should stay fresh for at least a couple of weeks. You can take out what you need whenever you want to make a salad or sandwich and then just reseal the bag. The plastic bags can also be reused.

Why does lettuce turn brown

The chemistry that takes place when lettuce leaves become brown is the same chemistry we see when an apple is cut and turns brown, when green guacamole turns brown or when a green olive ripens and turns black.

All these reactions occur when chemicals in the fruit or vegetable called polyphenols react with enzymes known as polyphenol oxidases. Enzymes are specialized protein molecules made within cells that serve as catalysts. In other words, they speed up chemical reactions.

Normally within a cell, the enzymes and the polyphenols are separated, but when cells are damaged, as in cutting an apple or tearing lettuce, their contents leak out and the polyphenols and the enzymes mix.

The result is a reaction that oxidizes the polyphenols and allows them to link up with each other to produce a brown pigment. When lettuce leaves are torn, some cells are damaged and the browning reaction begins.

But even if there is no tearing, even if we have a whole head of lettuce, there will eventually be browning. That’s because the aging of the cells also leads to damage and mixing of the polyphenols with the enzyme.

 


References

How Do Paper Towels Absorb Water? – Indiana Public Media
http://indianapublicmedia.org/amomentofscience/how-do-paper-towels-absorb-water/

http://www.scgov.net/sustainability

http://1800recycling.com/

Bounty (brand) – Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Bounty_(brand)

Banish the Paper Towel | The Energy Co-op
https://theenergy.coop/community/blog/banish-paper-towel

Bounty -vs- Scott Paper Towels by Emily Nester on Prezi
https://prezi.com/9g2ivndbuyde/bounty-vs-scott-paper-towels/

Paper: Bathroom Tissue and Paper TowelsSketch of capillary action in thin tubes. Source: Surface Tension
http://hyperphysics.phy-astr.gsu.edu/hbase/surten2.html

Capillary action in a paper towel. Surface tension overcomes gravity and the liquid is drawn up into the paper towel. Source: How Greywater moves through soil (capillary effect)
http://www.thegreywaterguide.com/how-greywater-moves-through-soil-capillary-effect.html

Cellulose – http://en.wikipedia.org/wiki/Cellulose
Water – http://en.wikipedia.org/wiki/Image:Water_molecule_dimensions.svg

Common lipids.png
http://en.wikipedia.org/wiki/Image:Common_lipids.png

Bounty is more absorbent
http://bountytowels.com/en-us/shop-products

Paper: Bathroom Tissue and Paper Towels
https://www.wbdg.org/ccb/GREEN/REPORTS/cgrtissuetowel.pdf

Paper Towel History – Invention of Paper Towels
www.ideafinder.com/history/inventions/papertowel.htm

Paper product milestones: Paper Towels
http://www.ipst.gatech.edu/amp/general/museum_faq.htm#towels


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