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Which Material Is Best For Hot Air Balloons: Nylon Or Polyester?

Researched by Heather K. 


The purpose of this experiment was to determine which material used in hot air balloons is the safest and toug..I became interested in this idea when I was on-line looking for a balloon information when I came across hot air balloon project ideas and I thought that would interest me and I would like to do it so I decided to try something in this area.

The information gained from this experiment may be used by anyone who is interested in hot air balloons or races them. Any students that are in the process of studying hot air balloons may also use it.



My hypothesis was that the polyester would be the stronger because of how much more it is used to manufacture hot air balloons.  You can heat polyester to a higher temperature without damage than nylon.

I base my hypothesis on sales figures which show polyester is much more popular for balloon construction and that the manufacturers use it the most.



The constants for all groups in this experiment were: 
* The size of the material 
* The shape of the cloth 
* The size of the wood stretching frame 
* The mass of weight dropped each time 
* The oven temperature in degrees Fahrenheit

The manipulated variable was the type of cloth; nylon and polyester.

The responding variable was the strength of the nylon and polyester.

To measure the responding variable I dropped a counter sink on the material and counted the number of impacts it took to tear the fabric.  I then heated samples of the same material in an oven and ran the tests again.



10 50.8x30.48 cm  squares of nylon
10 50.8x30.48 cm  squares of polyester
50.8x12.7 cm  pieces of wood
1 31x18 cm tray
1 oven
1 60.96 cm  measuring ruler
2 people helpers
counter sinker with holder
screw driver 



1. Cut 5 squares each of polyester and nylon 50.8x30.48 cm. 
2. Get 4 wood post that are 50.8x12.7 cm. 
3. Take two posts and screw drive the material around the edges. 
4. Twist the material on the boards around one (1) time and staple the material in place. 
5. Get someone to hold the ruler in place and get ready to drop the counter sink with holder. 
6. Make sure that you drop the counter sink from 2 feet above until the nylon is ripped or tore. 
7. Try it again three more times to get the results. 
8. Then repeat steps 1-7 on the polyester sheets of cloth until they tear or rip. 
9. When you are finished you count how many times it took you to drop the metal cones until the sheets of cloth tore or ripped and average it. 
10. Take the last squares of the polyester and nylon. 
11. Take and turn the oven on 250° Fahrenheit. 
12. Then stick one sheet of nylon in the oven on a tray. 
13. Take the nylon out after 1 minute. 
14. After they come out, see which one look like it is in the best shape. 
15. Then do steps 11-14 four more times on the other piece of polyester. 
16. When you are done, Take all the pieces of cloth and see which material looks like it could have lasted longer-in other words see which one is in the best shape out of all of them and whether it was polyester or nylon. 
17. Then, while they’re hot, do the first test on the last pieces of material and see whether the heat strengthened the material or not. 



The original purpose of this experiment was to see which material used in hot air balloons is the safest and toughest.

The results of the experiment were that the polyester outperformed the nylon for strength regardless of whether the cloth had been heated or not.  Polyester never broke even with 10 impacts of the counter sink.  The nylon averaged just two impacts of the metal sink before breaking.




My hypothesis was that the polyester would be stronger than nylon.

The results indicated that this hypothesis should be accepted because the polyester never broke, while the nylon tore after an average of two drops.  Polyester was the stronger material.

Because of the results of this experiment, I wonder if these results would show up the same if it were silk vs. nylon.

If I were to conduct this experiment again I would try to make sure the weight was the same for both materials and I would run the test several more times.

Balloonists and hot air balloon manufacturers might find these results useful.  Polyester should be safer for them to use.



Hot Air Balloon

A hot air balloon is a bag filled with heated air or a light gas so it rises and floats in the air. A balloon rises because the air inside the bag is lighter and less dense than the air surrounding. It was invented in the late 1700’s by the two inventors Jacques Etienne and his brother Joseph Michael Montgolfier, who were papermakers that started the balloon experiments with paper bags. On the date of June 4, 1783, the brothers sent up a large air filled balloon in the public gathering area in Annonay, France. The cloth used for the balloon was lined with paper and measured 35 feet in diameter.


The polyester is the material most manufacturers use for their balloons and it is highly recommended for the strongest. Polyester has a higher resistance to UV rays. The temperature inside the balloon can reach 300° and polyester resists heat damage fairly well. Polyester is any group of polymers that consist basically of repeated units of an organic salt and are used especially in making fibers or plastic. It’s also a synthetic, instead of a natural fiber. Polyester is wrinkle and mildew resistant, other important polyesters are unsaturated polyesters. Unsaturated polyesters contain unsaturated acid, which is a hydrocarbon acid. 


Nylon is not highly recommended or used by manufacturers of hot air balloons because it does not have as high of UV resistance as the polyester. It can only withstand at a certain temperature on the inside of the balloon, which is 50° less than the polyester can hold (250° instead of 300°). Nylon is any of the numerous strong, tough, elastic, synthetic polymer made materials that are fashioned into fibers, filaments, bristles, or sheets and used especially in textiles and plastics. Nylon is a term for a group of synthetic products, which are made from chemicals that have been made out of coal, water, air, petroleum, agricultural by-products and natural gas. Nylon is used primarily in fibers and fabric. It was first made into hosiery, which was available in 1940. It was the first synthetic fabric thought to be superior to natural fabrics. 


Balloons are usually made of synthetic fibers. Polyester and nylon are both used but the polyester is more popular in manufacturing due to its higher tolerance to temperature and UV light. 



"Balloons" Encyclopedia of Americana, 1999. Vol. 2. Pg. 117 

"Balloons," World Book Encyclopedia, 1991. Vol. 2, Pgs. 57-62

"Hot Air Balloons,"  December 20, 1999.

Lansdown, Jeff. "Balloons." [Online] Available email: from 

"Nylon," World Book Encyclopedia, 1995. Vol. 14. Pgs. 637-638.

"Polyester," World Book Encyclopedia, 1995. Vol. 15. Pg. 652.

 Young, Mary Beth and Dick. "Hot Air Balloon Fabric Info." [Online] Available email: from 

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