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jedi

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homebuilderfan

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I believe the Ford you are referencing was soybean based plastic not a hemp derived product.

Henry Ford had an extensive program to find uses for soybeans as a means to help farmers and improve the environment.
Really? This is the first time I heard about plastic made from soybeans in the forthy
 

wsimpso1

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Somebody is pulling your leg guys.

Just went looking. hemp strength of 10 MPa or 1400 psi. E-glass fiber is about 100 times that. Hemp modulus is about 2 GPa, or about 290 kspi. Modulus of E-Glass is 9 Mpsi or about 30 times stiffer. You could build an airplane with it substituted for glass, but you would have to use a lot of it. Probably would be so heavy it would never fly...

Billski
 

Jerry Lytle

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Really? This is the first time I heard about plastic made from soybeans in the forthy
My Dad had a 1938 Ford with some of that plastic. The plastic aged and cracked a long time before the car itself needed replacing. The gear shift knob and switch knobs on the dash were soybean plastic, all were in a sad state by 1945, when newcars became available again. I owned a 1946 Ford in 1960 which had a lot of plastic, but it must have been improved if it was soybean based, as most of it was in good shape 15 years after manufacture.
 

pictsidhe

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Somebody is pulling your leg guys.

Just went looking. hemp strength of 10 MPa or 1400 psi. E-glass fiber is about 100 times that. Hemp modulus is about 2 GPa, or about 290 kspi. Modulus of E-Glass is 9 Mpsi or about 30 times stiffer. You could build an airplane with it substituted for glass, but you would have to use a lot of it. Probably would be so heavy it would never fly...

Billski
I looked into hemp some time back. Fabrics were very pricey, higher than carbon. Properties were far better than Billski's figures, in the ballpark of glass. I just looked and the first paper I found was ~90GPa modulus and ~1GPa strength.
So, high cost was the killer. IIRC, it was also a bit fussy about the matrix used.
 

Aesquire

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A buddy once gave me a long lecture about the history of Hemp, and how it was legislated out of use by a Lumber Tycoon during a lull in wood use for construction and his successful efforts to sell wood to be made as paper, instead of hemp. With references and gestures. I looked it up. It's all true.

Hemp makes great paper. Pretty darn good rope. Certain strains have medicinal value, but that is not relevant to Aircraft design, nor are those strains used for rope or cloth or paper.

On a weight to strength basis, hemp fibers are probably best used in modern versions of the Ice composite aircraft carriers proposed and experimented with in WW2 for the North Atlantic.
https://en.wikipedia.org/wiki/Project_Habakkuk
 

Pops

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In my area Hemp was a good cash crop to grow in the 1930's. Now hemp grows wild everywhere. Beside the roads , fence lines, etc, any fields where it's not mowed often. How many ton's do you want, it would make the farmers happy.
 

cdlwingnut

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Sounds like someone trying to prove darwins theary was right and solve some of the pothead problem at the same time
 

jedi

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Spoiler alert:

My my dad worked for Ford Motor Co. in the 30s and 40s. His primary job was to find uses for soybeans and other plant products. He developed the process to make a soy milk and soy cream. Boyer ran the soybean development department that contributed to the plastic car demonstration. The "Carver Lab" building was still standing on Michigan Avenue last time I was back in Detroit.

Info from the Henry Ford book copied below.

Ford long had an interest in plastics developed from agricultural products, especially soybeans. He cultivated a relationship with George Washington Carver for this purpose.[100][101][102] Soybean-based plastics were used in Ford automobiles throughout the 1930s in plastic parts such as car horns, in paint, etc. This project culminated in 1942, when Ford patented an automobile made almost entirely of plastic, attached to a tubular welded frame. It weighed 30% less than a steel car and was said to be able to withstand blows ten times greater than could steel. Furthermore, it ran on grain alcohol (ethanol) instead of gasoline. The design never caught on.[103]
Ford was interested in engineered woods ("Better wood can be made than is grown"[104]) (at this time plywood and particle board were little more than experimental ideas); corn as a fuel source, via both corn oil and ethanol;[105] and the potential uses of cotton.[104] Ford was instrumental in developing charcoal briquets, under the brand name "Kingsford". His brother in law, E.G. Kingsford, used wood scraps from the Ford factory to make the briquets.
 

Aesquire

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Additional Ford ideas.

The engine block for the Model T was contracted to be shipped to Ford in a wood crate of very specific design. Bolted together, not nailed. The tires were to be shipped on custom designed steel pallets, 4 to a pallet. The suppliers were happy to pay the additional cost to get the big contract.

The pallet formed the floor pan and the crate had most of the wooden body structure of the car. Genius!

There are a couple of kit manufacturers who design the shipping crate to be repurposed as a work table. Smart is not dead.
 

wsimpso1

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I looked into hemp some time back. Fabrics were very pricey, higher than carbon. Properties were far better than Billski's figures, in the ballpark of glass. I just looked and the first paper I found was ~90GPa modulus and ~1GPa strength.
So, high cost was the killer. IIRC, it was also a bit fussy about the matrix used.
Please provide pick.
 

wsimpso1

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Most articles I found either just say hemp is strong or they require a subscription to read them. I did find another open article. https://www.hindawi.com/journals/amse/2013/325085/

244 MPa and 8.6 GPa, which is 35 kpsi and 1.25 Mpsi. These are still a quarter the strength and stiffness of even E-glass. Still would require four times the volume and thus nearly four times the weight to make strength and stiffness of an equivalent part in E-Glass.

Look, hemp is basically cellulose, so it will be in the range of cotton and wood for stiffness and strength. You will require a lot of it to get to strength in a composite. And when you go several times as much volume as for glass structures, it will also take several times as much resin to wet it out to finish making a structure. Then there is the irregular shape and poor straightness, which will make its packing efficiency poorer than glass, driving higher resin fractions in all manner of layups, with even more weight for any given structure.

WEIGHT IS THE ENEMY in airplanes. Using hemp for structures will result in a lot more weight... Flight is NOT a natural act for humans, so it is OK with me to use something other than natural materials in machines for human flight.

Billski
 
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