World Webbing formula

[White_widow]

I know we are going with styrofoam due to the lack of availability to other options, but the real answer is cellulose. Heck, screw nano-cellulose, unaltered wood has a tensile strength of about 300 MPa, which is in the same neighborhood as structural steel.

So for those of you who are doing enough homework to understand what I'm saying, here's what we need. We need a plastic. It has to make a quick state change. That tensile strength needs to be at least 50 MPa. It also needs to be flexible. This can be achieved by either bonding an elastomer to the polymer or adding a plasticizer to add flexibility. (I've only found three polymers that fit most of these categories.)

That by itself will extrude a fiber that can support weight. That, along with what you are using it for, the thickness of nozzle, the extrusion process, and method of extrusion, can change how you go about this.

This we can all agree on, and are currently bickering about as we have so very few choices.

Now here's where I am starting to go toward. Cyanoacrylate is too brittle and will make it impossible to let go. (If we have gloves, it'll be too slippery.) If we use other glues, it will be very hard to be able to wait for the solvent to evaporate, or the rate to cure by whichever method. It will either harden too quickly and not stick, or harden too slowly, and lose the ability to hold said weight in time of need. So, what does that leave us with?

Tackifieeerrrrrrrrssssssss! The only adhesives that can work for our project are pressure based adhesives. That is to say, the adhesives are activated by pressure. Pressure based adhesives are part elastomer, part tackifier. Some are permanent, some are temporary. That is all based on the curing rate of the elastomer. So consider our plastic to be the elastomer in the equation. The rest is a tackifier, or tackifying agent. Here is the beautiful thing though. It stops working in the cold, and works in the warm.

This means that it can't clog the shooter, and it will just be tacky enough to hold onto when it comes out of the shooter due to the temperature change in the carbon dioxide. When it heats up, it gets super sticky (No puns needed here please). When it is heated to super heats, it loses it's bond. We can play around with heat, but if we can start studying tackifiers, I feel like we wouldn't be any worse for wear.

 

[megajs]

well i just tried a design with the co2 charging a canister of the formula, BIG MISTAKE. i spent an hour trying to get the frozen formula out of the canister.
back to the drawing board

 

[megajs]

I know we are going with styrofoam due to the lack of availability to other options, but the real answer is cellulose. Heck, screw nano-cellulose, unaltered wood has a tensile strength of about 300 MPa, which is in the same neighborhood as structural steel.

So for those of you who are doing enough homework to understand what I'm saying, here's what we need. We need a plastic. It has to make a quick state change. That tensile strength needs to be at least 50 MPa. It also needs to be flexible. This can be achieved by either bonding an elastomer to the polymer or adding a plasticizer to add flexibility. (I've only found three polymers that fit most of these categories.)

That by itself will extrude a fiber that can support weight. That, along with what you are using it for, the thickness of nozzle, the extrusion process, and method of extrusion, can change how you go about this.

This we can all agree on, and are currently bickering about as we have so very few choices.

Now here's where I am starting to go toward. Cyanoacrylate is too brittle and will make it impossible to let go. (If we have gloves, it'll be too slippery.) If we use other glues, it will be very hard to be able to wait for the solvent to evaporate, or the rate to cure by whichever method. It will either harden too quickly and not stick, or harden too slowly, and lose the ability to hold said weight in time of need. So, what does that leave us with?

Tackifieeerrrrrrrrssssssss! The only adhesives that can work for our project are pressure based adhesives. That is to say, the adhesives are activated by pressure. Pressure based adhesives are part elastomer, part tackifier. Some are permanent, some are temporary. That is all based on the curing rate of the elastomer. So consider our plastic to be the elastomer in the equation. The rest is a tackifier, or tackifying agent. Here is the beautiful thing though. It stops working in the cold, and works in the warm.

This means that it can't clog the shooter, and it will just be tacky enough to hold onto when it comes out of the shooter due to the temperature change in the carbon dioxide. When it heats up, it gets super sticky (No puns needed here please). When it is heated to super heats, it loses it's bond. We can play around with heat, but if we can start studying tackifiers, I feel like we wouldn't be any worse for wear.

its also important we know how cold it needs to be to not work (winter situations and all that)

 

[White_widow]

Ok, so other than me, does anyone have any ideas about the formula? Any chemicals that aren't nylon related? Any plastics other than PVOH, Cellulose acetate, or Polystyrene. Any adhesives other than cyanoacrylate, polyisoprene, polyneoprene, or epoxy? Any solvents other than super critical CO2, acetone, or water? Any materials other than hot glue, polyurethane, urea, NCC or, graphene? All of these are my ideas, and my inspirational well is drying up. Does anyone have any ideas?

 

[Iron_spider]

I have an idea that's kind of based off of one of your ideas, the one with PVOH and graphene.

While graphene-reinforced PVOH has a higher tensile strength than regular PVOH, graphene makes it stiffer and takes away some of it's elasticity.

In my research I came across a high-melting ionic liquid called 1-ethylpyridinium bromide, which is miscible in PVOH. It acts like a plasticizer to PVOH. Together, PVOH and the ionic liquid make an elastomer. So maybe, the ionic liquid could give the graphene-reinforced PVOH it's elasticity back.

Just an idea though. What do you think?

 

[megajs]

Ok, so other than me, does anyone have any ideas about the formula? Any chemicals that aren't nylon related? Any plastics other than PVOH, Cellulose acetate, or Polystyrene. Any adhesives other than cyanoacrylate, polyisoprene, polyneoprene, or epoxy? Any solvents other than super critical CO2, acetone, or water? Any materials other than hot glue, polyurethane, urea, NCC or, graphene? All of these are my ideas, and my inspirational well is drying up. Does anyone have any ideas?

Something based around polyisobutylene may work

 

[White_widow]

I like it. Getting enough graphene (or ethylepyridinium bromide) would be difficult, but I like it. The ionic liquid would guarantee a decently strong bond. The elastomeric nature would allow for strain crystallization. The only thing lacking is tensile strength.

polyisobutylene is pretty good too. It's still lacking in tensile strength.

 

[Iron_spider]

Ok, I need clarification on something. I read somewhere that the tensile strength of PVOH is about 50 MPa. I also read (from a different source) that PVOH fibers have a tensile strength of 1600-2500 MPa.

So which should we be basing things off of? Trying to strengthen something that would have already been strong enough would be a waste of time and money. But, if the PVOH does need to be strengthened and we don't strengthen it enough, that would be a waste as well.

I think I figured out a good ratio of graphene to PVOH so that it will be about as strong as spider silk in tensile strength. That is, if we assume that PVOH is 50 MPa.

So, do we really need to be strengthening the PVOH?

 

[White_widow]

Ok, I need clarification on something. I read somewhere that the tensile strength of PVOH is about 50 MPa. I also read (from a different source) that PVOH fibers have a tensile strength of 1600-2500 MPa.

So which should we be basing things off of?

So, do we really need to be strengthening the PVOH?

I'd need to see the data, but generally speaking, I would believe 50 MPa and when combined with water, even less. Steel is about 300MPa (structural). I read an article that stated PVOH was made as strong as steel when combined with well dispersed clay platelets. While I think these science articles are terrible at listing anything that is "strong as steel", I take it to mean that PVOH is less that stainless steel.

I think that the 1600MPa was based either on films or fibers that are used to reinforce concrete.

Let's not forget that PVOH is the same material that they make gack out of. It's still strong, but it needs to be prepared well.

 

[Iron_spider]

http://www.eng.auburn.edu/files/centers/hrc/930-657.pdf

That's where I got the 1600-2500 MPa figure from. I guess what I want to know is, could our shooter can spin the PVOH fibers like the ones being described there, and with the same strength?

 

[White_widow]

That's referring to a copolymer and a different type of tensile strength. It actually says 6 MPa is the tensile strength.

 

[Iron_spider]

Alright, now I'm confused...

 

[White_widow]

Let's say that unmodified PVOH fibers are like 50 MPa (It's actually less). If you add water, it'll drop to 6 MPa (too much water.) If You make it with another stronger plastic, it'll shoot back up to 1000 MPa because they reinforce each other. This number will also change in preparation and what they make with it. Pellets, films, and fibers all have differing Tensile strength, flexural modulus, and properties.

From that same article:

" Physical and mechanical properties of commercially available PVA used as reinforcements in ECC are:
Diameter 39 μm
Length 8.12 mm
Tensile Strength 6 MPa
Elongation 6%
Oiling agent content 0.8%
Young’s Modulus 42.8 GPa "

All you are seeing is:

"PVA fibers typically have a tensile strength between 1600 and 2500 MPa, and is
considered a promising alternative to other fibers used in ECC."

You missed the part about:

"Despite these obstacles, PVA fiber still holds
great potential since the interfacial characteristics can be modified."

That means that the fibers you are thinking about, aren't the commercially available ones. They are the chemically modified ones.

 

[Iron_spider]

Ahhh ok I see. Thanks for clearing that up for me.

 

[Iron_spider]

To achieve Peter Parker webbing strength, what do you think the tensile strength of the plastic would need to be?

 

[White_widow]

2000 MPa. That's the tensile strength of Kevlar which is similar to actual spider webbing. Give or take a thousand. 300 MPa would be more reasonable though. That is the tensile strength of human hair and structural steel.

 

[Iron_spider]

Okay that's higher than I expected... Would somewhere within 500-1000 MPa be alright?

 

[White_widow]

Any of it would be alright, and appreciated. The higher the better, but all we need is about 40 MPa as long as we can create the fibers quickly enough. Nylon and polyethylene are around that.

 

[Iron_spider]

And 40 MPa could hold a lot of weight? The reason I ask is because I'm working on the formula in two ways. One is for fun, to see if we can get a formula that works closely to the one in the comics. And the other is for industrial applications, for use in new kinds of cranes and stuff like that.

Also, when you say polyethylene, do you mean high density polyethylene?

 

[White_widow]

High density Polyethylene is only 30 MPa.

http://en.wikipedia.org/wiki/Tensile_strength

There is a chart there that shows you a list of industrial strength tensile test results.

 

[Iron_spider]

I've seen it. I didn't see any polyethylene close to 40 MPa besides high-density. Other than that, there's ultra high molecular weight, but that's way over.

 

[White_widow]

Only when extruded the right way. That's another important detail. It doesn't matter how good our formula is if it doesn't get prepared correctly.

 

[spidey1081]

Hey guys. I don't know if this well help but I do remember reading somewhere about the web fluid being magnetic and that when the fluid is shot out through the spinnerets the webbing that the web lines will attract to each other to make different shapes. What do guys think?

 

[White_widow]

That sort of thing won't really help us. We need a proper spinneret to get the effect that we need.

Hey, is everyone here a fan of mythbusters? I'm going to go ahead and say that they are awesome. Fanboyism aside, they did an episode where they made ropes from various materials to see if they could scale a jail with it. It was episode 124 "motorcycle flip".

They tested three materials. One was bed sheets. Lame, we all knew that would work. Two was hair, and it had no friction, but it worked. Repunzel be darned. Third, and this was a doozy, TOILET PAPER. Read that again. They made a rope of one ply toilet paper and it held a person for the entire descent. now let me put that in perspective. Regular non serrated paper is 1 MPa. It will break even with only a pound of weight coming off of it. How did they do it? Well, the mythbuster took and twisted the toilet paper so that the serrated paper wouldn't be an issue. He then took a ton of those strands an wound them together. He took those and wound them with more, and of course he had a drill, but the point I got from it is that if we can make a spinneret, not that makes shapes, but winds them together like an old school braiding device, then we will be in business.

http://www.youtube.com/watch?v=zK2hKiL4TKA

http://www.youtube.com/watch?v=TAc6MPuodmI

 

[White_widow]

If someone is going to make a heated web shooter, I know the material for you. There is a material known as Polycaprolactone that is about the strength of nylon when cooled. Mix that while hot with a REALLY low viscous hot glue, and you should be good.

As for the rest of us, I think the next goal should be to find out what glue is in Duct tape.


http://www.youtube.com/watch?v=mMcOtNwqqxQ

Ok, so they used a lot of tape and it broke, but notice something, the tape is still stuck to the car. The polyethylene backing broke, but the tape still held the car. This adhesive is so remarkable that it will tap something, and it will hold it. It was so adhesive that it held the car up for an ascension, and a delay until the backing of the tape snapped. That's our glue, and if I'm not mistaken, it's a thermoplastic that will be affected by heat and cold.

Now imagine if the polyethylene backing was replaced by something stronger. Polyethylene is like 40 MPa. Yeah they used a lot of it, but this is just a test.