Has any one worked with Zylon?

[jbro2]

Just trying to get some more information regarding Zylon or zylon/carbon hybrid. I am looking to see if this fabric is worth working with and what the drapability, what resin type works best for it. I have been reading that this has much better abrashion resistance and heat resistance than Kevlar. Any Information would be appreciated, application wise i am looking to use it for a rear diffuser with exhaust ports on a vehicle. The problem i have been running into is the egt's and finding a soulution for a resin that doesnt break down over 200deg even after post cure.

 

[Moudoc]

So I'm not sure if zylon is necessary for what you want. I can't think your exhuast pressures are going to get that crazy. The resin question is a better one. bismaleimide is the resin of choice for high temp situations. It can be used with carbon fiber or fiber glass. Zylon is super crazy strong, but its only half as stiff as carbon fiber. If you are looking for high strain tubing zylon stretches like flubber, but stiffer cheaper alternative are all over the place. Zylon is better for impact structure because its elastically strains well. F1 recently added zylon as a back up plies for the cockpit. After the carbon fiber plies shatter, the zylon keeps the tub together. The wheels also have zylon tethers in the A-arms for the same secondary retension role. New material testing will definitely push you to the edge. If you want to design a car that will take repeated 100-mph impacts with only the driver worse for wear, zylon will take you there (with skill). If you just want hightemps, its all about the resin, bismaleimide. Carbon fiber and glass are good to 1000C as long as its sealed under a resin, but the resin won't last. If you want to go even higher tech and a lot greener. Try V.A.R.T.M thermo plastics like PEEK. Its good to 400F and its recyclable.

 

[jbro2]

Moudoc
Thank you for being the one and only person from multiple forums to give me an answer at all, never mind the knowledge you have on this product. I will be looking into the Bismaleimide, for the hi temp areas. Does that product require a post cure cycle or does it cure with Hi temp. properties? I was thinking that the zylon properties would be good for a specific area were the exhaust pipe would meet with the diffuser. The exhaust would need some sort of flex area so that its not attached at a ridged point do to normal movement in startup and different driving conditions. Would the V.A.R.T.M achieve the same result.

 

[jbro2]

Just read up quick on PEEK, not to familar with it but very interested. How would i go about working with this product is there any specific tools that i would need? I have vacuum equip. and i am currently working on an oven project that has taken a back seat for a little bit. Is PEEK a product in its finest powder form something that can be added to an Epoxy resin and post cured to achieve the most optimum performance properties?

 

[Moudoc]

Well BMI is definitely an auto clave material. It should be fine out of the box, it just takes a higher bake. The equipment for handling PEEK is special I guess because of the high melting temp. PEEK is a thermoplastic rather than a thermoset like resin meaning it has to be applied to the inplace fibers melted. Its a little thick and its use in composites is still R&D. VARTM means Vaccum Assisted Resin Transfer Molding. The vacuum helps thicker "fluids" move into the mold corners. Carbon fiber will oxidize if heated in air beyond say 300F. I would need to know your budget to win before I talked you too far into this. BMI systems use traditional autoclave facilities. I have not seen an out of autoclave process, but if you only need partial strength. You can test up your own method. Last warning, high strains composites need high strain matrix materials. Porosity and delamination will cause some pretty high reductions in max strain.

 

[jbro2]

Thanks Moudoc sounds like this will be a little outside my budget at this time. Autoclave is not going to be an option at this time either. But thank you for the information thats what these forums are great for. I think that the tooling cost will be to high for a product that is possibly only going to be a small batch.

 

[RPstress]

PEEK is usually limited to about 250°C (Tg is 143°C, but where it's a semi-crystalline thermoplastic it's ok to go a bit above the Tg for non-aerospace use). I'm not aware of it being used as an additive to thermosets. As Moudoc says, it's also quite viscous; it can be injection moulded with short fibers but I think you'd have trouble infiltrating it into a dry preform (claimed viscosity about 90 pascal-seconds for the 90G grade, cf. 0.02 to 0.05 for typical RTM/VARTM resins). You can buy it as a prepreg with carbon and glass from TenCate.

For the highest temp commercially available plastics suitable for matrixes check out polyimides, such as Cytec's Avimid N, which has a claimed dry Tg of 410°C (375°C wet). However, stay away from ones such as PMR-15 which have MDA in them, as they're bad for you. PBI, a thermoplastic (polybenzimidazole), can go even higher, but I don't know of it being available with continuous fibers. BMIs can be happily processed at 100 psi and maybe 200°C with a free-standing post-cure of maybe 230°C. PIs though may need 200 psi and 320°C. As Moudoc observes, curing BMIs out of autoclave (OoA) is not advisable. ACG do a BMI which they claim can be cured OoA, but they do warn that it will be much more porous.

Re Zylon (aka PBO), we've played with it a bit. It looks useful for armor, but it should be fairly useless for a weight-efficient structure, as laminates of it have very low compression strength (much like Kevlar). Unless it's a tension structure such as a sail, structure-wise you're better off for high temperature with glass (maybe carbon if temperature is <=300°C) in PI, or maybe alumina fiber such as 3M's Nextel, though that may be overkill. If you're tension-only the data from Teijin show reasonable retention of Zylon tensile properties at 400°C. Zylon also degrades quite quickly in sunlight (see North Sails's notes for rigging made of it).

 

[Moudoc]

Well BMI is definitely an auto clave material. It should be fine out of the box, it just takes a higher bake. The equipment for handling PEEK is special I guess because of the high melting temp. PEEK is a thermoplastic rather than a thermoset like resin meaning it has to be applied to the inplace fibers melted. Its a little thick and its use in composites is still R&D. VARTM means Vaccum Assisted Resin Transfer Molding. The vacuum helps thicker "fluids" move into the mold corners. Carbon fiber will oxidize if heated in air beyond say 300F. I would need to know your budget to win before I talked you too far into this. BMI systems use traditional autoclave facilities. I have not seen an out of autoclave process, but if you only need partial strength. You can test up your own method. Last warning, high strains composites need high strain matrix materials. Porosity and delamination will cause some pretty high reductions in max strain.

 

[Compositepro]

You are certainly looking at a lot of exotic materials which a probably not appropriate for your application. Zylon has some excellent tensile properties but very poor compression and poor sunlight resistance. It does have the stiffness of carbon, unlike aramid which is half that of carbon (to correct what was said above).

PEEK requires processing at 700F and does not blend with other resins well. Raptor Resins supplies BMI resins that can be used for vartm and other out-of-autoclave process, and can be cured at 350F.

 

[Moudoc]

Sorry for the double post. Damn cellphones. But carbon fiber is twice as stiff and zylon. E graphtized carbon = 77e6 psi and E zylon = 28-35e6 psi. The lower temp fiber are generally around 50e6 psi.

 

[Compositepro]

Standard modulus PAN carbon fibers, which are by far the highest volume used, is 30-35 msi(AS4,T300). Intermediate modulus is about 42 msi. Modulus can get higher than 120 msi. Kevlar is 15 msi. Oh, and oxidation of carbon fibers is not generally considered an issue until 600F.

 

[jbro2]

Well thank you all for the wealth of information. I was looking into the these exotic material only because of the appeal of it being just that. I had a hunch it was above and beyond what was needed but the only way to learn about things some times is it to try it. I really appreciate the time you guys have spent informing me on these products. Looks like i will need to get an injection molding machine and an autoclave to get crazy, but i dont have a million and that my only cover the machines, so that my have to go on the back burner for a bit. But i am open to suggestions on what a simple vac setup with a post cure will achieve.

 

[GregoireMC]

Hi,

Did you looked at the Cyanate ester resin?
It is thermosets and high temp (don't know about abrasion or impact resistance. Maybe it is complying to your requirements.

TenCate is supplying this resin, they are supplying resin for vartm/infusion and prepreg.