What is the melting temp of nylon or teflon

[arkypete]

I've had idea, usually I go lay down until it passes, but thiis has been around for ten or twelve years.
What would happen if some variety of plastic was injected into the lube grooves of a bullet to harden. It's my thought that nylon, teflon, polyethilene would be more resistant to gas cutting, may even scrape the barrel clean.
Jim

[wills]

"Nylons 11 and 12 have lower moisture sorption combined with superior resisce to fuels, hydraulic oils, and most automotive fluids. The melting points of nylon 11 and 12 (355 to 365°F) are the lowest of the commercial polyamides. These two polyaraides are often combined with plasticizers to generate a flexible, tough material suitable for tubing extrusion. Recently nylon 12/12 has been introduced with a slightly higher use temperature while main taining good fuel resistance. Nylon 6/6T resins, available from BASF Corporation Plastic Materials, have low moisture absorption and they are much stronger, stiffer, tougher, fatigue resistant, and more heat resistant than type 6/6 nylons. The Ultramid type 6/6T resins also have better resistance to hot oils and fats than type 6/6 nylons. Reinforced grades of type 6/6T nylon resins also are available."

"Nylon 4/6 is the latest version of the short repeat-unit polyamides. Its melting point of 565°F is 54 °F above that for nylon 6/6 and is the highest in the polyamide family. The inherent molecular symmetry of nylon 4/6 results in self -nucleation, rapid crystal growth and, thus, a higher level of crystallinity. This higher level of crystallinity leads to faster set up and, hence, faster inj ecti on -molding, cycles, up to 30% faster than for 6/6. Nylon 4/6 absorbs more water than nylon; however, its dimensional stability is similar to nylon 6/6 due to its high crystallinity"

[arkypete]

Wills

Thanks so much for your help. May I impose some more?

Nylons 11 and 12 have lower moisture sorption combined with superior resisce to fuels, hydraulic oils, and most automotive fluids. The melting points of nylon 11 and 12 (355 to 365°F) are the lowest of the commercial polyamides. These two polyaraides are often combined with plasticizers to generate a flexible, tough material suitable for tubing extrusion. Recently nylon 12/12 has been introduced with a slightly higher use temperature while main taining good fuel resistance. Nylon 6/6T resins, available from BASF Corporation Plastic Materials, have low moisture absorption and they are much stronger, stiffer, tougher, fatigue resistant, and more heat resistant than type 6/6 nylons. The Ultramid type 6/6T resins also have better resistance to hot oils and fats than type 6/6 nylons. Reinforced grades of type 6/6T nylon resins also are available.


Do nylons 11 and 12, shrink on cooling, stay the same or expand?

Jim

[wills]

http://www.machinedesign.com/BDE/materials/bdemat2/bdemat2_29.html

I should have used quotation marks and posted the link. I personally, dont know but perhaps the article will help.

[wills]

Here is some other stuff.

http://www.azom.com/details.asp?ArticleID=442
“Polyamide 6 - Nylon 6 – PA 6
Polymer Type
Thermoplastic

Advantages
Easier to process than Nylon 6/6 (castable), may be reaction injection moulded. Has lower mould shrinkage than Nylon 6/6 with good fatigue resistance. Useful improvement in stiffness can be obtained by inclusion of glass fibres, unlike acetals.

Disadvantages
Highest rate of water absorption and highest equilibrium water content. Lower strength & stiffness than Nylon 6/6. Higher stick slip than Acetal or PBT.

http://www.immnet.com/articles?article=2844
Nylon is a high-mold-shrinkage-factor crystalline plastic. It is not ideal for molding parts with thicknesses greater than .250 inch. Thicker walls are susceptible to uncontrollable mold shrinkage, internal voids, and molded-in residual stress.

http://www3.interscience.wiley.com/cgi-bin/abstract/104072574/ABSTRACT?CRETRY=1&SRETRY=0

The shrinkage of extended nylon 6 was studied by the methods of isothermal annealing and tempering. The shrinkage was discussed in comparison with that of amorphous polymer solids in the glass transition region. It was found that the annealing below the melting temperature of crystalline polymer solids showed two effects: one was the shrinkage of samples tracing the quasi-equilibrium states and the other was the relaxation process stabilizing the strain. The rate of shrinkage of nylon 6 during tempering became large at the two temperature ranges, i. e., one was the glass transition region and the other the neighborhood of elongation temperatures above 100°C. Because of the effect of relaxation stabilizing the strain, the rate of shrinkage during tempering decreased at intermediate temperatures between the two temperature ranges. A stabilizing effect also was found in the fact that type crystallites were stabilized during tempering.

http://www.freepatentsonline.com/4590242.html
Low-shrinkage nylon moldings are produced by activated alkaline lactam polymerization, preferably using the reactive injection molding technique, by a process wherein the polymerization is carried out in the presence of from 5 to 80% by weight of a polymer P which 1. is completely soluble in the lactam, 2. separates out in the course of polymerization at a conversion of from 1 to 50%, 3. is composed of one or more blocks which are compatible with polylactam and one or more blocks which are incompatible therewith, and preferably 4. possesses functional groups which are incorporated into the growing polylactam chain.

[montana_charlie]

I just want to see a picture of the heater that goes under a Lyman 450 which is used to lube a bullet with Nylon...

[PatMarlin]

Nylon is EXPENSIVE. That much I know.. [smilie=1:

[Frank46]

Wow. all that scientific jargon has given me a headache. Not quite sure but some plastics when heated tend to give off hazardous fumes or vapors. Might be the breakdown due to high heats. Instead of injecting the plastic with a lubrisizer type setup, how about precut rings to fit into the mold and then add your favorite alloy. Something similar to the wilke bands made out of copper tubing?. Frank

[arkypete]

Ok Guys tell me if I'm out to lunch on this.
It's my understanding that if the bullet is one to two thousandths larger then the bore, using a good lube you'll avoid leading and have the potential for good accuracy. In revolvers the bullet needs to fit the cyclinder mouths usually one to two thousandths larger the bore.
If the lube grooves are full of a plastic nylon, teflon, polyethilene there will more resistance to gas cutting, possibly better lubrication and support of the bullet.
Since I use .454 diameter bullets for all of my 45 Colt bullets, the chamber mouths are .453 and the barrel is .452, I'm betting that I'd have clean shooting bullet.
I don't get leading now, this is just a 'What the heck would this work?' problem.
Jim

[Johnch]

A idea

If you could get several different nylon, teflon, polyethilene tubing with varing OD's , but the right thickness
Then cut rings
Heat slightly and strech over the cast bullet and push it to the grease grove.
If it then shrank back to orignal size .
It would then act as a "lube" , filling the grease grove .
Stoping gas cutting
It would need to be just proud of the bullet after "lubing" the bullet

But a generous flair on the case might be needed to avoid cutting of the "lube"

I bet it would be easy to find at least 1 tubing that was the corect size for some type of bullet to try
To see if it would work .

Also I wonder if the cleaning product companys would come out with a specail cleaner to remove the nylon, teflon, polyethilene from the barrel :mrgreen: :mrgreen:

Johnch

[wills]

What about using "O" rings?

[montana_charlie]

"O" rings?
I was wondering when that would pop out...

BPCR shooters have been using LDPE for wads between powder and bullet for quite some time.
Low Density Poly Ethylene (I thnk that is the material) is much like the substances you have mentioned, and when used as an over-powder wad it is in the right place to prevent gas cutting. Some even think it has the ability to scrape fouling (lead and powder) out of the barrel, similar to the claims about copper gas checks.

Since copper and LDPE are already available for firearm use; and since lube grooves are meant to hold lubricant...not gaskets; I'm a little mystified about why your 'what if' question has been bothering you for as long as you say.

'What if' questions can be enlightening...and they can be maddening. Now, you've got me wondering about yours...and I don't even want to.
Here I am trying to figure out how to run a nylon rod through a hot glue gun to apply 'plasti-lube' to a rotating bullet, for Chrissake!

I just gotta stay outta this thread...
CM

[arkypete]

Montana
I had to giggle, and it's not my bourbon that did it.
The 'O' ring meandered across my mind also. Get Mountain Molds to make me a mold with square grease grooves for the 'O' ring to drop into. If memory serves that's a super duper silicone rubber or some such 'O' ring that might work.
I like the idea of using tubing, with one quirk, the type of tubing that shrinks when heated.

Montana
'What if' questions can be enlightening...and they can be maddening. Now, you've got me wondering about yours...and I don't even want to.
Here I am trying to figure out how to run a nylon rod through a hot glue gun to apply 'plasti-lube' to a rotating bullet, for Chrissake!

I've got a machinist that owes me a bunch of favors. My thought was to get a sizing die from Lyman. Have him drill and tap the holes from the factory. This way I could pressurize the molten nylon and have it flow through tubes, so that I could basically do the same thing the Lyman ot RCBS sizer does.
Or I might could use the sizer just as it is with enlarged holes and work up some sort of super heater.
Any way I'll have another bourbon and ponder this.
Jim

[swheeler]

Arkypete; Uncle Sam has some kind of driving bands for the Warthog round, not sure if it is nylon but the yellow stripes are something similar. One of these would make a nice single shot hunting rifle for the "mine is bigger" guys- ha

[arkypete]

Swheeler
What I'd like to have recorded is the look on their face when the gun went off.
Jim

[swheeler]

APete; If you could come up with a barrel cheap enough, the chamber could be removed and threaded for a breech plug, make a real "one of a kind" muzzleloader! Wonder what a 1.180 inch RB would weight? Can you say moose gun.

[carpetman]

Just cover the bullet with the toe of a pantyhose and see what happens.

[Ross]

Harvey Pro-Tex
Corbin Base Guard
Why not plastics instead of zink?

[shooter575]

Hey,what kind of plastic did the accelerator sabot rounds use?Home shop machinest mag had a series some years ago on making a hand press to injection mould using cut up milk jug material.