Identifying rope

[drjbrennan]

Do any of you folks have any methods for identifying the particular plastic that a synthetic rope is made from?
I have read about different smells when burnt or smouldering but not burning etc. Any hints would be most welcome.

[Willeke]

Working with plastics, even if not ropes, I know that different kinds of plastic have some differences in their smell, and also that it is hard to use that as a way to tell with which kind of plastic you deal. Often two different plastics, with completely different characteristics will have the same ingredients. Just slightly altered or added to. So their smell is nearly the same, but the rope made out of it will be completely different. Chemical tests may not work much better. At least not if you stay within one group like the polymeres.

And if a rope has been used it is worse, because it does pick up the smell of any thingnear that has a strong smell.

But I might be wrong, so do not give up just yet.

Willeke

[Jimbo_The_Kinky]

Try this for starters:
Fibres Guide How to Identify the Synthetic Fibres Used In Rope Making

I'll keep looking after din-din...

[Brian_Grimley]

Jimbo - thanks for the great find! It goes into my Favorites.

A reference that helps me understand rope materials, construction, properties and selection is "The Outdoor Knots Book" by Clyde Soles. It is certainly the best material that I have seen in any book on knots. If you get a chance, take a look at it.

The book also contains excellent examples of organizing information about a knot: Name, Other Names, Advantages, Disadvantages, Technique and Variation. The practical implications of this arrangement would be a good resource for those interested in database or knowledgebase construction.

I know that our Dan Lehman would be shy to mention it; however, he is acknowledged as a major contributor "who provided excellent commentary". Nice work Dan!

If you get a chance, check it out.

Cheers,
Brian.

[Fairlead]

I gleened some excellent information back in 2001 from a website run by Tension Technology International.
Try tensiontech.com/papers as a google search.
The paper title is - How to Identify the Synthetic Fibers Used in Rope Making by John F. Flory and Stephen J. Banfield

Gordon

[Dan_Lehman]

"THE particular plastic..." might be a faulty assumption:  i.e., maybe there is more
than one material.

A burn test distinction between PP & PE is that the forme burns rapidly and yields
a stretchable residue; the later slowly, with a non-stretchable residue.
And both are able to burn away from the igniting flame, whereas PS & PA
(polyester, nylon) are supposed to burn out, w/o supporting flame source.

Then there are "co-polymer" ropes, which mostly blend PP/PE, to achieve greater
strength & abrasion resistance (so the sales pitch goes), with floatable material.
There is a Norwegian (?) copolymer (Karat) of PS/PP.  I won't speculate on how
these might perform when lit.

It should be pretty obvious that some ropes are combinations of fibers, with the
"poly-DAC"/"polycombo" PP&PS being most common, the PS often put so its
fibers are on the surface, PP in the core (for laid ropes per yarn clump), though
not always thus.

But I'm not sure that the additional treatment of "coatings" won't affect the burn
tests.  I've had some sustainable burning from what is really hard to believe was
PP (though it does come in sikly multifilament).

--dl*
====

[KnotNow!]

Hi, Sort of silly after the previous posts... but either it floats or it sinks.  Specific gravity is a clue.  Then think how it was made.. some plastics are good for extrusion.. so if it is a filament or a ribbon there may be a clue.  I don't think I have ever seen nylon extruded as filament cordage.  Add this to Dan's post and maybe it will help.  Some plastics just never seem to be made into fillament.  Some never float.  Some burn under friction so they are very odd... I guess "don't rapel with this"...   so they never show up in the "sport" market.  But just think how you woud deal with it in the lab, you would look to:  specific gravity, burn rate, actual weight... and then consider the prior engineering... if it is a  strand and thread or a filament... the method  of making  is dictated by the material.  The folks who made it knew all the properties.  Study the properties and you will find the material.
 I'll now address your cordage: If you can tell natural from synthetic we will go from there?  We assume a synthetic; Does it float?  Then it is Polyethelene.  If it does not float then something else.  How is the sinking line made?  Is it filament or thread?  If it is made from a single thread then likely Nylon or Pollyester and in some cases Polypro. If made from a fillament.... might be Polypro.  Polypro burns or chafes at a really low point.  Don't climb with this.. Polypro will likely be made as filiment, split filament and rarely as thread.  See dans post above.  Poloyester or Nylon?  Very hard to tell.  Back off to where you found it, how it seems to have been made.  I welcome comment as I often can't tell.
 You will not find the high tec fibers in the dumpster.  Spectra, Dyeen and all their ilk will have cost you.  You find them for free send me a coil.
 In small thread and cordage you may find dacron, nylon, several "esters" at junk shops.  On the warf (dumpster diving) you will find all the commercial fishing stuff.  If the cordage works for you be happy!  

[Jimbo_The_Kinky]

I gleened some excellent information back in 2001 from a website run by Tension Technology International.
Try tensiontech.com/papers as a google search.
The paper title is - How to Identify the Synthetic Fibers Used in Rope Making by John F. Flory and Stephen J. Banfield

Gordon

Thanks, Gordon.

Would I be rude to point out I put a link to that very paper a couple of posts up?

To everyone else, Gordon is right.  I promised to continue looking & did.  Though I looked far & wide, I can't find anything better than this.

As to the stank (smell) tests, I have to go with tensiontech & suggest the best bet is to get some known samples (from a reputable rigger or cordage shoppe), burn them yourself & know for yourself how they smell.  But be careful if you think it's hemp!!  Too much testing of that one might make you fail a pee test!  (But you'll sleep well!)  

As for me, I won't trust my worthless hide to any rope I didn't see come off the spool, and scant few of those.  Sorry, I'll tie the knots & just stand over here & watch.

[Dan_Lehman]

Add this to Dan's post and maybe it will help.   ...
We assume a synthetic; Does it float?  Then it is Polyethelene.

Dan's post seems to have not helped enough.  PP, not PE, is the most broadly used
floating material (and has a lower SG than PE or HMPE or copolymers); also floating
are copolymers of PP/PE.

If it does not float then something else.

Or it might BE PP but sink--something I was shocked to discover--, being a special
commercial fishing line w/lead embedded to make it sink.  It's rather nifty stuff,
showing no sign of such hard components re flexibility, but drop it in water and
down it goes!

The Cordage Institute (www.ropecord.com) publishes a Technical Manual with the
burn-test information I conveyed, among other information.  (And I think that either
the company or some of principals of Tension Tech were key in writing much of it.)

--dl*
====

[KnotNow!]

I guess I just added to the confusion.  Sorry about that.  I have some of the lead core stuff, right off the reel.  I've been using it for decorative knots as it (at least in the two samples I have... same stuff, same diameter) much more "stand alone" than the regular lay.  Yepum, it sure sinks like a lead balloon.  But it does stand alone.. as would a three strand line hooked on one of them "performance enhancing" medications.  We can only get it in 3/8" and then only in some nasty silver with a color stripe.. but it takes paint well.    It is pretty cheap up here (Pacific North West USA).