Author Topic: Identification of cord material  (Read 8426 times)

DerekSmith

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Identification of cord material
« on: November 17, 2006, 12:01:49 AM »
Dan Lehman posted in an earlier thread a simple little scheme to help identify basic cord/rope materials.

snip....
If the material burns w/o continued support of a flame (lighter, say), it
should be PP or PEthylene--the former is sad to burn more vigorously
and yield droppings that can be stretched thin, and PE burns slowly
and has hard droppings.  Both burn w/black smoke.  Polyester also has
black smoke (and it comes in multifilament, like nylon), but should go
out once the flame is removed.
--dl*
====

I feel that Dan has prompted the thought that we could all contribute any knowledge tricks or test that we are aware of that could be used to build a means of identifying the nature of the cords we are using.

Nylon, Kevlar, PP, Cotton, Hemp, mixed etc. etc.  how do we find out what we are twiddling with?

I found this link to kick the thread going:-
http://www.tensiontech.com/tools_guides/fibres_guide.html#identification_testing

Any takers?

Does anyone have experience of actually trying these methods?

Derek

Willeke

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Re: Identification of cord material
« Reply #1 on: November 18, 2006, 12:16:47 AM »
This has been discussed before, some time ago. But I am sure there is a lot more info around.
But here is a link to the old thread. http://igkt.net/sm/index.php?topic=185.0

Willeke
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nor what a clever person can do with simple tools." - Ian Fieggen

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DerekSmith

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Re: Identification of cord material
« Reply #2 on: November 18, 2006, 12:54:50 AM »
Thanks Willeke,

Not much more there than in the first post.  It strikes me as strange that more has not been done on the subject.

I have Googled the subject but found very little.  I am supprised that the cordage manufacturers do not have anything published.

Do you know if the IGKT officials have any contact with manufacturers?

Derek

squarerigger

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Re: Identification of cord material
« Reply #3 on: November 18, 2006, 04:18:27 AM »
Hi Derek,

There is, unfortunately or fortunately, an absolute ton of information about determining the type of cord in a book by the Textile Institute, published in their "Handbook of Fibre Rope Technology" by McKenna, Heale and O'Hear, Chapters 1, 2, 4, 9 & 10 at least.  However, the book costs US$ 220.54 and, although I have the book, I am not willing to put this information on the web (it violates copyright).  Maybe the local library has a copy or perhaps the IGKT has a copy?  Also, I imagine that if you are a member of CRC or their assigns you may be able to get a reduced cost copy?  Good luck!

Lindsey

DerekSmith

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Re: Identification of cord material
« Reply #4 on: November 18, 2006, 12:05:03 PM »
Hi Derek,

There is, unfortunately or fortunately, an absolute ton of information about determining the type of cord in a book by the Textile Institute, published in their "Handbook of Fibre Rope Technology" by McKenna, Heale and O'Hear, Chapters 1, 2, 4, 9 & 10 at least.  However, the book costs US$ 220.54 and, although I have the book, I am not willing to put this information on the web (it violates copyright).  Maybe the local library has a copy or perhaps the IGKT has a copy?  Also, I imagine that if you are a member of CRC or their assigns you may be able to get a reduced cost copy?  Good luck!

Lindsey

Hmm, that could explain the shortage of information, it is sometimes the case that once a definitive document has been published, everyone defers to it, thereby creating a natural suppression of alternative texts.  This would be no issue if the handbook were on general distribution.

I fully concur with not violating copyright and understand your position re not posting the content of the Handbook verbatim.  Besides, if the work covers five chapters (at least) then it is probably too detailed to be of interest to most knot tiers.

I tend to be thinking towards the provision of a basic identification scheme which could take us to one of the major groups of materials as a starting point.  We possibly have enough information to do this with the simple tests of - Density >1<, melt test, burn test and burnt droplet test.  Where appropriate, the test could be augmented with photographs to depict 'a smoky flame' etc.  Then perhaps we could start to construct a spreadsheet of results for the major materials groups.

If readers expressed an interest in further identification within a particular group, then perhaps we could then raid the handbook for specific facts and information to be used to refine a sub spreadsheet, should the need ever occur.

I have checked the B.L. Library catalogue and the Handbook does not seem to have been lodged with them, but I will contact the Textile Institute to see if they will release information that we could use.

But to start off with, could forum members start by listing the types of fibre they would be interested in identifying.

If there is no interest at this stage, then I guess there will be no point in progressing the challenge further.

Fairlead

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Re: Identification of cord material
« Reply #5 on: November 18, 2006, 09:10:47 PM »
I would be interested in Kevlar and Polybenzoxylene (sp?) (PBO)

Gordon

Dan_Lehman

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Re: Identification of cord material
« Reply #6 on: November 19, 2006, 01:01:04 AM »
There is ... an absolute ton of information about determining the type of cord in a book by the Textile Institute, published in their "Handbook of Fibre Rope Technology" by McKenna, Heale and O'Hear, Chapters 1, 2, 4, 9 & 10 at least.
Hmm, that could explain the shortage of information, it is sometimes the case that once a definitive document has been published, everyone defers to it, thereby creating a natural suppression of alternative texts.  This would be no issue if the handbook were on general distribution.
...  Besides, if the work covers five chapters (at least) then it is probably too detailed to be of interest to most knot tiers.
This is hardly the case:  the book has maybe nothing expressly about making the
determination of fibre type--not at all in the sense of the work I drew from, the
Cordage Institute's Fiber Rope Technical Information and Application Manual (CIB .4),
a work of a seemingly proud organization that however presents it with some bothersome
words such as "Anyone making use of the information contained herein assumes all liability
arising from such use[.]" and "Quoting or excerpting any portion of this manual without
specific authorization is prohibited"--and I shall now go to Hades for these two offences.
 :P :-* :P  --terrific resource THIS is, geesh.  H.A. McKenna (pres. of Tension Technology
Inc.) is a main contributor to this work as well.

Quote
I would be interested in Kevlar and Polybenzoxylene (sp?) (PBO)
"PBO" is the correct spelling.  (One could sprain a tongue with some of these names.)
Hmm, they don't burn or melt (though I think some recent knots book gave a "melting"
temperature), and PBO's charring temp. is somewhat higher even than aramid's.
Interestingly, the CI High Temperature Working Limit given for aramid is 350^F
which is but 50^F higher than that for manila-sisal-cotton.  (And they are equal for
cold-- -100^F !?)  With the hi-tech revolution, there has been much burying of cables
to wire this area, and so one can find cable-pulling tape (solid, thin, tape in a
couple sizes (9-12mm?)) which is mostly a lubricated polyester (which lubricant
can be felt on one fingers after putting the tape aside), but also Kevlar.  I got
one such piece, and did the "not-burn" test--it didn't.  (-;

I think that in some cases, though, burning can be problematic with added
treatments and mixed fiber types--obviously w/the polycombo (PES & PP)
ropes.  Hmm, I have much CoEx rope (PP+PE), and should see whether
it favors one or the other components' characteristics.
I seem to recall one burn test where the subject didn't burn "appropriately".
 :-\

Reportedly, there are commercially available stain testing kits (for
when burn testing isn't feasible), though the capability to distinguish
types might be limited to a few (e.g., it might treat PP & PE alike, and
not treat aramids/LCAP/PBO at all).

--dl*
====
« Last Edit: November 20, 2006, 04:33:44 AM by Dan_Lehman »

squarerigger

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Re: Identification of cord material
« Reply #7 on: November 20, 2006, 08:28:07 AM »
I'm never really sure with Dan's replies whether or not he knows something but isn't telling or whether he knows nowt and is still telling nothing?  Cmon Dan "the book has maybe nothing expressly about making the determination..." and then you waffle on about some other book written by the same author (or one of the same authors).  What do you mean "has maybe nothing..." - does that mean you have read it and found it to be lacking or does it mean you haven't read it and are just making this up [has maybe nothing] based on what you have read in an entirely different document?  If you are trying to illuminate, you are not doing it, 'cuz it leaves this reader in the dark, although of course I have been blessed with your words...so maybe I should have been illuminated?  Help this poor slob to understand what the heck you are saying - did you read the book and are you saying it is no good as an opinion?  BTW - the book I referenced had a ton of information, but none of it was something that was either quick or dirty or even a combination of the two!

Having got that off my chest I am now searching for some illumination about how to help others determine the type of cord.  For cords made of natural fibers (fibres if you live in UK) then it seems as the only way for amateurs like me to find out what they are made of is to dust off the microscope I had as a kid and look at the piece under the 'scope.  All natural fibers char, so that isn't much help (it does differentiate a natural from a fiber impregnated with flammable material).  Natural fibers are irregular in cross section and in their length they are somewhat (sort of) kinked.  Those last statements (they char, are kinked) are based on what I have seen.  As to the plastics: polyamide (PA), polypropylene (PP), polyethylene (PE), polyester (PES) and their variants (HMPE, modified polyamide, etc.) it seems that we should be looking to the manufacturers to get some means of identification, surely?  How do we know who made the stuff?  Maybe it has a tracer tape, maybe it has a unique color, maybe a unique strand form or yarn form, or maybe we have to rely on good old-fashioned detective work at our local rope supply company?  I do not think that burn tests will definitively tell us which kind of line it is or is not, unless you just happen to have a thermometer that reads to within +/-25 degrees and up to 450 degrees and can be used with melting plastics - everyone has one of those, right?

Derek, if you are seriously trying to get an easy to use test method together, you'll have to set some sort of standard as to heat applied - that will assuredly make a difference (consider a blowtorch and a match or an oxy-acetylene flame - they all have differing tip or core temps, don't they?).  Heat applied and distance from and direction to the subject line, temperature and moisture content of the line at the start, temperature at the finish and then we could get into appearance of the melted piece, flames, smoke color (how do we tell if it black smoke from the piece or from dirt entrained in the piece?).  Or we could just rely on guess-work?  Or perhaps experience?  I guess I should just not sit here late at night trying to make sense of it.

Lindsey

 

KnotNow!

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Re: Identification of cord material
« Reply #8 on: November 20, 2006, 09:24:48 AM »
Hi Lindsey,
  Well, for the first shot over the bow: your books are an excelent guide to understanding the cord at hand.  The book you made reference to on the thread Quote: "Handbook of Fibre Rope Technology" by McKenna, Heale and O'Hear, Chapters 1, 2, 4, 9 & 10 at least".should be all we need beyond your books, GB's and Toss's.  It floats or it don't.  It burns or it don't.  Mostly I know what I buy at the point of sale and have the spec and how to expect it to behave.  Then I go home and prove it.  Our honored beach comber has unknown cord, unknown knots and unknow time to spend with it all.  If I get in too deep I'll call you (Lindsey) and ask you to look up the problem cord... in the event I get "up a stump" on cord I have 2000 friends to work with me.  I like the thread.  For me it comes to Specific Gravity (float or not float) and how it flames out or not.  Of course the whole thing about burning of cord comes down in practical use is how resistant is the cord to melting by friction.. or at least for me.  On site expermintation works for me.
  Frankly I look forward to Dan's posts.  If I don't want to read on I just skiip on forward as is my mood and then return so that I'll plow and puff and blow to understand.
  Back to the thread.  Every time I buy line of a "known material" I burned it, floated it and put it in my "knot books" so I have years of comparatives.  Lacking a copy of the "definitive book" you can still have your personal log of what you can buy and where you got it.  Lacking that pick up your copy of Philpott and sally forth, you will not go aground.
  Derek, as to your last post.  Yepum, I have kevlar, dyneen, and several more of (what I consider) exotics.  Of course I knew the intended limitation when I paid the money.  Nomex (a kin to kevlar) for the fire retardant suits for racing at NASCAR and flame throwers was one of my first concerns with alternative fabric and fiber.  Then much work with Kevlar for the susposed bullet resistant factor.
  I am old now and don't care if it burns, is bullet proof or can sing songs and put on a stage show.  However, buy the cord.  Then you need to decide if it comes up to the spec that the manufacturer states.. after all, your life is in the balance.
  Lindsey, I think Dan knows a lot.. As to I... It is the right moment to extract the info.  Might not be worth the effort for the site.. He is a pretty cool guy off line.
ROY S. CHAPMAN, IGKT-PAB BOARD.

DerekSmith

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Re: Identification of cord material
« Reply #9 on: November 20, 2006, 11:11:15 AM »

snip....
I do not think that burn tests will definitively tell us which kind of line it is or is not, unless you just happen to have a thermometer that reads to within +/-25 degrees and up to 450 degrees and can be used with melting plastics - everyone has one of those, right?

Derek, if you are seriously trying to get an easy to use test method together, you'll have to set some sort of standard as to heat applied - that will assuredly make a difference (consider a blowtorch and a match or an oxy-acetylene flame - they all have differing tip or core temps, don't they?).  Heat applied and distance from and direction to the subject line, temperature and moisture content of the line at the start, temperature at the finish and then we could get into appearance of the melted piece, flames, smoke color (how do we tell if it black smoke from the piece or from dirt entrained in the piece?).  Or we could just rely on guess-work?  Or perhaps experience?  I guess I should just not sit here late at night trying to make sense of it.

Lindsey


Good Morning Lindsey,

Yes, I am serious, at least to the point that board member interest allows the topic to progress (there being little point flogging a thread if the group has no interest).  I have been an analyst for the whole of my working life, so perhaps I can lend this topic a little of my experience.  Although we are all here for the knot, the nature of the cord influences the performance of the knot so markedly, I believe it is valuable to promote not only an awareness of the importance of the material, but with it, a means to find out or confirm just what that material is.  I will need to be guided by others as to the real importance of this, because as an analyst it is second nature for me to think this way and indeed it may be of no interest or value to anyone else.

If we are going to do this, then one of the key things to remember is that no one is going to have a lab, nor any of the specialist equipment you might find in one.  All the tests will need to be kitchen sink compatible, not just for reasons of cost, but also because if a test can be devised to run in a kitchen, it is likely to be reasonably safe (jeez, I can just picture the legal leeches sensing the smell of money as I typed those words !!).

For example, you mentioned that melting point was likely to be a valuable measure, but that no one has a 450 degree thermometer.  The point is, no one needs to buy a digital thermometer to find out if a piece of cord melts at the temperature of say 'nylon' - all you need is a piece of nylon.  If you have a number of reference samples then you have a thermometer with that number of graduations on it.  Big steps, yet each graduation is extremely accurate - far more so than any digital thermometer we could sensibly afford.  These are little tricks of the analytical world that we can use to our advantage.

Roy made a key point - a set of reference samples is the most valuable part of your test kit that you will ever own.  As part of this exercise, we might consider how to go about obtaining a set of reference samples because comparison is going to be our most powerful tool.  When you want to explain how PP melts and what it smells like, nothing beats doing it on a sample known to be PP and comparing your mystery cord to that observed reference.

I believe it is a relevant exercise, in fact I feel that it is an important part of the whole knotting experience.  If the topic takes off, it is probably the first topic to warrant a sub forum all to itself.  Perhaps called 'Cord Identification'.  Webmistress has said that to allow a new sub forum, she would need instruction from an Officer of the IGKT to authorise it, so what do you think - is this a topic of importance to the guild, is it likely to attract interest, should we give it a run?

Derek

KnotNow!

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Re: Identification of cord material
« Reply #10 on: November 20, 2006, 05:02:35 PM »
Hi Derek,
  You are a brave fellow.  I just care about how the line works for me and will leave the fine points for the IGTK.  The concept of a subthread is fine but I can't think that I have anything to add.  For me:  float, or not.  Burn or not.  Friction burn ( a function of the melting temp).  I am too simple of mind and need for the advanced thread (not to say it isn't a fine idea.. just to say I have not much to add to it).  You all know I tie knots and put one to the other with my truck and suv.  Tie the knots and stress to distruction so I know what I  need to tie in my line, for I've proven it over and over.
ROY S. CHAPMAN, IGKT-PAB BOARD.

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Re: Identification of cord material
« Reply #11 on: November 20, 2006, 06:17:35 PM »
Hi Derek and Roy,

Many thanks for your erudition - compare and contrast - I like that, because it makes sense and provides an immediate kitchen sink test (thank you Derek!), if the purpose is to eliminate a possible cord, but how does it work when you have, say, a piece of spun PES as opposed to a piece of filament PES - they don't look alike and they perform differently in knotting, but they are the same material, produced differently.  OK - maybe that is an exception and all we really need to know is "Is this a piece of nylon or not or, is this Kevlar or Dyneema?" and then we can move ahead with our splice or knot or whatever it is we need definitive information about.  Roy, you are absolutely right about testing to destruction as long as nobody's life depends on it.  Experience plays a big part in that, which experience you have in spades Roy.  The purpose of testing then comes up - why do we need to know?  If I am tying a few knots for a knotboard I probably need to know if a piece is going to react negatively to whatever glue or other treatment I am going to apply to the piece - otherwise, does it look nice is the only question.  If I am going to make a splice in a life-line tether, I prefer to defer to a test lab or the manufacturer for the information on what the fiber is, rather than to try a kitchen sink test.

Definitive statements - I like them!

Lindsey

Fairlead

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Re: Identification of cord material
« Reply #12 on: November 20, 2006, 06:38:42 PM »
Here is a web site I found back in 2001 - the paper on identification is still there but has a few of the later materials missing - take a look - it has most if not all your answers

http://www.tensiontech.com/tools_guides/fibres_guide.html

PS - I have asked TTI if it has been updated, if so can I have a copy

Gordon
« Last Edit: November 20, 2006, 06:42:17 PM by Fairlead »

DerekSmith

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Re: Identification of cord material
« Reply #13 on: November 20, 2006, 08:59:37 PM »
Thanks guys,

It looks a bit as though my exhuberance in this area is perhaps beyond the interests of the members.  I thought that might well be the case, especially as the best we could hope to achieve would be a general testing schema capable only of differentiating between the basic types.  Today the trend of using physical modification, of coatings, and of blending multi types of fibre, means that full identification of some cords would demand a state of the art lab in order to know what you are working with.

Still, I will pop up a couple of simple comparative tests which will allow a basic level of identification.

Derek

Fairlead

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Re: Identification of cord material
« Reply #14 on: November 20, 2006, 10:10:10 PM »
TTI got back to me within hours with the response that the paper had not been updated.
However they sent me a PDF file entitled FIBRES for Cable, Cordage, Rope & Twine - Comparative reference dated 2004 - Prepared by the Cordage Institute.
Because of copyright I cannot put it on this website, but if anyone GENUINELY interested in this subject would like a copy please email me (address in IGKT Membership Handbook) and I will forward a copy.

Gordon

 

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