Thermal Degradation of Nylon

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Thermal Degradation of Nylon

Postby cavepaw » Jul 5, 2012 3:32 pm

Hello everyone:

Does anyone know of any sources for data on thermal degradation of Nylon? I know it melts at 374-663F, but I'm curious if there has been a study on the weakening of rope before melting.

I've read that it's fine to use hot water (140F+) to clean ropes since such short time and a temperature so far below melting point is not doing any damage, but I'm having a hard time finding any scholarly articles that can verify this. Any sources of data or information you have on this would be greatly appreciated.
Paul Winter
President of the Nittany Grotto
Chairman of the Mid-Appalachian Region of the NSS
NSS 62053RL
cavepaw
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Re: Thermal Degradation of Nylon

Postby knudeNoggin » Jul 8, 2012 10:40 pm

cavepaw wrote:Hello everyone:
Does anyone know of any sources for data on thermal degradation of Nylon?
I know it melts at 374-663F,
but I'm curious if there has been a study on the weakening of rope before melting.

Whoa! Where'd you get those temperatures?
What I'm looking at now** says 258^C for Type 6.6 & 218^C for Type 6,
which is 496 & 424^F, resp., per some on-line converter.

[** Handbook of Fibre Rope Technology ]

The book has some interestingly inconsistent assertions,
though : in one place (Table 12.3, p.253) is gives as the
Safe Working Temperatures (Long term : > 1 month)
60 - 50 - 60 (all ^C) for, resp., Nylon - Polyester - HMPE (!)
and short-term ("up to 10 minutes")
70 - 200 (!) - 80 .

(Quite surprised to see HMPE working safely at nearly
half-way to its melting point of 150^C !)

Elsewhere, there comes a general statement that
nylon & polyester should be limited to 90^C, and
HMPE 50^C. !?

Back to Table 12.3, it also gives ("Information from yarn
manufacturers and other sources") :
Approx. values (over 0 .. 50^C range)
drop in strength (modulus) per 10^C [rise, presumably]
for resp. as above ... 2.5% (3%) - 2.5% (3%) - 6% (4%).

*kN*
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Re: Thermal Degradation of Nylon

Postby cavepaw » Jul 12, 2012 11:46 am

http://machinedesign.com/BDE/materials/ ... t2_29.html is where the Temperature data came from. It's a pretty large range depending which variant of Nylon is actually being used.

Those are pretty high values for temperature. 90C as the upper limit? If that's true then I'm impressed.
I bet manufacturers might have a safe operating range available too.
Paul Winter
President of the Nittany Grotto
Chairman of the Mid-Appalachian Region of the NSS
NSS 62053RL
cavepaw
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Re: Thermal Degradation of Nylon

Postby cavepaw » Jul 12, 2012 11:52 am

An exerpt from an article on rope care by Steve Hudson, President of PMI. Article can be foudn here. http://www.pmirope.com/news/blog3-9-10/

• Polyester: 275°F high temperature working limit
• Nylon: 250°F high temperature working limit
• Polyolefin (polypropylene, polyethylene): 150°-200°F high temperature working limit
• Aramids (Kevlar, Twaron): 350°F high temperature working limit
• HMPE (Spectra, Dynema): 150°F high temperature working limit
Paul Winter
President of the Nittany Grotto
Chairman of the Mid-Appalachian Region of the NSS
NSS 62053RL
cavepaw
Infrequent Poster
 
Posts: 4
Joined: Jul 5, 2012 3:00 pm
NSS #: 62053
Primary Grotto Affiliation: Nittany Grotto
  


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