Just one simple question…
How low temperatures (-25C) affect synthetic fibers and ropes?
I’ve heard that some of them “freeze” and so the friction and wear increases dramaticaly… Or this happens to natural ropes as well?
Just[Freezing]Knot
Just one simple question... How low temperatures (-25C) affect synthetic fibers and ropes? I've heard that some of them "freeze" and so the friction and wear increases dramaticaly... Or this happens to natural ropes as well?Just[Freezing]Knot
Simple? Material properties at extreme or unusual temperatures are notoriously hard to come by, with a few exceptions. Companies that need this information often have to do the testing themselves.
In other words, I wish you luck. 
On the other hand, -25_C isn’t too extreme, but I’m not going say that there’s no change in hardness, modulus of elasticity, strength, impact strength, coef. of friction, etc.
Hi, This is not proven fact but simply my obversations. Since most of our rope work is outdoors and since that often includes water as well as temperature extremes frozen rope is often wet frozen rope. I would not dare put a numerical value to the degradation but it is extreme. This is true regardless of material, as far as I can see. I think the natural fibers, since they actually absorb water are often nearly destroyed in the freezing process before the work even starts. That said I remember hanging wet lanudry on a sub zero day and having it freeze like a board and yet gradually dry without breaking… so it can’t all be bad. I have worked in extreme cold (-20 F not C){my rough calculation makes -25C about -45F and -20F about -29C} and seen rubber hose shatter and spring steel snap rather than flex and nylon rope fail at very low stress. Why not soak some samples and toss them into the freezer at home. Then put them to some tests against room temp samples and dry frozen samples. Pick some line that you can break by hand. Let us know what you learn. I suspect that mountaineering people and ice cave explorers have some rules of thumb regarding climbing rope. Maybe some of them can join the thread.
-40 C = -40 F. Or near enough not to matter.
-25 C is too cold for me, I never even been in a place that cold.
But the right person to ask this question is a sailor who sails in the cold winter weather. And some fishermen do, as well as many (motor driven) freighters. I have heard stories… but meet the people who told me those only next week if that soon.
Brian Toss, as a rigger, would have much of the info you need. Maybe it is available on his site. (His name came up because I just read this other post in which he is named as the person to ask.)
But if you go to the harbourside near your home and ask the old fellows there they might be able to tell you the stories (and give you the info) as well.
Willeke
(I corrected the temp in the first line after reading the next post.)
A quick answer is that different fibres can have different effects.
(Btw, -40 is the match temperature for ^F & ^C --equal, not merely close.)
There are tables of rope properties to be found on-line.
From one table near me now, I see -70^F as the low-temp. working limit for
both nylon & polyester; -20^F for polypropylene, which might be a concern for
rigging things for the Iditarod–to wit:
Rope Polyethylene hollow-braid rope. Strength: 1-1/2 times manila, lightweight, good abrasion resistance, average stretch, no loss of strength when wet, retains flex at -40 degrees F (polypropylene becomes brittle at -40)which takes consideration of PP 20^F colder than the above quoted limit, even!?
The lower limits given for PE, aramid, & HMPE in my table are resp. -100, -100, -200^F!
–should you have the need. (Manila, Sisal, & Cotton … -100^F.)
There have been some drop tests done on frozen climbing rope. Google is your friend.
(-;