This is a real numpty question I'm sure: I have various bits of string lying around, some are dyneema cored, others not. I cant remember which are which, is there a way to tell? (apart from the obvious trying to break it!)
Posted: 14/09/2009 19:16:18 By: Confused Re-roper |
The dyneem a will have a core the other more likely laid up in one system.
Posted: 14/09/2009 19:48:30 By: . |
Dyneema will not melt into the outer core if you attack it with a lighter, polyester will.
Posted: 15/09/2009 13:37:01 By: . |
Other than setting light to the stuff (another great method of simple ID), cut a good length of the core out and place it in a glass of tap water. Dyneema, which is essentially polyethylene (like your shopping bags, just with an ultra-high molecular weight -UHMWPE), has a density less than water and so will float. Polyester on the other hand has a density greater than water and so will sink...
Posted: 15/09/2009 17:23:23 By: Geek |
You can pull a tiny bit of the core out of the rope. The dyneema will be plaited and the polyester core will be a 3 ply twist...
Posted: 22/09/2009 13:47:14 By: Blackie |
Hmmmm HMPE (Dyneema) melt point 135 C Polyester melt point 256 C
Dyneema should melt first, unless my reference material is wrong
Posted: 22/09/2009 16:23:32 By: . |