[TowerTalk] Dyneema ropes from china

[Steve Maki]

On 05/12/19 14:45 PM, Richard (Rick) Karlquist wrote:

>> Yale Cordage, in some of their high strength ropes, uses what they 
>> call UHMWPE (Ultra High Molecular Weight Polyethylene), which they do 
>> NOT identify as Dyneema. They have manufactured these ropes for a long 
>> time...I'm guessing they make the fiber themselves, or they would call 
>> it Dyneema.

> Although Dymeema may be made from UHMWPE, it is considerably different
> from run of the mil UHMWPE.  UHMWPE has a coefficient of thermal
> expansion (CTE) of 220 ppm, and machines easily.  Dyneema has a NEGATIVE
> CTE (very rare), and is very difficult to machine.  These
> characteristics don't necessarily translate to good rope, but they
> at least differentiate it from ordinary UHMWPE.

Makes sense, I didn't dig very deep.

What makes a 'good' rope is a fascinating topic. I've been tempted in 
the past to try out some of the exotic types to use in the tower biz, 
but knowing that it will be dragged over barbed wire the 1st time it's 
used has made me back off on that.

-Steve K8LX