Originally Posted by Stumble
That rope is almost certainly not heat set, which is what you need for standing rigging. Heat setting radically changes the creep characteristics and compacts the strands, making the rope much stronger for the size. Which is pretty much required for standing rigging.
It is... on the specification list further is named:
- material: Dyneema SK75*
- UV stability and
- scrub solidity.
) In recent years Dyneema
lines have become popular very fast. Not surprising, since it has very little stretch and is also twice as strong as polyester. Moreover, it is so light that it floats on water
. This type of line is sometimes sold under the trade
name Spectra. Dyneema has a good chemical resistance. Mechanical properties are unaffected by seawater, oil
or other common chemicals. Also, the material is very durable.
Dyneema is available in three versions: SK75, SK78
since late 2009. SK75 and SK78 are very similar in terms of features, the biggest difference is the creep (elongation under continuous high load). SK75 has a little creep and SK78 not (negligible).
The SK90 variant is, as specified by DSM itself, 13% stronger than previous versions and of course lighter. Also the SK90 shows like SK75 little creep. Lines with creep are less suitable for backstays
, but the amount of creep in SK75 (and SK90) is small and therefore,
in addition to SK78, often this material also is used for backstays.
Dyneema fibers are smooth (self lubricating), are quite durable and have a low melting point. A good cover jacket is sometimes needed for additional protection. Sometimes an extra layer is used to ensure that the cover and the slippery core
don’t slide around. Dyneema is good UV resistance. Where the line does not wear you are fine to remove the cover largely in order to spare weight (rejuvenate). This works well for example for spinnaker sheets
. Splitting Dyneema: a Dyneema line gets 95% of the strength of the Dyneema core
, the cover mantle appears only wear. This is the line "core in core” splice. The easiest thing to split a "bare eye" in the line and eliminate the cover.
(Source: Material & Construction - Splicing