elfasa - 13-2-2013 at 04:36 PM
I hear the term Dyneema used a lot. I understand that its something to do with ropes (or lines) but I have literally no idea past that...
Is it to do with the material, the weave, coating ???? I have no idea.
I did a few searches online, and on forums, but didn't come up with much.
So; any and all info is appreciated !
Thanks
Tim
erratic winds - 13-2-2013 at 04:47 PM
From the plastics wiki!
Dyneema is a synthetic fiber based on ultra high molecular weight polyethylene, 15 times stronger than steel and up to 40% stronger than Kevlar. It is
usually used in bulletproof vests, bow strings, climbing equipment and high performance sails in yachting. Dyneema was invented by DSM in 1979. It has
been in commercial production since 1990 at a plant in Heerlen, the Netherlands. In the Far East, DSM has a cooperation agreement with Toyobo Co. for
commercial production in Japan. In the United States, DSM has granted a license to Honeywell, which had developed a chemically identical product on
its own. The Honeywell product is sold under the brand name Spectra.
The fibers feel slippery, similar to polypropylene and other hydrophobic fibers. Most people do not like the way Dyneema feels; for this reason, it is
not often used in fabric. The slipperiness also makes such fibers less suitable for use in fibre reinforced plastics.
Another problem, in some applications, is that Dyneema will creep, meaning it will deform when placed under any long term stress. Like other olefins,
it is very resistant to water, moisture, most chemicals, UV radiation, and micro-organisms.
Dyneema is the preferred material for sport kite lines for two main reasons. First the low stretch means that control inputs to the kite are
transferred quickly and secondly the low friction allows the kite to remain controllable up to about ten twists in the line.
All that is from http://plastics.inwiki.org/Dyneema
jellis - 13-2-2013 at 05:10 PM
I thought Dyneema was Eli's girl friend.
John Holgate - 13-2-2013 at 06:15 PM
I was under the impression that it is very similar to Spectra - just that it's another company's name for almost the same thing. Anyone know if that
is the case?
RedSky - 13-2-2013 at 06:36 PM
Spectra...why does that sound familiar
awindofchange - 13-2-2013 at 06:47 PM
Spectra and Dyneema are virtually identical. As stated, Spectra is owned and produced by Honeywell corp in the U.S. Dyneema is produced overseas.
Both are UHMWP lines.
Even though they are both virtually the same, the process in which they are used are totally different and really what sets one product apart from the
others. I like to use Tires as an example. When you look at a tire, whether it be a bicycle tire or a car tire - they are both pretty much the same
because they are both made from rubber. Obviously the process in which a Z-Rated High Performance Radial tire is made is much more intense and
technical than that of a 16" kids bicycle tire....but they are both rubber tires! Because of the way the Z-Rated tire is engineered, it has an
incredible performance advantage over the bicycle tire. The same can be said of kite lines. Even though there are thousands of lines made from UHMWP
fibers, how those lines are braided, woven and put together will determine the performance of those lines. Some companies make kite lines similar to
the bicycle tire, others like Shanti, Laser Pro Gold, Berry Blue - make kite lines the similar to the Z-Rated racing tires. Obviously the latter
lines will perform incredibly better and unfortunately will cost much more. I have seen Dyneema and Spectra lines that were pure junk and were like
flying on bungee cords...at least they were claiming they were Dyneema or Spectra.
Be careful when purchasing lines from different lesser-known kite manufacturers that brag that they include Spectra or Dyneema lines. Even though
they are made from the right materials, you may be spending hard earned money on cheaply produced line that will not perform.
elfasa - 14-2-2013 at 03:25 PM
Well, that's sorted that!
Thanks a lot guys, as always 
Tim
acampbell - 14-2-2013 at 03:45 PM
Good job as usual, Kent
Late to the party again but here is my take on the topic...
http://www.coastalwindsports.com/WhoseLine.html
acampbell - 14-2-2013 at 04:12 PM
There is another interesting anecdote about Spectra/ Dyneema that I just remembered and is worth mentioning as we learn about this fibers...
As strong, light, abrasion resistant, UV resistant and hydroscopic (wont absorb water) as these lines are, they are not resistant to HEAT.
On the other hand, the cheap cotton/ dacron- whatever blend line on a child's kite is relatively heat resistant. So if you are zinging down the beach
in a buggy or on a land board and you cross your lines with a typical inexpensive single line kite, you lose every time. The cheap line will drag
across your and "ZIP" , cut through your lines LIKE BUDDAH.
So when I drive down the beach and look out for other single line kites, I am not just being neighborly, I am looking out so that the $3 line doesn't
take out my $80-100 set!