Kevlar closing loops were standard in Racer reserves for a decade or so (early 1980s until the introduction of Cypres). Jump Shack specified non-coated Kevlar to prevent the adjustable quick-loop fro slipping, king of the same way Cypres specifies non-coated Spectra for reserve closing loops.
These days I mostly use 1000-ish Spectra (i.e. old tandem steering lines). That is because fashions in closing loops have always followed fashions in main suspension lines. For example, gutted 550 cord nylon was fashionable back when I started jumping. Hint: back then (late 1970s), military-surplus T-10 round canopies were still fashionable for students.
Dacron was fashionable - for closing loops - during the 1980s.
But Spectra never really caught on - for main closing loops - until tandems started using 1000-plus pound Spectra.
Vectran and HMA are far too skinny to hold a knot large enough and ugly enough not to slip through a container grommet, so we are probably stuck with closing loops made from old tandem steering lines for the foreseeable future.
Spectra also provides a lot less friction than other materials which is why they are so popular for closing loops. I believe that a Vectran closing loop would be less than desirable due to the increased friction on the closing pin.
I have a friend who is using a Kevlar closing loop...any one use one?
I am looking for Advantages and Disadvantages. Thanks
Maybe this is answered elsewhere and I missed it...
Are we talking main or reserve?
Reserve - If Cypres (or other cutter equipped), I would suggest using nothing other than what Airtek specifies as the cutter may not cut it.
Main - I still use 550 gutted... For this one, I would have to ask... why change? Plenty around, predictable and known breakage behavior.
550 has some stretch which means it provides some give (think spring action) when closing and holding closed. Kevlar and Spectra have no give; therefore tension is based more on how your pack job went.
Its frayed appearance is well known (easy to know when to change) and can be identified by the greenest of pin-checkers.
Its cheep. (free if you talk to your rigger and learn to trap your own)
Its friction is also well known. Remember friction is needed... too little and the pin will easily slip when you don't want it to.
I guess I'll refer to a well known jumper's pet question: "what is the problem you are trying to fix??"
Not against innovation, but this one does not click with me... I WOULD like to hear why the desire to change...