Gerissenes Slackline-Band aus Polyester-Dyneema-Mischung nach dem Zerreißversuch

We're back – and a webbing that doesn't hold what it promises

Hey everyone,

I've been almost completely gone for a very long time. There were things in life that needed my full and undivided attention. That's all I'll say about it.

Now it's over. I'm sweeping the dust and the shards aside and saying: we're back.

With a completely new shop, with new hardware of our own design in the pipeline, and with new webbing in the works. And with a failed attempt that I don't want to hide from you.

Broken slackline webbing made of a polyester-Dyneema blend, orange and blue, after the tensile test

A new webbing – and why it won't go on sale

We wanted to launch a new webbing: 20 mm wide, a blend of polyester and Dyneema (UHMWPE), ordered with a breaking strength of 30 kN. The samples looked promising. Then came the production run, and it didn't live up to what the samples promised.

On the pull tester it broke at 14.57 kN. That's less than half of the breaking strength we ordered.

Force-elongation chart of the tensile test: break at 14.57 kN instead of the ordered 30 kN

Why a blend can be weaker than either material on its own

On paper, a blend of polyester and Dyneema sounds like the best of both worlds: Dyneema is extremely strong and light, polyester is robust and UV-resistant. In practice, exactly the opposite can happen.

My guess: Dyneema barely stretches before it breaks, only about 3 to 4 percent. Polyester manages 12 to 15 percent. When both fibres sit in the same webbing, the Dyneema carries almost all of the load at first. It reaches its limit and snaps before the polyester really starts pulling its weight. After that, the polyester has to carry on alone, and it isn't built for that load.

So the fibres fail one after another instead of together. You can see it in the chart in the small drops at around 8.5 and 10 kN, long before the actual break. Those are very likely groups of fibres giving way early.

Second sample of the polyester-Dyneema webbing, red and yellow, with frayed fibres at the break

If you want to know more about how materials behave in slacklines, you'll find the basics in our guides Polyester vs. nylon and Material guide.

That's how we've done it since 2005

This webbing won't be sold as slackline webbing. If it doesn't hold what it promises, it doesn't go out.

We test every webbing we sell ourselves, on our own pull tester and, where needed, in an independent test lab. That applies to our slackline webbing just as much as to every sewn loop that leaves our workshop.

What happens to the webbing?

Now it's sitting here, quite a lot of it, and it looks damn good. I'm not going to throw it away. And that's where you come in:

What would you do with a 20 mm webbing that holds 15 kN?

Tent guy lines, lashing straps, dog leashes, bag straps, lanyards, something for your club, or an idea I haven't even thought of? Tell us in the comments on Facebook or send us an email. Every suggestion is welcome, even the crazy ones. The three best ideas get a piece of it for free.

What's coming next

The new shop is up. New hardware of our own design is in the works, and new webbing is on its way. Until then, you'll find our current range in the shop. And if you have any questions, just write to us.

See you on the line.
Michael

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