How to tell if cheap straps are nylon or polyester ?

**pig.slayer** · 03-09-2011, 17:14

I picked up a cheap ratchet strap for $3.50 to try the material as a tree hugger strap. (from the local elcheapo shop)
Injected the end loops etc and the weight for a 6' hugger is only 15 grams.

The material is quite soft but the rating on these "premium" straps is 400 kgs. This is probably worth a grain of salt though....

I have a fear that they are nylon straps ???

Last night I strung one up in the garage from wall to wall nice and taunt, then measured the strap length and hung 40 kgs from the middle of it overnight.
This morning it had stretched out 100mm in about 8 hours and sagged considerably.

Does this mean it's nylon if it did this ???

Or will they just stretch xx amount and then be fine.

**Cannibal** · 03-09-2011, 17:24

The burn test is my favorite way, plus you get to light stuff on fire in the process; how can that be a bad thing?

If you have any nylon scraps around, burn one. The smell is distinctive, as is the smell of polyester. Once you can identify one, you'll be able to identify the other. You only need a small thread or piece to accomplish the test. After that, you'll never go to an outdoor shop or fabric shop without a lighter in your pocket.

**Bubba** · 03-09-2011, 17:25

Just a guess. Take the weight off and see it over time they stretch back. If they do stretch back they may be nyon. If they do not stretch back they may be polypropylene.

**pig.slayer** · 03-09-2011, 17:30

If they don't stretch back and are polypropylene.

Are they okay to use or not ??

I can pre-stretch at home...

**Bubba** · 03-09-2011, 17:49

Yeah polypro should be good to go. I've seen polypro straps sold by AHE and JRB IIRC.

**nacra533** · 03-09-2011, 22:25

You'll learn to spot the difference by look and feel.

Polyester is usually tightly woven. The threads to make the weave are thin and neat.

Nylon is usually thicker, sometimes more loosely woven and possibly a little fuzzy. A very fine fuzz. Think dog collar or dog leash.

Polypro has a sheen to it, but not shiney. It's usually fuzzy and snags because it can be loosely woven.

If you google fabric id chart, there is a good one out there explaining burn test results.

**grok** · 03-09-2011, 22:58

Originally Posted by pig.slayer

If they don't stretch back and are polypropylene.

Are they okay to use or not ??

I can pre-stretch at home...

I think you answered your own question.

Just got some Polypropylene strap from strapworks.com . I know you are overseas from the US so that may not matter. Nylon does seem to have a little more of a shine. I am guessing you've done your homework on the stretch and thats why your asking. Poly is the way to go but if your under 160 like me, I can wrap toilet paper around a tree and hang from it.

**moimeme_81** · 03-09-2011, 23:43

personally I use some strap that stretch when there's weight on it and get back after (those used for securing a load on a trailer...) it's not ideal but it work I just need to plan how much they'll stretch so I don't have my butt touching the ground... in term of strength if they say it holds 400kg, it should do it even if they're cheap

chris

**pig.slayer** · 03-10-2011, 06:39

I have noticed tonight that the stretched length of thismorning is now 75mm shorter. ie: start length was 1800mm, stretched length was 1900mm and now after 8 hours of no load on them they have returned to 1825mm.

Might hack them up for the burn test, Will see.

I'm thinking they are nylon due to the stretch. If they have returned close to the original length is this a good indication of nylon ?? I'm thinking so.

**thekalimist** · 03-10-2011, 06:42

polypro to me is also a good bit coarser around the edges. its almost twiney. nylon has that super smooth almost plush fee. its also been my experience that nylon feels a good bit heavier. conversely without a material to compare this becomes a difficult test.

id say, considering they are ratchet straps, if they are around 3mm thick they are nylon; more like 1mm, they are polypro. this being solely from my experience with somewhat limited materials.