Laser safe flexible plastic?

Probably asked and answered, but can’t find it so asking anyway.

Is there a thin flexible plastic that’s laser safe and still pretty tough? Thing about the kind of plastic used on Nalgene bottle lids to retain them to the bottle. That stuff will actually even stretch a tad so you can remove and reinstall it, and I want to be able to do my own custom similar situation on a different bottle. Need it to last in normal outdoor use, so needs to be able to handle 110F or so as well as UV, without turning brittle. Will obviously need to be able to be bent into a U shape and not get unhappy, too.

Recommendations?

–Donnie

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This line from Johnson Plastics is what you are looking for.

Makes great rulers and protractors, as well as stencils. I don’t know just how UV tolerant it is though. Put a sample in the sun and find out. Then report back. That is how we find stuff out around here!

https://www.jpplus.com/lucentcollection

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Delrin. I have some that’s 1.5mm thick that would do admirably for your purpose and it cuts beautifully in the GF.

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Thanks. Samples of both on the way.

FWIW, a lot of backpackers are going to ultra lightweight everything. One of the things they’ve settled on is 1L Smartwater bottles for their water. They’re a great form factor for fitting in backpack side pockets, hold a lot, and are very tough for how light they are. One problem that bugs me is dropping my cap and getting it dirty, or worse, losing it. I think I can make a cap retention device just like Nalgene bottles have just by 3D printing a mushroom for the top (screwed on with a tiny stainless screw) that lets the laser cut tether stay on the cap while still letting the cap rotate, then you stretch it over the lip that’s under the cap. I’m skeptical the Delrin will be flexible or thin enough, but it wasn’t terribly expensive and I’m sure I’ll find other uses for it anyway. It’ll be here tomorrow and the Johnson pieces will be here Wednesday.

–Donnie

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Haven’t cut anything yet, but the 1/16" Delrin is definitely too thick and rigid. Haven’t looked for thinner yet, but the Johnson stuff showed up and I really think it’ll work.

Any thoughts on settings on the Glowforge to cut it? I haven’t done very much outside of Glowforge Proof stuff yet (just some EVA foam).

–Donnie

I thought I had saved my settings for the jp stuff but I can’t find them.
Here are some hints though. It is 0.025 thick and is a modified acrylic. So I’d try about 20% the burnation as med proofgrade acrylic for my first experiment.

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why not just use a shoe lace and some construction adhesive.

I don’t trust solutions that involve adhesive, for one. For another, I’d like a solution that’s a little more professional looking. And I like interesting challenges.

–Donnie

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You need to embrace adhesives but yes to the rest.

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I hear you, but gluing something to the top means the tether has to twist to take the cap off and put it on. I want a joint there that will let the cap spin independent of the tether. My first tests of this will likely be a 3D printed mushroom glued or screwed to the top. But ultimately I’d rather have a single piece, and I’ve found someone has already drawn a cap in Solidworks, so most of the heavy lifting is done.

—Donnie

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How about HDPE polyethylene? (Aka milk jug)
It’s laser safe, kinda melty but could easily be cut with scissors instead for what you’re doing.

Or get really crazy and cut acrylic to make a reverse mold for silicone?

I’ll bet that that modified acrylic from jp is going to work but I like the way you think.

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Well, time to test for a bit. Next up, a 3D printed cap to replace the screw monstrosity.

That’s the Johnson plastic cut at speed of 155 and 40% power.

–Donnie

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So I used a guy on Freelancer.com that a friend has successfully used in the past to draw complex 3D parts that are product-ready and in one day he completed the new cap. I’ve ordered a few samples and should have them on Friday. This guy is capable of turning his drawings into mold designs, too, should there end up being a market for this. There may not be, but if someone was able to find enough interest to make this thing:

Then these might be viable, too. FWIW, I used the above clip on a 17 day trip to Nepal to hold my main hydration source. I did break one on the trip, but that seems like it might have been a fluke. I had a spare and that one held up. This thing clips into the bottle under the ring that’s BELOW the ring my retainer hangs on to, so it’s compatible with my retainer completely.

–Donnie

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Dang, bad news. The Johnson plastic retainer broke today. Just seemed to get brittle at the bend. Barely touched it and it snapped.

Any other suggestions on tough but flexible plastic that’s laser safe?

–Donnie

What about leather?

it is laserable and flexible.

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I’ll have to agree with CA worth if Delrin is too stiff and the special acrylic work hardens to quickly leather is probably the way to go.

How about some thin paracord and some ferules?

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I’ll play with leather. Right now the caps are being printed on the assumption of a pretty dang thin piece of something, though, and I’ll bet I’ll want thicker leather. So while a reasonable idea, might require a different mushroom design. Not the end of the world, so we’ll see.

I have some proofgrade leather and that stuff is definitely thin. So thin I found it quite underwhelming for a different project, but maybe it’s thin enough for this as is. Hmm.

On the paracord idea, that DEFINITELY won’t work on the current mushroom. But do you have a link to ferules that might work? That has me curious for not only this project but some others.

–Donnie

Maybe polyethylene sheet? You can find clear versions at art suppliers for use as stencils; I use it as shims and its both smooth and durable.