<p>It is not a problem about origami so much as a problem of topology. If you are starting with a sheet of material its topology is genus 0. The shape you want, a sleeve, is genus 1 like a donut. The two are topographically unique and you cannot get from 0 to 1 without connecting the sheet to itself at some point, thus the glue. </p>

<p>If you had a <em>seamless tube</em> of fiberglass material, then you could get into the folding process that would give you the sleeve shape you want, but it is impossible with a flat sheet. </p>

CC BY-SA 4.0
2020-05-09T14:33:03.173Z
2020-05-09T14:33:03.173Z
rebusB
<p>Is it possible to make a collapsible origami bellow/sleeve without using glue? I am interested in that because i want to make a plunger engine that would use such a sleeve made of fiberglass sealed with tar. Any use of glue is precluded cause it would not withstand the pressure. </p>

CC BY-SA 4.0
2020-04-01T07:25:18.977Z
The right glue could take the pressure as well as the fiberglass. In effect you're using the tar as glue anyway, just on a different scale. You need a design to avoid peeling forces, and supporting the glued joint might be helpful (bike inner tube patches and their glue can easily hold 7 bar, but they're supported by the tyre)
Chris H
CC BY-SA 4.0
2020-05-09T14:34:29.210Z
Just curious, wouldn't the fiberglass break down with repeated flexing.
rebusB
<origami>
Is it possible to make a collapsible origami bellow/sleeve without using glue?
Francis L.
# Is it possible to make a collapsible origami bellow/sleeve without using glue?

(Asked by: username_0 on 2020-03-30)

Is it possible to make a collapsible origami bellow/sleeve without using glue? I am interested in that because i want to make a plunger engine that would use such a sleeve made of fiberglass sealed with tar. Any use of glue is precluded cause it would not withstand the pressure.

**Tags:** origami

> **Comments:**
> **username_1**: The right glue could take the pressure as well as the fiberglass. In effect you're using the tar as glue anyway, just on a different scale. You need a design to avoid peeling forces, and supporting the glued joint might be helpful (bike inner tube patches and their glue can easily hold 7 bar, but they're supported by the tyre)  
> **username_2**: Just curious, wouldn't the fiberglass break down with repeated flexing.  

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## 1 answers

### Answer by username_2 on 2020-05-09. Score: 2

It is not a problem about origami so much as a problem of topology. If you are starting with a sheet of material its topology is genus 0. The shape you want, a sleeve, is genus 1 like a donut. The two are topographically unique and you cannot get from 0 to 1 without connecting the sheet to itself at some point, thus the glue.

If you had a *seamless tube* of fiberglass material, then you could get into the folding process that would give you the sleeve shape you want, but it is impossible with a flat sheet.


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