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Hi All,
I’m working on an inflatable project that requires heavier fabric, like 420D or 840D. I’ve been working directly with fabric suppliers since bulk fabric isn’t for sale on here right now. The samples are welding well. Before I pull the trigger on an order, I figured I’d post here to see if anyone else is looking for bulk heavy fabric. The fabric would be cheaper for us all if I order in larger quantities. Here are the fabrics I’m looking at now:
- 420D 380gsm single sided TPU (gray)
- 420D 570gsm double sided TPU (blue)
- 840D 700gsm double sided TPU (white)
Colors are somewhat tentative. I don’t care about color really, so that’s flexible. We can work out specifics later. I’m mostly just trying to get a sense of interest. Thanks
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Hi Aaron, I’m interested in what tools people are using as well, but I have some info to add as well.
I don’t think flat seams (sometimes called pinch seams) like in the examples you provided are as strong as the lap seams like in a typical packraft. The pressure is more directly trying to tear the seam apart. Here is a youtube video about seams (for pool toys, but the idea is similar) https://www.youtube.com/watch?v=9F0fjaHhgzo
The other factor with this simple approach is that you get wrinkling which is a cosmetic issue and could affect the drag in the water. Wrinkles might be a more likely spot for holes to show up as well. But that’s just a guess. These wrinkles come from the inflation process causing compression in parts of the fabric. To avoid wrinkles, the final inflated packraft shape should be made of what are called developable surfaces. This special class of surface can be flattened into a flat pattern without warping. Cylinders and cones are classic examples of developable surfaces which is why you see the tubes of many inflatables taking on these shapes.
I’m working on some inflatable designs for fun. I’ve been using FreeCAD for making the 3D shape. You can then inflate the shape in Blender with the cloth physics pressure option to get an idea about wrinkling and the actual inflated shape. Blender also has a Paper Model plugin that says it can make flat plans of developable surfaces, but I haven’t got that to work yet. I haven’t found these tools to be particularly user friendly so I’m hoping someone else chimes in with other inexpensive software packages.
-Kevin
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