I bought some 40D TPU coated ripstop nylon from DIY packraft. I used it to make an inflatable sleeping pad. I 3D modeled and printed the “boston valve” and used a Coke cap (easy to replace) to top it off. I used scissors, ruler, marker, parchment paper, tape, and a clover mini iron to complete this project. I also used some Seam Grip to adhere the inflation valve and to seal up some pin holes. It measures about 21 x 72 x 3 inches. The pad weighs around 16 ounces, although I haven’t put the final product on the scale, still waiting for the seam grip to dry. See the pics below.
The Coke cap valve. It top part is the removable one way valve which inserts into the valve body. I used a small piece of flexible plastic to make the valve work. Its not perfect but I prevents most of the air from escaping when you are trying to blow it up. It actually seals better under more pressure.
Laying out and marking up the fabric.
After cutting out the two sides and the 80 baffles.
Using parchment paper to seal a 0.5 inches of each baffle to the main panel.
One side with all the baffles welded on.
In the process of sealing the baffles onto the other side of the pad.
Inside of the sleeping pad after all the baffles have been sealed to both sides. This is before the edges were sealed together.
An edge that needed a little more sealing.
First successful inflation. I had to go around and seal the edges again and with a larger seam allowance.
When testing the pad out, I could hear some of the seams separating. This photo shows how some of the baffles are pealing away from the main panels. I think this was just under initial stress from the first time I laid down on it. The peeling noise stopped after I laid down on if for a few minutes. If I make another I would use a slightly higher temperature and more pressure to stick the baffles in place. Looking at commercial pads, the welds look rounded as opposed to squared off like I did. I guess that would reduce stress along the edge of the weld.
I had to seam seal on side of one of the long edges. I used the selvedged edge of the fabric because I was trying to avoid a lot of cuts and get the most out of my fabric. I figured the TPU would melt and seal the holes. After inflating the pad, I could feel the air escaping the pin holes at the edge of the fabric. Next time I will trim the edge to avoid the holes of the selvedge.
Hopefully I can get some use out of it. This project cost maybe $40 for materials, plus another $25 for the mini iron.
