PVC vs PU coated for sleeping pad?

Are you getting the fabric from a super secret source or would you be able to share the source? I'd be quite interested in playing around with some of it myself. Thanks

–Chris

Hi Chris,

I have a side job that puts me in touch with a lot of textile mills. Occasionally, I can buy some over run product, but it's often in the 100+ yards range as in this case. So not a super secret source but not one that is really open to the public. With that said, I will be happy to sell you some at my cost if I get this. Although, doesn't look like anyone knows much about it on BPL.

BUMP.

Ryan

Double-sided PVC-coated fabric is 'standard' for thermal welding. Have a look at yachting gear: a lot of it is made that way. Most of the heavy dry-bags are the same.

Apparently you can also thermal weld PU coatings, but I know little about this. I suspect you would need a thick coating for it to be reliable.

Cheers

Heat sealable fabrics with a PU coating or PU film laminate are commonplace. The heat sealable nylon fabrics from Seattle Fabrics are TPU laminates, as were the fabrics that Bender used for his Kookabay inflatable sleeping pads. I used 30D and 70D nylon/TPU fabrics for two MYOG inflatable sleeping pads and a dromedary-style water bag.

I don't know much about PVC coated fabrics. Ryan, do you know the weight or color of the fabric you're considering buying?

Also, I remember reading that all of the major hydration bladder companies (platypus, camelbak, etc.) originally made their bladders with PVC, but switched to PU because it is far stronger and less prone to cracks and tears. This suggests to me that a welded PVC bond might not be as strong as a welded PU bond, but I'm only speculating.

Colin,

I did some more research on PVC and looks like it's pretty close to what you mention above. The bond is not as strong plus it's usually heavier than a comparable TPU product. So, looks like I will pass just based on the weight issue alone. Thanks for the input.

Ryan

Not sure if it matters but vinyl coated materials have a much higher tear strength than TPU coated ones. The best drybag material I ever found was a 6oz 200D vinyl coated polyester. It had the tear strength of a 500d cordura but was waterproof to 200psi and could be welded.