Hi. I have made packraft from extremtextil’s fabric. Sealing was no problem, more heat from the sealing iron is the answer. Did use 210 D tpu dobbel side for floor and singel side tpu 210 D for tubes.
You could use singel side 210D tpu for bonding strips, should work just fine.
But I do not see the point using tpu dobbel side fabric for tubes, not the fabric from extremtextil because the tear resistanse is poor and way lower than Matt’s nylon 66 210 D singel tpu. And a tizip could be added with no problem in Matt’s fabric, no advantage there to fabric fram extremtextil. The fabric from Germany is heavy compared to nylon 66 210d tpu. Except from price and shipping speed from Germany I dont see any point using extremtextil’s fabric.