We ran side-by-side on a 70D nylon shell last week: a silicone–urethane C0 finish kept AATCC 22 spray at 90/100 after 20× AATCC 135 washes with only about 5% drop in air perm and still showed about 10,000 mm on ISO 811, while our C6 control held 95 but yellowed after heat-set. Anyone else seeing seam tape adhesion or wet-out issues with standard 13 mm PU tapes on these newer chemistries at production scale?
Same here on a 70D C0 silicone–urethane: our 13 mm PU tape lifted by 3–5 washes until we corona-treated the seam path and switched to a polyether PU tape (e.g., Bemis 3914); we also dropped head temp about 5°C to reduce “skating” on the low-energy finish. Caveat: if panels sit overnight, a quick IPA wipe helps — any silicone bloom will kill adhesion like taping to a Teflon pan.
We had edge-lift by wash 4 on a silicone–urethane C0; an atmospheric plasma pass on the seam path plus a two-step seal (light tack about 125°C, then final about 145°C with lower nip) and bumping to 15 mm tape fixed it and reduced stitch wet-out. Small caveat: ISO 811 will read low if you test right off the press — letting it rest 24 h tightened it back up. @derekW003 we also found “plasma > corona” on these silicone-rich faces; quick ref: https://www.plasmatreat.com/.
IR flash the joint to about 95°C to drive off the slick DWR, then seal and “cool under pressure” for 10–15 s; after that, our standard 13 mm film stopped lifting past 15 washes — otherwise it’s like trying to sticker a waxed surfboard. @michaelR77 is right on activation; small caveat: ether‑lean films hydrolyzed faster for us, so an ether‑rich grade held up better but scuffed a bit more.
On 70D, quick isopropyl wipe pre-seal reduced wet-out; if ‘13 mm’ lifts, try co-polyamide film.