Last April, a US period care brand walked into our Shantou floor with 30,000 pieces of a leak-proof hipster on the order sheet — six SKUs, OEKO-TEX, the works. Their first sample looked fine. Then the 30-cycle wash test came back, and the TPU barrier had delaminated along the side wing. We pulled the laminator, found a 3°C cold drift on the bonding cell, and added a hot-melt grid under the absorbent layer. Sample three cleared 60 washes with zero delamination. That single account is probably the best 90-second tour of period underwear manufacturing in 2026 — and most of what goes wrong hides in the chemistry, not in the cut-and-sew.