Most converters specify a backsheet film by GSM and WVTR alone. That's like specifying a car by horsepower and color. There's real performance behind those two numbers — and most of it gets left on the table.
Below is the checklist Rhyfeel's engineering team walks every new customer through before we cut a sample roll.
1. What is the absorbent core composition?
SAP loading drives the breathability target. A diaper with a 12-gram SAP core and a thin pulp envelope wants higher WVTR than a 16-gram SAP core with a thicker pulp matrix.
2. What is the topsheet system?
The non-woven topsheet has its own MVTR. The two films work as a coupled system. We tune the backsheet WVTR to land at the system-level moisture release the wearer experiences.
3. What is the line speed?
A 350 m/min converting line tolerates a different basis-weight band than a 600 m/min line. We narrow the GSM band accordingly.
4. Print or no print?
If you're printing, what colors, what coverage, what register tolerance? An 8-color full-bleed graphic at 500 m/min on 12 gsm is one of the hardest jobs in hygiene printing — and one of the few our MIRAFLEX II handles routinely.
5. Emboss?
Micro or deep? Aligned to print register, or independent? Custom pattern, or one of our stock? An emboss is the easiest single change to the perceived tactility of a finished diaper.
6. Corona target?
What dyne value does your downstream adhesive or print system need? We deliver consistently within ±2 mN/m.
7. Hot-melt lamination, or separate non-woven station?
If you're running a separate non-woven step, you're paying for it. A pre-laminated textile-backsheet ships as a single roll.
8. What does the recycling story need to be?
Mono-material PE? Pattern-dot adhesives that preserve WVTR and recyclability? EPR-compliant content? These choices live at the spec stage, not the marketing stage.
Send us the answers and we'll ship a 50-meter trial roll within ten working days. Request a sample →