Tunneling in a laminate
Tunneling is a long pocket or wrinkle running in the web direction. One web was loose, the adhesive grabbed a wrinkle, and the tunnel is now part of the laminate.
Checks
- Stop and look at both webs just before the nip. A flutter or a slack edge becomes a tunnel once the adhesive grabs it.
- Even out the tension across the width. A baggy edge tunnels even when the center is tight.
- Check the adhesive laydown. A dry streak lets the webs move after the nip and wrinkle as they cool.
- You cannot iron a tunnel out after the adhesive has set. Fix the unwind, then re-run.
Materials in the directory
Compare flex-pack laminating films, flex-pack films.