Corrugated board sheet (single and double wall) manufactured from recycled fiber by Grupak

Is made from three papers: two liners (inner and outer faces) and one medium that forms the

flute. Double-wall corrugated board is produced from five papers: two liners, one central

medium, and two corrugated mediums (flutes).

Flute Types

Single wall: B, C and E flutes

Double wall: BC, BE, BB and CE combinations

Edge Crush Test (ECT) Ratings

Single-wall board: 3M, 19, 21, 23, 26, 29, 32, 35, 40, 44, 52 ECT

Double-wall board: 35, 41, 48, 51, 61, 71, 81 ECT