Single Facer and Double Facer Process on Corrugated Lines: Three Layers or Five — First Understand Forming

The core forming stages of a corrugated board line are the single facer and double facer: the single facer first presses the medium into a wave and bonds it to the inner liner, then the double facer laminates the outer liner on top. Understand these two steps and you understand corrugated board quality.

The Scenario: Two Key Points of the Forming Process

Corrugated board forming has two key points that are hard to master:

The Pain Points

• The wave forming and setting of the corrugating medium — uneven height and density weaken the board;
• The lamination and glue control of the liner bond — a weak bond leads to delamination and blistering.

The Solution: Understand Forming Through the Two Steps

Corrugated board forming comes down to two steps — the single facer and the double facer:

1. Single facer. It presses the medium into a wave through the corrugating rolls, applies glue and bonds it to the inner liner to form single-face corrugated — the foundation of the fluted structure.

2. Double facer. It laminates the single-face web with the outer liner under heat and pressure to form finished corrugated board — determining flatness and bond strength.

3. Multi-ply combination. By combining multiple single facers and double facers, you can produce 3-ply, 5-ply and 7-ply board to meet different load requirements.

The Result: Board Strength Is Guaranteed

With single facer and double facer processes under control, the flutes form evenly and the lamination bonds firmly — both strength and flatness are assured.