Four layer cardboard paper machine is mainly used for making cardboard paper. It is consists of headbox, wire section, press section, front drying section, oblique surface sizing machine, back drying section, calender section and reel section. The paper trimmed width is 3700mm.

Headbox: Including four air cushion type headbox, corresponding to top layer, lining layer, core layer and bottom layer. It controls and stabilizes the sizing of the pulp by controlling the gas pressure.

Forming section: Four layers include top layer, lining layer, core layer and bottom layer. The main components consist of breast roll, forming board, dewatering board, vacuum box, composite roll, suction couch roll, wire drive roll, wire guiding roll and paper machine framework. Top layer, lining layer, core layer and bottom layer are respectively equipped with a forming section respectively.

Press section: Including first press, second press, third press and fourth pressure. The first press is vacuum press with vacuum suction roll, which is equipped with one rubber coated metal roller and one vacuum press roll; The second and third presses are all MG press, and each of them is equipped with one upper and lower rubber coated metal roll; The fourth press is glossy press, which is equipped with one stone roller and one rubber covered metal roller. The first three presses are respectively equipped with wire guiding roll, felt suction box and upper & lower felts. These four presses are pressurized by the hydraulic cylinder pressure.

Front drying section: Φ1500/Φ1800 dryer droves in groups and is equipped with wire guiding roll , dry wire and closed gas hood.

Oblique surface sizing machine: one surface chrome-plated metal roller and one rubber coated metal roll. Its pressurized way is corrugated tire pressure.

Back drying section: Φ1500/Φ1800 dryer droves in groups and is equipped with guiding roll , dry wire and closed gas hood.

Calender section: Double roller calender, the upper and lower rollers are both metal rollers.  Pressurized way is corrugated gas tire pressure.

Reel section: Pneumatic horizontal reel machine. Pressurized way is cylinder pressure.