Method and apparatus for producing multi-ply corrugated paperboard

A method for producing a multi-ply corrugated paperboard comprising the steps of:

• guiding both a liner and first and second webs to a first laminating station having first and second pairs of corrugator rollers;
• preheating the liner to a temperature sufficient to bond a web to the liner;
• guiding the first web to the first pair of corrugator rollers to corrugate the first web with predetermined flute pitch and flute peak height and in turn laminating the first web to the preheated liner through bonding and thereby forming a single-faced, single-ply corrugated paperboard;
• guiding the second web to the second pair of corrugator rollers to corrugate the second web with selected flute pitch and flute peak height and in turn laminating the second web to said single-ply paperboard through bonding;
• pressing down the first and second webs on the liner using a press belt and thereby forming a single-faced and multi-ply corrugated paperboard;
• guiding said multi-ply corrugated paperboard to a paper guider and controlling a paperboard feeding velocity by means of a suction brake;
• uniformly tensioning and preheating said multi-ply corrugated paperboard;
• feeding a cover paper to the multi-ply corrugated paperboard passed from the paper guider such that the cover paper runs parallel to a bottom surface of said paperboard;
• uniformly applying adhesive on said multi-ply corrugated paperboard as well as to the cover paper;
• and
• guiding the multi-ply corrugated paperboard as well as the cover paper with adhesive to a heating plate and compressing the paperboard as well as the cover paper using a constant pressure while the paperboard and the cover paper pass over the heating plate to thereby form a double-faced and multi-ply corrugated paperboard.

An apparatus for producing a double-faced multi-ply corrugated paperboard comprising:

• uncoiling drums for feeding a liner and at least two webs to single-faced corrugated paperboard laminating means;
• said laminating means having
• at least first and second pairs of corrugator rollers for guiding and continuously corrugating the webs with either the same or different flute pitches and flute peak heights, each said pair of corrugator rollers including an upper roller and a lower roller, and
• biasing means for biasing the liner toward a first web to continuously laminate the liner to the first web to form a single-faced single-ply corrugated paperboard and for biasing the single-faced single-ply corrugated paperboard toward a second web to continuously laminate the second web to the single-faced single-ply corrugated paperboard to form a single-faced multi-ply corrugated paperboard;
• and
• cover paper laminating means for laminating a cover paper to the single-faced multi-ply corrugated paperboard to thereby form a double-faced multi-ply corrugated paperboard.

An apparatus for producing a multi-ply corrugated paperboard comprising:

• uncoiling drums for feeding a liner and at least two webs to corrugator rollers;
• at least two pair of corrugator rollers for guiding and continuously corrugating the webs, each pair including an upper roller and a lower roller;
• adhesive applying rollers placed about the corrugator rollers to apply adhesive on the webs;
• and
• biasing means for biasing the liner toward the webs to bring the liner into close contact with the webs, said biasing means comprising;
• a pair of belt drive rolls placed above the corrugator rollers;
• a press belt wrapped about the drive rolls;
• and
• a guide roll for guiding the press belt to partially wrap the press belt about the upper rollers.