Causes of Waste Paper from Corrugated Paperboard and Countermeasures

This article only discusses the causes and countermeasures of the corrugated paperboard waste products that affect the production cost, and analyzes and demonstrates the corrugated board production process.

First, the quality problems encountered by single-sided machines

1. Paper break problem

There are four main reasons for paper breakage, namely, the low moisture content of the base paper, excessive acceleration of the machine during the production process, insufficient tension on the base paper joints, and improper gap between the pressure roller and the lower corrugating roller.

Countermeasures:

1) Reduce the heated area of ​​the base paper in the preheater and preregulator, or open the sprayer to humidify the base paper;

2) Uniformly and slowly increase the speed;

3) After touching the original paper joint, immediately loosen the tension handle that controls the base paper, loosen the roll paper according to the direction of rotation of the base paper, hold the joint through the tightening belt, and then rotate the tension handle;

4) Adjust the parallelism of the pressure roller and the lower corrugating roller and the gap size. The clearance should be between 0.1-0.15mm.
2. Problems

the reason:

The single-sided machine with paper guides appears to be sloping: the gap between the paper guide and the lower corrugated roller is improper or the arc in the paper guide plate is worn; the single-sided paper without paper guide (ie, the suction-type single-side machine) is abnormal in the state of the paper suction. To.
Countermeasures:

1) The single-sided machine with paper guide should adjust the gap between the paper guide and the lower corrugated roller and keep it between 0.25 and 0.30mm. If the circular arc of the paper guide plate is seriously worn out, it should be replaced;

2) The suction type single-faced machine should check the suction device. If the clearance is too large, it includes air pressure, air holes, pipes, filters, etc.

3. Open glue problem

the reason:

a. The gap or pressure between the pressure roller and the lower corrugating roller is not proper.

Countermeasures:

Check the gap between the two rollers with a feeler gauge, or check the parallelism of the two rollers with the lead wire method. Under normal working pressure, the two rollers should be maintained at a clearance of 0.10 to 0.15 mm. Improper pressure should check whether the gas source, gas path and cylinder are normal.
b. Corn starch binder problem.

Countermeasures:

From raw material ratio, gelatinization temperature, time and other processes to consider. If the process is correct, consider whether the adhesive remaining in the reaction tank and the pipe in the previous day is deteriorating.

Second, the quality problems encountered on the double-sided machine

1. Open rubber problem

the reason:
a. If the glue problem causes the glue to be opened, the solution refers to the previous section; the downtime is too long, resulting in a large area of ​​corrugated board in the hot plate to open the glue.

Countermeasures:

In the production process, try not to stop or stop. If the parking is more than five minutes, the operator should cut off the layers of raw paper before the hot plate and open the corrugated board out of the hot plate.

the reason:

b. Conveyor belt runaway causes corrugated board edges to open.

Countermeasures:

Adjust the rectifying handwheel on the conveyor belt so that the conveyor belt always runs in the center of the pinch roller. Unqualified corrugated cardboard is detected in the stack and is manually hand-powed by polyvinyl alcohol.

2. Corrugated board deformation

There are many factors that cause distortion of corrugated cardboard, which involves the design of corrugated board ingredients, the quality of the base paper, the degree of perfection of equipment functions, the proficiency of operators, the stability of heating steam or heat-conducting oil, and the production environment and natural environment. If any one factor cannot meet the normal requirements of corrugated board, it will lead to deformation of corrugated board. Corrugated board warpage is usually perpendicular to the direction of the corrugated direction of the horizontal curvature and lateral curvature.

the reason:

a. The upper curve is higher in the moisture content of the paper than the top paper.
Countermeasures:
1) Increase the heated area of ​​the paper in the preheater;
2) Reduce the heated area of ​​the tissue in the preheater;
3) Increase the speed of the double-sided machine.

the reason:
b. Excessive moisture content in single-sided corrugated paper.
Countermeasures:
1) Reduce the sizing amount of single-sided machine base paper;
2) Increase the heated area of ​​the single-sided corrugated paper in the triple preheater.

the reason:

c. The weight, tightness, and tension of the paper inside are too different.

Countermeasures:
1) Putting an end to such incidents in the pre-production contract review phase;
2) Select paper, face paper and corrugated paper with close physical properties on the basis of raw paper cost;
3) Before the production, relevant information must be fed back to the cartons demander and negotiated with the cartons demander.
the reason:
d. The lower curvature is that the moisture content of the facial tissue is higher than that of the liner paper.
Countermeasures:
1) Increase the area of ​​single-sided corrugated paper in the triple preheater.
2) Reduce the amount of single-sided corrugated paper on a double coater and increase the adhesive viscosity.

Third, the vertical and horizontal cutting unit quality problems

1. Corrugated cardboard cuts have frizzy feathers. Cause: Vertical slitting is the slitting or bluntness of the slitting knife.
Countermeasures: The upper and lower slitters are close together and are ground on a regular surface grinder.
Cause: The cis-cut burrs are not a straight line or the blade wear becomes blunt.
Countermeasures: Adjust the cross cutting of the top wire or replace the new cross cutting knife.

Fourth, the stacker quality problems

Incorrect stacking of corrugated board will also cause warp and deformation of corrugated board. When the corrugated board comes out of the stacking machine, it is under the top sheet of paper. Therefore, at the corrugated cardboard stacking machine, a person should stack a corrugated cardboard with a thickness of about 20 cm per sheet to prevent misalignment caused by the difference in paper quality and moisture content.