Common Problems and Solutions in Corrugating Machine Production

1. Cardboard bonding

(1) The importance of bonding

Reliable bonding is necessary for the formation and maintenance of corrugated cardboard frame, and is also important for the final packaging quality of corrugated cardboard boxes. Poorly bonded cardboard can block or stop other post-processing equipment, causing losses to production.

(2) Inspection of bonding quality

PAT method is a method to measure bonding quality in laboratory. In actual production, operators on corrugated board production line usually tear the lining paper by hand to check the bonding quality of the board. If the bonding is good, some corrugated core paper fibers should be adhered to the lining paper. If the bonding is not good, the lining paper and corrugated core paper will be separated completely.

(3) Reasons for poor adhesion

(1) Reasons for poor bonding of cardboard on one-sided machine

Occurring at the edge of cardboard

A. The pressure between the lower corrugated roll and the pressure roll is insufficient.

B. Deviation of parallelism between lower corrugated roll and pressure roll

(2) It occurs in the middle of the cardboard. The change of the width of the cardboard causes the wear in the middle of the corrugated roll, which makes the supply of adhesives insufficient.

(3) Occurs in the entire width of the cardboard.

A. The improper clearance between rubber-coated rollers and scraper rollers results in insufficient adhesive film (too thin).

B. Coating rollers are too far from the lower corrugated rollers.

C. The adhesive level in the rubber disc is too low.

D. The quality of adhesives is not good.

E. The temperature of corrugated rollers is not high enough.

F. The pressure of the pressure roll is not uniform or sufficient.

G. Dissatisfactory coating of adhesives, insufficient preheating of paper, winding of preheater or insufficient temperature.

H. Paper moisture content is too high, winding angle of preheater and corrugated core paper preparer is not enough, or single-sided machine speed is too fast.

(2) Reasons for poor adhesion of cardboard on double-sided machine

Occurring in the middle of cardboard

A. The pulling force of single-sided corrugated cardboard causes excessive deviation of guide roll (floating roll), which results in insufficient coating of adhesives.

B. Due to the insufficient pressure on the cardboard in the middle of the hot plate due to thermal expansion, the problem can be limited by the blower unit.

C. Due to insufficient evaporation in the central part of the cardboard, the adhesive can not be completely gelatinized. If the temperature of the hot plate can not be increased, the only way is to reduce the speed.

(2) Occurs in the entire width of the cardboard.

A. The adhesive coating is unsatisfactory, the preheater winding is not enough, the belt pressure is not enough, the speed is too fast or the hot plate temperature is too low.

B. Insufficient adhesive film.

C. The quality of adhesives is poor.

2. washboard phenomenon

The so-called washboard phenomenon refers to the corrugated cardboard made of corrugated cardboard, which produces concave phenomena along the ridge between the corrugated peak and the ridge of the corrugated peak on the surface of the paper. The shape of the corrugated cardboard is similar to that of the household washboard, so it is called the washboard phenomenon.

(1) The root causes of the washboard phenomenon of corrugated cardboard:

It is mainly due to improper gluing of adhesives, which is caused by excessive glue aggregation on both sides of the Lengfeng peak. This situation is particularly harmful to low-quantity carton paper.

(2) The concrete methods to control the phenomenon of cardboard washboard are as follows:

(1) The most direct and effective way to eliminate and reduce the washboard shape is to adjust the quantity of facial paper and change to higher quantity carton paper (but it will increase the cost).

The use of high-quality adhesives can reduce the amount of Lengfeng sizing;

(3) Control the heating winding surface of the surface paper on the preheater, because the boardboard paper is too dry to absorb more glue, which is easy to produce the phenomenon of rubbing board;

(4) Adjust the parallelism of sizing roll and paper guide roll of compound glue machine and the gap between them, and strictly control the pressure of guide roll (press roll) to prevent the increase of glue loading after collapsing.

3. Inversion

(1) Single-sided corrugation of cardboard

Reason analysis:

Corrugated roll wear;

(2) The gap between upper and lower tile rollers is too large;

The weight of tile paper is too heavy and too thick.

(4) too much moisture in tile paper;

The plasticity of tile paper is poor without preheater.

Resolvent:

Replacement of tile rollers or grinding;

(2) Adjusting the clearance of two-watt rollers to 0.5mm;

(3) Replacing tile paper;

(4) Increasing the preheating angle of tile paper;

_Pass the tile through the preheater.

(2) Double-sided corrugation of cardboard

Reason analysis: 1. Reversing after gluing by double-sided machine is caused by too small gap between gluing roll and ballast roll; 2. Reversing after drying machine, floating ballast roll on conveyor belt can not move up and down freely and press corrugated deformation; 3. Excessive gluing amount, corrugated paper absorbs a lot of water in glue and softens, and falls along the direction of dryer operation; 4. Quality of corrugated paper.

Solutions: 1. Adjust the clearance between double-sided machine, ballast roll and rubber-coated roll to less than 0.2 mm of single-sided cardboard. It is preferable to insert the ballast roll freely and drive the ballast roll to rotate corrugated without deformation; 2. Adjust the free movement of floating roll on the conveyor belt of dryer; 3. Reduce the amount of rubber-coated to uniformly distributed corrugated peak, instead of drifting corrugated roll. Suitable in ditch; 4. Replace tile.

4. Wrinkle

(1) inside paper crease

Reason analysis:

The thickness of tile paper is uneven.

(2) Input corrugator directly without preheating;

(3) The braking of both ends of tile paper is inconsistent;

(4) Water imbalance of tile paper;

_The guide rollers are not parallel.

Resolvent:

(1) Replacing tile paper;

(2) Wallpaper through the preheater;

(3) Adjusting the balance of tile braking;

(4) Increase the preheating area of tile paper or replace tile paper;

(5) Correction of paper guide rolls.

(2) Wrinkle of facial paper

Reason analysis:

The guide rolls are not parallel.

(2) Inclined paper inlet of dryer;

(3) Water imbalance of tile paper;

(4) The tension at both ends of tile paper is unbalanced.

Resolvent:

(1) Correction guide roll;

(2) Correct the paper inlet of the dryer;

(3) Increase the preheating area of tile paper;

Change tile paper.

(3) Wrinkle of tile paper

Cause folding: the strength, moisture and thickness of both ends of tile paper are uneven, and the brake is insufficient.

Solution: adjusting preheating surface