Effect of sizing on corrugated board production line on product quality

Corrugated board production line sizing plays a decisive role in the quality of corrugated board. Good sizing determines the quality of the product. This will be the endless pursuit of corrugated box enterprises.

The standard sizing means that the sizing position is accurate, there is no misalignment, the adhesive is evenly and smoothly glued on the entire peak, the outline of the paste line is clear, and no adhesive is projected laterally from the corrugated fiber and is not dragged. Paste traces.

The bad sizing is mainly related to the equipment and adjustment of the corrugated board production line, the quality of the adhesive, and the quality of the base paper. The common quality problems caused by poor sizing mainly manifest in the following aspects:

Dropping glue

There are dirt on the rubber roller, such as paper scraps, corn starch agglomerates or other foreign materials, etc., or the foreign material on the roll surface is blocked, resulting in the glue roller can not be smashed, only a small amount of adhesive can be transferred, and It is easy to be wiped off. When the glue is applied, there will be insufficient glue on the peak, and intermittent gluing will occur. In this way, the surface of the corrugated cardboard will show signs of layering of the paper and the core paper, and the compressive strength, side pressure strength and adhesive strength of the carton will be reduced.

When the gap between the upper and lower corrugating rolls is too wide, the upper roll cannot contact the lower corrugated roll and there is not enough adhesive on the corrugation peak.

Adhesive lateral ejection phenomenon

When the viscosity of the adhesive is too high or too low, or the content of borax in the adhesive is too high, lateral spraying of the adhesive tends to occur during high-speed operation of the production line. This causes warpage of the cardboard or softness of the cardboard, adhesion of the carton. Strength, side pressure strength and compressive strength will be reduced accordingly.

Guide paw marks or vacuum marks

Traces of guide jaws or vacuum marks appear on the sizing part. The cartons made of such corrugated cardboard often break during use, and the side pressure strength of the corrugated cardboard and the compressive strength of the carton are greatly reduced. The corrugated cardboard produced by a single-faced machine with guide jaws often shows the presence of lead marks on the gluing section, ie, a clear, adhesive-free mark, which is usually due to bending, wear, or misalignment of the guide jaws. When the pressure is high, the binder accumulates on the baffle, and the hardened cornstarch rubs off the adhesive on the roller and forms a blank trace of the leader. In addition, the corrugated paper has a high moisture content, and the occurrence of the quality problem may occur due to abrasion of the corrugation roller or the occurrence of a wide range of adhesives on the rubber roller to be wiped off by the foreign matter. The single-faced machine without guide jaws often shows vacuum marks on the sizing section, mainly due to too much vacuum in the corrugating roller; too much vacuum will over-bond the corrugated base paper to the corrugating roller, causing the core paper to sag, gluing. The roller cannot apply adhesive to the cratered core paper.

Severely blurred intermittent sizing

This phenomenon occurs before the top roller, the main reason is due to the distance between the guide jaw baffle and the corrugated roller is too large, the guide jaw baffle is damaged or worn, the moisture content of the corrugated paper is high, the pressure on the pressure roller is not uniform, corrugated There is dirt on the roller, the brake on the core paper paper is slack, the pressure on the corrugating roller is uneven or the pressure is too low, there is no vacuum on the corrugating roller or there is no vacuum at the moment.

Irregular sizing shapes

The irregular sizing shape is mainly caused by the unevenness of the corrugation caused by the inaccurate position of the guide jaws and the core paper passing between the various rollers. The quality of the core paper, dirt on the corrugating roller, rough wear on the surface, wear of the guide jaws, Damage, bending, foreign matter on the guide jaws, lack of guide jaw vacuum pressure or vacuum hole plugging, improper pressure on the pressure roller, too much or uneven brake tension on the core paper, etc.

Insufficient or no adhesive on adhesive

Adhesive viscosity is too low, jamming of the top rollers, and the gap between the squeegee roller and the top roller are too small, which can result in insufficient sizing. The gap between the top roller and the corrugating roller is too large, the steam condensate drips on the top roller, the adhesive liquid level in the glue amount is too low, the contact between the bottom corrugating roller and the pressure roller is bad, and the middle of the corrugating roller is high and Misalignment can lead to no adhesion.

Adhesive oversizing

Excessive adhesive sizing is usually due to excessive gap between the squeegee and squeegee, or excessive viscosity of the adhesive. This not only results in adhesive waste, but also causes problems with the laundry board or warpage of the board. The emergence of serious, there will be significant wrinkles.

Effect of corrugating roller on sizing

Corrugated rollers have depressions, dirt on the surface, damaged or worn corrugating roller, uneven pressure of corrugating roller clamps, corrugating roller corrugation non-parallel can cause corrugation problems, directly affect the bad sizing.

Poor sizing at the slit edge

Corrugated cardboard longitudinally edged paper and corrugating medium are not bonded, and the looseness of the paper occurs. The main reason is that the slitting tool is not sharp, the slitting machine is running at a high speed, the slitting knife overlaps too much, and the slitting edge has a guide. Claw or vacuum marks, non-uniform moisture content at the edge of the tissue, different paper webs cause uneven wear of the corrugating roll, and adhesive caking on the pressure roll or lower corrugating roll.

Author / Ji Yutian Source: China Packaging News