Cardboard surface “washboard phenomenon” solution, cardboard uneven appearance

Cardboard along the corrugated peak on both sides of the uneven shape, but also accompanied by bubbling phenomenon, this is the “washboard phenomenon.”This phenomenon occurs mostly in the base paper with low quantity.Washboard phenomenon board uneven, will seriously affect the effect of the printing process.

1. Causes of washboard phenomenon:

It is the surface of the cardboard is not flat taut, but with the outline of the flute and undulate, shaped like washboard.Generally because of paper and single side corrugated board laminating process, adhesive coating is not good, extruded to both sides of the flute peak adhesive surplus too much, in the bonding drying process, resulting in the surface paper on both sides of flute peak compact and form.

At the start of the adhesive veneer to check the amount of adhesive coating at any time, if there is a very small line on the face paper, glue for the best state, there will be no washboard phenomenon;If appear thick double line, explain besmear glue quantity is too big, can appear washboard phenomenon.Quantitative low tissue paper is more serious.

2. The washboard phenomenon can be controlled by the following methods:

(1) The most simple and reliable method is to replace the surface paper with high quantity, which can obviously eliminate the washboard phenomenon, but this will increase the cost, making the carton cost significantly higher.If the user can accept it, use it; if not, consider using other methods.

(2) To improve the viscosity of corn starch adhesive, in order to reduce the amount of glue on the back of the flute peak, can significantly reduce the washboard phenomenon, but the cost changes little.

(3) the use of quantitative low and dry surface paper, if the glue water intake is too much, also easy to appear washboard phenomenon, can use wetting method (turning over water method, humidification, etc.) to make the paper adsorption of a certain amount of water, then use.

(4) Adjust and control the parallelism and clearance between cots and pressure rollers.Clearance to moderate, generally with corrugated board just through.When using surface paper with low gram weight, it is necessary to pay attention to the clearance between the cots and the pressure rollers to reduce the amount of glue.Strictly control the pressure between the pressure rollers can reduce the washboard phenomenon.

(5) Make full use of the paper horizontal and vertical texture characteristics.The fiber direction of surface paper should be parallel to the corrugated direction, the longitudinal thread of surface paper and corrugated board direction is “10″ word mounted, can eliminate the rub board phenomenon.But sometimes because the web paper width does not conform to the carton size and waste paper, increase the cost.

(6) The radius of the corrugate tip of the worn corrugate roll increases, and the protruding corrugate will absorb more glue, leading to the “washboard” phenomenon;Corrugate rolls should be replaced.

Post time: Aug-21-2020