Analysis of common problems in the paste box process

1, the bonding fastness is not high, the carton is degummed

Degumming refers to the cracking of the adhesive mouth due to insufficient bonding fastness. The main reasons are summarized as follows:

(1) The adhesive has insufficient viscosity or insufficient glue.

(2) The adhesive and the carton material do not match.

(3) The adhesive part of the carton is subjected to surface treatment such as laminating, glazing, etc., and it is difficult for the adhesive to penetrate the surface layer and penetrate the paper, and the carton is difficult to adhere.

(4) The pressure is insufficient after folding and applying the glue, and the pressing time is not long enough, which is not conducive to sticking and firming.

For the above problem of the paste box caused by the adhesive, the adhesive suitable for the carton material should be selected, and the selection and use of the adhesive is also very particular.

First of all, the higher the viscosity of the adhesive can not be mistaken, the better the paste box effect. The viscosity is high, the strength of the adhesive is also high, and the wrinkling rate is also increased. In the case where the rubber roller of the automatic folder gluer is operated at a high speed of 112 rpm, the recommended viscosity of the adhesive is 500 to 1000 cps.

Second, the adhesive has a strong bonding force. Because the instantaneous pressure of the molding machine of the automatic folder-gluer is not very large, and during the high-speed operation of producing 30-40 cartons per minute, the pressing time is not long, and the adhesive with strong adhesion is even light. Pressure can also be used to firmly bond the carton.

In addition, the ambient temperature of the paste box workshop will also have a certain impact on the adhesive. If the paste box temperature is too low, the adhesive will solidify immediately, affecting the adhesion fastness, even if the amount of glue is no longer effective. Of course, the less the amount of glue applied, the more sensitive it is to room temperature, so in the winter, the temperature of the paste box workshop should be kept above 20 °C, and the air conditioner can be adjusted if necessary. In the paste box workshop, a large-scale easy-to-see thermometer is also installed to check and control the working environment at any time. For paste products, they should be dried at room temperature before leaving the factory. In winter, avoid undue delivery.

For laminating and glazing cartons, there are four ways to solve the problem that the paste box is not strong:

First, a die cutter is placed at the adhesive mouth during die cutting to puncture the surface of the adhesive to facilitate penetration of the adhesive.

Secondly, the surface layer of the adhesive mouth is worn by the edging device attached to the automatic folder gluer to facilitate the penetration of the adhesive.

Thirdly, the hot melt adhesive is sprayed onto the adhesive portion, and the material on the surface of the adhesive is melted at a high temperature to improve the fastness of the paste.

Fourthly, when the box design is carried out before printing, the glued portion can be left in advance at the edge of the sheet to be coated and glazed.

For the case that the paste box is not tight due to insufficient pressure, the pressure of the press part of the folder gluer can be increased, the pressing time can be prolonged, or the adhesive with strong adhesive force can be replaced.

2, carton deformation

There are three main reasons for the deformation of the carton:

(1) Some die-cut versions are hand-made, often because of the inaccuracy of the carton size, and the carton is deformed when the box is glued.

(2) The concentration of the adhesive is low and the water content is large, which causes the cardboard to absorb moisture and the carton is not flat after molding.

(3) The folder gluer itself is not adjusted.

To solve this problem, as long as the quality of the die-cutting is stable, choose a suitable adhesive and adjust the folder-gluer.

3, the carton sticks skew

There are three main reasons for the skew of the carton stick:

(1) The groove of the indentation line is too wide and the pressure of the indentation is not enough, so that the pressed line is not full, and it cannot be accurately folded according to the indentation line when folded.

(2) The folding transmission is improperly adjusted, and the conveying speeds of the left and right sides of the cassette are inconsistent, causing the sticking of the stick.

(3) The folding lever is not properly installed.

Solution: Reduce the groove width of the indentation line and increase the indentation pressure; adjust the folding transmission so that the conveying speed of the left and right sides of the carton is the same; re-install the folding rod.

4, the adhesive mouth is not aligned

Misalignment of the adhesive mouth means that the adhesive mouth is misplaced, and the misaligned paper box cannot be formed well. This phenomenon is usually caused by the accuracy of the adjustment of the machine. Further, it is mainly because the operator's understanding of the box type and the folder-gluer machine has insufficient influence on the operation level. Therefore, strengthening the training of operators, improving their operational skills and their understanding of complex box types can effectively avoid the problem of misalignment of the adhesive mouth.

5, sticking glue

Overfilling means that excess adhesive flows out of the adhesive. This phenomenon is mainly caused by misalignment of the adhesive mouth and excessive use of the adhesive. By grinding the adhesive mouth and reducing the amount of glue, the occurrence of glue overflow can be effectively reduced.