In the process of gluing, everyone encountered various problems. At the same time, a variety of solutions also appeared. The following is a detailed analysis of some problems and the causes:
1. The pasting fastness is not high, the carton is degummed
Degumming refers to peeling off due to insufficient adhesive fastness. The main reasons are summarized as follows:
① The viscosity of the adhesive is not enough or the amount of glue is not enough;
②Adhesive and carton material are not suitable;
③ If the sticky part of the carton is subjected to surface treatments such as coating and glazing, it is difficult for the adhesive to penetrate the paper through the surface layer.
④ After folding and coating, the pressure is not enough, and the pressing time is not long enough, which is not conducive to strong adhesion.
The solution to the problem of not sticking firmly:
(1) For the above problem of unsatisfactory gluing of boxes caused by adhesives, an adhesive should be selected that is compatible with the carton material to be pasted. The choice and use of adhesives are also very particular.
First of all, in the selection of adhesives, it is also necessary to analyze the specific circumstances. According to the carton of different materials and conditions, the selection of adhesives can refer to the following:
1) For packaging color boxes without surface treatment, use paper-to-paper adhesives when sticking boxes;
2) For the box with the surface covered with film, the adhesive used for bonding the film to the paper is used;
3) If the surface is over-oiled, the adhesive used for bonding oil to paper is used;
4) Adhesives with low temperature resistance should be selected for products sent to cold climate regions;
5) High temperature resistant adhesives should be used for products sent to tropical regions;
6) The automatic folder gluer has high speed and short pressing time, so the adhesive with fast drying time should be selected;
7) The speed of manual gluing is slow, and the adhesive with slow drying time can be selected for long pressing time;
8) When gluing a linear box, the pressing and curing time can be shorter;
9) When gluing the bottom box automatically, the pressing and curing time should be correspondingly longer;
10) Use adhesives with a slower drying time in summer;
11) In winter, choose an adhesive with a faster drying time.
Secondly, the adhesion of the adhesive is stronger. Because the instantaneous pressure of the molding section is not very large, and the high-pressure operation process of producing 30-40 cartons per minute, the pressing residence time is not long. The self-adhesive strong adhesive, even if gently pressed, can be firmly attached to the carton.
Finally, the ambient temperature of the workshop will have a certain impact on the adhesive. If the temperature in the workshop is too low, the adhesive will solidify immediately, affecting the adhesion firmness, even if the amount of glue is too large, it will not work. Of course, the smaller the amount of glue, the more sensitive it is to the room temperature, so in winter, the temperature of the workshop should be kept above 20 ° C as much as possible. Conditioners can be equipped with air conditioners for adjustment. In the operation workshop, a large and easy-to-see thermometer should be installed to check and control the working environment at any time. For pasted products, they should be dried at room temperature before leaving the factory. In winter, do not rush to deliver them before drying.
(2) For the carton with lamination and glazing treatment, there are the following four methods to solve the problem of unsound gluing:
①Place a needle knife at the adhesive mouth during die cutting to pierce the surface of the adhesive mouth, which is conducive to the penetration of the adhesive;
②Use the edging device attached to the automatic folder gluer to grind the surface of the adhesive mouth to facilitate the penetration of the adhesive;
③ Spray hot-melt adhesive to the adhesive part, use high temperature to melt the material on the surface of the adhesive mouth, and improve the firmness of the paste box;
④When designing the prepress box, you can leave a glued area on the edge of the box to be coated and polished in advance.
(3) For the phenomenon that the glue box is not strong due to insufficient pressure, the pressure of the crimping part of the gluer can be increased to prolong the crimping time or replace the adhesive with strong adhesion.
2. Deformed paper box
There are three main reasons for the deformation of the carton:
①Some die-cutting plates are made by hand, often because the precision is not high, the carton is inconsistent, and the paste box is deformed;
② The concentration of adhesive is low, and the water content is large, which causes the paperboard to absorb moisture and deform, and the carton is not flat after molding:
③The folder gluer itself is not adjusted well.
This problem can be solved by ensuring the stability of the die cutting quality, selecting the appropriate adhesive, and adjusting the folder gluer.
3. The sticky mouth of the carton is skewed
There are three main reasons for the skew of the sticky mouth of the carton:
① The indentation groove of the indentation steel wire is too wide, and the indentation pressure is not enough, so that the indentation line is not full, and the indentation line cannot be accurately pressed when folding;
② Improper adjustment of the folding transmission, the conveying speed of the left and right sides of the box disc is inconsistent, causing the sticky mouth to skew;
③ The folding rod is not installed properly.
Solution: reduce the width of the indentation groove of the indentation steel wire and increase the indentation pressure; adjust the folding transmission to make the conveying speed of the left and right sides of the carton consistent, and reinstall the folding rod
4. Incorrect alignment of sticky mouth
The misalignment of sticky mouth means that the sticky mouth is misaligned, and the misaligned carton cannot be well formed. This phenomenon is usually caused by the inaccurate adjustment of the machine. Further, it is mainly because the operator has insufficient knowledge of the box type and the folder gluer, which affects its operation level.
Therefore, strengthening the training of operators, improving their operating skills and their understanding of complex boxes will effectively avoid the problem of misalignment of sticky mouths.
5. Sticky mouth overflow glue
Spilled glue refers to excess adhesive flowing out of the sticky opening. This phenomenon is mainly caused by the misplacement of the paste box and the excessive amount of adhesive. By grinding the sticky mouth and reducing the amount of glue, the occurrence of glue overflow can be effectively reduced.
