With the expansion of the carton market, there are more and more cartons made without a carton ordering machine, because the ordered carton will damage the items inside. Therefore, the glue box machine is an indispensable piece of equipment in the carton factory, and then there are often some problems when gluing boxes, so let’s take a look at how to solve them.
1. The bonding fastness is not high, and 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 viscosity of the adhesive is not enough or the amount of glue applied is insufficient.
(2) The adhesive and the carton material do not match.
(3) The sticky mouth part of the carton has been surface processed by lamination and glazing. It is difficult for the adhesive to penetrate the surface layer and penetrate into the paper, and the carton is difficult to stick.
(4) The pressure after folding and gluing is insufficient, and the pressing time is not long enough, which is not conducive to the strong paste.
For the above-mentioned problems of poor pasting caused by the adhesive, the adhesive suitable for the carton material should be selected, and the selection and use of the adhesive are also very particular.
First of all, it cannot be mistakenly believed that the higher the viscosity of the adhesive, the better the gluing effect. The higher the viscosity, the higher the adhesive strength and the higher the wrinkling rate. When the glue roller of the automatic folder gluer runs at a high speed of 112 revolutions per minute, the recommended viscosity of the adhesive is 500-1000cps.
Secondly, the adhesive force of the adhesive is stronger. Because the instantaneous pressure of the forming part of the automatic folder gluer is not very large, and during the high-speed operation of producing 30-40 cartons per minute, the pressure time is not long. Applying pressure can also bond the carton firmly.
In addition, the ambient temperature of the gluer workshop will also have a certain impact on the adhesive. If the temperature of the pasting workshop is too low, the adhesive will solidify immediately, affecting the bonding fastness, even if the amount of glue applied is too large, it will not work. Of course, the less glue is applied, the more sensitive it is to room temperature, so in winter, the temperature of the gluer workshop should be kept above 20 °C, and air conditioners can be installed if conditions permit.
In the folder-gluing workshop, a large and easily visible thermometer is also installed to check and control the working environment at any time. For the pasted products, they should be dried at room temperature before leaving the factory. In winter, do not rush to deliver the products before they are dry.
For the carton that has been covered and varnished, there are 4 ways to solve the problem of the glued box:
First, place a needle and thread knife at the sticky mouth during die-cutting to puncture the surface of the sticky mouth to facilitate the penetration of the adhesive.
Second, use the edging device attached to the automatic folder gluer to grind the surface of the sticky mouth to facilitate the penetration of the adhesive.
Third, the hot melt adhesive is sprayed to the sticking mouth part, and the material on the sticking mouth surface is melted at high temperature to improve the fastness of the glue box.
Fourth, when designing the box shape before printing, you can leave a gluing part on the edge of the box to be covered and varnished in advance.
For the phenomenon that the folder is not strong due to insufficient pressure, you can increase the pressure of the pressing part of the folder gluer, prolong the pressing time, or replace the adhesive with strong adhesion.
2. Deformation of the carton
There are three main reasons for the deformation of the carton:
(1) Some die-cutting plates are made by hand, and the size of the carton is often inconsistent due to low precision, and the carton is deformed when the box is pasted.
(2) The concentration of the adhesive is low and the water content is large, which causes the cardboard to absorb moisture and deform, and the carton is not flat after forming.
(3) The folder gluer itself is not adjusted well.
Post time: Aug-23-2022