Thirteen.Skinning

There are two common skin phenomena: one is in the packaging bucket of glue surface skin, the other is in the glue tray surface skin.

■ The surface layer of glue in the packing bucket produces crusts

1)If the temperature of glue filtration packaging is too high, it is easy to form crust in the barrel when the temperature drops, which is common in high temperature in summer. Because the glue is cooled slowly, it is easy to occur if the goods are urgent and cannot be packed at the appropriate temperature.

2)The packaged glue will also produce crust if it is exposed to sunlight.

■ Produce crusts in the surface layer of glue on the glue tray

1)The glue tray has a dead Angle (such as the right-angle shape of the glue tray) during the glue rarely flow, the surface of the glue moisture will slowly volatilize, forming a film and crust.

2)The baking road has hot air blowing directly to the glue tray

3)The surface of more glue foam foam is very thin, easy to film.

Foam is also divided into bucket foam and glue foam two cases

■ In-barrel foam

This situation is mainly due to the violent shaking in the process of handling foam, in addition to the infiltration of more water stirring will also produce more foam.

■ Slow out of the glue tray when there are more serious foam

1)Failure of the glue defoamer or insufficient measurement

2)the speed of the upper cots is too high and the mixing of the glue is too strong

3)The level of the rubber layer and the upper cots are in an inappropriate position, and a large amount of gas is brought into the upper cots when they rotate.

4)The glue viscosity is too high, and the glue foam wall is thick and not easy to burst.

■ More glue foam, the consequences are as follows:

1)Influence the speed of composite (laminating speed)

2)When the amount of glue is large, part of the foam is coated with the film, and the foam enters the baking channel before leveling after bursting, or enters the baking channel before bursting, and then dries and breaks to form empty points. After composite, the phenomenon like fisheye and pinhole is generated.

3)It is easy to produce glue crusts in the glue tray.

In the way of dealing with more foam, the common way is to add defoaming agent, but we must pay attention to the type, quantity and stirring method of adding defoaming agent. If the operation is improper, it is easy to cause the phenomenon of fisheye and peeling force decline.

Fifteen. paperhanging

Simply speaking, pasting is the paper and paper bonded together, so that it has better strength and stiffness, such as cardboard boxes, corrugated boxes. The same kind of paper is called to mount, and there are all kinds of common hanging tags.

At present, most pasting adhesives used for pasting have low solid content and contain more moisture. Because of the structure of the paper, there are a lot of capillary tubes in it.

After pasting, due to capillary action, moisture is quickly absorbed by the paper and rises to the glue layer, affecting the glue layer and surface layer.In a short time, it is difficult to volatilize water completely, especially in winter, and the adhesive layer contact for a long time. Due to the hydrophilic characteristics of water-based adhesive, the existence of water will certainly destroy its structure, resulting in a decline in performance.Its main performance is the decline of adhesion, peeling film and adhesive layer is separated, in addition, if the water is not completely volatile that the next process such as die cutting, indentation and so on, easy to cause foaming phenomenon.

This requires that the moisture content of the paper itself should be low. After the composite pasting, the products should be placed for a long time and in a dry and warm environment as far as possible, so as to volatilize the water and reduce the influence of water on the adhesive layer.

Sixteen. drying speed

The drying speed of glue directly affects the speed and efficiency of laminating, and is also an important aspect for customers. The main factors that affect the drying speed are: the temperature of the drying channel and the ventilation volume, the solid content of the glue, the solvent structure of the glue.

■ Temperature and ventilation of the drying channel

Seventeen.odor