Sticky Bubble Causes
Self-adhesive label bubble is the end user in the labeling process often encounter the phenomenon, the main causes of the reasons are the following: glue coating uneven: the surface of the adhesive material from the surface material, adhesive and the end Paper from the three parts of the composition, from the manufacturing process by the surface coating, surface material, coating the bottom layer, adhesive, from the type coating (silicon layer), the end of paper, back coat or back seven parts. Uneven coating is mainly film suppliers in the coating when the glue occurred in the process of trapping.
1, the labeling machine pressure wheel design is poor, the pressure is not enough: General automatic labeling machine main components include reel, buffer wheel, guide roller, drive roller, reel, stripping plate and pressure roller (labeling roller). Automatic labeling process is the labeling machine on the sensor issued by the labeling object ready to mark the signal, the labeling machine drive wheel rotation. As the reel label on the device for the tension state, when the end of paper close to the stripping plate to change the direction of operation, the label because of their own material has a certain degree of firmness, the front is forced out of the end of paper, ready to label, The object is located in the lower part of the label, under the action of the pressure wheel will be separated from the end of the label evenly on the object. After labeling, the sensor below the roll label sends a stop signal, the drive wheel is stationary, and a labeling cycle ends. If the pressure roller of the labeling machine is defective in the pressure setting or structural design, it will also cause the foaming in the process of labeling the label. Please re-adjust the pressure of the roller or coordinate the manufacturer of the labeling machine;
2, electrostatic effect: for the film-like materials, static electricity will lead to the label on the bubble. There are two main reasons for the emergence of static electricity: First, with the climate and the environment, cold weather and air drying is the main reason for static electricity. In the northern region of China in the winter use of self-adhesive labels, often in the labeling process to produce static electricity. In addition, the material, as well as the material and the labeling machine related parts of the friction and contact will also produce static electricity. In the automatic labeling machine on the labeling, the static electricity will cause bubbles, affecting the labeling effect. If the static electricity is very serious, will produce spark discharge, which is a trigger factor in the fire, while the electric shock will also cause the operator to misuse the phenomenon. Suggestions for Electrostatic Solutions:
1) reasonable control of the operating space temperature and humidity, the ideal temperature of 20-22 ℃, relative humidity of 50%;
2) Use copper wire discharge. Copper wire is located above the material, with the labeling machine insulation after grounding, self-adhesive label on the charge through the metal wire to the earth discharge to reduce the self-adhesive label on the purpose of static electricity. The following figure shows the installation of copper wire in the bottle and labeling parts. Also in the outdoor installation of the ground is also a method.
Also in the transparent bottle paste transparent film label when the label paste surface often have bubbles generated. Transparent bottles are mainly hard glass or can be deformed plastic deformation, such products after the bubble can cause the following reasons:
(1) the surface of the bottle is not clean enough, flat: the bottle should be washed and dried in advance, according to the shape of the surface of the bottle, such as the regular surface or spherical body, when the label by the conveyor belt clamp fixed, especially flat plastic bottles ;
(2) not selected according to the bottle material suitable properties of the film material: soft bottle should choose such as PE, PVC, PP and PP without PP and PP synthetic materials; rigid bottle should choose PET, BOPP , PS fabric;
(3) the speed of the labeling machine, labeling method is not appropriate: labeling the bottle when the speed should be slightly faster than the label of the speed, so as to avoid the bubble generation. Before labeling, completely eliminate static electricity, make the label firm out of the standard, from the end of paper. Labeling machine should not use the brush, sponge roller, vacuum adsorption way labeling, should be installed with a certain strength of the rubber scraper with the label contact, and the scraper to maintain a certain angle and intensity. Soft bottle labeling to adjust the labeling speed, scraper strength, angle, the relationship between the distance;
(4) the end of paper selection is not appropriate: should choose a good smooth paper at the end of paper, such as PET material at the end of paper, so that the adhesive in its surface smoothness, labeling after wetting,
(5) Another bottle of impurities, plasticizers, glue from the chemical reaction, the printing surface solvent is activated and other factors will lead to the production process of labeling the bubble.