Barcode Printing Technology Solutions for Plastic Packaging (3)

(b) Plate Making

In addition to the basic requirements, the following two points should also be taken into account when making bar code printing:

1. The original film with extremely high precision is selected and should be compatible with the gravure printing process (the correction of the strip width of the film is compatible with the gravure printing process).

2. The rest of the cable is relatively deep and the cable is relatively dense. This is because the lightness of the network cable is light, and it cannot guarantee sufficient hiding power. Part of the light is transmitted and the reflectance is reduced. If the network cable is too thin, the network cable is easily deformed, and the edges of the printed bar are not neat, which may easily lead to difficulties in reading and writing.

(III) Printing

Bar code printing is relatively higher than ordinary plastic packaging printing requirements. The following issues should be noted during the printing process:

1. Barcodes and other patterns are printed at the same time. Sometimes, ink bleed and squeegee position adjustment are used to adjust the hue. In this case, priority should be given to the reading of barcodes. If you can't balance it, you must remake the plate.

2. The firmness and wear resistance of the ink film of the plastic film should be given enough attention, especially the surface-printed packaging. If the firmness and abrasion resistance of the printing ink are not good, the ink may be detached and the barcode may be damaged during the circulation of the product. As a result, it is not read.

Polyethylene, polypropylene, etc. are non-polar materials, and special attention should be paid.

3. The ink should maintain a certain viscosity, the viscosity should not be too small. If the viscosity is small, the hiding power of the ink is low and the reflectance is low. In particular, the contents are dark-colored products such as watermelon seeds, pickles, soy sauce, and soy sauce. If the empty hiding power is low, the content color will darken the empty color, making the empty color closer to the stripe color, resulting in lower contrast. The viscosity of white ink (or other background ink) should be increased to ensure sufficient hiding power.

4. Select high-quality ink to avoid the appearance of ink and other phenomena. The ink should have a high transfer rate to ensure the density of the ink. In addition, the ink should also have sufficient high temperature stability to prevent the barcode from changing color during compounding and post-processing.

5. Strictly control the printing tension, drying temperature and other process conditions, try to avoid shrinkage changes in size.

(d) Compound

There are two points to note in the compounding process:

1. Stretching. In the compounding process, if the temperature of the drying oven is too high or the tension is too high, film stretching will occur, resulting in deformation of the barcode. Therefore, the drying oven temperature and various tensions must be strictly controlled to avoid stretching.

2. If adhesives are added during the compounding process, the film must be protected from creases at the place where the AC agent is applied. Although wrinkles can be removed in front of the composite head, due to the solvent containing ethyl acetate, wrinkles under the pressure of the coating roller and the pressure roller may cause the ink in the bar code portion to be dissolved and cause breakage. Affect the reading effect.

(v) Packaging methods

Inflatable packaging has the same appearance as ordinary packaging, so it has no other influence on barcode printing and reading, and vacuum packaging and shrink packaging should be given some attention.

1. Vacuum packaging, because the contents of the package are mostly irregular shape, vacuum packaging bag tightly attached to the surface of the contents, an irregular three-dimensional shape, the surface is not smooth, so that the bar code deformation can not be read. Therefore, the vacuum packaging inner bag should not be directly printed bar code, an additional bag printing bar code and other graphics.

2. Heat-shrinking packaging: For the heat-shrinkable packaging film used in beverages and fruit and milk bottles, the position of the barcode after shrinking the film must be taken into account when printing the barcode; second, the longitudinal and transverse shrinkage factors should be calculated, and the barcode should be used when making the barcode. The size is adjusted in advance; thirdly, a high shrinkage film with uniform shrinkage is selected. At the same time, ensure that the strips are in the same plane after heat shrinking.