Innovative Process of Packaging Screen Printing Decoration (II)

4. Storage ink printing screen points

(1) The viscosity of the prepared ink is about 300-500Pa·s. In the printing, the viscosity of the ink should be adjusted with thinner according to the material and printing speed of the substrate.

(2) When printing patterns or logos with light-storing inks, polyester screens of 200 mesh/inch or less should be generally selected, and screen printing with 80-120 mesh/inch can achieve better light-emitting effects.

(3) Print the light-storing ink on the white substrate as much as possible to improve the luminous effect and persistence time of the printed graphic.

(4) When the thickness of the printing ink coating is controlled at 130-150um, the light emitting effect is the best. Therefore, it can be achieved by printing it twice with 80 mesh/inch screen printing (if thick printing is used once). thickness.

(5) When the substrate is a transparent object, the white ink should be printed before printing the light-storing ink, so that the light-emitting effect can be improved.

5. Applications

(1) Ink Formula (Quality Ratio) PVC Ink (SS-777): Light Storage Material (PLO-7D) = 50:50

(2) Printing method

1 Plated with 100 mesh/inch screen.

2 Copper plates are not printed twice on offset paper.

(3) Afterglow brightness value of the printing ink layer The afterglow brightness value of the printing ink layer.

Crystal glue printing

The use of crystal glue (the main component is a polymer transparent resin) printed on the gold, silver card paper with a three-dimensional effect of crystal glue droplets called crystal glue printing. The viscosity of the crystal glue is very high, the printing ink layer is very thick, and the printing pressure required is large.

There are two types of crystal glue used in printing: thermosetting and UV-curing. If thermosetting crystal glue is used, the screen should be properly heated during printing. Immediately after the printing, dry it on the infrared heat drying device. The new UV-curable crystal glue film on the market is now faster, with better wear resistance and lightness. In addition, in order to enhance the three-dimensional impression of the crystal glue, the crystal glue is dried to a crystal-like three-dimensional effect before being leveled.

Crystalline gloss printing

Crystalline luster printing means that the surface of the produced print is transparent, and the crystalline layer of glittering material is contained in the ink layer. When the incident angle of sunlight or light changes, it can produce a brilliant and colorful sparkling special decorative effect. Glitter material is mostly made of particles that are colored after being dyed by a polyester spray layer or particles that are crushed with special flash fibers.

In the case of crystal gloss printing using a screen printing method, crystalline glitter particles are incorporated into a binder to produce a screen printing ink, which is directly printed on a printed article to be decorated. It is worth noting that because the flash crystals are contained by the ink layer and the ink transportability factor is taken into consideration, the flash crystals with too coarse particles cannot be selected.

Mirror ink printing

Mirror ink is a metallic screen printing ink. It is made of plastic resin mixed with special metal powder. It belongs to solvent evaporation type ink. It is printed on the back of transparent plastic film and can get metallic color mirror printing effect, just like hot stamping. effect.

Mirror ink printing points are as follows:

(1) Due to the low viscosity of mirror ink, screens with a higher mesh number should be selected, polyester screens of 270-300 mesh/inch are usually used, the tension of the stretching net should be slightly lower, and the solvent resistance type photoresist should be coated. .

(2) The network distance should be smaller.

(3) Select a relatively high hardness squeegee, usually its hardness is HS80-85.

(4) Since the relative density of metal toner, plastic resin, additives and additives is different, the components in the ink will be delaminated during storage, so be sure to mix thoroughly before use.

(5) To prevent the occurrence of plugging, care should be taken not to print in places where air flows.

(6) In order to prevent the decrease of specular gloss caused by the absorption of moisture by ink, moisture should be avoided during printing and storage, and drying should be performed immediately after printing in a low-temperature environment.