Post-press Finishing Technologies for Special Surface Effects of Printing
Gold & silver surface finishing for printed maters (post-press I)
1) Hot foil stamping—products are adorned with an outstanding appearance of luxury and gorgeousness with distinctive metallic luster and strong visual effects. Holographic foil stamping has excellent anti-counterfeit and decorative effects, while hot stamping foil transfer can be achieved by thermal pressure.
2) Cold foil stamping technology—places on the surface that are needed to be stamped shall be printed with PV adhesive. Stamping foil is made of a special electric aluminum with heatless melting adhesive. When impress roller has no heat, stamping foil transfer can be accomplished by the performance of tack force of the adhesive and pressure between rollers.
3) Gold print—quick, but the luster effect is not ideal. It is achieved by offset printing
4) Pseudo metal etching—screen frosting—good luster effect, low speed, high cost.
5) Bronzing technology is to smear special metallic powder on designated points, so as to achieve shining metallic effects—using PS and offset printing press to print a thin layer of base glue. The coating roller of bronzing machine can absorb gold powders and spray them evenly to the paper. 4 special polishers rub through powders on paper to polish them and to enable powders to be firmly pasted with the base glue, and then use high-vacuum multi-path absorbing system to clear surplus powder.
Stereo-effect surface finishing of printed maters (post-press II)
1. Embossing—use relief and intaglio plates to press relief effect without ink, which can achieve beautiful, lively and strong three-dimensional effects.
2. Dew drop—apply clean plastic drop process to obtain crystal effect, with good three-dimensional performance and water & damp resilience, long durability, and anti-UV-light function. Small scale of production could be done manually, while large-scale industrial production may apply special dew drop machine—semi-automatic or full-automatic. The technology is simple.
3. Crushing—apply crush roller and blanket cylinder on paper or artificial leather material. Figures can be gained by electrograph or corrosion—the technology is the simplest.
Special surface luster finishing of printed maters (post-press III)
1. Refraction finishing—apply fine-groove embossing technology on hot stamping foils or aluminized paper materials to produce fine depressed and relief lines ranging in different directions. Different refraction to light produced by theses lines would make printed maters shining and figures life-like. It can also be used for anti-fake. ¤1) traditional refraction technology is to arrange straight lines and curves regularly into geometric figures. Lines are the basic element influencing effect. One product generally adopts 4-6 angles, more angles are not recommended. ∮2) New refraction technology has integrated computer technology with traditional plate-making and stamping technology, which can render various refraction effects according to curve changes of figures.
2. Crystalline shining luster finishing
Crystalline luster finishing means that the surface or transparent ink layer of printed maters have crystalline substances.
Two technologies 1) spraying bonding method 2) ink printing method—adopting screen technology.
3. Laser rainbow luster finishing
Laser packing film finishing usually adopts computer matrix photoengraving technology, 3D true-color holographic technology and multiplex and dynamic imaging techniques. Trough film pressing, rainbow-like dynamic 3D holographic figure is transferred onto base material of PET.BOPP.PVC or coated layer, and achieve laser effects on the surface through compounding, hot stamping, transferring etc.
4. Pearl luster finishing