Transparent Plastic UV Printing Common Problems and Solutions

Compared with traditional ink printing, UV printing does have a great advantage, but printing UV ink on the surface of plastic substrates is still a challenging task. The biggest problem with UV ink printing on plastic substrates is how to make the UV ink firmly adhere to the surface of the plastic substrate, that is, the problem of adhesion. In the curing of UV inks, the internal components are cross-linked and aggregated, and the volume changes instantaneously to generate greater internal stress, which affects the adhesion of the ink to the substrate. Therefore, the plastic sheet must be surface-treated before printing in order to increase the surface tension of the plastic sheet and increase the adhesion of the ink. Currently, the corona treatment is used more often.

Although the problem can be solved by treating or modifying the surface of the substrate, the fundamental solution is to seek and develop UV inks with good adsorptivity, low shrinkage stress, and low cost. Registration is also one of the common problems in UV plastic printing. Plastic sheets are harder and less flexible than paper, causing problems with overprinting during the printing process. In this regard, when the plastic sheet is positioned, it is only possible to use a side-indicating rule, and it is not possible to use a side-pull gauge so as to avoid the lack of strength of the pulling gauge to cause overprinting. In addition, the heat generated by the infrared lamps during the start-up of the UV lamp is also sufficient to deform the plastic sheet, resulting in inaccurate overprinting and inaccurate print sizes.

For this problem, Manroland uses cold-UV technology from Eltosch on its offset printing equipment. This technology uses a replaceable reflector to reflect the generated infrared light when the UV lamp is started, and uses a cooling source to cool it during operation. The emitted UV light is used to cure the UV ink. New Advances in UV Printing Technology The latest UV three-dimensional raster ink UV-1278N has been introduced in China. It is mainly used for printing three-dimensional grating diaphragms. Different from the traditional hot press molding process, the new process adopts the screen printing method. The ink is printed on the packaging machine 'target=_blank> transparent film, and the column grating pattern is formed directly; the three-dimensional grating ink can also be directly printed on the printed matter. The formation of three-dimensional patterns, but also selectively print patterns to make the three-dimensional, the printed pattern of three-dimensional effect is obvious, and hot-pressed grating board comparable, for the three-dimensional printing has opened up a new method. Using this ink to print the grating diaphragm can greatly reduce the production cost and increase the production efficiency. The printing substrate may be a transparent plastic film, such as PVC, PC, PET, or paper, metal, glass, ceramic, etc. The screen mesh number is preferably 200-350 mesh. The ink is colorless and transparent, the UV light is rapidly cured, the cured film is not yellowed, the adhesion fastness is good, and the toughness is good.

Subaru CD74 offset printing press for UV printing For printing companies that use a wide variety of substrates, such as commercial printing companies, packaging and label printing companies, and for printing companies that use double-sided printing to produce greeting cards or book covers, the Speedmaster CD74 The perfection machine is an ideal model. In addition to the standard models for single-side printing and double-sided printing, the Speedmaster CD74 also has a wide range of printing units and coating units. It can be a machine with a dual coating machine, or it can integrate functions such as UV polishing. The models that come together can also be a machine that coats paper before finishing printing or after printing, and is completely configured on demand.

UV inks and coating oils are rapidly gaining popularity in the printing industry. They can be better adhered to non-absorbent materials, not only not easy to fall off, but also have a high gloss. The Speedmaster CD74UV offset press follows this trend. At the same time, it is the world's first offset press awarded the title of "Best UV Printing" by Germany's printing and paper insurance and protection agencies. All elements involved in UV printing are integrated into the CD74. It can be said that the CD74 has opened up a precedent for production technology, equipment operation and investment protection.