How To Purchase a UV Varnish Spot Coating Machine

The UV varnish coating machine is divided into offline Overall(full) coating machine and spot coating machine and online printing coating machine. UV varnishing machine is generally a stand-alone operation, the processing speed is slow, the quality stability is slightly poor, and often need to be online treatment.

  At present, large offset printing manufacturers in China and abroad use printing online spot coating, in order to improve the speed and quality of varnishing, it can be said that the development trend of printing online coating machinery.

 The printing and coating coupling is coated with a printing unit, and its basic form is to use the last printing unit of a sheet-fed offset press for varnishing. There are generally two forms of UV varnish coating by using the printing unit: one is to use the wetting device for glazing coating, and the other is to use the ink delivery device for glazing coating.

  Using the existing printing unit on the sheet-fed lithography press for varnish coating, the production footprint is small, while saving additional equipment investment, is currently the simplest and most economical option. However, its varnish coating effect is not very good, and it is only suitable for coating simple and not demanding products.

Independent glazing unit on the printing machine for on-line glazing, high production efficiency, stable glazing quality. It can use resin plate can also use traditional rubber blanket for glazing, and the printing device, all are monitored and controlled by the printing press control center, such as the transverse and longitudinal registration adjustment of the photosensitive resin plate, diagonal registration adjustment.

  The on-line coating device can be used for thick and uniform glazing of the entire surface of the substrate or local graphics. The glazing can be used for both rubber cloth and flexible plate for fine local glazing. It can be waterbase varnishing and UV varnishing.

  When choosing an online coating system, the advantages of roller glazing are obvious, but the investment is relatively large. Roller coating can accurately control the thickness of the varnish coating, does not depend on the printing speed, and is rarely affected by fluctuations in the glazing oil viscosity.

  More representative is the use of closed ink knife system coating device, which is composed of ceramic mesh roller, closed ink scraper and soft resin coating plate roller. This online glazing speed is fast, high efficiency, mesh roller can be quickly replaced, the selection of different mesh rollers can be accurately completed according to the requirements of coating, not only to obtain full glazing coating, but also accurate spot coating.

   UV varnishing has become an important means of post-press processing, with the continuous maturity of glazing technology and glazing process orientation of non-polluting, consistent operation, glazing product diversification of the development direction is becoming increasingly clear, it will also achieve great results in the processing of export products packaging, varnishing technology will be the most promising development of a packaging printing surface processing technology.