Just a few years ago, during many speeches at printing symposiums, every speaker argued that oxygen inhibition in flexo plate exposure had a salutary effect on the quality of the elements reproduced on it. Sharpening the vertices of the points, minimal differences in the height of the elements on the printing plate, e.g. lower fine points relative to full appliques was supposed to cause correspondingly greater pressure in printing while printing the tiny raster points delicately. But that was already the case...
Today, the Development Departments of polymer board manufacturers are racing to find a way to produce a polymer that will be characterized by a so-called flat printing point / flat top /. The same speakers convince us that it is their plate that has this point flatter than others.
What is the truth? Of course, we can obtain a flat spot on a flexo plate with more or less success in various ways, for example, by an additional technological process, i.e. laminating the plate with a TIL / Thermal Imaging Layer / or exposing the plate in a suitable gas environment or by exposing the polymer during exposure to a strong and stable LED light. All of these techniques pass the test but are combined with additional processing in the technology of creating the printing printing plate or with a significant investment in equipment, such as exposing machines with a gas environment or appropriate lasers with LED strips.
However, the Japanese company TOYOBO has set its sights on creating a raw material, a polymer flexo plate, which, in its construction, will prevent the interference of oxygen in the exposure process, completely ruling out the effect of oxygen inhibition. Both manufacturers and distributors of polymer plates know how difficult it is to produce a new raw material with breakthrough properties. It is no mean feat to make it stable in the printing process and be able to call it a New Generation product. Toyobo, after successfully launching the QS plate in 1.14 and 1.7mm versions in 2012, was only ready to show the QZ plate in 2015. And in 2018, the same plate in a new version was called the New Generation flexographic, water-based plate. This just shows how labor-intensive and difficult it is to produce a new polymer.
QZ114 New Generation plate is so much a breakthrough in flexo technology because in its structure, construction it has a unique layer that effectively eliminates the phenomenon of oxygen inhibition.
You do not need additional treatments or complicated equipment to get a flat point / flat top /. I can already hear the voices of my colleagues in the industry that such materials are already available on the market. Yes ...
However, what is most innovative about this board is the construction of the polymer part. It consists of several layers and, as I mentioned about the oxygen barrier, successive layers cause the polymer to irradiate with different sensitivity depending on whether it is back-lighting - forming the base, or the main one responsible for mapping the printing elements. We know from experience that the, let's call it , "old", QZ114 plate could also achieve a flat point, but at the same time it was characterized by a greater increment in printing. This, with a large transfer of Printing inks to the material, gave the effect of too strong and pronounced cut-off in tonal transitions.
The New Generation QZ plate, thanks to its varying sensitivity, makes it possible to achieve a stable and always the same effect in the backlighting process - the thickness of the base. Thanks to this, even imperfect exposing machines with large jumps in exposure energy and power drops can reproducibly produce a plate base with the same properties.
At the same time, with the platerate sensitivity of the plate, the top layer responsible for building point vertices is very sensitive during back-exposure. As a result, the vertex of the point is created very precisely, while the layer cutting off the polymer from oxygen interference makes it possible to obtain a point with the characteristics of a flat vertex.
Another middle layer of polymer at the same time creates a very stable and strong base for the smallest points on the die. This gives even the smallest points on the die a base and shape that allows stable printing at high volumes and speeds.
The multilayer nature of the polymer structure means that we can get the smallest points in the high lights on the plate without additional treatments, while maintaining a broad gradient even in the shadows.
TOYOBO's water-based flexo plate offers a mix of benefits in terms of short processing time, environmental friendliness and reduced electricity costs. Our customers also value in it high transfer and ease of operation. The new-generation QZ plate complements the above advantages with a very stable and flat printing point. The reproduction of minimal points, assuming that they are stable and durable in long print runs, makes it a suitable product for very demanding customers. Especially for printers who, in addition to environmental friendliness, focus on fast response time to customers' needs and choose polymers that guarantee high printing quality parameters....
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