Fingerprint Safe,Biometric Fingerprint Safe,Portable Fingerprint Safe,Fingerprint Lock Safe Box Ningbo Reliance Security Technology CO.,Ltd , https://www.reliancesafes.com
Since KBA has found in the test that the results obtained by the two systems are basically the same, but the level of automation and the investment involved in manual operations have changed, their advantages and basic principles are also different.
At the end of each shift and from one type of varnish to another type (eg from UV to water, or from water-based varnish containing special effects pigments to pigment-free varnish) The glazing unit and the conveyor system must be cleaned. Varnishing of varnish is part of everyday work on composite and dual glazing presses, but can also occur on other types of glazing presses. These operations should be very short and require very little investment from the press operator.
Manual cleaning takes time and increases downtime. When using a simple polishing pump and scraper that is not installed in the conveyor system, the average time for each glazing device is between 20 and 25 minutes, and the operator cannot perform other work during this time.
In contrast, all of the varnish-related parts are thoroughly cleaned on an automated conveyor system like Harris & Bruno, in just a few minutes, depending on the varnish used, the size of the press, and The degree of automation. This is not always the case, as the level of automation provided for in-line glazing units has long been inferior to the level of automation of offset printing units.
Harris&Bruno system: single glazing line
A Harris & Bruno automatic varnish delivery system can be cleaned in three to eight minutes, depending on the type of varnish used and the size of the press. Since the cleaning process is initiated with a button and runs automatically, the operator can go to other tasks after a few seconds.
Fully automated prerequisites
The level of automation can vary greatly. Fully automatic means that all the components associated with the varnish – even the return hose of the glazing drum – can be cleaned by simply touching a button without the need for manual pumping, valves Conversion and subsequent cleanup. In order to achieve completeness, it should be possible to convert from one type of varnish to another type of varnish in a single delivery system. The use of a single line eliminates the need for manual conversion of hoses or valves, eliminating the risk of accidental mixing of the coating.
As a prerequisite, the oil scraping system must be fully embedded in the control unit, and the filling and discharge valves of the doctor chamber must be automatically controlled. This is the case with our Hydro-Comp oil scraping system, which is a standard part of the H&B conveyor system.
In order to avoid mixing of the different varnishes in the same line, a part of the cleaning process must be carried out in a manner known to us (an H&B patent). This requires the use of a new varnish to squeeze all of the residue of the cleaning agent or varnish out of the system and into the waste container.
There are two optional devices that can be optimized for automatic operation. An in-line heating module is particularly useful in warming UV coatings to obtain a good viscosity, which uses sensors to continuously measure the temperature in the anilox roll. There is also a special glazing oil circulator SCC which has the function of cooling and agitation to enable the varnish with rheological problems to work well.
Single and dual piping systems: both positive and negative reasons
Previously, to avoid cross-contamination, two separate sets of varnish lines were absolutely required. Although the conversion time is shorter than the basic manual system, Harris & Bruno believes that this advancement is achieved at the expense of automation because the hose must be reconnected or the valve must be switched. Moreover, such devices require twice the number of pumps and valves, which in turn double the cleaning and maintenance effort and make the system more prone to failures and operational errors, thereby increasing costs.
In a single varnish line, there is no risk of cross-contamination if the system can be operated with a patented purification method. If this is the case, then the system can be fully automated and the operator's intervention reduced to less, so preparation and downtime are shorter than using two lines. If a system is only half the size of another system, it will require 50% less maintenance and will be less affected by operator error.
Nonetheless, a separate glazing delivery system or, more precisely, an SCC is desirable or necessary for some special applications. This is the case, for example, when using high viscosity media or expensive glazing oils that require a small amount of loading, or when the glazing oil requires special handling such as cooling or agitation and gentle pumping. Some examples are glazing oils containing pearlescent or rainbow pigments, certain metallic pigments, perfumes, certain high viscosity foaming varnishes, UV flexographic printing inks and certain opaque white coatings.
new progress
Harris & Bruno and KBA continue to work together to improve the operability and maintainability, reliability and automation of the unit. Currently, two major projects are approaching maturity.
* The project is to integrate the control of the varnish delivery into the main console of the press. The system then uses a graphical user interface like a press. This also makes programming of the timer settings easier and provides a visual display of the operating state of the pumping system.
The second project considers the automatic adjustment of the pumping system based on different viscosities or changes in viscosity during production. KBA’s glazing seminar has clearly shown that this is a topic that many printers rarely care about.
Polishing pump used
More than 80% of all anilox glazing and inking systems are powered by diaphragm pumps, which in most cases operate on compressed air. This type of pump is still a good result of compromises in terms of flow, reliability and price.
The big disadvantage of the diaphragm pump is the pulsation, but this has no effect on the advanced and stable scraping system. In contrast, pulsation actually works well during the cleaning process.
The consumption of a large amount of air has also been criticized as a disadvantage. The pump with the correct power level fills the doctor chamber in the varnish line at a very slow rate. On the Harris & Bruno system, this speed is about one stroke per second and the pumping capacity is about 9 liters per minute. This is more than the large absorption of 3.6 liters per minute required for full field glazing in large format presses. When operating at this speed, the pump's air consumption is equal to about 0.3 kW, which is comparable to the energy consumption of an equivalent flow pump.
in conclusion
The great advantage of the well-designed automatic conveyor system used in the online glazing unit in the offset press is the reduced downtime of the press.
Automatic replacement of varnish technology
Foodjx Guide : Due to automation, changing from one glazing to another is no longer a time consuming task. Users of the KBA sheetfed press can choose between Harris&Bruno's single-line pumping system or Tresu's dual-pipe system.