Starting in 2017, the huge installed capacity of unit flexo printing machines marks the arrival of label flexo printing. Unit flexo with multi-function, fast, set standards, high degree of automation, environmental protection, etc. are in line with the trend of today's label printing. The full rotary letterpress central drum printing machine with its huge market stock of the market, and the natural advantages of some special technology, temporary status can not shake. Now with flexo printing machine and full rotary letterpress central drum printing machine how to choose Automatic Non-Stop Winding System to do a brief analysis, for reference!
The functional use of flexo printing machine and full rotary letterpress central drum printing machine are often inevitable - feeding, printing, laminating, die-cutting, waste matrix, rewinding and other functions. for this function, choose Automatic Non-stop winding machine system Consider the following elements:
1, Unwinding tension should be balanced within ± 0.2N. For example, full rotary letterpress central drum printing machine, due to its traction is soft drum, tiny tension change will influence printing accuracy immediately, resulting in uneven drawing variables of materials, registration is not good, especially for tension-sensitive plastic sheet , Aluminum sheet.
2, Tension adjustment need one step in place. Currently there are different types of Automatic Non-stop winding machine in China and abroad, the solution way is not the same, for the label industry, due to its narrow features, tension is not large, the operation to avoid cumbersome and misuse, You should choose to adjust the tension in one step, So single-stage tension is better, multi-stage tension adjustment is not easy control tension, likely to cause paper failure and A, B tension inconsistent, affecting the printing batch consistency.
3, Convenient feeding unit. Now The material roll diameter or the total length of the material become more and more bigger and longer, try to avoid the phenomenon of multi-joint waste, then the material due to the roll diameter becomes larger or the number of meters longer, the total weight has increase doubled, in order to avoid Material damage artificial feeding is outdated, then the Automatic non-stop unwinder need to have a convenient feeding mechanism as an auxiliary mechanism.
4, A, B material independent web guide system. In order to ensure the edge alignment of the paper to avoid influence collect waste material when die-cutting, A, B materials need to have their own independent web guide system to ensure the edge alignment.
5, Diameter detection accuracy ≤ 1mm. Since the purpose of the Automatic non-stop system is to reduce waste, then the automatic material picking, the accuracy of existing materials for the detection of the diameter is very important. There are a variety of proven techniques for diameter detection, such as external ultrasonic inspection and laser inspection. The limitation of ultrasonic wave lies in that the acoustic wave is affected by many factors, such as temperature, humidity, noise, etc., can affect the speed of sound wave propagation and cause the instability of the diameter detection. An error of 1mm precision results in three or four roll of material The residual, but contrary to the original intention of reducing waste.
6, Catch the tail function. The so-called catch function is that, if the worker inputs the wrong diameter required for the splice, as a remedy, when the material is leaving the core, it can detect the material at this moment by the direct action and must take Material splice, so as to avoid printing machine downtime, resulting in material waste.
7, Stable and reliable control system. Automatic Non-stop winding system of the principle can not be separated from the tension of the compensation unit, the compensatory unit of the linear compensation requirements are quite high, speed compensation caused by tension instability affect the printing registration, compensation is too slow, causing a gradual tension instability affect printing registration , So a good reliable and stable control system is particularly important, it can be a parabolic linear compensation, the connector without waste, high yield printing, speed and jogging will not affect the accuracy of the printing registration, material correction is more accurate.
8, Rewinding tension accuracy within ± 0.2N. The Rewinding tension of high precision is not for the purpose of its printing, is that when the exchange of materials, if the tension of the roller is too large, but also indicates that the tension accuracy fluctuations, then the moment in the material rewinding, it is easy to lead to floating roller failure, Exceeding its floating range, resulting in the failed feed, which in turn lead to the entire press downtime. The control of tension accuracy lies in the PLC operation of winding speed compensation, which directly tests the effect of the rewinder.