UV curing process the scope of the design and management (a)

    Fusion U.S. company "to deal with the window" is a UV curing process the scope of a short title. The success of UV curing technology, namely the scope of its technology must be as much as possible to deal with a wide window. In order to do this, we must design and manage a number of such a window. Curing process design includes an accurate determination of the final product must have the characteristics of, and these properties must also meet the requirement. Any one engaged in the work of UV-curable are clearly aware of: the work in different conditions, different materials and different conditions, equipment, etc., and maintain the stability of these characteristics is very difficult indeed.

   Therefore, the characteristics of each product must be detected and evaluated. As previously mentioned, these key features are usually detected with very simple, but they can provide the management "to deal with window" or resolve the issue of the efficiency of all the features needed information. Once any of these properties do not meet the requirement, the most typical are the most frustrated concludes: "not completely curable." This is like you said to the doctor, "I was sick," as the diagnosis of the disease do not have any substantive help, the doctors want to know is where you really uncomfortable.

    Typically, the process of UV-curable judged good or bad, simply to see if it reached the curing. Is the most common measure of a curing process usually see it under ideal conditions, how fast curing. However, if these conditions then they will change what happens? If only the upper limit of curing conditions to accept the assessment, we will lose to know Where the opportunity to defect. Moreover, if we can not separate properties for each assessment, analysis of defects will have missed all the causes and sources of opportunity. UV-curing process of assessment or to explore the source of the problem means that in conditions related to controllable variable in the upper and lower limits of the location of a clear defect. If the curing process by reducing the production line had to curing speed, then some of the curing conditions will inevitably have reached the limit. So as to arrive at the conclusion that to be typical of the need for more light or more Photoinitiators can better work. However, this conclusion is likely to be wrong, what is wrong with it? - Is likely to curing process is wrong.

    Once all of the features of products and performance by 11 to distinguish between, you can start to proceed with the design and expand the "processing window" of the work. First of all, we must ensure that the objectives of the search for a correct understanding. For example, "curing" the concept of the study with the specific characteristics of change, such as adhesion, hardness, flexibility, gloss, anti-scratch, corrosion resistance, as well as a number of other characteristics, these characteristics may apply to special applications. Evaluate the width of the window to deal with the window means achieve the desired characteristics of the effect of the premise, measurable scope of the production process variables. The simplest and most commonly used variable is the speed of production. Of course, talking about here refers to the speed of UV-curable liquid material in UV light running speed, in meters / minute or feet / minute to measure. Most of the UV-curing equipment can be run at the data shows, this window can be simply divided into the maximum speed and minimum speed of the two. Speed on the equivalent of production efficiency, as the number of paper printed per hour or per minute as the amount of work completed.

   If the device has confirmed that run faster than the fastest speed, will not be able to get acceptable results. This "curing loss" and curing itself, in the acceptance of application-specific request has its own unique meaning. On the other hand, if the lower speed, from a product side will also bring about damage. From the substrate melting or wrinkling, to ink or paint and other components of gasification will have consequences. Typically, in the coating or ink performance affected before a critical point, some due to excessive heat caused the problem already exists. Therefore, the actual window is usually the minimum and a variety of heat damage.

   Find a way to address the limits of a window on dealing with the concept of the window to indicate that any UV-curing process are all in accordance with the "Speed - the energy" to run the curve. According to this curve, the speed and energy into a simple inverse relationship. For example, if the speed of doubling the surface absorbed energy was reduced by half. UV-curable technology curve will apply to specific UV inks, substrates and lamps in. With the speed of the increase in energy reduction in surface energy by receiving less and less, and ultimately will not be enough to completely curable. The energy absorption capacity is the critical point of curing window a limit. Legend, the energy level along the axis running. In many UV curing process, the energy density or radiation or even more important than the energy itself. At the other extreme, the slower the speed of energy will increase, the minimum is usually defined as a coating damage (excessive fixation) or even heat damage to a critical point.

   To deal with the real value lies in the window: it is the UV curing process control. If the window wide enough, curing process can withstand ultraviolet light materials, substrate, conveyor speed, voltage, temperature, lighting changes and ink thickness of some common conditions change. Dealing with the diversity of the window, however, the actual products, there are some essential characteristics must be at the same time. These specific properties of curing has a separate window. In fact, dealing with all the specific properties of the window just curing a direct reflection of the window. In use, a large number of characteristics need to use to deal with very narrow window, but also very sensitive to fluctuations in process variables, and thus difficult to control. In some cases, upper and lower limits of the gap between the very small, so the process of subtle changes in the affordability of the poor. For example, some increase the speed, ink surface will be tacky; and to slow down, but will that be too high substrate temperature, leading to the substrate melting, wrinkling, this is a process there is no window
Now, we find that the task is becoming increasingly complicated. Energy, in this process is the arrival of the workpiece surface of a specific wavelength range of ultraviolet energy. Objects arrived in the intensity of the work of the surface energy (or radiation) have a significant effect on curing, but also for a variety of different substances have different effects.

   There are many commercial equipment to the characteristics of these lamps to measure, and to help detect these characteristics in dealing with the impact of the window. Must know that different manufacturers to produce the radiation detector will arrive at different measurement results, these measurements are also difficult to compare. Some UV radiation is within the scope of the integrated energy for testing, while others on the part of ultraviolet spectroscopy to distinguish between radiation energy; some only report on the radiation dose, and some specialized tests radiation intensity, while others Some two functions may be both. From these can provide a complete data equipment, it can obtain information on the characteristics of those most. (For a guide to energy test instruments can be seen behind the "curing process measurement methods" section). Had been learned about how the spectral distribution, radiation and energy of the impact of curing, as well as the characteristics of how to effectively apply the ink and other products, such as knowledge of the operation. In order to analyze and improve curing, these characteristics also need to curing materials with the performance of the combination of test results.

   In fact, the "energy" to carry out thorough, accurate measurement must be included on the wavelength, the absorbed dose radiation and information. Irradiation intensity: including the most important peak radiation. Because the distribution of radiation intensity lamp graphics primarily a function of shape There is a certain relationship, but unless the lamps were out of focus, otherwise the function will remain unchanged. Radiation intensity measurement units are mW / cm2 or W / cm2. Radiation intensity from the lamp electrical input power, lamp efficacy, radiation output, launching the efficacy (by the geometry of the lamp, lamp size and light the focus of such decisions) and other factors. Spectral distribution: only on the energy and wavelength of the relative measure (see Figure 7), usually, the parameters for different radiometer design different subject to certain restrictions. The distribution of ultra-violet lamp is essentially a decision of the radiation spectrum. Radiation dose: Simply put, is the amount of radiation combined. It is time for radiation and radiation product. Dose said, it must include the spectral distribution of the information, otherwise it for comparison and analysis will be of no value. Infrared heat: surface infrared energy received by the substrate temperature is a major factor. It is by the tube surface temperature and its surface area generated. (It should be noted here that although the spectral distribution should be covered, including infra-red radiation energy the whole band, currently on the market is not a commercial radiometer can be directly measured the infrared radiation.)

   Infrared thermal effect is to interfere in the processing window of high-energy limit, must pass a special reflector, have filters or other means to reduce the surface obtained by infra-red. Research on the tool in Figure II has demonstrated three practical methods for dealing with the impact of the window, they can not change the ultraviolet chemical formula to deal with circumstances broaden window. 1) Select the appropriate spectral distribution of the lamp - that is, the wavelength of light emitted more easily lead to ink Photoinitiators response - This allows faster completion of curing process. 2) As shown, choose a smaller diameter, output power of larger, more efficient reflector to collect the tube, you can increase the radiation intensity (not to be confused with the dose), which will enhance the entire curve, that is, to broaden the upper limit of the process window (L1). 3) to reduce heat generated by tube (or improved cooling light conditions), we can reduce the adverse thermal effects to the surface to send a greater dose of UV energy and not lead to heat damage. This effectively extends the lower limit of the window handle. Processing window with previously mentioned how not to over-curing ink surface circumstances, achieve the desired ink and substrate adhesion method, which is in fact a simple example of broadening the window handle. In order to more vividly illustrate this point, but also in order to begin the following analysis, are here to select a specific performance and evaluate it. First of all, make sure to achieve the effective limits of this process. Figure III demonstrated after curing coating performance and radiation hardness of the energy relationship between the function (remember that energy with the increase in the rate of decline). There are many ways to choose any of them are able to judge the hardness of the above. Vertical dotted line part of the experiment may reach acceptable hardness areas. Its left side, said the material is too soft, or the required material is not curing good (curing loss). In its right side, excessive crosslinking reaction will lead to material "too brittle", in addition to energy can lead to excessive heat loss. Here the impact of any one factor in the success of curing also dealing with the window constraints.