How to improve the stamping process of printed mat

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How to improve the stamping process of printed matter

from the basic stamping process, we can see that the three basic elements of stamping are: temperature, pressure and stamping time

in order to obtain the ideal hot stamping effect, the process parameters such as hot stamping temperature, hot stamping pressure and hot stamping speed must be reasonably mastered; In addition, the quality of raw materials related to bronzing must also be guaranteed, such as the hot stamping suitability of the substrate, the performance of anodized materials and the quality of hot stamping plates. If something goes wrong, it will affect the final hot stamping effect. Today, Anmei mall will analyze it

select the appropriate substrate. There are many substrates that can be bronzed, usually paper, such as coated paper, whiteboard, white cardboard, cloth paper, offset paper, etc. However, not all paper bronzing effects are ideal. If the surface is rough and the paper is loose, such as books and periodicals paper, poor offset paper, etc., because the electrochemical aluminum layer can not be well attached to its surface, the unique metallic luster can not be well reflected, and even can not be bronzed. Therefore, the substrate for bronzing should be paper with dense texture, high smoothness and high surface strength, In this way, we can get a good hot stamping effect and fully reflect the unique anodized luster

select the appropriate electrochemical aluminum model according to the different substrates. The structure of electrochemical aluminum has five layers, namely: polyester film layer, peeling layer, color layer (protective layer), aluminum layer and adhesive layer. There are many types of electrochemical aluminum, common ones are No. 1, No. 2, No. 8, No. 12, No. 15, etc. In addition to gold, there are dozens of colors, such as silver, blue, brown red, green, scarlet and so on. When choosing electrochemical aluminum, we should not only choose the appropriate color, but also choose the corresponding model according to the different substrate. Different models have different properties and the range of materials suitable for ironing. Generally, No. 8 is used most for hot stamping of paper products, because No. 8 anodized aluminum has moderate adhesion and good gloss, which is more suitable for hot stamping of general printing paper or polished paper and varnished cloth. If stamping on hard plastic, you should choose other corresponding models, such as No. 15 electrochemical aluminum

the quality of electrochemical aluminum is mainly controlled by visual inspection and hand feeling, such as checking the color, brightness and trachoma of electrochemical aluminum. Good quality anodized aluminum requires uniform color, bright and clean after hot stamping, and no trachoma. Generally, the fastness and tightness of anodized aluminum can be checked by rubbing it by hand or trying to stick its surface with scotch tape. If the anodized aluminum is not easy to fall off, it means that the fastness and tightness are better, which is more suitable for hot stamping small text patterns, and it is not easy to paste the version during hot stamping; If you gently rub the anodized aluminum and it will fall off one after another, it means that its tightness is poor and can only be used for hot stamping with sparse graphics and texts; In addition, pay attention to the broken ends of electrochemical aluminum. The less the broken ends, the better

it is worth noting that anodized aluminum must be properly kept and stored in a ventilated and dry place. It cannot be mixed with acids, alkalis, alcohols and other substances. Measures such as moisture-proof, high-temperature protection and sun protection should be taken, otherwise the service life of anodized aluminum will be shortened

make a hot plate. Hot stamping edition generally has copper edition, zinc edition and resin edition. Relatively speaking, copper edition is the best, zinc edition is moderate, and resin edition is slightly poor. Therefore, for fine hot stamping, copper plate should be used as much as possible. For the hot stamping version, its surface is required to be flat, the lines of graphics and texts are clear, the edges are bright and clean, and it is required to step into the track of rapid growth without pits and burrs. If the surface is slightly uneven or slightly scratched or hairy, you can gently wipe it with fine charcoal to make it flat and smooth. The etching depth of the hot stamping plate should be slightly deeper, at least more than 0.6mm, and the slope should be about 70, so as to ensure that the hot stamping pictures and texts are clear, reduce the occurrence of contiguous and paste plates, and improve the printing resistance at the same time. The design of words, lines and patterns for hot stamping is very particular. The text should be as thick and thin as possible, and the density should be reasonable. If it is too small and thin, it is easy to miss the pen and dash; Too thick and too dense, it is easy to paste

control the hot stamping temperature. The hot stamping temperature has a great influence on the melting degree of the falling off layer of hot-melt silicone resin and adhesive. The hot stamping temperature must not be lower than the lower limit of the temperature resistance range of anodized aluminum, which is the lowest temperature to ensure the melting of anodized adhesive layer

if the temperature is too low and the melting is not sufficient, the hot stamping will not be on or firm, and the imprint will be weak, incomplete, missing pens, broken lines or flowers; If the temperature is too high, it will melt excessively, causing the anodized aluminum attached around the imprint to melt and fall off and produce a paste. At the same time, high temperature will also make the synthetic resin and dye in the color layer oxidized and polymerized, and the imprint will blister or appear fog spots, and cause the surface of the aluminum layer and the protective layer to oxidize, so that the hot stamping products will reduce the brightness or lose the metallic luster. Generally speaking, the electrothermal temperature should be adjusted between 80 ~ 180 ℃. For those with large hot stamping area, the electrothermal temperature is relatively higher; On the contrary, it is lower. The specific situation should be determined according to the actual temperature of the printing plate, the type of anodized aluminum, the picture and text condition and other factors. Generally, the most suitable temperature should be found through trial ironing, and the lowest temperature and clear picture and text lines should be taken as the standard

it is necessary to reasonably control the hot stamping pressure. Hot stamping pressure is closely related to the adhesion fastness of anodized. Even if the temperature is appropriate, if the pressure is insufficient, it will not be able to make the anodized aluminum stick to the substrate, or cause fading, imprinting and blooming; On the contrary, if the pressure is too large, the compression deformation of the pad and substrate will be too large, resulting in a paste or imprint thickening. Therefore, the hot stamping pressure should be carefully adjusted

when setting the hot stamping pressure, we should mainly consider: electrochemical aluminum property, hot stamping temperature, hot stamping speed, substrate, etc. Generally speaking, when the paper is solid, smooth, the ink layer of printing is thick, and the hot stamping temperature is high and the speed is slow, the hot stamping pressure should be smaller; Otherwise, it should be larger. In addition, similar to hot stamping, it should also be noted that for smooth paper, such as coated paper and glass paperboard, it is best to choose hard backing paper, so that the impression obtained is relatively clear; On the contrary, for the paper with poor smoothness and coarser, the pad should be soft, especially when the hot stamping area is large. In addition, the hot stamping pressure must be uniform, such as 4.2 logarithmic sweep: if it is found that the evaluation of the implementation of the industry plan and important policies for local hot stamping is not done well or there is tingling during the trial printing, it may be that the pressure here is uneven, so you can pad thin paper on the flat plate there for appropriate adjustment

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