Hot stamping process is favored by people because of its unique surface decorative effect. From the basic process of hot stamping, it can be seen that in order to obtain the ideal hot stamping effect, hot stamping temperature, hot stamping pressure, hot stamping speed and other process parameters should be reasonably mastered. The quality of the raw materials related to bronzing must also be guaranteed. This article shares the relevant content affecting the effect of bronzing, for friends’ reference:
Bronzing process is after a certain temperature, pressure to hot gold foil instantly the gilding plate pattern, text attached to the substrate surface. In the cosmetic container box printing, the application of bronzing process accounts for more than 85%. In graphic design, bronzing can play the role of finishing touch and highlighting the design theme, especially for trademarks and registered names, the effect is more significant.
01 The Choice of Substrate
There are many substrates that can be gilded, usually paper, such as coated paper, white board paper, white card paper, woven paper, offset paper and so on. But not all paper bronzing effect is ideal, if the surface of rough, loose paper, such as book paper, poor offset paper, because the anodized layer can not be well attached to its surface, the unique metallic luster can not be well reflected, or even can not hot stamping.
Therefore, bronzing substrate should be selected dense texture, high smoothness, high surface strength of paper, so as to obtain good hot stamping effect, the unique anodized luster is fully reflected.
02 Choice of Anodized Model
The structure of anodized aluminum has 5 layers, namely: polyester film layer, shedding layer, color layer (protective layer), aluminum layer and adhesive layer. There are more anodized models, common L, 2, 8, 12, 15, etc. In addition to the aureate color, there are dozens of kinds of silver, blue, brown, green, bright red. The choice of anodized aluminum not only to choose the right color, but also according to the different substrate to choose the corresponding model. Different models, its performance and the range of suitable hot materials are also different. Under normal circumstances, paper products hot stamping is the most used number 8, because the number 8 anodized aluminum bonding force is moderate, gloss is better, more suitable for general printing paper or polished paper, varnish hot stamping. If hot stamping on hard plastic should choose other corresponding model, such as 15 anodized aluminum.
The quality of anodize is mainly by visual inspection and feel to check, such as the color of anodize, brightness and trachoma. Good quality of anodized aluminum color uniform, hot stamping after smooth, no trachoma. For anodized fastness and tightness can generally be rubbed by hand, or with transparent tape to try to stick its surface for inspection. If the anodized is not easy to fall off, it means that the fastness and tightness are better, and it is more suitable for hot stamping small text patterns, and it is not easy to paste the version when hot stamping; If you gently rub the anodized aluminum have fallen off, it means that its tightness is poor, can only be used for sparse text and patterns hot stamping; In addition, we should pay attention to the broken end of anodized, the less the broken end, the better.
Note: anodized aluminum must be properly kept, should be stored in a ventilated and dry place, can not be mixed with acid, alkali, alcohol and other substances, and must be moisture-proof, high temperature, sun protection and other measures, otherwise the anodized aluminum will shorten the service life.
03 Hot Stamping Plate Production
Hot stamping plate is generally copper, zinc and resin version, relatively speaking, the best copper, zinc moderate, slightly poor resin version. Therefore, for fine hot stamping, copper plate should be used as much as possible. For the hot stamping plate, the surface is required to be smooth, graphic lines are clear, edges are clean, no pitting and burr. If the surface is slightly uneven or mild scrape, fuzz, can be used fine charcoal gently wipe, make it smooth.
Hot stamping plate corrosion plate depth should be slightly deep, at least 0.6mm above, the slope of about 70 degrees, to ensure that hot stamping graphics clear, reduce the occurrence of continuous and paste version, and improve the printing rate. The design of the words, lines and patterns of hot stamping is very particular. Text and patterns should be as moderate as possible, reasonable density, such as too small too fine, easy to lack of pen break; Too thick too dense, it is easy to paste version.
04 Temperature Control
Hot stamping temperature has a great impact on the melting degree of the hot melt silicone resin off layer and adhesive, hot stamping temperature must not be lower than the lower limit of anodized temperature range, which is to ensure the lowest temperature of anodized adhesive layer melting.
If the temperature is too low, the melting is not sufficient, will cause hot stamping is not strong, so that the imprinting is not strong, incomplete, misprint or blur; While melting temperature too high, excessive, around the imprinting of electrochemical aluminium melting loss and also produce paste version, at the same time, the high temperature will cause the color layer of synthetic resin and the dye oxidation polymerization, imprinting porphyritic blister or mist, and lead to aluminum oxide layer and protective layer surface, make the hot stamping products to reduce brightness or lose their metallic luster.
In general, the electric heating temperature should be adjusted between 80 ~ 180℃, hot stamping area is large, the electric heating 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, anodized type, picture and text conditions and other factors, usually through the trial to find out the most suitable temperature, should be the lowest temperature and can imprint a clear picture and text lines as the standard.
05 Hot Stamping Pressure
Hot stamping pressure and anodized adhesion fastness is very important. Even if the temperature is appropriate, if the pressure is insufficient, it can not make the anodized and the substrate stick firmly, or produce the phenomenon of fading, misprint or blur; On the contrary, if the pressure is too high, the compression deformation of the liner and substrate will be too large, resulting in paste or coarse printing. Therefore, we should carefully adjust the hot stamping pressure.
When setting hot stamping pressure, the main consideration should be: anodized properties, hot stamping temperature, hot stamping speed, substrate, etc. In general, paper firm, high smoothness, thick ink layer of printing, and hot stamping temperature is high, the speed of slow, hot stamping pressure should be smaller; On the contrary, it should be larger.
In addition, similarly, hot stamping pad should also pay attention to, for smooth paper, such as: coated paper, glass cardboard, it is best to choose hard backing paper, so that the impression is clear; On the contrary, for poor smoothness, rough paper, the cushion is best soft, especially the hot stamping area is larger. In addition, hot stamping pressure must be uniform, if the trial printing found that local misprint or blur, may be here the pressure is uneven, can be in the flat pad on the paper, appropriate adjustment.
06 Hot Stamping Speed
Contact time and hot stamping fastness is proportional under certain conditions, and hot stamping speed determines the contact time between anodized and substrate. Hot stamping speed is slow, anodized and substrate contact time is long, bonding is relatively firm, is conducive to hot stamping; On the contrary, hot stamping speed, hot stamping contact time is short, anodized hot melt silicone resin layer and adhesive has not been completely melted, willcause a misprint or blur. Of course, hot stamping speed must also adapt to the pressure and temperature, if the hot stamping speed increases, the temperature and pressure should also be appropriately increased.
Company Name: Fuzhou Huaguang Color Printing Co., Ltd.
Email: Send Email
Address:Building 4, No. 20, Zhaoyu Road, Gaishan Town