How to control the process quality of Thick Cardboard Gift Paper Boxes packaging combination?

How to control the process quality of Thick Cardboard Gift Paper Boxes packaging combination?

In recent years, with the intensification of competition in the tobacco industry, the increase of external pressure on tobacco control and the improvement of people's aesthetics, people have more and more demanding requirements on the quality of cigarette packets, which also promotes the continuous improvement of the design level of cigarette packets. In order to highlight the brand personality and achieve special design and decoration effects, the combination process is more and more applied to the field of cigarette packet printing.

The "Seven Wolves" (blue) cigarette pack printed by a company adopts the combination process of "ordinary offset printing + gravure printing + hot stamping +UV offset printing + embossing + hot stamping + die cutting". The specific production process is: Ordinary offset printing (three color blue), sheetlet gravure printing (silver text), hot stamping (bottom silver), UV offset printing (two color gradient blue) + water light oil, press convex and convex hot stamping (Septwolong Logo frame), die cutting.

The following author takes the 7 processes in the above combination process as an example, and peers to discuss the key points of quality control of the cigarette package combination process.

1. Ordinary offset printing (three-color blue)

In this process, the three colors of blue that need to be printed are shading blue, gradient blue and dark blue, and the ink color of the three colors of blue overprinting part is difficult to control, and the different shades are easy to cause color difference. In the process of offset printing, it is required to control the ink color in the standard sample within the range of the upper and lower limits, and △E≤1.5, and always pay attention to ink, water, ink, abrasion, back dirty, powder and other quality problems. Taking into account the first offset printing surface is not connected to the light, and the three color blue ink will turn red after drying, so this process needs to use a spectrophotometer to measure the L, A, b value of the three color blue, and as a basis to investigate the change in ink color. In addition, but also leave enough time for ink drying, in order to avoid the next gravure printing process caused by quality hazards (such as blotting nozzle, etc.).

2. Gravure printing on sheet paper (silver text)

Gravure printing has two main shortcomings: one is the plate-making process is complex, the price is high; Second, most gravure printing inks contain toluene solvents, and toluene solvents not only pollute the environment, but also harmful to human health, so it is particularly necessary to control the majority of packaging and printing enterprises. In the process of gravure printing, in order to make the gravure printing ink better printability, it is usually necessary to add some solvents, such as slow drying agent, additives to adjust the ink performance, etc. These solvents will have a certain impact on the residual VOC of cigarette packs. Therefore, in the gravure printing process, it is forbidden to add isopropyl alcohol, n-butanol and other volatile solvents in gravure printing ink, even if the solvent is added within the allowed range, but also in strict accordance with the process regulations. In addition, it is necessary to install supporting ventilation equipment in the printing workshop.

In the process, the operator also needs to pay special attention to the control of ink viscosity, otherwise it is easy to appear text trailing, freckles and other phenomena; Pay attention to the text thickness, rough edges and other phenomena; The amount of ink storage of various groups of ink slots should always be consistent, a small amount of ink is added many times, so as to maintain the stability of the ink layer of printing products.

3. Hot stamping (silver base)

In this process, the main check hot stamping pattern registration accuracy (and film contrast), hot stamping fastness and color (pay attention to control the temperature, if the temperature is high, printing surface color is easy to dark, but also pay attention to the bottom silver can not appear defective and hot paste phenomenon). In addition, hot stamping pressure to moderate, pressure will affect the quality of UV offset printing.

Among them, hot stamping fastness is one of the parameters is particularly important, once the control is not good, in the way when the UV offset printing bottom silver will be UV offset printing ink counter loop down, not only influence the quality of the cigarette package, and counter loop down to the bottom of the silver will soon accumulate on the rubber blanket, light image network loss, or cause local image printing. And with the continuous operation of the equipment, the silver powder will also be transferred to the ink roller ink transfer system, accelerating the wear of the ink roller. Therefore, in this process, according to the characteristics of the printing paper, the selection of appropriate anodized aluminum, to ensure that the hot stamping silver can be firmly attached to the surface of the paper.

4 UV offset + water varnish

In the UV offset printing process, pay attention to lamination, text and text incomplete, scratch, printing false phenomenon. In addition, when glazing, the amount of light oil should be moderate, and pay attention to avoid scratching, blotting nozzle, flower version and other phenomena. In particular, after glazing, the first ordinary offset printing process printing ink tends to change in the direction of blue and yellow. Therefore, it is necessary to strictly control the ink color of the first ordinary offset printing process, so as not to cause large color fluctuations after glazing.

5. Pressure bump

In the Septwolves Logo shading pressure concave and convex, the pressure should be moderate, can not appear burst phenomenon, and concave and convex version and the bottom mold can not be misplaced.

6. Embossing and stamping (Septwolves Logo outer frame)

The quality control of this process is a difficult point of the combination process, which belongs to "hot stamping, hot stamping". The following defects are easy to appear in the processing process.

(1) jagged edge phenomenon. This phenomenon is the concave-convex hot stamping process itself has a defect. Concave and convex hot stamping is hot stamping, pressure concave and convex two processes completed at the same time, so the edge of the contact surface is usually not very smooth, and in the whole process of processing pressure is difficult to maintain uniform, coupled with anodizing there will be different quality problems, so this kind of defects are easy to appear. Control measures are mainly: in the production process will be hot plate temperature and pressure adjustment and reduce fluctuations; The anodized aluminum is placed for a period of time before hot stamping.

(2) Ramming phenomenon. The main reason for this phenomenon is that the binding force between UV offset printing ink printed on the bottom silver and after hot stamping anodized is poor, and the hot stamping process itself has a certain temperature and pressure, so after hot stamping anodized strip printing, the ink will stick to anodized, leading to the phenomenon of pulling ink. Therefore, the key to control the process is to ensure that the bottom silver hot stamping must be firm.

7. Die cutting

Cigarette packs in the process of die cutting mainly pay attention to check whether there are cutting rough, indentation line pressure improper, die cutting specifications are not allowed, die cutting precision is poor and so on.

Cigarette package combination process according to the characteristics of various printing and processing technology, foster strengths and circumvent weaknesses, accumulating experience, establishing suitable for quality control mode, through the standardization of process control, quality control, process to stabilize tobacco package quality, use quality management tools, improve the quality management level, to adapt to the development trend of future tobacco package printing industry.