[Chinese Packaging Network News] At present, the beer packaging on the market, mostly using pre-printing process production. Beer boxes printed directly on single corrugated cardboard are almost impossible to see on the market. Beer box pre-printing firstly has a large improvement in printing quality, rich printing layers, graphic clarity, layout ink color brightness, colorful, overprinting accuracy, product replication effect is good; followed by carton die-cutting molding accuracy High, neat and clean edge of the carton, the carton compressive strength will not be damaged.
1. Reasonable selection of beer box pre-printing process
Embossing, gravure printing and offset printing are the three major printing processes. Soft printing equipment investment is less, the use of water-based ink meets the requirements of environmental protection, the production process is easy to operate, the ink coating is relatively stable, printing color difference phenomenon is less. It also has the characteristics of fast plate making speed, high printing speed, wide printing adaptability, etc. The surface rough cardboard can also get good imprint, suitable for printing the field and line layout. However, the quality of printing fine screen products is not as good as offset printing and gravure printing. The gravure printing process has a thick and uniform ink layer, a rich print layer, a strong texture, a fast printing ink drying speed, a fast printing speed, and an extremely high printing plate printing rate, which is suitable for printing a large number of printed matters, and is advantageous for reducing Cost of production. However, the high investment in gravure printing equipment, the relatively high cost of plate making, and the cumbersome operation of plate replacement, also present certain pollution problems. Offset printing and plate making are convenient. It can not only print the field version, line version, but also can print the fine textured version, and the printing reproduction effect is good. The printing price is relatively cheap. According to the characteristics of the product and the actual conditions of the factory, choosing an appropriate printing process is an important way to improve the quality and economic benefits of the pre-printed beer box. In general, products with small print areas, simple layouts, and partial texts that need to be frequently changed or need to be reprinted many times can be flexo-printed. Fine printing products, large print layout area, and fewer prints per batch can be used for flat printing. The gravure printing process can be used for products with a large number of prints, long-term layout, large layout and fine and complicated layout. The number is not particularly large, and lithographic printing presses can be used for printing.
2, preprinted whiteboard paper choice
Pre-printed beer box face paper generally uses single-coated white paper. There are three types of whiteboard quality grades, first-class products and qualified products. Selecting the right whiteboard paper for printing depends on the characteristics of the product. This is an important part of improving the quality of the cartons. The author believes that the principle of selecting whiteboard paper for making beer boxes should be: Products with high quality, long-distance transportation and large printing layout should adopt 250g/133 or 300g/m. Excellent quality or white goods paper, etc.; general and low-grade products, small print products, and products transported on short distances, can be selected from 200g/133 or 250g/In. Qualified products are printed. In order to control the quality of whiteboard paper, we must first select good quality and reliable manufacturers for procurement, and we must "compared with the three." The raw paper that is stored in the warehouse should be checked and controlled according to the standard. The whiteness, hue, color stability, and powder dropping of the whiteboard paper have a great influence on the printing quality, and strict inspection and control must be emphasized. We have had this experience: Some kind of white paper box made the apparent discoloration and yellowing on the paper after drying, and was returned by the brewery. In response to this quality problem, in the future when we purchase orders, we require the manufacturer to provide paper samples so that physical comparisons can be made when batches of raw materials are inspected for storage. In addition, we also carry out simple light resistance ("exposure") inspection of white paper, such as the white paper on the sun or strong light irradiation for about 20min, to see if there is no fading, discoloration, or reject the rejected products use.
3. Technical control of printing and related links
There are printing color differences and discoloration phenomena in the beer box, as well as quality problems such as the occurrence of dirt on the layout, stencil printing, ink imprinting, and overprinting, which are all quality problems that the daily customers complain about. Therefore, it is an important task for carton printing companies to put the quality of good beer box products in print. A considerable part of the preprinted cartons nowadays are lithographic. To improve the quality of offset printing, we must pay particular attention to strict control of process technology, operation technology, and maintenance of equipment. Process technologies and operating techniques include the scientific and rational arrangement of printing color sequences. For example, when printing, reasonable arrangements can be made based on the characteristics of the substrates, the differences in the structure of the printing machines, the differences in the layout of the printed pages, the characteristics of the original color, and the differences in ink characteristics. Printing color sequence to improve the quality and effectiveness of the product's printing process. For the printing of green and blue pre-printed beer boxes on the spot or line layouts in the field or area, the quality of the discoloration is most likely to occur during long-distance transportation. We use TRR offset printing inks, plus 3% TPP. The use of ~ 608 anti-friction agents for blending enhances the abrasion resistance of the ink. In addition, we use a wear-resistant glazing for glazing, improving the abrasion resistance of printing inks and preventing the appearance of color fading problems.
4. Process technology control to improve the overall strength of the beer box
In the problems of daily product quality, the compressive strength of the carton is one of the most outstanding problems. Therefore, beer manufacturers generally attach great importance to the control of the strength of the beer box. Looking at the practice of carton production process, the author believes that improving the strength performance of beer boxes should mainly be controlled from the following aspects:
1) Control the production process of single-side machine
The quality of corrugated board produced by a single-sided machine directly affects the overall compressive strength of the carton. The process practice shows that the speed, temperature, and adhesive of a single-sided machine have a great influence on the processing quality of corrugated cardboard. If the speed of the single-sided machine is too fast or too slow, it will affect the hardness and adhesive strength of the cardboard. Especially when the base paper has high water content and the production speed of the machine is too fast, it is easy to shorten the preheating time, and the time for “eating glue” on the corrugation peak is short, so that the binding effect and forming hardness of the cardboard are reduced. If the speed of the machine is too slow, the cardboard is heated for a relatively long period of time, the paperboard tends to become brittle, and too high a temperature will cause the adhesive to solidify prematurely, affecting the bonding quality effect, all of which will reduce the strength of the paperboard. Therefore, the production speed of the machine should be based on the situation of the moisture content of the base paper, the preheating area and the temperature, etc. The comprehensive consideration of reasonable control can ensure the production quality of the corrugated board. In the production process, we must also pay attention to the control of a moderate amount of glue, grasp the relationship between the speed of the machine and the pressure of steam, temperature and the amount of adhesive coating, to prevent the occurrence of blistering, false rubber, and degumming. In order to better maintain and improve the strength of the carton.
2) Choose a paper with a corrugated layer
Corrugated cardboard is composed of cardboard and corrugated paper (or linerboard). If the moisture content is greatly different between them, then after absorbing the adhesive and heating, the paper will have a noticeable expansion and contraction. The difference is likely to cause curling of the cardboard and decrease the strength of the carton. Therefore, it is best to check the moisture content of the base paper before it is used on a web-fed paper machine. It is best to select liner papers and corrugated papers (or linerboards) with similar moisture content for production in order to prevent the cardboard from curling. In addition, the quality of the base paper used in the corrugated layer has a great influence on the overall compressive strength of the carton. Therefore, in order to increase the compressive strength of the carton, corrugated paper or cardboard with a high ring index should be selected as the corrugated paper. , This can greatly improve the compressive strength of the carton.
3) Control the process of applying paper
Corrugated cardboard and face paper only achieve a uniform, flat wear and tear state, so that the cardboard is bonded into a solid overall structure, in order to better improve the compressive strength of the carton. In order to control the laminating process technology, we must choose and deploy a good adhesive so that the viscosity, fluidity and other properties of the adhesive can be adapted to the machine characteristics (including speed, structure, etc.) and the temperature and humidity of the production environment. In addition, according to the characteristics of the product, choose the appropriate machine for production, such as thicker, harder, or flat surface paper, can be used to automatically paste the machine, which will help prevent foaming, sticky Inadequate quality of the ills.
4) Control die cutting and indentation process
Die-cutting indentation should mainly pay attention to mastering the plate-fitting technology, adjusting the pressure, rubber strips, and selecting die-cutting indentation molds that match the thickness of the indentation blade. When loading, it is necessary to ensure that the pressed indentation line is clear but it is not prone to popping. The pressure adjustment should be gradually and lightly adjusted, and must not be reversed to avoid damage to the steel blade and pressure plate. At the same time, when using sponges and rubber strips, the thickness of the strips must not be too high to prevent slippage of the semi-finished cardboard when die-cutting, resulting in serious damage to the corrugated boards. The printing plate layout, dimensional die cutting are not allowed, and the carton strength is reduced. Such phenomena.
5) Control the carton molding process
The combination of the lap joints of the beer box is now generally fixed by adhesive bonding. The area of the lap joint tongue is small, and the sizing area is usually between 75-90cm. The adhesion of this part is firm, which has a great influence on the strength and the packaging quality of the entire carton. Therefore, you must not ignore the lap joints of the sticky process control. Some companies once had poor bonding and made the calendered brewery produce a bulk phenomenon. They were dealt with by the brewery for rework, and they suffered economic losses. Later, after careful analysis and research, the adhesive process was improved. The original white latex (polyvinyl acetate latex) and cY-C chemical paste adhesive were mixed and mixed at a ratio of 6:4, and approximately 3% was added. Cyclohexanone, which increases the viscosity and permeability of the adhesive, solves the problem of poor adhesion of calendered tissue paper, and improves the adhesive strength of carton forming.
In summary, to improve the product quality of pre-printed beer boxes, it is necessary to carry out careful check control from all aspects of procurement, production, and inspection, organize production, guide production and supervise production according to standards, and formulate scientific and reasonable production technology. Measures can make the printing quality of the facial paper and the processing quality of the carton be improved to meet the requirements of the market.
