Packaging Tips: How to Improve the Moisture Resistance of Beer Carton

The base material of the beer cartons is base paper, which includes corrugated paper, cardboard, white paperboard, etc. They are very sensitive to moisture and are most likely to generate moisture when wet in the environment. If the beer cartons are damp, their strength will be greatly reduced, affecting the normal circulation of the product and the quality of the packaging. Therefore, we must pay attention to the effective control from the source of production, through the checks of raw materials and production technology to improve the moisture resistance of beer cartons.

Keywords: beer box, base paper, carton moisture-proof process

Recently, some customers have consulted on how to solve the damp problem of carton boxes. According to the author's 28 years of experience in carton factories and printing plants and the relevant knowledge, the following opinions and methods are available for reference.

The base material of the beer cartons is base paper, which includes corrugated paper, cardboard, white paperboard, etc. They are very sensitive to moisture and are most likely to generate moisture when wet in the environment. If the beer cartons are damp, their strength will be greatly reduced, affecting the normal circulation of the products and the quality of the packaging. This can be done by means of machine drying, sun drying and wind blowing. Of course, it is important for carton moisture protection to focus on effective control from the source of production, and to improve the moisture-proof performance of beer cartons through the checks on raw materials and production technology. This is an important part of the production process.

The Correct Understanding of the Effect of Paper Quality on the Moisture Resistance of Carton

The quality of cardboard and corrugated paper directly affects the moisture resistance of the carton. Among them, the tightness of the base paper, the degree of sizing, and the water absorption of the front and back surfaces have great influence on the moisture resistance of the base paper. The tightness and sizing degree of the base paper are good, and its water absorption index is low, and its moisture resistance is good. In the production process practice, we found that the strength of corrugated board produced by corrugated paperboard, corrugated board tightness, and poor glue application was also poor. This is because the base paper with poor tightness has loose fibrous structure and it is easy to absorb moisture in the external environment (including the steam emitted by a single-sided machine). On the other hand, the sizing degree of the base paper is poor, and the paper surface is also easy to absorb the moisture in the external environment. Therefore, according to the actual conditions of the production process, it is very important to control the quality of the base paper. The current national standard corrugated paper does not have sizing degree and positive and negative water absorption test items. Liner board has only positive and negative water absorption test items, and the coverage of the quality control of the base paper has certain limitations. In this regard, we have formulated corporate standards for corrugated paper and cardboard based on the actual quality of production. We have adopted the simple method of rapid inspection for the sizing and water absorption indexes of the base paper. The approach is: randomly extracting a roll of paper. Drop water droplets on the surface of the paper to observe the speed of seepage of the water droplets on the paper. The standard unit is ≥60S. The raw paper that was not able to meet the inspection standards was not returned to the warehouse. All of these were returned. Through the adoption of such control measures, the quality of the base paper was improved and the moisture resistance of the carton was significantly improved. In addition, due to the different quality levels of linerboard and corrugated paper, there are certain differences in technical specifications. Therefore, high-end beer packaging is best to choose a high-quality base paper to make cartons, which is also an important process to improve the moisture resistance of preprinted beer cartons. Measures.

Relationship between technical indicators and moisture-proof performance of whiteboard paper and principles of its rational use

Usually the surface paper of the preprinted beer cartons is white paper. When it is pasted, it is on the outermost layer of the corrugated boxes. Therefore, it is also most likely to come into contact with the outside air moisture. Therefore, some technical indicators of the whiteboard paper directly affect the entire carton. Moisture resistance. According to the practice experience of the production process, the author believes that the printing surface roughness, smoothness, glossiness and water absorption of the whiteboard paper have a great influence on the moisture resistance of the carton. Therefore, when ordering, it must be emphasized that these technical indicators should be controlled within the scope of national standards. Even higher than national standards may be required to improve the moisture resistance of the carton. In particular, the white paper used in the post-printing process is coated with a glazing technology. The poor quality of the paper surface is easy to absorb oil, so that the paper surface lacks the required oil layer and brightness, and it is easy to absorb external moisture.

In accordance with the national standard GB/T10335.4-2004 "coated white paper" requirements and technical specifications, coated white paper quality products, first-class products and qualified products of three, and have white and gray bottom of the points, and There are certain differences in technical indicators. In the production process practice, we found that whiteboard paper with high quality grade has a higher brightness on the paper surface after coating, and conversely, it lacks brightness significantly, and its moisture resistance is also poor. Therefore, according to the difference in the quality of the product and the difference in the ambient temperature and humidity of the place of sale, the appropriate grade of whiteboard paper is selected for printing, which can both take into account the economy of moderate packaging, and can better achieve moisture-proof packaging and meet the quality requirements of market use. . According to the author's quality control experience, the principle of choosing preprinted whiteboard paper quality grades is: the product grade is general; the sales and use period is short; the product sales and use environment humidity is relatively dry; the carton printing layout ink coating area is relatively large , preprinted whiteboard paper can be selected as appropriate, first-class goods or qualified products can be printed. Conversely, higher product quality, longer sales and use cycles, relatively high ambient humidity for product sales and use, and printing of whiteboard paper for superior products, which are also improved Important technical measures for moisture resistance of printing carton.

Improve moisture resistance of preprinted beer cartons through postpress processing control

As mentioned above, the absorption of moisture caused by external factors of the beer cartons begins with the preprinted paper on the outermost layer of the carton. Then, the preprinted whiteboard paper is controlled by the technical specifications of the base paper and the layout design of the printing paper (printing ink coating area is large. And its hygroscopicity is low, so as to improve the moisture resistance of the carton, after all, its effect is limited. To achieve durability, wear resistance and better moisture-proof effect, can be achieved through the use of coating, coating, calendering process. Among them, the film coating process works best, but the production cost is higher, the packaging cost is increased, and the material recovery and utilization also cause great difficulties and troubles. This process is only suitable for high-end products and long-distance transportation product packaging. . Glossing and calendering paper is a more commonly used processing technology. Its moisture-proof and anti-friction effect depends on glazing paint, commonly known as varnishes, and its production process is relatively simple and economical. Through polishing and calendering, a bright and smooth protective layer can be formed on the surface of white paper. Most of the packaging of mid-range beer and other products adopts calendering or glazing processes. Therefore, according to the characteristics of the product, choose the appropriate post-press processing technology, so that the moisture-proof effect and the appearance quality of the product packaging are better balanced.

Doing a good job of keeping the base paper properly

Both the production process and the theoretical analysis show that the quality of the base paper is a prominent factor in the production of carton for the production efficiency and product quality. It is especially important to do a good job of quality control and proper storage of the base paper. Doing a good job of keeping the base paper is also a non-negligible part of ensuring product quality and stability. Relatively speaking, the standard value of the base paper is not always constant. In many detection experiments, we found that some base papers have some changes in their quality indicators after a certain period of inventory. This has a certain relationship with the original paper storage time and storage conditions. Because the base paper has strong moisture absorption characteristics, it is very sensitive to air humidity. When the base paper is damp, the moisture will increase significantly. Therefore, it is very important to do a good job of inventory and storage of the base paper. From the viewpoint of moisture protection, when the base paper is stacked, the height of the wood frame should be used, and the spacing from the ground should be greater than 25cm, and it should not be too close to the wall, and the spacing should not be less than 40cm. Therefore, the place where the original paper is piled must be kept clean and dry, with good ventilation, and the raw paper must not be blindly stacked in a damp place. The warehouse temperature for storing the base paper should be controlled between 20°C and 25°C, and the relative humidity of the environment should be able to control about 60%. When the base paper is used, it should pay attention to the advanced use. If the moisture content of the base paper is too high, it can be put into use after being stored for a long time, which is beneficial to the loss of moisture and improve the processing quality of the paperboard.

Preprinted kraft paper glazing process

Glossing is a commonly used process for post-printing of packaging products. After the surface of the product is coated with glaze, the printed product can enhance the properties of water resistance, light resistance, friction resistance, and stain resistance, as well as increase the surface brightness of the product. The grade of the product has been greatly improved. Gloss coating has a variety of structures, such as oil-based coating varnish for printing presses, water-based and oil-based varnish for varnishing, solvent-based varnish, and UV varnish. The characteristics of glazing coatings are different, and the process effects of product surface processing are also somewhat different. The same is the bright type of paint, because of the material properties, different formulations, the gloss effect, wear resistance, etc. are also different. With matte coating, the surface of the printed product has almost no glossiness, but it has a certain sense of art. Some products have a matte coating and the process effect is no less than that of a bright coating. Whether it is light or matt coating, the coating must have good water resistance and abrasion resistance in order to protect the surface of the print.

UV glazing process for pre-printed beer cartons

UV glazing, also known as UV glazing or curing glazing, UV glazing oil mainly consists of photosensitive resin, reactive diluents, photoinitiators and additives, the principle is: in a certain wavelength of ultraviolet radiation, the system The photoinitiator radical initiates the unsaturated double bond in the resin, and the keying polymerization reaction occurs rapidly, allowing the crosslinked conjunctiva to solidify. Since China's accession to the WTO, the demand for green environmental protection has also been rising. Therefore, UV glazing has received widespread attention with its excellent glazing effect, non-toxic and non-polluting features. The water-soluble UV varnish is a process improvement based on the original UV varnish, which overcomes the irritating defects of the conventional UV varnish. The product has strong gloss, does not fade, does not change color, fast drying, paper size is stable, non-toxic after drying, is conducive to environmental protection and other advantages, suitable for post-press processing of food packaging. The color printing surface paper after water-based UV polishing can enhance the light resistance of the surface ink layer, improve the heat and moisture resistance of the tissue paper, and better protect the product.

Prepressed beer cardboard box paper calendering process

Calendering, also known as polishing process, its main production process is: the first polishing machine with a smooth coating on the surface of the white paper, when the surface coating of the print is dry, the product passes through the calender After the hot pressing of the stainless steel belt on the hot roller, after cooling and peeling, the surface of the paper surface is formed with a high-gloss mirror effect, which can increase the surface finishing effect of the product, improve the protection performance of the product, and make the product surface printing ink layer. To achieve light, wear-resistant and moisture-proof effect, the grade of the product can also be improved to some extent. Therefore, the calendering process has been increasingly applied to the post-press decorative process of beer packaging.

Preprinted laminating process for beer cartons

Lamination is a common finishing process for pre-printed carton paper. After being coated, the printed product can achieve waterproof, anti-fouling, anti-discoloration, heat-resistance, light resistance, and friction resistance. At the same time, it can enhance the glossiness, aesthetics, puncture strength, and tensile strength of the product and improve the use of the product. Life and packaging quality. The general process of laminating is: After the product is printed, the laminating machine is used to composite the plastic film with the surface of the printed material into an integral structure to form a printed matter of paper and plastic. The coating process is divided into a coating film and a pre-coating film; there are also thermal and cold coating processes. Film-coated adhesives are also available in different types, both water-based and solvent-coated. Solvent coating film has a high brightness, but there is a problem of environmental pollution, and the solvent of the water-based film adhesive is water, and there is almost no pollution to the product and the environment. Therefore, it is widely used for the surface finishing of packages such as beer and soy sauce. Because the coated products need to be classified for processing during recycling, the regeneration process is relatively complicated and the production cost is high. Some packaging products are being replaced by calendering or UV coating processes.

Through the rational design of the carton forming process to achieve moisture-proof

In the past, when we used beer breweries in a brewery, there was a situation in which, after beer filling and packaging, when the finished products were transported online or stacked in warehouses, some cases in the carton exhibited moisture permeability. : Freshly-filled beer has a certain temperature. After the box is filled with a certain amount of hot steam, it cannot be quickly emitted. So the hot steam is immediately absorbed by the carton liner (cardboard paper) and penetrates into the corrugated paper until the outermost layer. Whiteboard paper. After moisture absorption occurs in the Carton Box, deformation and compressive strength decrease rapidly, which affects the quality of the package. Through quality tracking and analysis, we found that Paper Boxes with the same quality of paper did not appear to exist in other breweries. This shows that the environmental and process characteristics of the beer production line are different, as well as the differences in the moisture resistance of the carton. In response to these circumstances, we have adopted appropriate technical measures in response to local conditions, through the reasonable design of the carton molding process, to achieve a better moisture-proof effect. The practice is: When making the die-cut version, design in the appropriate position of the side of the beer box (that is, the sides of the side), respectively, hit two round holes with a diameter of 18mm, the outer diameter of the four holes away The indentation line and the side indentation line are 40mm and 3.5mm, respectively, so that after the brewery in-line bottling and packing, the four diffuser holes in the carton can quickly exhale the hot steam inside the box and form air. The phenomenon of convection can effectively avoid the phenomenon of moisture absorption and moisture permeability in the carton box. By adopting such a process improvement, the beer box we produced was tested on the online packaging of the brewery and achieved a good moisture-proof use effect. The customer also accepted this improved process with satisfaction.

Proper storage of beer cartons

Irrespective of the quality of the base paper of the beer cartons and the kind of post-press decoration and protection technology, their moisture-proof protection performance is limited. Therefore, the carton factory or breweries, after the completion of the production and storage of cartons, should pay attention to the inventory of moisture-proof storage, the warehouse should maintain good ventilation and drying conditions, the temperature is controlled at 20 °C ~ 25 °C It is appropriate. Carton products should not be piled directly on the ground, but padding should be used to stack up, to prevent moisture absorption and make the strength of the carton greatly reduced. Carton out of the use of the library should not be afraid of trouble, more time and effort, the first carton into the library out of the first use, to prevent the cartons stacked a long time, resulting in moisture deformation and affect the quality.
To sum up, to improve the moisture resistance of beer cartons, it is necessary to combine the quality control of raw paper and the rational design of the production process. From the raw materials, production process processing links of the source of product quality, strict control of production process technology and operation technology The control can not only improve the moisture-proof performance of the beer cartons, but also effectively improve the overall quality of the beer cartons, so that the appropriate packaging can better meet the requirements of different users and different market environments. This is also the quality of the carton industry. The goal of control.