With the arrival of wet weather, there are more and more complaints about the quality of the cartons, which absorb moisture and become soft. In this way, the base paper inspection and production process control, to improve the product quality of the carton has very important significance. The relation between the quality index of the base paper and the moisture-proof performance of the carton
The quality of the carton board and corrugated paper directly affects the moisture-proof performance of the carton. Among them, the tightness of the base paper, sizing degree, front and back absorbency and other indicators have a great impact on the moisture-proof performance of the base paper. And the base paper tightness, sizing degree is good, its water absorption index is low, and its moisture-proof performance is good.
We found in the production process practice through detection and comparative analysis, box board paper, corrugated paper tightness, sizing degree is poor, the strength of the corrugated cardboard out of production is also poor. This is because the compact of the base paper, its fiber tissue appears loose, easy to absorb the water in the external environment (including the steam emitted by the single-sided machine). On the other hand, the sizing degree of base paper is poor, and the paper surface is easy to absorb the moisture in the external environment. Therefore, according to the actual situation of the production process, it is very important to control the quality of base paper.
But the current national standard corrugated paper has no sizing and positive and negative hydroscopicity test items, box board paper only positive and negative hydroscopicity test items, the coverage of base paper quality control still has some limitations. In this regard, according to the actual quality of production, we have developed enterprise standards for corrugated paper and box board paper. On the sizing and absorbency indicators of base paper, a simple method is adopted for rapid detection. The practice is to randomly extract a piece of web paper, drop water on paper, observe the infiltration speed of water droplets on paper, the standard unit is ≥60S.
We will return all the base paper that fails to meet the inspection standard. By taking such control measures, the quality of the base paper has been better improved, and the moisture-proof performance of the carton has been significantly improved.
In addition, due to the different quality levels of box board paper and corrugated paper, there are certain differences in technical indicators, therefore, high-grade beer packaging is best to choose high quality grade of base paper to make cartons, which is also an important technological measure to improve the moisture-proof performance of pre-printed beer cartons.
The dry-proof performance of the whole carton is affected by the dry-proof performance of the dry-proof performance of the whole carton. The dry-proof performance of the dry-proof performance of the whole carton is affected by the dry-proof performance of the dry-proof performance of the whole carton. The dry-proof performance of the dry-proof performance of the dry-proof performance of the whole carton is affected by the dry-proof performance of the dry-proof performance of the whole carton. According to the practical experience of the production process, the author thinks that the roughness, smoothness, gloss and water absorption of the printed surface of the whiteboard have a greater impact on the moisture-proof performance of the carton. Therefore, when ordering, we must emphasize that these technical indicators should be controlled in the range of national standards, or even higher than the national standards, in order to improve the moisture-proof performance of the carton.
Especially post-press processing using glazing process of white board, paper coating quality is poor easy to absorb oil, so that the paper lacks the due oil layer and brightness, it is easy to absorb the outside water. According to the national standard GB/T10335.4 -- 2004 "coated Whiteboard" provisions and technical index requirements, coated whiteboard is divided into excellent products, first-class products and qualified products, and there are white and gray bottom, and the technical index has a certain difference. In our production process practice, we found that the white board with high quality grade has higher brightness after glazing-on, on the contrary, it is obviously lack of brightness, and its moisture resistance is poor. Therefore, according to the different quality grades of food and the difference in the ambient temperature and humidity of the place of sale, select the appropriate grade of white board for printing, which can not only take into account the economy of moderate packaging, but also better achieve moisture-proof packaging and meet the quality requirements of the market.
According to the author's quality management experience, the principle of selecting the quality grade of preprinted whiteboard is: the product grade is general; Short sales and use cycle; The environmental humidity of the product sales and use is relatively dry; Carton printing page ink coating area is large, pre-printed whiteboard can choose Grade I or qualified products for printing. On the contrary, the product grade is higher; Long sales and use cycle; The product is sold and used in a relatively high humidity environment; If the printing ink coating area is not large, high-quality white board paper can be used for printing, which is also an important process measure to improve the moisture-proof performance of pre-printed cartons.
The moisture absorption caused by the external factors of the carton mentioned above starts from the outer layer of the carton. Then, the preprinted whiteboard is controlled by the technical index of the base paper and the printing layout design (printing ink coating area is large, its moisture absorption is low). To improve the moisture resistance of the carton, its effect is limited after all. In order to achieve durable, wear-resistant and better moisture-proof effect, can be achieved by the use of laminating, glazing, pressing processing technology to achieve. Among them, the film coated process effect is the best, but the production cost is higher, increase the cost of food packaging, and also to the material recycling caused greater difficulties and trouble, this process is only suitable for high-grade products and long-distance transportation of product packaging.
glazing, pressing face paper, is a more commonly used processing technology, its moisture-proof, anti-friction function is by glazing coating, commonly known as glazing oil, its production process is relatively simple and economic. By glazing, calendering can make the white board surface form a layer of bright, smooth protective layer, general, low grade beer and other products packaging most using calendering or glazing process. Therefore, according to the characteristics of the product, choose the appropriate post-press processing technology, so that the moisture-proof effect and appearance quality of the product packaging, have been better consideration.
Through the reasonable design of the carton forming process to achieve moisture-proof
In the past, when we produced beer boxes in a brewery, there has been such a situation: after beer filling, packaging, finished products online delivery or stacking warehouse, some local box box moisture phenomenon, the reason is: The beer that has just been filled has a certain temperature, and a certain amount of hot steam formed in the box after packing cannot be quickly released, so the hot steam is immediately absorbed by the paper in the carton (box board paper) and permeates into the corrugated paper, until the outermost whiteboard paper. After the moisture absorption of the carton, the deformation and compressive strength of the carton quickly appeared, which affected the quality of the package.
Through quality tracking and analysis, we found that cartons with the same paper quality did not have the above situation in other breweries, which indicates that the environment and process characteristics of beer production line are different, and also affect the difference in moisture-proof performance of cartons. In view of these situations, we take corresponding technological countermeasures according to local conditions, through the reasonable design of the carton forming process, to achieve better moisture-proof effect.
How to do it is: In the production of die cutting plate, two round holes with diameter of 18mm are designed to be drilled respectively on the appropriate positions of the side label (i.e. both sides of the side) of the beer box. The outer diameter of these four holes are 40mm and 3.5mm respectively on the shaking cap indentation line and side indentation line. In this way, after online filling and packaging of beer by the brewery, The 4 loose pores on the carton can quickly drain out the hot steam in the box, forming the air convection phenomenon, which can effectively avoid the moisture absorption and permeability of the carton. By adopting this process improvement, the beer boxes produced by us have been tested by the brewery online packaging, and achieved better moisture-proof use effect, and the customers have satisfactorily accepted this improved process. To sum up, only by combining the control of base paper quality with the reasonable design of production technology, can the moisture-proof performance of the carton be better improved.