Cartons are the outer packaging of commodities and are a kind of paper containers that are commonly used in commercial economic activities. On the one hand, they protect goods and facilitate transportation. On the other hand, they can intuitively identify the names, quantities, and manufacturers of goods in containers. Such as profile, with a simple, economical, practical packaging effect. Therefore, improving the passing rate of carton product quality, effective promotion of goods and meeting the requirements of customers, and improving the economic efficiency of enterprises are of great significance.
Must focus on strengthening product quality control
Strict control of raw materials can guarantee the quality of carton production. We know that the quality of raw materials directly affects the processing quality of cartons. It can be said that raw materials are the source of quality control for cartons and are very important. Among them, the quality of the binder and the base paper has a great influence on the quality of the cartons. Adhesive (commonly known as glue) is an important raw material for corrugated cardboard, and its quality is an important factor in determining the quality of cardboard products. The main material of the adhesive is starch. The degree of starch fineness, protein and fat content affect the performance of the adhesive. If the use of poor quality starch, such as when the protein and fat content of starch is too high, and the fineness of the starch is lower than a certain number, despite the high degree of oxidation during production, but the viscosity at the time of discharge is generally only 20 seconds , The glue will become thicker after storage for a few days, which will cause it to lose its proper fluidity, and it will also have a large foam when used, which will affect the uniformity and viscosity of the glue coating. , it is prone to blistering, degumming, and poor bonding quality problems. In addition, the technical specifications of the base paper also affect the quality of corrugated board processing. Among them, the corrugated paper, boxboard ring pressure strength, quantitative, moisture, burst resistance index, folding resistance and water absorption and other indicators, then directly to the corrugated box molding Strength quality. Therefore, according to the actual situation of the company, it is necessary to purchase some necessary inspection equipments, check and accept the quality standards of raw materials, and it is worthwhile to carry out effective inspection and control of the raw materials that are stored in the warehouse. Through the implementation of inspection and control measures, enterprises can make scientific and accurate testing of the quality of raw materials, fundamentally eliminate unqualified raw materials, ensure the processing quality of cartons, and effectively control the source quality of production.
Must pay attention to strengthening the quality control of corrugated board processing
Control the production process of single-side machine to ensure the processing quality of corrugated cardboard
The quality of corrugated board produced by single-sided machining will directly affect the overall compressive strength of the carton. Process practice shows that the speed, temperature and adhesive of the single-sided machine have a great influence on the processing quality of corrugated board. 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 moisture of the base paper is high, if the production speed of the machine is too fast, the warm-up time is short, and the time for receiving the rubber coating on the corrugation peak is short, so that the binding effect and molding hardness of the cardboard are reduced. If the speed of the machine is too slow, the cardboard will heat up for a relatively longer period of time, the cardboard will easily become brittle, and excessive temperatures will cause premature curing of the adhesive, 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 conditions of temperature and humidity at the production site, the level of the moisture content of the base paper, the preheating area, and the size of the temperature. 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 machine speed and steam pressure, temperature and adhesive coating amount, to prevent the corrugated board from foaming, false rubber, degumming bad phenomenon. In this way, the strength of corrugated boxes can be improved.
Reasonable control and selection of good base paper to improve the processing strength of cardboard
Corrugated cardboard is generally composed of kraft paperboard or cardboard and corrugated paper or cardboard. If the moisture content between them is too great, then after absorbing the adhesive and heating, the paper's expansion and contraction changes. There will be significant differences, which will easily cause the cardboard to curl and reduce the strength of the carton. Therefore, it is best to check the moisture content of the base paper before it is used on a roll paper machine. Select the kraft paperboard or boxboard with a similar moisture content and the corrugated paper or cardboard to match the production to prevent the paperboard 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 improve the compressive strength of the carton, special attention must be paid to the selection of corrugated paper or linerboard with a high cyclic pressure index as the corrugated layer. The paper can greatly increase the compressive strength of the carton.
Control the quality of paperboard stickers to prevent the occurrence of adhesive quality defects
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. The control of tamping process technology is to select and deploy a good adhesive so that the adhesive's viscosity, fluidity, and other properties are compatible with 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 to carry out the production, which will help to prevent foaming, degumming, false plastic and adhesive quality problems.
We must scientifically and reasonably arrange the production process and do a good job in the inspection of the production process
The production process of corrugated paperboard with white cardboard is used. When the whiteboard paper has a high basis weight and a large thickness, if the miscellaneous machine is improperly used, blistering and degumming are likely to occur during the process of embossing. In particular, the paper with calendering process is used. Due to the poor flatness of the paper, the paperboard after the paperboard is not properly compacted and flattened, and it is difficult to obtain good adhesion between the whiteboard paper and the corrugated paperboard, and it is easy to cause partial paper ( Uplifting site) Foaming or degumming. According to our experience and understanding of the production process, the thicker, harder and calendered whiteboard paper should be arranged on a fully automatic laminating machine because of its structural advantages and the high viscosity of the glue used. It is better to ensure that the surface paper and the corrugated paperboard are dressed in a flat manner, so that the paperboard is firmly bonded. The semi-automatic and manual laminating machines use relatively low glue, and are suitable for thin, soft whiteboard papers. Therefore, arranging production operations not only helps ensure product quality, but also fully and effectively utilizes production equipment. . In addition to scientific and rational arrangements for production processes, quality inspection during the production process is also an important part of ensuring product quality. In the production process of corrugated cardboard gluing, the main focus should be on the inspection of the viscosity of the glue, as once the glue is out of the question, Will cause large quantities of defectives or waste products. For the semi-manufactured paperboard after the test is applied, the “tearing method†can be used to test, that is, the paper is peeled off from the corrugated board and the adhesive strength is observed. From this, the viscosity, thickness, evenness and roll gap of the glue can be judged. The adjustment of other parts of the machine has reached a more appropriate level. Through the inspection of the production process, problems can be discovered and corrected in time to ensure the quality of corrugated cardboard.
Must pay attention to the printing technology of good products
Technology of the loading process
The process of printing directly on corrugated board is very important. How the flatness of the printing plate directly affects the printing quality of the corrugated printing plate, therefore, the plate base of the printing plate should be cleaned before sticking to prevent the thickening of the local plate due to foreign matter adhesion. If the blank area in the layout is relatively large, using a small number of small printing plates for patch printing, the same batch of plates should be used to prevent the printing quality from being affected by the thickness error of different batches of plates. . After the plate is pasted, the edge of the plate should be sealed with a sealant to prevent the ink and oil from penetrating the back of the plate during the printing or cleaning process, lowering its adhesive strength and displacing the plate, resulting in overprinting. No quality issues.
Color control of printing
The quality of water-based ink directly affects the pure and color effect of carton printing color. Therefore, we should pay attention to the selection of ink with stable quality. This is a very important control link. The ink with good quality is fine and uniform, and it should be diluted with water or alcohol solvent. There should be no precipitation or agglomeration phenomenon. There is no obvious foaming phenomenon when stirring. When blending with other inks, the affinity property is good and should be compatible. , pure ink with tone. In addition, maintaining the ink roller's good accuracy and cleanliness, as well as printing at an appropriate printing speed and a constant speed, is also an important part of preventing printing chromatic aberration.
Control of layout printing clarity
In order to improve the clarity of the layout printing, it is necessary to select a printing plate with good wear resistance, elasticity, and moderate hardness, and to control the printing plate production process and quality to prevent the occurrence of stencil and unclear printing quality problems. On the other hand, the ink layer of the ink roller should not be too thick, and the pressure of the ink roller and the printing pressure should be appropriate, so that the printing ink is uniform, and there is no obvious relief mark on the surface of the paperboard. If the layout has both fine lines, text, and a large area of ​​the field or line layout, a thin layer of tape can be properly placed on the corresponding area of ​​the large area of ​​the layout so that the small layout will be basically the same as the ink of the large area layout. The layout has been pasted due to excessive pressure, affecting the clarity of layout printing. If the pressure and ink supply required for the layout and the small layout of the layout structure are relatively large, the small layout can be printed separately from the physical layout, that is, dividing the same panel into two prints can better avoid Printing stencil defects, to ensure the clarity of product printing.
Improve the control of product overlay accuracy
Some corrugated paperboards have more or less warpage due to poor flatness. Thus, if the pressure between the roller and the paper guide roller is too small, it is easy to make the paperboard transport position inaccurate. In addition, when the paper feed chain and the front gauge are worn and loose, they can easily cause overprinting of the paperboard. Therefore, according to the thickness of the corrugated board during printing, a proper gap between the roller and the guide roller is adjusted. At the same time, attention should be paid to the abnormal phenomenon of the paper feeding chain and the front gauge, and corresponding measures should be taken to deal with it so that the paper feeding chain and the front gauge can maintain a high degree of stability when feeding paper to improve the overprint accuracy of the product.
Control the carton forming adhesive process
The junction of the lap joints of the carton is now generally formed by adhesive bonding. Due to the small area of ​​the lap joint, the sizing area is usually about 75-90cm2. The adhesiveness of this part is firm, which has a great influence on the strength and package quality of the entire carton. Therefore, the adhesion process control of the lap joint must not be ignored. We used to have bad bonding on the lapped tongue, which made it easy for the calendered carton to be bulked up. The customer's quality complaints and rework of the return transaction also caused economic losses. Later, after careful analysis and research, we improved the adhesive process by mixing the previously used white latex (polyvinyl acetate latex) and CY-C chemical paste adhesive in a ratio of 6:4, and adding approximately 3 % Cyclohexanone, which increases the viscosity and permeability of the adhesive, solves the problem of poor adhesion of calendered tissue, and improves the adhesive strength of the carton forming.
In summary, the reasons that affect the quality of corrugated box products are many, there are factors of raw materials, but also the reasons for the technology; there are operational factors, but also the reasons for the objective machine; there are a variety of factors, there are many Reasons for coexistence of bad circumstances and so on. Therefore, as long as we pay attention to the source of raw materials and the quality of the production process, strict, serious technical control and process control can not only effectively prevent the occurrence of various quality problems, but also can better reduce the occurrence of various ills. The production efficiency and product quality have been improved.