We generally refer to the bursting of paper as the crease line of a corrugated carton when it is processed, folded, packaged, and stacked. Bursts seriously affect the appearance of the carton and are one of the major quality defects of the cardboard. Especially during the dry season, the explosion problem has caused many carton companies to suffer. This not only seriously affects the quality of the carton and causes a sharp rise in the rejection rate, but also delays the delivery period, causing the company to suffer economic losses. Through continuous exploration, the author summarized some methods for improving the bursting line and hoped to help the carton industry.
The corrugated box industry refers to two types of cartons, one is corrugated cardboard as the printing substrate, and the other is the flexo-printed cartons that are nailed/glued after ink printing. The flat PS printing, and then through the pit, beer cut and nail / sticky craft cartons, commonly known as box or color box. There is a big difference between the materials used in the two types of carton and the processing technology. Therefore, the influencing factors and control methods of the explosion are also very different.
Cardboard Burst Influencing Factors
There are many reasons for the quality problems of cardboard, and so is the bursting. The root cause involves various factors such as materials, environment, methods, and operators. Mainly in the following areas:
Cardboard moisture content is a key factor affecting carton blowout. Paper is a kind of hydrophilic material, water absorption will become soft and tough, and water loss will become hard and brittle. When the moisture content of the paperboard is low, the impact of moisture on the carton explosion is mainly reflected in two aspects: on the one hand, the folding resistance of the paper decreases, the stiffness of the paperboard increases, and the possibility of carton bursting increases. The paperboard core is increased in flat compressive strength, and the toughness of the paper in the surface is reduced. When the pressure line is pressed, the paper in the surface is easily damaged and the carton bursts. The test data showed that a piece of paper with a surface of 250 g/m2 noodle board paper and a five-ply board with an ECT of 9000 N/m, when the moisture content was less than 8%, the carton began to burst. When the paper is changed from paper to kraft linerboard, which has very good folding-resistance, the carton burst resistance is significantly improved, but if the moisture content is less than 6%, the cartons begin to burst. Therefore, it is very important to keep the cardboard moisture to prevent the carton from bursting.
The folding resistance of the corrugated surface and the paper itself also has an important influence on the bursting of the cardboard. In general, the calf is more durable than the dried noodles, and the softwood is more resistant to folding than the hardwood pulp. The paper made from the raw pulp is more resistant to folding than the recycled pulp. If the carton factory can reasonably select the paper according to the changes in the weather humidity, it can also prevent the carton from bursting to some extent.
The greater the strength of the corrugated paper, the greater the tension that the paper is subjected to during the forming process of the press wire, and the easier it is to cause the cardboard to burst. The more layers of cardboard, the easier it is to burst. For example, three-hole cardboard is more prone to bursting than double-hole cardboard, and double-hole cardboard is easier to produce explosive lines than single-hole cardboard. Paperboards with A crucibles have higher hardness than paperboards without A crucibles and are therefore more prone to bursting.
Improper handling of the printing slot can also cause the carton to burst. For example, if the positions of the up-down concave and convex rollers of the press line device are misaligned, when the pressure is too large, the line burst will occur.
When corrugated cardboard faces a large gap between the weights of the paper and the paper, the cardboard is prone to bursting. The greater the difference in grammage, the more likely the popping occurs. For example, a carton of 140g/lot paper 250g is more susceptible to bursting than a carton of 140g/lot paper. Therefore, attention should be paid to the balance of the paper's grammage when it comes to dispensing paper.
Cardboard burst control method
Maintaining the moisture content of corrugated board is the best way to control the board burst. The moisture content of the corrugated board from the tile line is controlled between 12-18%, and the moisture content during the printing should be maintained at 10-13%. Due to some objective conditions, people often think that controlling moisture is not easy. Here, we will introduce some more effective methods:
First of all, the traditional method of adjusting the processing technology of corrugated cardboard has a certain effect. Usually we can use the following methods to control:
· Adjust the paste's formula to increase the moisture content of the paste.
·Appropriately increase the amount of paste. It has been proved by practice that increasing the amount of paste can effectively increase the moisture content of the paperboard, and increasing the amount of paste can also improve the adhesion effect to some extent.
• Properly reduce the contact area between the base paper and the preheating wheel to avoid excessive evaporation of water on the preheating cylinder.
• Reduce the residence time of the cardboard on the hot plate. By maintaining a higher speed, reducing the length of the hot plate, and reducing the hot plate vapor pressure, etc., the excessive moisture evaporation of the cardboard when passing the hot plate is avoided. When using this method, care must be taken to ensure that the cardboard does not come off.
(to be continued)
The corrugated box industry refers to two types of cartons, one is corrugated cardboard as the printing substrate, and the other is the flexo-printed cartons that are nailed/glued after ink printing. The flat PS printing, and then through the pit, beer cut and nail / sticky craft cartons, commonly known as box or color box. There is a big difference between the materials used in the two types of carton and the processing technology. Therefore, the influencing factors and control methods of the explosion are also very different.
Cardboard Burst Influencing Factors
There are many reasons for the quality problems of cardboard, and so is the bursting. The root cause involves various factors such as materials, environment, methods, and operators. Mainly in the following areas:
Cardboard moisture content is a key factor affecting carton blowout. Paper is a kind of hydrophilic material, water absorption will become soft and tough, and water loss will become hard and brittle. When the moisture content of the paperboard is low, the impact of moisture on the carton explosion is mainly reflected in two aspects: on the one hand, the folding resistance of the paper decreases, the stiffness of the paperboard increases, and the possibility of carton bursting increases. The paperboard core is increased in flat compressive strength, and the toughness of the paper in the surface is reduced. When the pressure line is pressed, the paper in the surface is easily damaged and the carton bursts. The test data showed that a piece of paper with a surface of 250 g/m2 noodle board paper and a five-ply board with an ECT of 9000 N/m, when the moisture content was less than 8%, the carton began to burst. When the paper is changed from paper to kraft linerboard, which has very good folding-resistance, the carton burst resistance is significantly improved, but if the moisture content is less than 6%, the cartons begin to burst. Therefore, it is very important to keep the cardboard moisture to prevent the carton from bursting.
The folding resistance of the corrugated surface and the paper itself also has an important influence on the bursting of the cardboard. In general, the calf is more durable than the dried noodles, and the softwood is more resistant to folding than the hardwood pulp. The paper made from the raw pulp is more resistant to folding than the recycled pulp. If the carton factory can reasonably select the paper according to the changes in the weather humidity, it can also prevent the carton from bursting to some extent.
The greater the strength of the corrugated paper, the greater the tension that the paper is subjected to during the forming process of the press wire, and the easier it is to cause the cardboard to burst. The more layers of cardboard, the easier it is to burst. For example, three-hole cardboard is more prone to bursting than double-hole cardboard, and double-hole cardboard is easier to produce explosive lines than single-hole cardboard. Paperboards with A crucibles have higher hardness than paperboards without A crucibles and are therefore more prone to bursting.
Improper handling of the printing slot can also cause the carton to burst. For example, if the positions of the up-down concave and convex rollers of the press line device are misaligned, when the pressure is too large, the line burst will occur.
When corrugated cardboard faces a large gap between the weights of the paper and the paper, the cardboard is prone to bursting. The greater the difference in grammage, the more likely the popping occurs. For example, a carton of 140g/lot paper 250g is more susceptible to bursting than a carton of 140g/lot paper. Therefore, attention should be paid to the balance of the paper's grammage when it comes to dispensing paper.
Cardboard burst control method
Maintaining the moisture content of corrugated board is the best way to control the board burst. The moisture content of the corrugated board from the tile line is controlled between 12-18%, and the moisture content during the printing should be maintained at 10-13%. Due to some objective conditions, people often think that controlling moisture is not easy. Here, we will introduce some more effective methods:
First of all, the traditional method of adjusting the processing technology of corrugated cardboard has a certain effect. Usually we can use the following methods to control:
· Adjust the paste's formula to increase the moisture content of the paste.
·Appropriately increase the amount of paste. It has been proved by practice that increasing the amount of paste can effectively increase the moisture content of the paperboard, and increasing the amount of paste can also improve the adhesion effect to some extent.
• Properly reduce the contact area between the base paper and the preheating wheel to avoid excessive evaporation of water on the preheating cylinder.
• Reduce the residence time of the cardboard on the hot plate. By maintaining a higher speed, reducing the length of the hot plate, and reducing the hot plate vapor pressure, etc., the excessive moisture evaporation of the cardboard when passing the hot plate is avoided. When using this method, care must be taken to ensure that the cardboard does not come off.
(to be continued)
PVC floor surface has a layer of special processing by high-tech transparent wear-resistant layer, super wear-resistant layer special surface treatment and fully guarantee the ground material has excellent wear resistance, wear-resisting layer PVC floor surface according to the different thickness under normal circumstances can be used for 5 to 10 years.
Laboratory Flooring,Plastic Laboratory Flooring,Laboratory Pvc Flooring,Rubber Flooring For Laboratory
Neiqiu Huachi Rubber Plastic Technology Co., Ltd. , http://www.huachifloor.com