During the use of the carton, there are two main problems: First, the fat bag or bulging bag; Second, the damage of the carton. The reasons for our analysis of the problem are as follows:
First, the cause of the problem
(a) Fat bag or drum kit
1. improper selection
The height of the A-tile is the highest, and the same paper, although it withstands vertical pressure performance, suffers less flat pressure than the B-type and C-type. After the cartons of A-tiles are loaded with products, the cartons are subjected to horizontal and vertical vibrations during transportation. Repeated impacts between the packs and the cartons cause the wall of the cartons to become thin, resulting in a fat pack or bulging.
2. Effect of stacking finished shovels
When the product is stacked in the finished product warehouse, it is usually piled up high, generally two piles of shovels. During the stacking process of the carton, the change of the strength of the carton, especially the bottom box, is a "creep" process characterized by relatively stable loads acting on the carton for a considerable period of time, and the carton undergoes continuous bending deformation under static load. If the static pressure is maintained for a long period of time, the carton will collapse and collapse, so the bottommost carton piled on the shovel board often swells and some of it is crushed. When the carton is subjected to vertical pressure, the deformation of the center of the box surface is the largest, and the crumple-like crease like a parabola is bulging. The test proved that when the corrugated box is under pressure, the strength is best at the four corners and the strength is the worst at the midpoint of the transverse edge. Therefore, the feet of the upper shovel plate are directly pressed in the middle of the carton, so that a concentrated load is formed in the middle of the carton, which may cause the carton to break or permanently deform. There are also gaps in the blade that make the box corners of the carton fall in. These can cause the carton to pack or bulge.
3. The exact size of the box height is not determined
The height of the carton box of the carbonated beverage box and the water tank is generally determined as the bottle height of the bottle of the inner product plus about 2 mm. Since the carton is piled, the static load is subjected for a long time, and the shock, vibration, and jolt in the transportation process cause the wall thickness of the carton to change. Thin, increased in height, making the box taller than the height of the bottle, thus making the carton more obvious.
(b) The extensive damage to the carton is mainly due to the following factors:
1. Unreasonable carton box size design
The length, width and height of the carton are related to the damage of the carton. The size of the carton is generally determined according to the number of bottles to be loaded and the bottle height. The length of the box is the number of bottles in the long direction x the diameter of the bottles, the box width is the number of bottles in the width direction x the diameter of the bottles, and the box height is basically the bottle height. The perimeter of the four sides of the box is equivalent to the entire side wall supporting the carton pressure load. Generally, the longer the perimeter, the higher the compressive strength, but this increase is not proportional. If the perimeters of the four sides are too large, that is, the number of bottles contained in the product is relatively large, the gross weight of the whole box product is large, and the requirements for the carton are also high, and the compressive strength and bursting resistance are required to ensure the use performance of the carton. Cartons are more likely to break during circulation. In the market, the 596mL × 24 bottle pure water tank is the most damaged in all the cartons, because it has a large gross weight and is a single-carton, which is prone to damage during circulation.
In the case of the same length and width of the carton, the height has a greater influence on the compressive strength of the empty box. With the same length of the four sides of the carton, with the increase in the height of the carton, the compressive strength is reduced by approximately 20%.
2. The thickness of corrugated board does not meet the requirements
Because the corrugating roller is subject to wear during use, the thickness of the corrugated board does not meet the specified requirements, so that the compressive strength of the carton is low, and the strength of the carton is also reduced.
3. Corrugated deformation of the carton
The corrugated paperboard itself is soft, the plane strength is low, and the rigidity is also low. The corrugated paperboard box made of such paperboard has low compressive strength and puncture strength. Because the corrugated shape is directly related to the compressive strength of the corrugated board. Corrugated shapes are generally classified into U-shaped, V-shaped, and UV-shaped. The U-shaped stretch is good, elastic, and high in energy absorption. Within the elastic limit, when the pressure is removed, it can still be restored to its original shape, but because the stress point of the arc is unstable, the flat pressure strength is not high. V-type contact with paper surface is small, poor adhesion, easier peeling. With the help of the combined forces of the two diagonal lines, the force is good and the flat pressure strength is high. However, if the external force exceeds the pressure limit it is subjected to, the shape of the cocoon is destroyed and the pressure cannot be restored after it is eliminated. UV-type take the advantages of the above two types of 楞 type, high pressure strength, good elasticity and elastic recovery ability, is an ideal 楞 type.
4. Unreasonable design of carton layers in carton
The unreasonable design of the number of cardboard layers will lead to an increase in the damage rate of the outer packaging carton. Therefore, the number of cardboard layers used in the carton should be taken into consideration based on the weight, nature, stacking height, storage and transportation conditions, and storage time of the packaged goods.
5. The adhesive strength of the carton is poor
To judge whether the carton is good or not, just peel the adhesive surface by hand. If the original paper is found to be peeled off, it indicates that the paper sheet is well bonded; if it is found that there is no tearing of the paper fiber at the peak adhesion, or white Powder, then it is a false stick, which will cause the carton compressive strength is low, and affect the strength of the entire carton. The adhesive strength of the carton is related to the grade of the paper, the preparation of the adhesive and the manufacturing equipment and process operations.
6. Unfair print design of carton
The corrugated shape and structure of the corrugated board determines the bearing capacity of the corrugated board. Printing will cause some damage to the corrugated board. The size of the pressure and the size of the bearing area are the main factors affecting the compressive strength of the carton. If the printing pressure is too high, it is easy to crush the corrugation and reduce the height. Especially when printing at the press line, in order to perform forced and clear printing at the press line part, the entire paper board will be crushed and the compressive strength of the carton will be greatly reduced. Therefore, printing should be avoided as much as possible. When the cartons are full-printed or printed around, the ink has a wetting effect on the paper surface, in addition to the pressure of the embossing roller on the corrugated cardboard, which in turn reduces the compressive strength of the carton. When the general carton is fully printed, its compressive strength is reduced by approximately 40%