First, the predetermined carton pressure strength
The carton requires a certain compressive strength because the carton stacked in the lowest layer of the carton is subjected to the pressure of the upper carton during the storage and transportation process. In order not to collapse, it must have a suitable compressive strength and the pressure resistance of the carton. The intensity is calculated using the following formula:
P=KW(n-1)
P----carton compressive strength, N
W----Carton weight after loading, N
n----stacking layer number
K----stacking code safety factor stacking layer number n is obtained from the stacking height H and a single carton height h, n=H/h
The stacking code safety factor is determined according to the number of layers of the stacking code. The national standard stipulates:
Storage period less than 30d, take K=1.6
Storage period 30d-100d take K=1.65
Storage period is greater than 100d, take K=2.0
2. Jinan Carton Factory calculates the compressive strength of the carton according to the raw materials: After the carton compressive strength is predetermined, the appropriate carton board and corrugated paper should be selected to produce corrugated boxes to avoid waste caused by blind production; Calculated according to the ring pressure of the base paper There are many formulas for the compressive strength of the output box, but the more concise and practical is the kellicutt formula, which is suitable for estimating the compressive strength of the 0201 type carton.
Third, the method of determining the compressive strength of the carton
Due to various factors in the production process, the final compressive strength of the carton produced by the raw materials is not necessarily consistent with the estimation result. Therefore, the final method for accurately determining the compressive strength of the corrugated box is to compress the carton after the container is treated with constant temperature and humidity. Test machine test; for small and medium-sized factories without test equipment, a wooden board can be placed on the carton, and then an equal amount of heavy objects are piled on the wooden board to roughly determine whether the compressive strength of the carton meets the requirements;
Fourth, Jinan carton factory http:// analysis of factors affecting the compressive strength of the carton
1. Raw material quality: The base paper is the decisive factor in determining the compression strength of the carton, as can be seen by the kellicutt formula. However, the influence of other conditions in the production process of corrugated cardboard is not allowed to be neglected, such as the amount of binder, high-impact impregnation, coating, and composite processing.
2. Moisture: The carton is made of corrugated cardboard with too high water content, or it can reduce its compressive strength when stored in a humid environment for a long time. Fiber is a kind of water-absorbent. When the rainy season and the humidity in the air are high, the relationship between the moisture content of the paperboard and the atmospheric environment is very important.
3. Box type: Box type refers to the type of box and the size ratio of boxes of the same type, which have a significant influence on the compressive strength. Some carton boxes are made of double-layer corrugated cardboard, and the compressive strength is obviously improved compared with the single-layer box of the same specification; under the same conditions, the higher the box, the worse the stability and the lower the compressive strength.
4. Printing and opening: Printing will reduce the compressive strength of the carton. Products with venting requirements are opened in the box surface, or punching the handle hole on the side of the box, which will reduce the strength of the carton, especially the large opening area, biased to a certain side, etc., the impact is more obvious.
5. Processing process deviation: In the process of box making, the pressure line is improper, the groove is too deep, the combination is not strong, etc., and the pressure resistance of the box is also reduced.
6. Carton dynamic performance test: For the packaging of some specific commodities, such as ceramics, glass products, electrical appliances, instruments, etc., it is also necessary to check the cushioning performance of the carton on the goods, that is, to simulate transportation, handling, vibration, drop and other tests;
Drop test: The carton after the packaged product is dropped from the specified height according to the posture of the package, and the goodness of the packaged goods in the carton after a certain number of times, or the number of times the carton is dropped when the carton is damaged.
Bevel impact test: Rotate the carton onto the trolley, then slide it off the slope of a certain height and finally hit the baffle. It is similar to the emergency braking situation during transportation.
Vibration test: The carton is packaged on a vibrating table and subjected to vibration in the horizontal and vertical directions, or simultaneously subjected to two-way vibration, and the time elapsed after checking the condition of the product or the destruction of the product carton after a certain period of time.
Hexagonal drum rotation test: Put the carton into the hexagonal rotary drum equipped with the impact plate, rotate according to the specified number of revolutions, and then check the damage of the goods and the carton.
The above dynamic experiments are destructive, and the ability to improve the resistance to damage to cartons and merchandise is the use of cushioning, baffles or other protective measures when packaging goods. In addition, some packaging cartons also need to be sprayed, weather-resistant and other experiments, according to the contractual agreement between the two parties.
Eva Colorful Building Blocks is consist of four different but classical colors. Made from Eco-friendly, closed cell, non-smell and non-toxic Eva Foam material, passes ASTM and EN71 certificates, the safety of this product is the last thing needs to be worried.
The Foam Building Blocks are easy to store and carry cause it is packed with a PVC bag with zipper. Also after a long time of playing, the blocks can be cleaned easily with water thanks to its closed cell foam.
Eva Colorful Building Blocks,Colorful Building Blocks,Colorful Eva Foam Building Block,Eva Colorful Foam Building Block,Colorful Foam Building Block,Colorful Educational Building Block
Huizhou Melors Plastic Products Factory , http://www.melorsfoam.com