1. Appearance quality:

1. Printing quality: The pattern handwriting are printed clearly, the chromaticity is consistent, the brightness is bright; the printing position error does exceed 7mm for the large box, the small box does exceed 4mm;

2. Sealing quality: there are no loopholes around the box body, there is no unevenness seam after each box cover is closed;

3. Dimensional tolerance: the inner diameter design dimensional tolerance of the box should be kept within ±5mm for the large box ±3mm for the small box, the overall dimensions are basically the same;

4. Cover folding times: the corrugated carton flap is opened closed 180 degrees reciprocally folded more than 5 times, the total length of the cracks in the surface inner layers of the first second types of boxes the inner layer of the third types of boxes is more than 70mm;

In addition, the jointing specifications are required, the edges are neat, no corners are folded, the box surface is allowed to have obvious damage stains.

2. Kunshan carton compressive strength influencing factors

The carton compressive strength is the most important quality index required for many commodity packaging. During the test, the corrugated carton is placed between two pressure plates, the pressure when the carton is crushed is the compressive strength of the carton, expressed in KN.

1. The predetermined compressive strength of the carton

The cartons are required to have a certain compressive strength, because the cartons stacked in a very low layer are subjected to the pressure of the upper carton during the storage transportation of the packaged goods. In order to collapse, they must have appropriate compressive strength. The strength is calculated using the following formula:

P=KW（n-1）

P----carton compressive strength, N

W----Weight after loading the carton, N

n----stacking layer number

K-stacking safety factor

The number of stacking layers n is calculated according to the stacking height H the height of a single carton h, n=H/h

The stacking safety factor is determined according to the number of layers of goods stacking. The national standard stipulates:

Storage period is 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. Calculate the compressive strength of the carton according to the raw materials

After the compressive strength of the carton is predetermined, the appropriate carton board corrugated base paper should be selected to produce the corrugated carton to avoid the waste caused by blind production;

There are many formulas for calculating the compressive strength of cartons according to the ring compressive strength of the base paper, but the more concise practical is the Kellicutt formula, which is suitable for estimating the compressive strength of 0201 cartons.

3. Methods to determine the compressive strength of cartons

Due to the influence of various factors in the production process, the compressive strength of the final carton produced with raw materials may be exactly the same as the estimated result. Therefore, the final method to accurately determine the compressive strength of the corrugated carton is to use the carton to compress the carton after constant temperature wet treatment. Testing machine test; for small medium-sized factories without testing equipment, a wooden board can be covered on the carton, then the same amount of heavy objects can be stacked on the wooden board to roughly determine whether the compressive strength of the carton meets the requirements

4. Factors affecting the compressive strength of cartons

1) Quality of raw materials

The base paper is the decisive factor in determining the compressive strength of the carton, which can be seen the kellicutt formula. However, the influence of other conditions in the production process of corrugated board cannot be ignored, such as the amount of adhesive, the change of flute height, impregnation, coating, composite processing.

2) Moisture

The carton is made of corrugated cardboard with too high moisture content, stored in a humid environment for a long time, will reduce its compressive strength. Fiber is a kind of strong water absorption. In the rainy season when the air humidity is high, the moisture balance between the moisture in the cardboard the atmospheric environment is very important.

3) Box type

Box type refers to the type of box the size ratio of the same type of box, they have a significant impact on the compressive strength. Some cartons are made of double-layer corrugated cardboard, their compressive strength is significantly higher than single-layer boxes of the same specification; under the same conditions, the higher the box, the worse the stability the lower the compressive strength.

4) Printing opening

Printing will reduce the compressive strength of the carton. For products that require ventilation, opening holes on the surface of the box punching the handle holes on the side of the box will reduce the strength of the carton, especially if the opening area is large, the effect is more obvious.

5) Processing deviation

5) Deviations in processing technology. Improper crimping, excessively deep grooves, weak bonding during the box making process will also reduce the compressive strength of the box. 

3. 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 test the cushioning performance of the cartons to the commodities, that is, to simulate transportation, loading unloading, vibration, drop tests;

1. Drop test

Drop the carton after the packaged goods the specified height in a different posture, check the goodness of the packaged goods in the carton after a certain number of times, the number of drops when the carton is damaged.

2. Inclined impact test

Rotate the carton on a trolley, then slide it off a slope of a certain height, finally hit the baffle. It is similar to an emergency braking situation during transportation.

3. Vibration test

Place the carton packaged goods on a vibrating table, subject them to horizontal vertical vibration, at the same time two-way vibration. After a certain period of time, check the condition of the goods the time elapsed when the carton of the goods is destroyed.

4. Hexagonal drum rotation test

Put the carton into a hexagonal rotating drum equipped with an impact plate, rotate it according to the specified number of revolutions, then inspect the damage of the goods the carton.