Back freight, is the most concern thing for the packaging box manufacturers. Why customer return the paper packaging boxes, the most reason is the box is too soft. During our packaging manufacturing career, the most reason for sales reture is that the boxes are too soft.
Corrugated color boxes become the first choice of most products packaging by its excellent printing and buffer performance. The first priority of the packaging box is to protect goods, so paper box's compressive strength determines its ability to fulfill its responsibilities.
The greatest damage to goods is its packaging box can’t be hard up, at critical moment, paper packaging box cannot be soft!
Methods of resolution:
corrugated board is consist by surface paper, Medium paper,inner paper and fluting paper.
Single wall corrugated board, called two layers corrugated board.
Double-wall corrugated board, called theree layers corrugated board.
Triple -wall corrugated board, called five layers corrugated board.
Four- wall corrugated board, called seven layers corrugated board.
1. Material
If the box is too soft, the customers' first reaction will be to blame packaging plant "jerry”. It is conceivable that the material is the decisive factor. If there is no suitable material, design, production and more efforts, finally still are jerry-built projects.
The layer and thickness of corrugated paper can decide the compressive strength of corrugated color box.
The same layer of different corrugated boards, core paper will determine the stiffness and strength of corrugated board.
Sometimes, customers want the box to be hard enough, blindly increase the thickness of the surface of paper, actually has a poor effect.
2. Box- shaped
Different box types have different compressive strength. We often design different box types according to the weight of the products, and the function of the box packaging(sales packaging or logistics packaging) ,to meet the needs of customers against compressive strength.
(Box type and the compressive strength: c>b>a)
3. The direction of the corrugated paper
For corrugated carton, the longitudinal compressive strength is much higher the horizontal.
Tube type folding paper color box adopts vertical stripes, the corrugated stripe is to perpendicular to the ground.
3. The direction of the corrugated paper
The corrugated stripe of disc folded paper color box is to parallel with the shorter side, this arrangement is to obtain relatively high compressive strength as far as possible.
4. Box size design
The compressive strength for the four corners of corrugated carton is the highest, more farther from box angle, lower compressive strength.
Experiments show that: Aspect ratiofor the highest compressive strength: 1.4:1;
If regard stacking and beauty: 1.5:1 is the best proportion.
If regard handling, when built-in content is less than the total weight 20 kg, length is less than 70 cm, width is less than 40 cm, it is the most convenient handling.
The best aspect ratio for Compressive strength is L:W=1.4:1
The best aspect ratio for Stacking stability is L:W=1.5:1
The best aspect ratio for beautiful modelling is L:W=1.618:1
Taken together, the best aspect ratio is L:W=1.5:1
5. Moisture
When sorrugated paper moisture content is in 9% ~ 12% , the degree of burst and compressive strength are the best.
Customers often complain the box is too soft,.To catch delivery, has not been dry enough, the cartons are package and deliveied. After sealing ,water cannot release, the box will be soft.
Even box has been delivered, if improper storage, if encounter damp weather,and air humidity is more than 50%, box water content will be overweight.
If there are any evil wet weather, need a smoke wet machine, Keep the temperature and humidity of the workshop.
Temperature is 23°C+-2°C
Humidity is 50%+-5%.
6. Corrugated Paper moulding pressure
Some customers don't want to see the cut surface of the corrugated box, and there are some factories to prevent the bad paper moulding, increase the pressure of the press machine too much, or glue roller pressure, led to the compressive deformation of the corrugated board, then damage the compressive strength of corrugated paper box.
Maintaining the original corrugated shape, the compressive strength is the highest.
Corrugated board is flatten by automatic paper moulding machine, the corrugated paper become thinner.
7. Goods package direction
When package the goods into the corrugated box, Try to make the product stand, to make full use of the support of goods itself.
8. Warehouse stacking
Superimposed stacking, because of the diagonal line, line to line, so the compressive strength is high, but transportation is not stable, easy to tip over.
Crisscross stacking, good stability, but low compressive strength.If the carton length ratio is designed to be 1.5:1, can care about compressive strength.
Compressive strength, is not only the responsibility of the production process, in the process of storage and transportation, scientific stacking and carefully put is also important.
