Cardboard stiffness refers to the ability of cardboard to resist deformation when subjected to a certain load, and is usually used to evaluate the strength and hardness of cardboard. The cardboard stiffness test can be calculated by measuring the deflection over a certain span. Common test methods include three-point and four-point bending methods. Cardboard stiffness is very important for some applications that need to remain flat and stable, such as cardboard used for packaging needs to have enough stiffness to protect the contents inside.
There are two main methods of measuring cardboard stiffness:
Beam bending test method:
The beam bending test method is a commonly used method to measure the stiffness of cardboard. This method uses a three-point bending Tester for measurement. A cardboard sample of a certain size is placed between two fulcrums, a standardized load is applied, and the stiffness index of the cardboard is calculated by measuring the deflection and bending moment of the cardboard under load, namely bending stiffness. The higher the index, the better the stiffness of the cardboard.
Box compression test method:
The box compression test is a method for evaluating the stiffness of paperboard by measuring its strength when subjected to a compressive load. This method uses a box-type compression testing machine for measurement. A cardboard sample of a certain size is placed on a compression platform, a standardized compression load is applied, and the stiffness index of the cardboard is calculated by measuring the deformation rate and compression force of the cardboard under load, namely Box compressive strength. The higher the index, the better the stiffness of the cardboard.
NBCHAO reminds you: the measurement results of cardboard stiffness are affected by many factors, including cardboard quality, light conditions, measurement methods and instruments, etc. Therefore, care should be taken to control these factors during measurement to ensure the accuracy of measurement results.
