Introduction
As a packaging material, corrugated cardboard's impact resistance directly impacts its ability to protect the contents during transportation. Lateral breaking resistance is one of the key indicators to measure the impact resistance of corrugated board in the direction perpendicular to the board surface. The transverse breakability tester provides a quantitative basis for evaluating the mechanical properties of corrugated cardboard by simulating the actual impact conditions. Based on relevant standards and technical literature at home and abroad, this paper discusses the application of this instrument in the evaluation of impact resistance of corrugated cardboard.
Instrument principle
The transverse breakage tester usually adopts the pendulum impact principle. The instrument holds the specimen on a specific fixture, allowing the pendulum to be released from a predetermined height and impacting the center area of the specimen. By measuring the energy change before and after the impact of the pendulum, the energy required for sample rupture, i.e., the transverse breakability value, is calculated. The process can be expressed as:
E = mgh1 - mgh2
where E is the energy absorbed by the specimen (unit: joule), m is the mass of the pendulum, g is the acceleration of gravity, h1and h2They are the initial height of the pendulum and the height of the rebound after impact.
Test methodology
Testing is carried out according to standard procedures. Specimens should be taken from flat areas of corrugated cardboard to avoid wrinkles or damage. The common specimen size is 100 mm × 100 mm, and the number is not less than 10 to ensure statistical reliability. Before testing, the specimen needs to be adjusted to equilibrium under standard temperature and humidity conditions. Instrument calibration includes pendulum shaft friction verification and energy scale verification. During the test, the pendulum impact velocity should be kept stable, the rupture energy value of each specimen should be recorded, and the average value and coefficient of variation should be calculated.
Performance correlation analysis
The lateral breaking resistance is closely related to the multi-layer structural characteristics of corrugated cardboard. The shape of the corrugated core layer, the weight of the tissue paper and the strength of the adhesive all affected the test results. The results show that the breakage resistance value increases with the increase of core paper stiffness, and the relationship can be roughly described as a linear trend. In addition, changes in ambient humidity can lead to changes in the moisture content of cardboard, which in turn affects fiber binding, and environmental conditions need to be recorded during testing to assist in data analysis.
Data application
The test data can be used to compare the impact resistance of corrugated board in different processes and guide production process adjustments. For example, comparing cardboard data from different flute types (e.g., A-column, C-column) can evaluate the contribution of structural design to breakage resistance. Long-term monitoring data helps establish a baseline for quality control and detect fluctuations in material performance in a timely manner. The data can also be used as a packaging design input parameter to calculate safe transport thresholds.
Notes:
During operation, it is necessary to ensure that the specimen is clamped evenly to avoid local stress concentration. Regularly check the wear of the pendulum bearings to prevent energy loss. The fixture should be cleaned after testing to prevent the accumulation of paper scraps from affecting accuracy. If the specimen breaks at the clamping edge, the data should be considered invalid and retested. The test parameters of different standard systems (such as ISO and ASTM) may be different, and it is necessary to confirm the consistency of test conditions when comparing the data.
Epilogue
The transverse breakability tester provides a reliable method for evaluating the impact resistance of corrugated cardboard. Through standardized testing and data analysis, the structural properties of materials can be effectively reflected, providing support for packaging material research and development and quality control. In the future, combined with digital sensor technology, it is expected to achieve higher accuracy and automation of the testing process.
References
1. Standard for testing methods for physical properties of corrugated cardboard, Compilation of International Standards for Packaging Material Testing, 2020.
2. Mechanical Properties Evaluation Technology of Paper Products, Journal of Paper Science and Technology, No. 3, 2019.
3. Research on the impact resistance mechanism of packaging materials, Journal of Transportation and Packaging Engineering, 2021 Supplement.