Overview
The Cardboard Breakage Tester is a specialized testing device used to evaluate the resistance of cardboard, corrugated cardboard, and other related packaging materials to rupture under uniform vertical pressure. It works by clamping the specimen between a specific area of ring chucks and applying continuously increasing pressure under the specimen through a hydraulic or pneumatic system until the specimen breaks. The instrument records the maximum pressure value at the moment of rupture, known as breaking resistance, usually expressed in kilopascals (kPa) or pound-force per square inch (psi). This indicator is one of the key parameters to measure the mechanical strength, reliability and durability of packaging materials.
Technical principle
The breakage test is essentially a static strength test, which comprehensively reflects the tensile strength and elongation of cardboard in multiple directions. The testing process follows clear international and domestic standards to ensure comparability and accuracy of results. The core calculation formula is:
P = F / A
Among them, P represents the breaking resistance (unit: kPa), F is the total force applied when the specimen breaks (unit: N), and A is the effective area of the test film (unit: m²). The standard method strictly specifies the test speed, clamping force, film characteristics and other conditions. For example, common test speeds range from 95±5 mL/min. Different standards have specific provisions on the size of the specimen and the pretreatment conditions (temperature and humidity), and the temperature and humidity balance treatment should be carried out under standard atmospheric conditions before the test.
Application:
In the packaging industry, the application of cardboard breakage tester runs through the whole process of raw material acceptance, production process monitoring and finished product inspection.
First of all, in the raw material link, it is used to test the breaking strength of the incoming containerboard paper and corrugated base paper to ensure that it meets the procurement specifications and ensure the quality of the final carton from the source. Secondly, during the production process, regular sampling tests on the produced corrugated cardboard can monitor the stability of the production process, such as the quality of the adhesive and the corrugated molding effect. Finally, the inspection of the finished carton or cardboard is the direct basis for whether it can achieve the predetermined protection level, and whether the contents can resist external extrusion, impact and other risks during transportation.
The test data can be directly used to judge whether the product meets national or industry standards, such as GB/T 6545 "Determination of Corrugated Cardboard Burst Strength", ISO 2758 "Determination of Paper Burst Resistance", etc., which are also an important basis for quality grading and performance benchmarking within enterprises.
Influencing factors
The breakage resistance of cardboard is not determined by a single factor, but is affected by a combination of materials and process factors. Understanding these factors can help you make targeted quality improvements.
| Fiber raw materials and pulping process | Long-fiber slurries generally provide higher strength. Chemical pulp is better than mechanical pulp. |
| Paper quantitative and laminated structure | Quantitative increase generally improves breakage resistance. Multi-layer cardboard enhances performance through lamination effects. |
| The flute type and combination of corrugated cardboard | Different flute types (such as A, B, and C flutes) have different contributions to the breakage resistance of cardboard planes. |
| Adhesive quality and bonding effect | Insufficient bond strength can lead to separation between layers, significantly reducing overall breakage resistance. |
| Ambient temperature and humidity | Too high moisture content of the material will significantly reduce the bursting strength, so it needs to be treated with constant temperature and humidity before testing. |
Operational points
To ensure accurate and reliable test results, operators need to undergo professional training. Key operating points include: the specimen should completely cover the clamping area without wrinkles; The clamping force should be uniform and in line with the standard to prevent the specimen from sliding or prematurely rupture; Calibrate instruments regularly using standard aluminum foil sheets to verify the accuracy of hydraulic systems and pressure sensors. The test film should be replaced regularly according to the frequency of use to avoid fatigue or damage affecting the results.
Routine maintenance mainly includes keeping the instrument clean, especially the clamping area; Regularly check the hydraulic oil status and system tightness; Lubricate moving parts as recommended by the manufacturer. Establishing complete instrument use, calibration and maintenance records is a basic requirement of the quality management system.
Conclusion
As a key equipment for the detection of basic physical properties of packaging materials, the breakage resistance data provided by the cardboard breakage tester is an important scientific basis for evaluating the impact resistance and extrusion resistance of cardboard. Through standardized testing, it effectively serves the research and development, quality control and performance evaluation of packaging materials, helping manufacturers and users predict the performance of packaging during circulation, thereby optimizing material use, reducing costs and ensuring product safety. As the packaging industry becomes increasingly demanding for performance, the standardized and accurate use of this instrument will continue to play an important role.
References
GB/T 6545-1998, Corrugated cardboard -- Determination of bursting strength.
ISO 2758:2014， Paper — Determination of bursting strength.
TAPPI T 403 om-15， Bursting strength of paper.
Packaging Testing Technology, China Light Industry Press.