Definition
The carton puncture strength tester is a specialized testing equipment used to evaluate the dynamic impact resistance of packaging materials. It measures the maximum energy required to resist puncture by simulating the sudden puncture of a cardboard or corrugated box by a sharp object, which is usually expressed in joules or kilogram-forces. This indicator is directly related to the protective performance of packaging against the impact of unexpected sharp objects during transportation and warehousing.
How it works:
The equipment is designed based on the principle of energy conversion and mechanical balance. Its core component includes a swingable swing arm with a poke-through head of a specific geometry at the end. During testing, the swing arm is released from a predetermined height, and its gravitational potential energy is converted into kinetic energy, driving the piercing head to pierce the specimen fixed to the fixture vertically. During the puncture process, the work done by the specimen resisting puncture is accurately recorded by the remaining swing angle of the swing arm or the sensor signal. According to the law of conservation of energy, the puncture intensity E can be calculated by the formula E = m * g * (h₁ - h₂), where m is the equivalent mass of the swing arm system, g is the acceleration due to gravity, and h₁ and h₂ are the starting height of the swing arm and the maximum height reached after puncture, respectively.
Measurement method
The measurement process follows standardized steps. First, the specimen of the specified size is prepared according to relevant standards (such as ISO 3036, GB/T 2679.7) and conditioned under standard temperature and humidity conditions. The specimen is clamped flat on the equipment fixture to ensure that there is no loosening or uneven preload. Adjust the swing arm to the horizontal starting position and lock it, releasing the mechanism so that the swing arm falls freely to complete the puncture. The puncture intensity value is displayed directly by the device or converted by a calibration curve. Each group of specimens was tested multiple times, with arithmetic mean as the final result and standard deviation calculated to evaluate data discreteness.
Influencing factors
Test results are influenced by multiple factors. In terms of materials, the fiber type, slurry ratio, laminate structure and moisture content of the paper base will change its toughness and tear resistance. In the instrument parameters, the shape and sharpness of the puncture head, the quality and release stability of the swing arm, and the uniformity of the clamping force of the fixture may all lead to data fluctuations. Environmental conditions such as temperature and relative humidity can affect the physical state of paper fibers. In the operation process, the flatness of specimen placement, the timing of swing arm release and the level calibration status of the equipment also need to be strictly controlled.
Applications:
This equipment is widely used in packaging manufacturing and use-related industries. In the production of cartons, it is used for raw material cardboard factory inspection, production process optimization and finished product quality verification. In the field of logistics and transportation, it provides a reference for impact resistance data for packaging design, helping to balance protective performance and material costs. Third-party testing agencies conduct conformity certification according to standards. In addition, the device is also a routine evaluation tool in packaging R&D laboratories in industries such as electronics, consumer goods, and food packaging.
Selection reference
Technical parameters and functional requirements should be comprehensively considered when selecting. The measurement range should cover the estimated strength value of the material to be measured, with a certain margin. The accuracy and resolution of the equipment should meet the requirements of relevant standards for repeatability and reproducibility. The puncture head specifications must comply with the applicable standards. The equipment should be equipped with automatic release, electronic angle measurement and data statistics functions to improve test efficiency and reliability. The structure design should be stable and the fixture should be easy to adjust. At the same time, consider the supplier's technical support capabilities, the availability of calibration services, and the adaptability of the equipment to the laboratory environmental conditions.