Selection suggestions
The compressive strength of cardboard is a key index for evaluating its compressive performance, which directly affects the bearing capacity and transportation safety of packaging containers. Choosing the right testing machine is crucial to ensure the accuracy and reliability of test results. This article will provide a reference for selection from the aspects of technical parameters, standard compliance and practical application requirements.
Performance parameter considerations
The core performance parameters of the testing machine directly determine the effective range and accuracy of the test. The following aspects should be focused on when selecting:
Force value range
The maximum compression force expected to be tested should be covered with an appropriate margin. For example, if the maximum compressive force of the sample is expected to be 5000N, it is recommended to choose equipment with a range of not less than 6000N. A small range may lead to overload, and a large range may reduce the measurement accuracy in the low force range.
Accuracy level
According to the requirements of relevant standards (such as ISO 3035, GB/T 6546), the accuracy of the force value system of the testing machine should usually not be less than ±1%. The resolution of the displacement measurement system also needs to meet the standard specifications to ensure the accuracy of the deformation data.
Test speed
The compression test requires the platen to move at a constant speed. The test speed range (e.g. 12.5±2.5 mm/min) is usually specified in the standard. When selecting a model, it is necessary to confirm whether the speed control range and accuracy of the testing machine can meet the requirements of the applicable standards.
Structure and function
The mechanical structure and additional functions of the testing machine affect the ease of operation and the diversity of testing.
Space dimensions
The compression tester's platen size, headroom distance between the upper and lower platens (opening height), and stroke must be able to accommodate the maximum size of the sample to be tested (e.g., full box or corrugated cardboard side pressure specimen).
Platen parallelism
The upper and lower platens should be kept highly parallel during testing, which is a key mechanical property to ensure even pressure distribution and avoid deviations in results.
Data collection and processing
Modern equipment is usually equipped with a computer control system, which can automatically collect the force-displacement curve and directly calculate the maximum compressive force, compressive strength and other results. Whether the software supports the relevant standard testing process and whether the report format is flexible are also important considerations.
Standard conformity verification
Ensuring that the selected equipment and its methods meet the technical standards recognized by the target market or industry is the basis for selection. Different standards may differ in specimen preparation, fixtures, test speeds, etc.
The common relevant standards are listed below:
| ISO 3035 | Determination of flat compressive strength of single-walled and double-walled corrugated board |
| ISO 13821 | Determination of compressive strength of corrugated board edges (short column method) |
| GB/T 6546 | Determination of corrugated cardboard edge compressive strength |
| GB/T 2679.6 | Determination of flat compressive strength of corrugated base paper |
| TAPPI T822 | Corrugated cardboard edge compressive strength test |
When selecting, request a declaration of conformity or calibration certificate for the equipment to the relevant standards from the supplier.
Application scenarios
The choice is based on the type of daily testing in the laboratory and the possible future needs.
High-frequency test environments should prioritize equipment durability, stability, and automation to improve efficiency and reduce operational errors.If the laboratory needs to perform ring pressure strength (RCT) and other tests in addition to standard side pressure and flat pressure tests, it should consider whether the equipment supports the replacement of corresponding fixtures or accessories, that is, the expandability and versatility of the equipment.The equipment should be able to work stably in the temperature and humidity environment of the laboratory. For laboratories that need to simulate testing in specific climatic conditions, consider whether the equipment can be used in or in conjunction with a temperature and humidity chamber.
Technical support
Reliable technical support and after-sales service are important factors to ensure the long-term stable operation of equipment. It is recommended to pay attention to whether the supplier provides comprehensive installation training, operational guidance, regular calibration services, and timely technical response and maintenance support.
Selection process suggestions
It is recommended to follow the following steps for systematic selection: first, clarify the list of test standards and the scope of test samples mainly followed by the laboratory; Secondly, based on the standard requirements and sample characteristics, the requirements for core parameters such as force range, accuracy, speed, and space size of the equipment are determined. Subsequently, the matching degree of different models of equipment in terms of functional characteristics, standard compliance, and expansion ability is evaluated. Finally, comprehensively consider the supplier's technical support capabilities and full life cycle costs to make a decision.
Summary
Choosing a cardboard compressive strength tester is a comprehensive decision that balances technical parameters, standard requirements, practical applications, and long-term service. By systematically evaluating all of the above factors, a reliable, suitable and forward-looking equipment can be selected for the laboratory, so as to provide solid data support for the quality control and research and development of paperboard and paper packaging products.
References:
ISO 3035:2011, Corrugated fibreboard — Determination of flat crush resistance.
ISO 13821:2020, Corrugated fibreboard — Determination of edgewise crush resistance (short column test).
GB/T 6546-2021, Determination of edge compressive strength of corrugated cardboard.
TAPPI T822 om-21, Edgewise Compressive Strength of Corrugated Fiberboard (Short Column Test).