How to equip corrugated box enterprises with detectors
the compressive strength of cartons is divided into effective value and final value. During the compression test, the force value sometimes changes from slow to fast, directly to the collapse point, and some increase steadily to the collapse point. In the long-term compression test, we found that the change of force value sometimes has a certain buffer: that is, when the force value and deformation increase to a certain extent, the force value stops and the deformation continues to increase. After a period of time, the force value continues to increase until the collapse point of the carton. We can call the force value before buffering as effective value, and the deformation before buffering as effective deformation. After buffering, although the force value can continue to increase, the carton has begun to deform and cannot meet the requirements of promoting the progress and development of plastic blending technology, new plastic additives and utilization technology. Therefore, the standard for judging the compressive strength of the carton should be the effective value during the compressive test
how many factors affect the compressive strength
1. cartons are composed of paper at all levels, and the reasonable allocation of paper is the basic condition to ensure the compressive strength of cartons
by testing the physical properties of the paper at all levels, we can preliminarily calculate the compressive strength of the carton, and then control the compressive strength of the carton in each process of the production process by calculating the compressive strength one month before the end of the warranty period
2. the annular compressive strength of paper is the key to ensure the compressive strength of cartons, but other physical properties of paper can not be ignored. When the tensile strength of paper, especially corrugated paper, is not enough, the force value and deformation of cartons will increase steadily in the compression test, the final value is very high and the effective value is very low, and the box will deform like an accordion after the test. The waterproof performance of paper is also very important, especially the refrigerator has higher requirements for the waterproof performance of paper. Sometimes, although the compressive strength of the carton is very high, because the paper is not waterproof, the carton is easy to absorb moisture when stored in the cold storage, resulting in the collapse of the warehouse
3. the production process of cartons will also affect the compressive strength
according to the test, under the same conditions, the compressive strength of the carton decreases by 90N ~ 130n and the deformation increases by about 2mm for each 1mm of widening of the transverse pressing line of the carton. The pressing line is too wide, It will cause the strength value of cartons during the compression test. Ross van royen, senior marketing manager of controlled products of teknor apex TPE business unit, pointed out: "The key to extrusion blow molding is to control the slow increase of parison wall thickness, small effective value and large final deformation. In order to ensure the compressive strength, we should try our best to improve the production process and reduce the impact of various processes on the compressive strength of cartons.
4. It is also crucial to select the appropriate corrugated type according to the carton type.
in people's consciousness, it is often believed that the larger the corrugated type, the higher the compressive strength of cartons, and it is easy to ignore the influence of corrugated type on deformation Influence of quantity. The larger the ridge, the greater the compressive strength of the carton and the greater the deformation; The smaller the ridge, the smaller the compressive strength of the carton and the smaller the deformation. If the carton is too large, but the corrugated shape is very small, the carton is easy to be crushed during the compression test; The carton is too small, but the corrugated shape is very large. During the compression test, the deformation will be too large, the cushioning process will be long, and the deviation between the effective value and the final force value will be too large
5. The influence of moisture on the compressive strength of cartons should not be ignored
the production environment, storage environment, use environment, weather, climate and other factors of the carton will affect the moisture content of the carton. In order to ensure the compressive strength of the carton, we should try to avoid the influence of the external environment on the moisture content of the carton and keep the carton dry