As a key component of low-speed elevators, the aging degree of the plastic low-speed elevator compensation chain after long-term use directly affects the safety of elevator operation, and needs to be comprehensively evaluated through multi-dimensional testing methods. First, the appearance can be inspected to carefully observe whether there are discoloration, cracks, deformation or wear signs on the surface of the low-speed elevator compensation chain. Plastic materials are prone to molecular structure changes under long-term light and oxidation. The surface may lose its original gloss and show aging characteristics such as yellowing and whitening. The generation of fine cracks may indicate a decrease in material toughness, and it is necessary to be vigilant about the risk of fracture; the distribution and degree of wear marks can reflect the friction between it and components such as guide rails and cars. Severely worn areas are often weak points in strength.
Touch inspection is also an important link. The texture and elasticity changes of the low-speed elevator compensation chain can be sensed by hand contact. Under normal conditions, the plastic low-speed elevator compensation chain should have uniform texture and moderate elasticity. The aged material will become stiff and brittle due to polymer chain breakage or excessive cross-linking. When touched, it can be clearly felt that the hardness has increased and the flexibility has decreased, and even partial fragmentation occurs under slight pressure. At the same time, the chain link connection parts should be checked to see if they are loose or deformed due to aging to ensure the stability of the overall structure.
Thickness measurement with the help of professional tools can deeply evaluate the degree of wear. The friction between the low-speed elevator compensation chain and the surrounding parts during long-term operation will cause the thickness to be thinned. Use calipers and other equipment to measure at multiple points in different positions and compare the original data or design standards. If the local or overall thickness exceeds the allowable deviation, it means that the wear has affected its load-bearing capacity. In particular, the area with uneven thickness may cause safety hazards due to stress concentration. It is necessary to combine other test results to determine whether it needs to be replaced.
The bending test can intuitively reflect the flexibility and fatigue resistance of the material. Select a typical section of the low-speed elevator compensation chain, bend it with slow and uniform force, and observe its performance during deformation. Normal materials should be able to bend flexibly and return to their original state without obvious creases or cracks; if the resistance increases and the action is stiff during bending, or the surface turns white or micro-cracks appear after bending, it indicates that the plastic has aged and become brittle, and the internal structure is damaged, resulting in a decrease in mechanical properties, and it cannot withstand the frequent stretching and bending loads during elevator operation.
Tension testing is a key means to verify the load-bearing capacity of the low-speed elevator compensation chain. Special equipment is used to apply gradually increasing tension to the low-speed elevator compensation chain to simulate its stress state during elevator operation, and to observe the deformation and damage of the material in real time. The tensile strength of the aged plastic decreases, and it may deform, crack or even break when the load is lower than the design load. By recording the critical tensile value and comparing it with the initial performance index, it can accurately determine whether its safety margin meets the use requirements and provide a quantitative basis for maintenance decisions.
Microscopic testing can reveal the aging mechanism from the material structure level. Microscopes and other equipment are used to observe tiny samples of the low-speed elevator compensation chain and analyze microscopic characteristics such as the arrangement state of the polymer chain and the bonding between the filler and the matrix. During the aging process, the polymer chain will degrade and break, the originally dense structure will become loose, and the filler and the resin matrix may separate. These changes will directly lead to the degradation of material performance. Through microscopic analysis, not only can the degree of aging be accurately determined, but also technical direction can be provided for optimizing material formulation and improving durability.
In addition, it is crucial to establish a long-term monitoring mechanism in combination with elevator operation data. Statistics on the elevator's operating time, frequency, load and other parameters are analyzed to analyze their correlation with the aging speed of the low-speed elevator compensation chain. For example, in elevators that operate at high frequencies and with heavy loads, the aging process of the low-speed elevator compensation chain is usually faster. By making longitudinal comparisons of regular inspection data and drawing aging trend curves, the remaining service life of the low-speed elevator compensation chain can be predicted, and maintenance plans can be made in advance to avoid sudden failures affecting the normal operation of the elevator, thus achieving a shift from passive maintenance to active prevention and ensuring the safety and reliability of the elevator system.
