1. Impact test
Transportation, use, and storage can often cause items to collide and vibrate, resulting in defects or rendering the product unusable for a certain period of time. Furniture, especially due to its large size and weight, is particularly susceptible to impacts and is typically placed at the bottom to determine its positioning. To ensure stability, casters used for furniture should possess excellent impact resistance.
The European caster test standard specifies an impact test method. It involves installing the caster vertically on a test platform positioned on the ground. A 5KG weight is dropped freely from a height of 200mm, targeting the wheel edge of the caster for impact. In the case of two wheels, both wheels must be impacted simultaneously. Throughout the entire experiment, no part of the caster is allowed to detach. Moreover, once the experiment is concluded, the casters should not have any damage to their rolling, rotation around the axis, or braking function.
In summary, items can suffer from collisions and vibrations during transportation, use, storage, and more. This can lead to defects or render products unusable for a period of time. Furniture is especially vulnerable due to its large size and weight, often being placed at the bottom to determine its placement. For stable furniture casters, it is crucial to have strong impact resistance. The European caster test standard outlines a method where a 5KG weight is dropped from 200mm height to impact the wheel edge of the caster, ensuring it remains intact and unaffected by the experiment. After completion, the casters should not exhibit any damage to their rolling, rotation, or braking.
2. Static load test
It is ideal for the universal wheel to maintain stable movement on the ground, although in reality, this is mostly a theoretical concept. Uneven surfaces, thresholds, tracks, and potholes cause the casters to momentarily lose contact with the ground. As a result, when the casters suddenly bear excessive weight or when three out of four casters touch the ground, they have to support the entire load of the furniture. The European standard for testing the static load of the caster involves fixing it onto a horizontal and smooth steel test platform using screws. A force of 800N is then applied in the direction of the caster's center of gravity for a duration of 24 hours. After this period, the force is removed, and the condition of the caster is evaluated. To qualify, the caster should not deform beyond 3% of the wheel's diameter. Additionally, it should continue to roll smoothly without any damage to its rotation around the axis or braking function.
3. Resistance performance test
To ensure accurate performance testing, it is important to keep the caster dry and clean. Follow these steps: place the caster on a metal plate that is insulated from the ground. Make sure the edge of the wheel is in contact with the metal plate. Load the caster with 5% to 10% of its nominal load. Now, utilize an insulation resistance value tester with a nominal open circuit voltage of 500V. It is essential that the measured resistance value fluctuates within 10% and the product's loss does not exceed 3W. Measure the resistance value between the caster and the metal plate. For conductive casters, the resistance should not exceed 104 ohms. However, for antistatic casters, the resistance should fall within the range of 105 ohms to 107 ohms. It is crucial to adhere to these guidelines for accurate and reliable testing.
4. Reciprocating wear test
The assessment of casters' durability involves the reciprocating wear test, which aims to replicate the real-life rolling conditions that casters experience during daily use. This test includes two variations: the obstacle test and the no obstacle test. To conduct the test, the casters are correctly installed and placed on the designated testing platform. Each caster is subjected to a load of 300N, and the test frequency varies between 6 and 8 times per minute. One test cycle encompasses a forward movement of 1 meter, followed by a backward movement of the same distance. This pattern is repeated to mimic real-life back-and-forth rolling movement.
The tests are carried out on a specially designed platform that includes metal obstacles with a width of 50mm and a height ranging from 2mm to 3mm. The casters with an H type are subjected to 5,000 cycles for the obstacle test, and 30,000 cycles for the no obstacle test. On the other hand, the casters with a W type must endure 70,000 cycles for the obstacle test and 20,000 cycles for the no obstacle test on a smooth, horizontal test bench without obstructions.
During the tests, it is crucial that no casters or any other components detach from the casters. Additionally, after completion of the test, each caster must be capable of functioning normally. The rolling, pivoting, and braking functions of the casters should remain intact, without any damage.
Measurement of rolling resistance and rotation resistance is an important aspect in various industries. Rolling resistance refers to the force required to keep a rolling object in motion on a surface, while rotation resistance pertains to the resistance faced by rotating objects. These measurements are significant in fields such as transportation, engineering, and manufacturing.
To measure rolling resistance accurately, several parameters need to be considered. These include the type of surface, applied force, speed of the object, and the load it carries. Various instruments and apparatus are used to conduct these measurements, such as force sensors, dynamometers, and rolling resistance test machines. By applying precise force and monitoring the movement of the object, the rolling resistance can be determined.
Similarly, rotation resistance measurement is crucial for evaluating the efficiency and performance of rotating equipment. This includes machinery such as engines, turbines, bearings, and gears. By measuring the resistance faced during rotation, potential problems like friction, misalignment, or structural issues can be identified. This allows for timely maintenance and troubleshooting, thereby ensuring optimal functionality and minimizing downtime.
In both cases, accurate measurements are essential for improving efficiency, reducing energy consumption, and enhancing product quality. By understanding the factors affecting rolling resistance and rotation resistance, manufacturers and engineers can make informed decisions regarding design, materials, lubrication, and operational parameters.
Overall, rolling resistance and rotation resistance measurement are critical practices in various industries. They enable businesses to optimize their processes, ensure safety, and enhance overall performance. By continuously monitoring and analyzing these resistances, organizations can make informed decisions to improve their products, reduce costs, and stay competitive in the market.
To manage the direction and movement of a caster, force must be applied to overcome resistance. This resistance is affected by factors such as load, wheel diameter, wheel material, wheel surface shape, and the terrain where the caster operates.
The rolling resistance of a caster is tested by fixing three casters onto a three-arm base and applying a test load of 300/600/900N to the base. The casters are then horizontally pulled at a speed of 50mm/S for 10 seconds, with the horizontal traction force measured after five seconds. To pass the test, the measured force must not exceed 15% of the test load.
Rotational resistance is tested by placing one or more casters onto a linear or circular motion tester and applying a test load of 100/200/300N to each caster. The casters are then horizontally pulled at a speed of 50mm/S while rotating, with the maximum horizontal force recorded. To pass the test, the measured force must not exceed 20% of the test load.