Test Method For Casters

1. Impact test

Any item may collide and vibrate due to transportation, use, storage, etc., but the product will be defective or even unusable for a certain period of time. Furniture is often vulnerable to impact due to its large size and weight, and it is located at the bottom to determine whether the furniture is placed or not. Stable casters should have good impact resistance. The impact test method in the European caster test standard is: install the caster vertically on the ground test platform, and make the weight of 5KG (±2%) fall freely from the height of 200mm to impact the wheel edge of the caster. If it is two wheels, both wheels should impact at the same time. No part of the caster was allowed to separate during the entire experiment. And after the experiment is completed, the rolling of the casters, the rotation around the axis or the braking function should not be damaged.

2. Static load test

The universal wheel should always run stably on the ground, however that is almost a purely theoretical state. On uneven surfaces, or when crossing thresholds, tracks and potholes, the casters briefly leave the ground. So when they are suddenly overloaded or when 3 of the 4 casters touch the ground, they must carry the load of the entire furniture. The test process of the static load of the caster in the European standard is that the caster is fixed on a horizontal and smooth steel test platform with screws, and a force of 800N is applied along the direction of the center of gravity of the caster for 24H. After the force is removed for 24 hours, the condition of the caster is checked. If the deformation of the caster does not exceed 3% of the diameter of the wheel, and the rolling of the caster after the experiment is completed, the rotation around the axis or the braking function is not damaged, it is qualified.

3. Resistance performance test

When testing this performance, the caster should be kept dry and clean. Place the caster on a metal plate insulated from the ground, keep the edge of the wheel in contact with the metal plate, and load the caster with 5% to 10% of its nominal load. Use an insulation resistance value tester (nominal open circuit voltage is 500V, the measured resistance value fluctuates within 10% and the loss on the product does not exceed 3W) to measure the resistance value between the caster and the metal plate. For conductive casters, the resistance should be no more than 104 ohms, while for antistatic casters the resistance should be between 105 ohms and 107 ohms.

4. Reciprocating wear test

The reciprocating wear test of casters simulates the actual rolling situation of casters in daily use. It is divided into two types: obstacle test and no obstacle test. Install the casters correctly and place them on the test platform. The load of each test caster is 300N. The test frequency is (6-8) times/min. One test cycle includes a back-and-forth movement of 1M forward and 1M back and reverse. The test is performed on a test platform with obstacles (metal obstacles, width 50mm, height 2mm-3mm). 5000 times (H type casters) or 30000 times (W type casters). 70,000 cycles (H-type casters) or 20,000 cycles (W-type casters) on an unobstructed horizontal test bench. No casters or other parts are allowed to detach during the test. After the test, each caster should be able to run its normal function. After the test, the rolling, pivoting or braking functions of the casters should not be damaged.

5. Rolling resistance and rotation resistance measurement

When the caster moves or wants to control its running direction, the force must be transmitted to the caster through the object and overcome a certain resistance. The size of the resistance depends on: load, wheel diameter, wheel material, wheel surface shape, and the situation of the site where the caster rotates. Wait. For the test of rolling resistance, the standard is to install three casters on a fixed three-arm base. According to different test levels, a test load of 300/600/900N (including the mass of the base) is applied to the base. A horizontal traction force makes the casters on the test platform travel at a speed of 50mm/S (allowable deviation ±5%), and keep it for 10S. Due to the large friction force and an acceleration when the caster rolls at the beginning, the horizontal traction force is measured after the test is carried out for 5S, and its size does not exceed 15% of the test load to be qualified. Rotational resistance testing is performed by mounting one or more casters on a linear or circular motion tester so that it is oriented 90° to the direction of travel. According to different test levels, a test load of 100/200/300N is applied to each caster. Apply a horizontal traction force to make the casters on the test platform travel at a speed of 50mm/S (allowable deviation ±5%), and rotate within 2S. Record the maximum horizontal traction force that makes the caster rotate, and its size does not exceed 20% of the test load to be qualified.