Test method for casters
Test method for casters
Casters must be tested before they are put on the market to meet the standards for use. So what are the common caster test methods? What are the requirements in the test?
1. Impact test
Any items for transport, use, preservation conditions will impact vibration may be produced but the product such as adverse even cannot be used in a certain period of time, type furniture with its big, weight and other characteristics are often vulnerable to the impact, and at the bottom to determine whether furniture placed smooth castor is more should have good impact resistance. The impact test method of the European caster test standard is: the caster is vertically inverted installed on the ground test platform, so that the weight of 5KG (±2%) from the height of the position of 200mm free drop impact caster wheel edge, if two wheels, two wheels should impact at the same time. No part of the caster is allowed to separate during the whole experiment. After the experiment is completed, the caster’s rolling, axis rotation or braking function should not be damaged.
2. Static load test
The universal wheel should always operate stably on the ground, but that is an almost purely theoretical state. On uneven surfaces, or when crossing thresholds, rails, and pits, casters will briefly lift off the ground. So when they are suddenly overloaded or when three of the four casters touch the ground, they must carry the load of the whole furniture. The static load test process of castor in European standard is that the castor is fixed on the horizontal smooth steel test platform with screws, and 800N force is applied along the center of gravity direction of the castor for 24H. After 24 hours of force is removed, the condition of the castor is checked. The deformation of the castor is not more than 3% of the diameter of the wheel, and the rolling of the castor after the completion of the experiment. No damage to shaft rotation or braking function is qualified.
3.Resistance performance test
The casters shall be kept dry and clean when tested by placing them on a metal plate insulated from the ground, keeping the edges in contact with the metal plate, and loading the casters with 5% to 10% of their nominal load. use insulation resistance tester (nominal open circuit voltage is 500v, the measured resistance value fluctuation within 10% and the loss on the product does not exceed 3w) to measure the resistance value between the castor and the metal plate. for conductance casters, the resistance is not less than 104 ohms, while for antistatic casters, the resistance should be between 105 ohms and 107 ohms.
4. Reciprocating wear test
Castor reciprocating wear test to simulate the casters in daily use the actual rolling, the two points with and without obstacles obstacles test test, the trundle put to the test platform is installed correctly, each test caster wheel load of 300 n, test frequency for six to eight times/min, a test cycle includes forward 1 m and 1 m back to reverse a movement back and forth, Test 5000 times (H casters) or 30000 times (W casters) on a test platform with obstacles (metal obstacles, 50mm wide, 2mm-3mm high). 70000 cycles (H casters) or 20000 cycles (W casters) on a horizontal test bench without obstacles. no casters or other parts are allowed to detach during the test. after the test, each caster shall be able to operate its normal function, and the rolling, shaft rotation or braking function of the caster shall not be impaired after the test is completed.
5. Rolling resistance and rotation resistance measurement
when the caster moves or controls its direction, the force must pass through the object to the caster and overcome a certain resistance, which depends on the weight, diameter of the wheel, material of the wheel, shape of the wheel face, and the situation in which the caster rotates, etc. for rolling resistance test, the standards are three casters will be installed in a three arm of the base, according to the different levels of tests, the 300/600/900 n load test (including the quality of the base) applied to the base, put a horizontal traction made the caster wheel speeds on the test platform of 50 mm/s (deviation plus or minus 5% allowed), keep 10 s. since the friction force is large and there is an acceleration at the beginning of caster rolling, the horizontal traction force is measured after 5s test, and its size does not exceed 15% of the test load. the rotary resistance test is performed by installing one or more casters on a linear or circular motion tester so that the direction is 90° from the driving direction. a test load of 100/200/300n was applied to each caster according to different test levels. a horizontal traction force was applied to make the casters on the test platform travel at a speed of 50mm/s (±5% deviation allowed) and turn within 2s. the maximum horizontal traction force to turn the casters is recorded, and its size does not exceed 20% of the test load.