wooden clothes' lockers - Specification
1988 Edition

The strength tests simulate practical use by applying various loads and forces including static, fatigue, and impact loads to different parts of the furniture. These loads are applied according to prescribed values and cycles to assess initial strength, durability under repeated use, and resistance to misuse. Accuracy in load measurement is maintained within ±15%, and loads are applied using calibrated masses or devices ensuring consistent force distribution. Static loads are held for a minimum of 10 seconds per cycle with a recommended maximum loading rate of six cycles per minute, allowing for reliable and repeatable evaluation of structural integrity.

The sustained load test is performed when the vertical static load test shows deflections exceeding defined thresholds based on material type. The furniture item is positioned on the floor, and a uniform load specified in the standard is applied on the top surface and maintained continuously for seven days. Post this duration, the maximum deflection is measured and compared against permissible limits: span/150 for wood-based materials, span/250 for particle board, and span/100 for other materials. This test ensures the furniture can withstand long-term static loads without excessive deformation.

Impact testing requires a specialized impactor apparatus with a mass not less than 17 kg (excluding springs), total assembly weight around 25 kg, and a striking surface made of a flat leather pad sprinkled with fine dry sand. The device includes springs of specific length and spring rate to control impact force. Fatigue tests utilize equipment capable of applying repeated cyclical forces or movements to simulate everyday usage stresses, assessing the furniture's durability under prolonged cyclic loading. These apparatuses conform to the detailed specifications prescribed in the standard to ensure consistent and accurate testing.

Self-assembly furniture must be assembled strictly following the manufacturer's instructions, selecting the most adverse assembly option if multiple configurations exist. Before testing, all components, joints, and fittings should be thoroughly inspected for defects, and all fasteners tightened securely. After each test level, fittings are retightened as necessary. The testing sequence should follow the specified order at the designated test level. Any new defects or changes observed after testing are documented. Notably, loosened fittings during testing are not considered failures but manufacturers are advised to recommend periodic tightening to users for maintaining structural integrity.

For a table or trolley to pass the strength tests, there must be no visible damage such as cracks, fractures, or permanent deformations following testing. Additionally, the permanent deflection of the legs after load removal should not exceed one fourteenth of the table's height. The furniture must successfully endure static loads simulating normal usage, fatigue loads representing repetitive stresses, and misuse loads depicting higher-than-normal forces. Compliance with these criteria ensures the item’s safety and durability under expected service conditions.