Office Chair Leg Drop Test

The office chair leg drop test primarily refers to the BIFMA chair leg impact test standard, evaluating the structural strength, deformation, and functional stability of chair legs and connecting parts by simulating impact scenarios in daily use.

I. Test Equipment and Conditions
The test requires an impact tester that meets precision requirements, capable of accurately controlling impact energy, speed, and angle. The impact head is hemispherical with a diameter of 50mm and must be made of a material that combines hardness and toughness. The test environment should maintain a temperature of 20℃±5℃ and a relative humidity of 40%-70% to eliminate the influence of environmental factors on material properties.

II. Test Procedures

1. Preloading: Apply a vertical load of 1334N (300lbf) to the chair for 1 minute to simulate daily load conditions and ensure structural stability.
2. Impact Positions and Frequency:
   • Chair Leg Impact: Perform impacts 50mm above the contact point between each chair leg and the ground. The impact energy is 10J for standard office chairs and can be increased to 15J for heavy-duty office chairs. Each chair leg undergoes 10 impacts with an interval of no less than 10 seconds.
   • Connecting Part Impact: Conduct 5 impacts on key connecting points between the chair legs and the seat, with an energy setting of 5J, focusing on inspecting the strength of welded or mortise-and-tenon structures.

III. Test Result Evaluation

1. Structural Integrity: After impact, check for fractures in the chair legs or loosening or separation of connecting parts. If any of these occur, the test is immediately deemed a failure.
2. Deformation: Measure the deformation in the direction of impact on the chair legs using a measuring tool with a precision of 0.01mm. The maximum allowable deformation is 10mm for standard office chairs and 15mm for heavy-duty office chairs. Exceeding these limits requires further evaluation of potential impacts on user safety.
3. Functional Testing: Perform operations such as lifting, rotating, and tilting the chair to ensure there is no stuttering, abnormal noise, or functional failure. For example, the gas lift should operate smoothly, and the rotating mechanism should have no resistance.

IV. Differences from Dining Chair Testing
Dining chair leg drop tests focus more on structural stability (such as push-pull rocking tests), leg load-bearing capacity (single-leg stepping tests), and edge safety (cotton thread dragging verification). In contrast, office chair tests strictly adhere to the BIFMA standard, using impact energy and frequency as core parameters, more closely resembling the actual conditions in office settings where chairs are frequently moved or subjected to external impacts.