Office Chair EN Test

The Office Chair EN Test is a comprehensive test conducted in accordance with the EN1335 standard, covering three dimensions: ergonomic testing, stability testing, and strength and durability testing.

Ergonomic Testing:

1. Seat and Backrest Angle Linkage: A rigid mannequin is used to measure the change in the angle between the seat and backrest during reclining. If the backrest lags by more than 15 degrees, it is judged as 'insufficient support synchronization,' which may affect the natural curvature of the spine.
2. Seat Depth and Popliteal Space Control: The 'popliteal baseline measurement method' is employed, where a 5-centimeter diameter cylinder is pressed vertically against the front edge of the seat. If the displacement is too small (the cylinder is fully compressed) when the pressure value drops to 0.5 Newtons, the chair cannot accommodate users with different leg lengths, potentially causing blood circulation issues.
3. Armrest Height Matching: A laser distance meter is used to measure the vertical distance between the armrest and the desktop. If it is less than 20 centimeters or more than 28 centimeters, it is judged as 'work surface interference,' which may lead to abnormal pressure on the shoulders, neck, or lumbar spine.

Stability Testing:

1. Forward Stability: Tests the critical state of ordinary chairs and chairs with footrests when tilting forward to ensure they do not tip over during normal use.
2. Lateral Stability: Simulates actions such as getting up from one side to verify the chair's resistance to tipping under lateral forces, avoiding the risk of sideways tipping.
3. Backward Stability: Evaluates the connection strength between the backrest and the base and the overall balance when the user leans back and reclines.

Strength and Durability Testing:

1. Static Strength:
   • Seat Impact: A 50-kilogram steel hemisphere is dropped freely from a height of 20 centimeters onto the seat. If the deformation of the welds or connectors exceeds 3 millimeters, it is judged as structural failure.
   • Seat Load: The seat withstands a vertical pressure of 120 kilograms for 60 seconds, and the backrest withstands a 45-degree directional pull to test the weld strength and the chair leg's bending resistance. Cracks or excessive deformation in metal components indicate failure.
2. Dynamic Durability:
   • Seat and Backrest: The seat undergoes 100,000 vertical pulse loads (at a frequency of 30 times per minute), and the backrest completes 50,000 reclining cycles (with a load of 350 Newtons). The moving parts must remain fully functional, and the height settlement should not exceed 15 millimeters.
   • Swivel Function: Chairs with swivel functionality must complete 20,000 cycles of rotation with a torque of 35 Newton-meters to verify the wear resistance of the bearings and seals.
   • Reclining Function: When the backrest is reclined to the maximum angle, the relative displacement between the seat cushion and the backrest should be less than 8 millimeters to prevent clothing from getting caught in the gap.