Office Chair Sample Processing

The processing of office chair samples should follow the steps below to ensure that the test results accurately reflect their chemical emission characteristics:

1. Morphological Adjustment
The sample should be unfolded into a form that is most conducive to the release of harmful substances. For assembled or foldable office chairs, the armrests should be fully extended, the backrest adjusted to the maximum angle (e.g., 120°-180°), and all adjustable components (such as drawers and casters) adjusted to the maximum exposure state. This step aims to increase the contact area between the material surface and the air, promoting the release of volatile organic compounds (VOCs) and formaldehyde. For example, if the backrest is adjustable, it should be fixed at the maximum tilt position; if the armrests are height-adjustable, they should be raised to the highest point.

2. Pre-treatment Condition Control
The sample should be allowed to stand in a specific environment for 24±2 hours to stabilize its initial state. Environmental parameters should be strictly controlled: the temperature should be 23±2°C, and the humidity should be 45±10%RH to avoid material expansion/contraction caused by high temperature and humidity or low temperature and humidity, which could affect the emission rate. The distance between samples should be ≥300mm to prevent interference from pollutants released by adjacent samples. In addition, the background concentration in the pre-treatment area should meet the requirements of formaldehyde ≤0.006mg/m³ and TVOC ≤0.05mg/m³, which can be achieved through an air purification system or an independent ventilation chamber to exclude interference from environmental background on the test results.

3. Sample Placement and Exposure Optimization
The office chair to be tested should be assembled according to standard procedures and then placed in a test chamber. During placement, ensure that all surfaces (seat cushion, backrest, armrests, base, etc.) are fully exposed without any obstruction or overlap. For example, the seat cushion should be laid flat without wrinkles, the backrest should be fixed vertically, and the armrests should be extended to a horizontal position. This step maximizes the contact area between the material and the air inside the chamber, allowing for an accurate assessment of its chemical emission potential. If the sample contains detachable components (such as a seat cushion separated from the frame), they should be processed separately and their positions marked.

4. Targeted Treatment During Testing
Formaldehyde testing should only target the seat surface and backrest parts, excluding hard materials such as steel and iron (e.g., brackets and casters). During testing, the seat surface and backrest should be removed and placed separately in an environmental climate chamber (e.g., a 1m³ climate chamber), with the temperature (23±1°C), humidity (50±5%RH), and air flow rate (0.1-0.5m/s) controlled to simulate actual usage conditions. This step focuses on soft materials (such as sponge and leather) that are in close contact with the human body and have a higher risk of emission, improving testing efficiency.