Office Chair Sponge Standard

The office chair sponge standard primarily involves core indicators such as density, support, resilience, and service life.

I. Density Standard
The density of the sponge for the seat of a regular office chair should not be lower than 25kg/m³. Government procurement standards further specify that the density of the seat sponge should be ≥25kg/m³, and for other parts (such as the backrest and armrests), it should be ≥18kg/m³. Mid-to-high-end products typically use high-density sponges with a density above 45kg/m³. These sponges provide sufficient hardness while offering stable support to the body, preventing large-area collapse, and providing a moderately elastic sitting experience, suitable for office workers who sit for more than 6 hours a day on average. High-resilience molded sponges with a density of 45-50kg/m³ are the mainstream choice in the market, balancing support, comfort, and service life. It should be noted that higher sponge density is not always better: a density exceeding 60kg/m³ can result in an overly hard sitting experience, potentially causing discomfort over prolonged use; a density below 25kg/m³ may lack sufficient support, leading to noticeable collapse after several months.

II. Resilience and Compression Set
Resilience rate is a key indicator for measuring the recovery ability of sponges. The standard requires a resilience rate of ≥45%, meaning the sponge can quickly return to its original shape after being compressed, reducing fatigue from prolonged sitting. The 75% compression set is a core parameter for evaluating the sponge's fatigue resistance, with the standard stipulating that its value should be ≤5%. This indicator represents the proportion of thickness that cannot be recovered after the sponge is kept in a 75% compressed state for 22 hours. A lower compression set value indicates stronger resistance to collapse and a longer service life for the sponge. For example, high-resilience sponges that meet the standard can maintain structural stability after long-term use, while inferior sponges may experience a decrease in support due to compression deformation.

III. Service Life and Suitable Scenarios
The combined performance of density and resilience directly affects the lifespan of office chairs. High-density sponges (45-50kg/m³) are suitable for high-frequency use scenarios due to their dense structure and strong tear resistance; low-density sponges (<25kg/m³) are prone to aging and are typically only suitable for low-frequency use or temporary seating. Government procurement standards achieve a balance between cost control and durability through density grading (seat ≥25kg/m³, other parts ≥18kg/m³), ensuring long-term use needs in public office scenarios.