Understanding Office Chair Components - Zhangzhou Delux Furniture Co., Ltd.

The comfort, durability, and safety of an office chair depend on the collaboration of its various components. From the armrests you touch daily to the hidden base mechanism, each part has an irreplaceable function. Here’s a detailed breakdown of the key components of an office chair:

1. Armrests: The "Invisible Supports" for Your Arms

Armrests are easily overlooked but crucial components that directly affect shoulder and neck fatigue.

Basic Function: They support the weight of the forearms, reducing the need for continuous shoulder muscle exertion and preventing shoulder and neck soreness caused by a "hunched" posture. A properly heighted armrest should allow the elbows to bend naturally at 90°, with the forearms parallel to the desk.

Advanced Designs:

Multi-directional Adjustment: High-quality office chairs feature armrests with height (±5cm), forward/backward (±3cm), and left/right rotation (±15°) adjustments. These adapt to different heights, desk levels, and usage scenarios (e.g., retracting armrests while typing, expanding them for relaxation).

Material Differences: PU-padded armrests are ideal for long-term leaning, silicone ones are non-slip and skin-friendly, and metal-framed armrests are more durable, suitable for public spaces.

Hidden Features: Some niche designs integrate armrests with the desk, allowing temporary placement of cups or notebooks to save desktop space.

Popular 4D/6D Armrests: Currently, 4D armrests (adjustable in height, width, depth, and angle) and 6D armrests (adding swivel and tilt adjustments) are trending. They offer finer customization, catering to diverse postures like gaming, writing, or video calls.

2. Base Mechanism: The "Heart" Controlling Dynamic Experience

The base mechanism, hidden under the seat, is the core mechanical component of an office chair. It regulates reclining, weight-bearing, and locking, earning it the title of "invisible commander."

Recline Function: Using internal springs and dampers, the backrest can tilt backward (typically 100°-135°). Coordinated with seat linkage, it distributes hip pressure. Dampers adjust recline resistance—heavier users need higher resistance to prevent sudden backward movement.

Locking Mechanism: Most mechanisms support 3-5 angle locks, such as 100° (work), 115° (relaxation), and 135° (noon break), meeting different needs.

Weight Capacity: High-quality mechanisms use high-strength alloy, bearing over 150kg. Inferior plastic mechanisms are prone to breaking, posing safety risks.

Special Designs: Premium ergonomic chairs feature "adaptive mechanisms" that automatically adjust recline force based on the user’s weight, eliminating the need for manual knobs—perfect for frequent posture changes.

3. Gas Lift Cylinder: The "Safety Core" for Height Adjustment

Connecting the seat and the five-star base, the gas lift cylinder is key to seat height adjustment, with safety directly affecting users.

Working Principle: It adjusts height through compression and release of internal high-pressure nitrogen (purity ≥99.9%). High-quality cylinders have chrome-plated, rust-resistant surfaces and wall thickness ≥1.5mm.

Safety Certifications: Look for SGS and BIFMA certifications. Level 4 cylinders (highest grade) have built-in explosion-proof steel balls, ensuring slow descent even if damaged, avoiding "explosion" risks.

Adjustment Range: Standard lifting stroke is 10-15cm, fitting heights 150cm-190cm, ensuring knees form 90° when feet flatly touch the ground.

4. Five-Star Base & Casters: The "Foundation" for Mobility and Weight-Bearing

Five-Star Base:

Material determines stability: Steel bases have the highest capacity (≥300kg), suitable for heavy users; nylon is lightweight and rust-resistant, ideal for homes or offices; aluminum balances strength and aesthetics but costs more.

Ground Contact Area: Larger base spans (usually 60-70cm) reduce tipping risks.

Casters:

Soft PU casters are suitable for wooden floors, quiet and scratch-resistant; hard nylon casters work well on carpets with low rolling resistance.

Swivel bearings determine smoothness—high-quality ones rotate 360° without jamming, while poor ones easily get stuck or fall off.

5. Backrest & Lumbar Support: The "Guardians" of the Spine

Backrest:

Its curved design must fit the spine’s S-shape. The upper part (thoracic vertebrae) supports shoulder blades, preventing hunching; the lower part (lumbar vertebrae) protrudes to maintain the natural forward curve.

Material Differences: Mesh backrests are breathable, suitable for long sitting; sponge + linen combinations offer strong support, ideal for winter.

Lumbar Support:

Adjustable lumbar support is a hallmark of ergonomic chairs, moving up/down (±4cm) and forward/backward (±2cm) to precisely support lumbar vertebrae 3-5, avoiding 悬空 (suspension).

Dynamic lumbar support (e.g., spring or airbag structures) tightens when leaning forward and relaxes when reclining, fitting better than fixed supports.

6. Seat Cushion: The "Cushion" for Pressure Distribution

Seat cushion design directly affects hip and thigh comfort, preventing numbness from long sitting.

Materials:

High-density sponge (density ≥50D) has good resilience, resisting collapse; memory foam fits the hip curve but has poor breathability, requiring a mesh layer.

Mesh cushions, woven from high-elastic nylon, offer optimal breathability—great for summer or those prone to sweating.

Shape:

A "waterfall" front reduces pressure on thigh roots, promoting blood circulation; the rear is slightly higher to prevent sliding.

Seat depth adjustment (±5cm) fits different leg lengths, ensuring 2-3cm of space between the back of the knees and the cushion edge.

Conclusion: Component Collaboration Defines Experience

A good office chair is more than a stack of parts. For example, armrest adjustment must match desk height, base recline needs to link with lumbar support, and gas lift height must align with base stability. Understanding these functions helps you choose wisely and extend chair life through proper adjustments (e.g., daily lumbar support checks, monthly caster lubrication), making "long sitting" less of a health burden.