Office Chair Frame Production

The production of office chair frames requires adherence to the following key steps and design considerations:

1. Basic Frame Production The core structure of an office chair frame is typically formed using steel tube bending processes, with a focus on constructing the chair's bottom frame. The steel tubes must be bent into preset shapes according to design drawings to form the foundational structure supporting the seat cushion. The seat cushion is fixed to the frame through welding, ensuring uniform welds without cold welds to guarantee overall load-bearing capacity. This step requires strict control over the steel tube wall thickness (usually 1.5-2.5mm) and bending radius to prevent excessive material deformation that could reduce structural strength.

2. Stability Enhancement Design Seat comfort and stability are achieved through a dual mechanism:

• Spring System: Independent pocket springs or continuous springs are fixed beneath the seat cushion to provide elastic support. The springs should be evenly spaced (recommended 8-10cm apart) to prevent localized sagging.
• Steel Bar Reinforcement: A steel bar with a diameter of 6-8mm is fixed longitudinally in the center of the spring array, secured through welding or clips, to prevent lateral displacement of the springs and enhance overall torsional strength. This design can increase the seat's lifespan by over 30%.

3. Backrest Structure Optimization The backrest must conform to ergonomic curves, with a focus on controlling the following parameters:

• Curvature Design: The upper part of the backrest tilts backward by 10-15°, while the lower part protrudes forward by 5-8°, forming an S-shaped curve that fits the natural curvature of the spine.
• Material Combination: Before filling with foam, a 3-5mm thick particleboard can be attached to the inner side of the backrest frame and fixed with air nails. The particleboard should be moisture-proof treated to prevent absorption and deformation, enhancing the backrest's impact resistance by 25%.

4. Chair Leg and Caster System The chair legs adopt a five-claw radial structure, with key designs including:

• Tubular Radial Arms: The outer ends are flattened into an arc shape, with a width controlled at 30-40mm for easy positioning of the mounting base.
• Drainage and Ventilation Design: Holes with a diameter of 8-10mm are drilled at the bottom outer ends of the chair legs, spaced 15-20cm apart, to prevent water accumulation and metal rusting.
• Caster Fixation: The mounting base uses a clip-on structure with built-in elastic plastic bushings (Shore hardness 60-70HA) and check claws to fix the wheel axle through mechanical engagement, replacing traditional threaded connections to solve height inconsistency issues and enable 3-second quick disassembly.

5. Support System Integration Core support components must meet dynamic usage requirements:

• Hydraulic Device: A gas spring with a stroke of 80-120mm is selected, with a load-bearing capacity of ≥120kg, tested according to ISO 9283 standards.
• Rotating Bearing: Double-row tapered roller bearings are used, with an inner diameter matching the gas spring (usually φ50mm), enabling 360° damped-free rotation.
• Mobile Wheel Set: The casters are recommended to have a diameter of 50-60mm, with a wheel surface made of polyurethane material (hardness 75-85A) for a balance of quietness and wear resistance.

6. Patented Technology Improvements Addressing traditional structural flaws, the new chair frame adopts a modular design:

• Axle Fixation: Clips replace welding, allowing for ±0.5mm tolerance compensation to ensure the height difference of the five-claw wheel set is ≤1mm.
• Ventilation Optimization: The drainage holes are redesigned at a 45° angle, combined with a vertical support structure for the wheel axle, improving ventilation efficiency by 40% and extending the lifespan of metal components.