The Process of Making Office Chairs

The process of making office chairs mainly consists of the following six steps:

Step 1: Making the Bottom Frame
Workers first place square steel tubes into a hydraulic press and bend them into square bottom-pad frames with rounded corners through mechanical pressure. Subsequently, they weld support steel plates to the frame openings to ensure structural stability. Some processes use automated equipment to bend the steel tubes and directly weld the cushion parts to the frame, improving efficiency. The key to this step lies in the geometric accuracy of the frame and the strength of the welds, which directly affect the chair's load-bearing capacity.

Step 2: Installing Springs and Stabilizing Structures
S-shaped springs are hung on the frame, typically extending from the front to the back of the seat to provide longitudinal support. Horizontal rods are placed and the springs are clamped to increase stability; steel bars are fixed in the middle of the springs to prevent deformation after long-term use. Some designs use three supporting steel bars connected in reverse to the springs to disperse pressure through mechanics, enhancing seating comfort. The spring's elastic coefficient needs to match the foam density to prevent cushion sagging.

Step 3: Making the Backrest Frame
The armrest interfaces are connected to the backrest through welding, and burrs on the steel surface are ground down to ensure a smooth contact surface. When constructing the back frame, special attention is paid to components such as the spinal support area and armrest attachments, with rough edges removed through mechanical grinding to prevent leather scratches. The frame's curvature design should conform to ergonomics, fitting the back curve to reduce fatigue from prolonged sitting.

Step 4: Processing Leather Materials
Black leather is cut using a utility knife based on plastic templates for components such as headrests and armrests, avoiding natural leather flaws (such as scars and color variations). After cutting, the leather is smoothed to ensure even spreading and prevent wrinkles. Some processes use cardboard templates for secondary cutting to ensure pattern accuracy. The leather thickness is typically 1.2-1.5 millimeters and should be wear-resistant and breathable.

Step 5: Processing Foam Materials
The leather is adhered to a hard foam cushion, and a foam pad larger than the leather edges by 2-3 centimeters is cut out to reserve sewing space. The foam density in the back should be higher than that in the seat cushion (typically 45-50kg/m³) to provide sufficient support. The seat cushion adopts a layered design: the bottom layer is high-density foam (35-40kg/m³), and the top layer is covered with soft, fluffy foam (20-25kg/m³), with interconnected rectangular structures cut to enhance breathability. The leather should be marked with crease lines according to the foam spacing, and sewn to form natural depressions that fit the body curve.

Step 6: Assembling Components
The metal frame is wrapped with foam pads and covered with the sewn leather skin, with screws used to fix the cover plates to the frame. Adjustable-height armrests, hydraulic rods, and pneumatic rods are installed, connecting the seat bottom support rods to the metal base. Finally, five universal wheels are installed, and the headrest and armrests are inserted into preset slots. Some processes adopt modular installation: first assemble the wheels and pneumatic rods, then fix the chassis and seat plate, and finally connect the back panel to the seat plate with corner brackets, simplifying the process and improving stability.