Office Chair Backrest Broken

If the backrest of an office chair is broken, targeted repair measures can be taken according to the specific damage situation:

I. Fracture Situations

1. Plastic Part Fracture:
   • If the fracture surface is flat, it can be directly bonded with AB glue or foundry adhesive. After it dries, reinforce it with a 92mm 304 stainless steel connecting plate and M5 flat-head screws. If necessary, tighten it with stainless steel straps.
   • If the fracture surface is complex, a homemade adhesive can be made: dissolve chopped foam board in gasoline, add baking soda to thicken it, and then adjust the color with spray paint. Drill holes in the fracture surface with an electric drill, insert rivets dipped in the adhesive into the holes for fixation, fill the gaps with a mixture of graphite powder and baking soda, drop 502 glue for reinforcement, and finally sand it smooth and spray paint.
2. Connecting Rod Fracture: According to the material (such as metal) and size of the broken rod, purchase a matching new rod and fix it through welding or special connectors (such as clips or bolts). If the pneumatic rod is broken, the entire pneumatic device needs to be replaced.

II. Loose Situations

1. Loose Adjusting Rod Screws: Use a cross-head screwdriver to unscrew the plastic cover plate at the base counterclockwise. After exposing the metal fixing frame, use a wrench to tighten 6-8 fixing screws symmetrically (operate at 90° intervals to prevent uneven force).
2. Spring Clip Failure: Use needle-nose pliers to re-insert the slipped spring hook into the clip slot. If the spring is deformed, purchase a spring of the same specification online (with a diameter of 3-5mm and a price of 5-15 yuan), measure the length of the original spring, and then replace it.
3. Excessive Pneumatic Rod Clearance: Remove the dust cover and rotate the black adjusting knob counterclockwise (test the rebound resistance every 30°) to increase the support force. If no tools are available, temporarily wrap the joint with a 3cm-wide tape cut from a bicycle inner tube or tie the movable joints with rubber bands to maintain stability for 3-7 days.

III. Other Types of Damage

1. Support Structure Deformation: Use a hydraulic press or pipe wrench to carefully correct the metal frame, restore it to its original shape, and then test its load-bearing stability. For a deformed plastic frame, it needs to be softened by heating and then shaped (pay attention to controlling the temperature to avoid melting).
2. Fabric Damage: Small-area damage can be mended with fabric of the same color. For large-area damage, remove the old fabric, cut new fabric to wrap the backrest, and fix the edges with hot-melt adhesive or a staple gun.
3. Spring Loss of Elasticity: Turn the chair over, remove the fixing screws of the old spring, install a new spring, and ensure that the clips at both ends are firm. Test whether the rebound force is even.

Before repair, cut off the power and gas (if it involves a pneumatic device), and wear gloves during operation to prevent scratches. If the damage is severe or the structure is complex, it is recommended to contact professional repair personnel or replace the chair with a new one.