Repair Guide for Broken Office Chair Backrest

The repair of a broken office chair backrest should be selected based on the material and extent of damage, as detailed below:

I. Repair of Metal Frame Breakage

If the breakage occurs in the metal frame, mechanical reinforcement is the preferred method:

1. Connecting Plate Fixation: Use a 92mm long, 304 stainless steel connecting plate, paired with M5 screws to drill two holes on each side of the breakage for fixation. This method enhances structural stability by dispersing pressure points and is suitable for minor breakages in non-load-bearing areas.
2. Welding Repair: If professional welding conditions are available, first clean and grind the breakage surface to expose the original metal color. Use low-heat input processes such as TIG welding, grind the weld points after welding, and apply anti-rust paint. Note: Welding may alter the stress distribution of the metal and requires an assessment of the overall frame strength before use.

II. Repair of Wooden/Plastic Backrests

For breakages in non-metal materials, a combination of adhesion and reinforcement is required:

1. Glue Adhesion: After cleaning the breakage surface, use AB glue (quick-drying type) or white glue (requiring 24-hour curing) for adhesion. If the breakage surface is flat, direct adhesion can be performed; if there are gaps, fill with wood shavings or plastic fragments to enhance the connection.
2. Secondary Reinforcement: Install wooden strips (for wooden backrests) or plastic sheets (for plastic backrests) on the inner side of the adhesion surface, fixed with screws or glue; or wrap ropes around the breakage for external support.
3. Traditional Craft Reference: Drawing on the repair method of pear wood armchairs, insert a wooden stick matching the hole diameter at the breakage and apply glue. Drill holes on both sides and fix with wooden dowels, then fill with wood shavings and grind smooth. This method is suitable for classical-style office chairs but requires high manual precision.

III. Handling of Connector or Filler Issues

If the breakage is caused by loose connectors or filler collapse:

1. Tighten Connectors: Check if screws, rivets, and other connectors are loose and tighten them with the corresponding tools; if connectors are damaged, replace them with parts of the same specifications.
2. Replace Fillers: Remove the backrest cover, take out the collapsed foam or sponge, and replace it with new filler with a density of ≥30kg/m³ to ensure support.
3. Auxiliary Fixation: For plastic or thin metal connectors, use stainless steel zip ties to wrap and fix them at key points to prevent further loosening.

IV. Simple Emergency Measures

If immediate repair is not possible, temporary measures can be taken:

1. Conceal Breakage: Put on a fabric chair cover, choosing a dark or patterned style to conceal the damage, but avoid leaning heavily on it.
2. Weave Support Net: Use thick ropes to weave a grid between the backrest frame, forming a support structure similar to an ins-style curtain to disperse back pressure.

Precautions:

• Before repair, assess the extent of damage. If the frame is severely deformed or the material is aged (e.g., metal rusting, plastic embrittlement), it is recommended to replace the chair.
• Metal welding requires professional tools, and wooden repair requires ensuring the glue is completely dry (white glue requires more than 24 hours) before use.
• Emergency measures are only for short-term use; long-term leaning may worsen damage or pose safety hazards.