Office Chair Sponge Replacement

Replacing the sponge in an office chair requires preparing tools and materials and following standardized steps, with attention to safety precautions during operation.

Tools and Materials Preparation

1. Tools: Prepare an Allen wrench, screwdrivers (cross or flat-head), a wrench or socket set, pliers (combination and needle-nose), and a rubber mallet.
2. Materials:
   • New Sponge: Accurately measure the length, width, and thickness of the old sponge (it is recommended to take multiple measurements and average them). Choose the density and thickness based on body weight. High-density sponge (25-35KG/M³ or higher) is recommended. For individuals weighing under 50kg, select a thickness of 6-8cm; for 50-75kg, choose 8-10cm; and for over 75kg, opt for 10-12cm.
   • Purchase Channels: Search for "high-density sponge" or "office furniture sponge" on e-commerce platforms such as Alibaba (1688) or Taobao, or contact the original manufacturer's customer service for spare parts inquiries.

Replacement Steps

1. Safe Inversion and Base Separation: Invert the chair onto a soft-padded surface. Locate the four fixing screws connecting the seat cushion to the five-star base or chassis (usually found at the bottom of the seat cushion). Use an Allen wrench to unscrew them, separating the seat cushion from the base.
2. Dismantle the Seat Cushion Shell: Examine the edge of the seat cushion. If there is a U-shaped iron strip or plastic baffle fixed with screws, use a screwdriver to remove the screws. For some models, you may need to first remove the large screw beneath the backrest adjustment lever and lay the backrest down before proceeding.
3. Remove the Old Sponge: Open the shell and take out the old sponge. For second-hand chair modifications, remove the U-shaped staple gun pins and pull out the ropes securing the leather cover and sponge pad before removal.
4. Install the New Sponge:
   • Direct Replacement: Place the new sponge inside the seat cushion shell.
   • Second-Hand Modification: Place the new sponge pad on the old sponge and cut out the shape. Stack multiple layers (e.g., stack two layers for a one-inch high pad, it is recommended to stack several layers) and place them back in position.
5. Secure the Seat Cushion Shell:
   • Regular Replacement: Reinstall the shell and tighten the screws.
   • Second-Hand Modification: Tighten the seat cushion leather cover and use a U-shaped staple gun to fix the edges of the leather cover according to the original staple hole arrangement. Pull the leather cover tight for each side, and complete the repair after stapling all four sides.
6. Reassemble the Chair: Reconnect the seat cushion to the base and tighten the fixing screws.

Precautions

1. Before operation, ensure that the chair's gas lift is at its lowest position or fully deflated. Invert the chair onto a soft carpet or cardboard to prevent scratches on the floor and chair body, while also protecting the operator.
2. When modifying a second-hand chair, if the seat comfort is insufficient, increase the number of sponge pad layers to enhance support.