1. Cushion and backrest fabrics: imported environment-friendly leather with fine lines and even colors.
2. Sponge: The "East Asia" high quality flame retardant foam from Hong Kong is applied with density ≥45kg/m, rebound rate ≥50, compression deformation rate≤5.5, Elongation ≥140m, tear strength ≥ 1.7n /CM, hardness ≥80N when pressing at 25%,Indentation hardness ±20N,Tensile strength ≥85Kpa,75% compression permanent deformation 10%, tear strength ≥ 1.7n /cm, hardness ≥130 when pressing at 65%.
3. Spring: The snake-shape spring is adopted with the alloy spring after heat treatment, and is treated with rust prevention and annealing measures.
4. Base material: solid wood frames, hardwood with high quality moisture content less than 9% and multi-layer plywood with thickness ≥5mm, treated by chemical treatment such as insect control, anti-corrosion and moisture-proof.