Let me talk about the evolution of the container floor. The anti-corrosion treatment of solid wood floor was used for the container bottom plate before, and then gradually replaced by the anti-corrosion treatment of multilayer plywood. A key difference between the container floor and ordinary plywood is that anti-corrosion treatment must be carried out. The meaning of anti-corrosion includes two levels of anti-corrosion and anti-insect. It must contain two chemical components: fungicide and insecticide. The first is to increase the service life of the container floor and make the service life of the wooden floor close to the service life of the container; the second is to prevent harmful organisms (such as wood rot fungi, wood pests) from spreading with the circulation of the container. Because the prevention of the spread of pests belongs to the level of sanitation and quarantine, it is also called the immunity treatment of the container floor, but the essence is the anti-corrosion (including insect-proof) treatment of wood and plywood.