1. A detailed description of the flame-retardant properties, flame-retardant properties and oxygen index of PVC pipe
s. The ignition point of PVC pipes generally means that when chemicals reach a certain temperature, they will naturally ignite and burn. PVC pipes will not ignite spontaneously, will not support combustion, and can self-extinguish, so there will be no problem of ignition point. PVC pipe is a kind of incombustible material. When it comes into contact with flame, it will burn, but when the flame is removed, it will be extinguished immediately. This is its non-flammable and self-extinguishing characteristics.
2. The oxygen index of PVC is 48. The oxygen index refers to the minimum oxygen concentration required for flaming combustion of a material in a mixture of oxygen and nitrogen under specified conditions. It is expressed as the value of the volume percentage of oxygen. A high oxygen index indicates that the material is not easy to burn, and a low oxygen index indicates that the material is easy to burn. Under the specified test conditions, the minimum oxygen concentration when the material just maintains the flame combustion in the O2 and N2 mixed gas at room temperature is expressed as a percentage of the volume. The higher the oxygen index, the better the flame retardant performance.
3. PVC pipe connection method. When a large area of the pipe is damaged, the entire pipe needs to be replaced. The pipe can be replaced by a double socket connector; the solvent method can be used to deal with the leakage of the solvent bond. At this time, the water in the pipe must be drained first, and negative pressure is formed in the pipe, and then the adhesive is injected into the pores of the leakage part. Because the pipe is under negative pressure, the adhesive will be sucked into the pores to achieve the purpose of stopping leakage. .
The patch bonding method is mainly aimed at the leakage of small holes and joints in pipes. At this time, choose a pipe of the same diameter with a length of 15-500px and cut it longitudinally. According to the method of bonding joints, the inner surface of the casing and the outer surface of the pipe to be patched are roughened, and then the glue is applied to the leaking area. The glass fiber method is to prepare a resin solution with epoxy resin and curing agent. After impregnating the resin solution with glass fiber cloth, it is evenly wound on the surface of the leaking part of the pipe or joint, and becomes glass fiber reinforced plastic after curing.