The inflatable rubber plug is a late model rubber product in a special and high added value applied technology of polymer materials way. Heat the tip of a steel plastic composite pipe to make the plastic layers internal and external of which soften by high - frequency heating. Then the inflatable rubber plug makes the plastic layers flow award to the tip of the pipe, such then the plastic layers merge at the lip to seclude the iron skeleton from the air. The inflatable rubber plug has following characteristics:

    1.     low cost and high work efficiency;

    2.     dispensing with other raw materials, no wastage;

    3.     molding in integral, smooth appearance, perfect merger and not easily shed off.