Ventilating pipe and manufacturing method thereof

The invention relates to a ventilating pipe and a manufacturing method thereof. The ventilating pipe comprises a hollow outer pipe body. A polyurethane layer is arranged on the inner wall of the outer pipe body. The manufacturing method of the ventilating pipe comprises the following steps that (a), the hollow outer pipe body and an inner pipe body are provided, the inner pipe body is inserted into the outer pipe body, and a filling space is formed between the inner wall of the outer pipe body and the outer wall of the inner pipe body; (b), polyurethane foam is sprayed into the filling space; and (c), the inner pipe body is taken out after the polyurethane foam is solidified. According to the ventilating pipe, asbestos which is applied in a traditional air pipe is replaced by the polyurethane, and thus better noise reduction and vibration reduction effects can be achieved; in addition, the ventilating pipe is simple in structure and low in manufacturing cost. The manufacturing method of the ventilating pipe is simple, convenient and easy to implement, low in cost, easy to popularize and free of pollution.