AN AIR DUCT FOR AIR CONDITIONING SYSTEM OF AUTOMOBILE AND MANUFACTURING METHOD THEREOF

摘要

A manufacturing method of an air duct for a vehicular air conditioner according to the present invention comprises: a first step (S1) of injecting at least one resin of homo-polypropylene resin, high-density polyethylene, and medium-density polyethylene into the front end part of an extruder through the hopper of the extruder, and then melting the resin; a second step (S2) of injecting a foaming agent through a side feeder at the rear end part of the extruder, mixing the foaming agent with melt formed in the first step (S1), and then extruding a mixture of the foaming agent and the melt into a melted sheet; a third step (S3) of forming a foaming body by foaming the foaming agent embedded in the extruded sheet; and a fourth step (S4) of molding the foaming body into an air duct by injecting the foaming body into a molder, wherein the rear end part of the extruder is connected to the front end part of the extruder and has temperature maintained to be below the temperature of the front end part. An air duct, which is used for a vehicular air conditioner and is molded by a manufacturing method according to the present invention, is light and has a high insulation property so that a vehicle can be lightened and cooling and heating efficiency can be improved; and has a high durability due to the high mechanical property thereof.