Conventional extruder nozzle
A twin screw extruder nozzle pressure feeds and supplies molten plastic to an extruding mold by using a screw cylinder. A conventional extruder nozzle includes a body receiving the molten plastic from the cylinder of the extruder, a head supplying the molten plastic in the body to the extruding mold, a poppet mounted in the body, and a vent ring on an external circumferential surface of the poppet and removing gas in the molten plastic.
However, according to the conventional single screw extruder nozzle, the gas is exhausted when the molten plastic passes around the external circumferential surface of the poppet, but there is no constitution for effectively extracting the gas from the molten plastic. Therefore, a large amount of the gas is contained in the molten plastic extruded through an extruding hole, and inferior products are produced due to the gas. In addition, since the vent ring does not effectively extract the gas from the molten plastic, an additional drier may be needed in order to dry the gas in the molten plastic. Therefore, equipment may be complex and product cost may be high.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Detailed Description of Invention Therefore, the present invention has been made in an effort to provide an extruder having advantages of making high quality extrusion products by effectively exhausting gas in molten plastic flowing at a high speed.
In addition, the present invention has been made in an effort to provide an extruder having further advantages of having a low possibility of polluting the air by effectively removing organic compounds in an extracted gas.
A sheet production extruder according to an exemplary embodiment of the present invention may include: a controller drying raw materials by using preheated air, and supplying dried raw materials; a heating cylinder receiving the dried raw materials from the controller and melting the dried raw materials so as to make molten plastic; and a nozzle assembly receiving the molten plastic from the heating cylinder, extracting gas from the molten plastic, and supplying the molten plastic from which the gas is extracted to a cavity between first and second dies. Furthermore, since a large amount of organic compounds are contained in the extracted gas, the air may be polluted if such organic compounds are not removed and are exhausted to the exterior.