Use Of Screw Barrel Extruder

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    We have previously written about the advantages of screw extruders for extruding plastic welding. In a Screw Barre-based extruder, the rotating screw grinds the electrode as it passes through the Screw Barrel . Both the mechanical energy of the rotating screw and the heat introduced along the extruder barrel plasticize the feed. The barrel can be heated with hot air or coil heaters.
    Screw extruder with hot air heating
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    Principle of hot air heating screw extruder
    The working principle of the two screw extruders is the same, and the welding rod is pulled into the moving screw (1). During this process, it passes through a feed sleeve (2) that prevents the rod from twisting. After entering the screw, the knife (3) cuts the electrode into small pieces. The screw moves the rod forward, generating heat through compression and friction. The air heater provides hot air to preheat the substrate (4) before welding.

    In the air heating model, hot air for preheating is allowed to flow around the extruder barrel in the preheating chamber (5). Combined with the frictional heat of the screw, this causes the welding rod to plasticize and mix into a homogeneous substance. The extrudate then leaves the nozzle (6).

    This technology provides a simple and robust design for the extruder.
    Screw extruder with coil heating (for example, WELDPLAST)

    Principle of spiral heating screw extruder
    The working principle of the two screw extruders is the same, and the welding rod is pulled into the moving screw (1). During this process, it passes through a feed sleeve (2) that prevents the rod from twisting. After entering the screw, the knife (3) cuts the electrode into small pieces. The screw moves the rod forward, generating heat through compression and friction. The air heater provides hot air to preheat the substrate before welding.

    In the coil heating model, the coil heater (4) provides the extra heat required for plasticization. The heater surrounds the entire extruder barrel (5), and the built-in thermocouple (6) in the barrel measures the temperature of the plastic and transmits the information to the control system (7) to ensure precise temperature control. The extrudate then leaves the nozzle uniformly at a precisely controlled temperature. The temperature of the preheated air is measured by a separate thermocouple and regulated by the same control system.

    This technology makes temperature control more precise.