Aluminum Extrusion Troubleshooting

Bow

Problem Description

The extrusion shows smooth longitudinal curvature, often appearing after cooling or handling.

Cause–Correction Mapping
  • Bearing squareness
    Cause in: Die

      Corrections

    • Square the bearings perpendicular to die face; flatten bearings perpendicular to metal flow.

  • Improper cooling on run-out table
    Cause in: Equipment

      Corrections

    • Make necessary modifications of cooling.

  • Improper height of lead-out table
    Cause in: Equipment

      Corrections

    • Adjust lead-out table to proper height.

  • Non-uniform wall thickness of profile by design
    Cause in: Profile

      Corrections

    • Use differential cooling at press.

    • Increase or decrease bearing lengths.

  • Press alignment
    Cause in: Equipment

      Corrections

    • Align press.

  • Uneven billet temperature
    Cause in: Equipment

      Corrections

    • Adjust temperature as required.

  • Uneven metal flow
    Cause in: Die

      Corrections

    • Adjust Ports to control metal flow.

    • Increase or decrease bearing lengths.

Please note that the information provided in this article is intended to be a general guide to the causes and corrections of Bow in aluminum extrusion. However, it is important to note that the specific cause and correction of any particular defect will vary depending on the specific extrusion process, alloy, and other factors. Therefore, it is important to consult with an experienced and professional engineer to ensure that the correct diagnosis is made and the most suitable correction is chosen.