Aluminum Coil Transport Services

Aluminum coil ID crush from improperly sized or positioned saddle blocks is a more significant concern than with steel coils because aluminum is softer and deforms more readily under concentrated loading at the coil ID contact points. Saddle blocks that are undersized for the coil OD allow the coil to bear on its ID edge at the saddle contact locations, deforming the inner wraps in ways that prevent proper mandrel engagement during processing. For softer aluminum alloys in thin gauges, ID deformation from saddle contact can propagate through multiple inner wraps before the damage is visible at the coil ID surface.

Painted and coated aluminum coil for building products, transportation panels, and architectural applications arrives with factory-applied coatings that define the end product's appearance and performance. A paint surface abrasion from coil-to-coil contact on the trailer, a coating transfer from a contaminated saddle block surface, or a pressure mark from a binder positioned against the coil face all create surface defects that show up when the coil is processed and the coated sheet is inspected at the slitting or roll forming line.

Aluminum coil edges, whether mill edges or slit edges, are dimensional features that affect roll forming die engagement and part edge quality in stamped components. Edge damage from handling impacts, binder contact against coil edges, and coil-to-coil contact on the trailer all create edge irregularity that causes processing problems downstream. For tight-tolerance roll formed profiles where edge condition affects the forming die contact geometry, incoming coil edge quality is a production parameter that transport handling directly influences.

Aluminum coil is lighter than steel coil of the same dimensions, but large-diameter, wide aluminum coil still represents substantial weight that requires appropriate saddle block sizing and positioning. The lower density of aluminum means a coil of equivalent OD and width to a steel coil weighs less, but that weight is still concentrated at the saddle contact points in the same way. Saddle blocks sized for steel coil weights may be appropriate dimensionally for aluminum coils but may use contact materials that are too hard for aluminum's softer surface without the rubber facing that prevents coil OD marking.

Aluminum coils in contact with unprotected carbon steel saddle blocks in a wet environment develop galvanic corrosion at the contact points. That corrosion appears as a rust stain pattern on the coil OD surface that is very difficult to distinguish from the contact mark geometry. For bare aluminum coil destined for anodizing or painting after processing, galvanic contamination at the saddle contact points creates adhesion failure in the subsequent surface treatment at those locations.

Continuous processing lines running aluminum coil operate on production sequences where specific alloys, gauges, and coating conditions run in a planned order that minimizes changeover time and scrap. A coil delivery that arrives out of the planned processing sequence forces the line to either run out of sequence, which increases changeover cost, or hold the delivered coil until the planned slot in the sequence arrives, which requires staging space the facility may not have.