Holding tolerance in curving…that is really what it’s all about. If your part doesn’t fit properly, it just won’t work! Alexandria Extrusion Company’s experience in the marine, recreation, architectural and medical imaging industries allow us to curve aluminum extrusions to closer tolerances than you will probably ever require. In detail below, are different methods in which Alexandria Extrusion Company can provide you with exacting specifications for your formed aluminum extrusion products.
Some of the typical applications of formed extrusions include Automotive: structural and decorative parts; Marine: boat gunnels, windshields and structural members; Medical: C arms for electromedical imaging; and Aerospace: structural and Architectural applications.
Critical factors to determine before bending are the alloy, temper and cross section of the extrusions. Deformation of the inside or outside radii can also be a design issue and determines which forming process to use. Before beginning the design process consider these parameters:
• What tolerances are expected on the inside, the outside dimension radius, and the overall length of the part?
• What surface areas are critical for appearance?
• What mechanical strength is required?
Some examples of the bending process are:
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Ram or Push Bending:
• Single axis controlled
• Programmable bend angles
• Can perform close proximity multiple plane bends
• Only 1 radius can be bent at a time
• Highly portable
• Inexpensive tooling
• Good bend precision with low per-bend cost |
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Rotary Draw Bending (Hydraulic method):
• Single axis controlled resolution to .1 degree
• 90° maximum bend per bend
• Only 1 radius can be bent at a time
• Bend process with or without mandrel
• Bend precision is good
• Not portable
• Wiper and backstop are manually adjusted
• Moderate tooling cost |
Rotary Draw Bending (Electric method):
• Faster setups than hydraulic
• More accurate and repeatable than hydraulic
• Multiple axis PLC controlled
• Very accurate bend and movement
• Bend precision is excellent
• Bend process with or without mandrel
• Moderate tooling cost
• Rotations are automatic for variable plane bends
• Electric rotary draw method beneficial for:
• Numerous bends per part
• Bends are close proximity to each other
• Multiple bend radii are needed on the same part
• Bends are out of plane on round parts
• Both small and large radius bends are required
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3 Roll Bending:
• Can roll full 360° part
• Large radius bending only
• Can roll horizontally or vertically
• Limited to single plane bending per cycle
• Maximum bend radius is unlimited
• Bend precision is very good
• Profiles are preferably symmetric
• Moderate tooling cost |
Stretch Forming:
• Elongation control for unparalleled accuracy and consistency
• Bend precision and consistency is excellent with high to medium per–bend cost
• Non-symmetric profiles are readily formed without twist
• Maximum bend radius is unlimited
• Can bend, twist and lift simultaneously
• Minimal surface distortion and traffic marking
• Maximum diameter 180° bend at full tonnage = 70”
• Minimum diameter 180° bend at full tonnage = 15”
• 300” part length capability
• Tooling typically is higher than other forming/bending methods
• Arms can swing only to 180°
• Minimum bend radius is generally 2-3 times greater than other forming/bending methods
• Bend radius cannot be modified without additional tooling charge
The bending, shaping, and forming of aluminum is best accomplished with input from our engineers during the design phase of your projects. Alexandria Extrusion Company offers an in-depth aluminum extrusion seminar at your site where we can educate designers and engineers about aluminum extrusion designing options, alloys and cost drivers. If you have questions or need assistance with your designs, please contact your sales specialist.
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