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5 basics of the aluminum window frame bending process

Aluminum window frames

The sleek look and low maintenance required for aluminum replacement windows make them a great option for many modern homes.

Pros of aluminum window frames

aluminum windows in a modern house are low maintenance: Aluminum requires less upkeep than wood; and most of today’s options have a factory-baked or anodized finish, which means you don’t have to worry about corroding (though you’ll read about one noteworthy exception to that rule below.)

  1. Lightweight and strong: Aluminum is lighter than other materials, which can make it easier to install properly. It’s durable and will last longer than your typical vinyl options.
  2. Flexibility: The material is easily manipulated, making it a good option for windows that have an unusual shape.
  3. Narrow sight lines: The narrowness of many aluminum frames won’t distract from the view.
  4. Reasonably priced: These frames are generally more affordable than wood or fiberglass.

Cons of aluminum window frames

  1. Poor insulator: Aluminum doesn’t hold in heat as well as other materials. However, weather-stripping and thermal treatment can make this less of an issue.
  2. Condensation: Moisture or even frost can form inside aluminum-frame windows, leading to problems. However, you can fix this problem by using non-conductive material between your panes.
  3. Not beach friendly: Aluminum frames may be water resistant, but they can suffer corrosion from salt water and sea air.
Bending Aluminium Window Frames
Bending Aluminium Window Frames

Bending aluminum window frames add an incredible amount of character to any structure. Just looking at these frames does not express the incredible process that goes into producing them. The bending of aluminum window frames calls for specialist machinery and a lot of skill.

Many people assume that in order to bend an aluminum window frames simple machinery is used. In fact, quite a specialist window frame bending machine is used and each section reacts differently to bending. A typical open-back box section such as a pocket outer frame used on shopfront systems is actually quite easy to bend. The clip-in plate used to close it off is also easily shaped. Things get complicated when you move onto more complex sections such as curtain walling sections that have the front nose for the pressure plate and caps.

5 basics of aluminum window frame bending process

There are two bending processes for curved aluminum window frames: roll bending and stretch forming

What is a roll bending?

window frame bending machine

The roll bending process induces a curve into bar or plate workpieces. There should be a proper pre-punching allowance.

Roll-bending is a process whereby we obtain cold process deformation with a wider bend radius that theoretically can range from 5 times the cross-section to infinity. To achieve this process, the equipment used consists of plate bending machines. Read More:

What is stretch forming?

window frame bending machine

Stretch forming is part of metal forming where the metal is bent or “stretched” to create perfectly shaped parts.

When installing windows into a historic or unique building, the windows often must be fitted to curved, arched, or unconventional openings. This requires that the aluminum frame is stretch formed for a custom, tight fit.

Stretch-forming aluminum is the process of shaping aluminum sheets into contoured curves with the ability to stretch and bend. In order to produce the desired shape, the aluminum material is wrapped around a form while being held under constant tension. This forms precise dimensions and specific contours while limiting wrinkling and gaps. Stretch forming allows for aluminum to be shaped into curves and arches of different sizes and shapes, with arc lengths varying to fit the window opening. The aluminum frame can be finished in paint or anodized.

Read More:

How to choose?

When bending a customized extruded and bent aluminum window frame, the size of its cavity must be confirmed first. If the cross-section of the cavity is greater than 100mm, we recommend the use of the stretch-forming process. In this case, forcibly using the roll-bending process will cause the rupture of the aluminum window frames.

Then we confirm what is the bending radius of the bent aluminum window frame.
If it is greater than 180 degrees, our recommendation is to use the rolling process.

Are the extrusions already powder-coated or anodized?

The stretch-bending process can ignore these problems. In the bending process, we can use a specially customized polymer material roller, so that the surface of the aluminum window frames will not be damaged

Have the sections already been cut to length?

Please refer to our window frame bending machine parameter table. In fact, there are a number of ways to bend sections that might be a bit short for comfort on the average bending machine.