Aluminium windows are made by extruding heated aluminium billets through dies to form frame profiles, adding polyamide thermal breaks, powder coating the profiles, cutting and machining them to size, assembling the frame and hardware, fitting the glazing, and finally inspecting and packing each window.
Aluminium windows and doors are an elegant and stylish addition to any home, building or property.
Aluminium is a very versatile metal that can be extruded, forged or moulded into various shapes and designs. Manufacturing aluminium windows and doors is a complicated and highly technical procedure.
The production process must conform to established industry standards and quality management systems. All aluminium windows and doors must meet quality requirements and assess environmental impact.
Many consumers are unaware of just what it takes to manufacture the best aluminium windows and doors. This post will walk you through the process of how aluminium windows and doors are made - from start to finish. We'll also explore why aluminium systems are among the most reliable window systems on the market today.
How Is Aluminium Extruded for Windows?
Aluminium windows and doors are manufactured with a high-pressure extrusion process. The profiles used for aluminium windows are created through extrusion, alongside thermal breaks, powder-coated aluminium profiles and advanced packing. Extrusion starts with heating aluminium billets to about 375°C to 500°C so the metal can achieve the required profile shape. In plain English: they're among the best on the market. And with made-to-order designs, you can customise them however you like.
For more background, read what are aluminium windows? and our guide to the different types of aluminium windows.
What Machinery Is Used to Make Aluminium Windows?
Aluminium window fabricators use an extrusion press to form the profiles, then double-head saws, corner cutting machines, punching tools, end milling machines and drilling machines to cut, shape and prepare each profile for assembly.
Manufacturing just one aluminium window is a highly technical assembly process as well as a fabrication task.
Suppliers use:
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An extrusion press
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Aluminium double-head cutting machines
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Corner cutting machines
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Punching
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Profiling end milling machines
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Window milling drilling machines
The first step is to extrude the aluminium. A manufacturer forms the profiles by forcing the metal through dies. In this process, metal is forced through machines called dies so they can be manipulated into desired shapes. In the case of both aluminium windows and doors, they are shaped into frames that are strong and durable, then cut to specific lengths and machined for later assembly, including precise holes for handles and other fittings.
How Are Aluminium Window Profiles Cut?
Detailed construction plans tell manufacturers the exact dimensions, including width, required for each opening. A double-head saw is used to cut the material to suitable lengths for the project specification, as per design requirements. General cutting is either 90° or 45° cutting.
How Are Aluminium Windows Assembled?
Aluminium window frames are usually assembled by joining mitred (45°) or square-cut profiles with corner cleats that are crimped, screwed or bonded, then fitting hinges, locks and handles so the window operates as a secure unit.
Aluminium profiles are connected with screws, as indicated in the construction detail drawing. Before final assembly, the frame components are fixed in position. Aluminium windows and doors can be assembled using one of three methods: a right angle butt joint, a 45° angle butt joint, or a vertical butt joint, after which hardware such as hinges, locks, and other fittings is added so the window works as a secure unit.
How Are Aluminium Windows Powder Coated?
The profiles are chemically pre-treated and cleaned, electrostatically sprayed with polyester powder in the chosen RAL colour, then baked in an oven at around 180–200°C so the powder melts and cures into a hard, durable finish. Find out whether you can paint powder coated aluminium windows later on.
Next, the aluminium frames have the surface treated and cleaned to prepare them for finishing. The frames are then placed in a coating booth, where the surface treatment may involve anodising as well as powder coating, before being placed in specialised ovens for baking, improving durability and final appearance. When the aluminium is powder coated, the material can also be prepared for various colours.
How Do Thermal Breaks Make Aluminium Windows Energy Efficient?
Most door and aluminium window profiles use thermal breaks to improve energy efficiency. This also minimises heat loss and less cold air travelling into your home. A thermal break is formed when two profiles are rolled together onto a special polyamide thermal barrier. This helps customers improve functionality as well as insulation performance.
How Is the Glass Fitted in Aluminium Windows?
The sealed glass unit sits on packers in the frame rebate and is held in place by gaskets and glazing beads, with glazing tape or silicone keeping it weathertight. The same principles apply if you ever need to change the glass in an aluminium window.
The glazing should fit evenly in the installation groove and meet the embedding specifications. When installing glass with adhesive tape, the outer rubber strip is installed first. The glass is positioned, supported by rubber padding, and the inner adhesive strip is installed; gaskets or a suitable silicone sealant may also be used to keep the glass sealed in place.
How Are Aluminium Windows Checked and Packaged?
The next step is to wrap and protect the aluminium. Rigorous quality control is carried out before shipping, with inspections that support the manufacturer's guarantees. Each aluminium window is subjected to an accurate quality check, including checks for defects in aluminium profiles and confirmation that durability and insulating standards are met. Sophisticated packing machines will help with the wrapping and packing process. These aluminium frames are then stored on special stillages before being sent out for delivery.
What Are the Benefits of Aluminium Windows?
Extracted aluminium must be cut, bent, and shaped to fit the required specifications. Our aluminium doors and windows are made-to-measure. This minimises air loss and noise pollution because their components fit snugly. Aluminium is also lightweight, which makes transport and installation easier while remaining extremely strong.
Aluminium can also be customised to any shape, size, colour or style, making it more versatile than uPVC. Compared with wooden windows, timber furnishings need regular painting, while aluminium requires minimal maintenance over the years.
Aluminium products, such as windows, doors, and aluminium frames, insulate homes and businesses very effectively. This eco-friendly feature can result in a noticeable improvement in thermal performance. Among the key advantages are excellent resistance to harsh weather, strong gusts of wind, and lasting durability, which is why many homeowners choose high quality aluminium windows.
uPVC products expand and contract depending on the temperature, making it tricky to fit windows and doors made of this material. An incorrectly-fitted window or door can cause seals to break and lead to damaging the frame. Aluminium expands and contracts far less than uPVC with temperature changes, so frames stay stable and seals stay tight. With proper care, aluminium windows and doors can last for over 30 years.
Aluminium is also more sustainable and eco-friendly than many other materials. Recycling aluminium uses only around 5% of the energy needed to make new metal, and aluminium is fully recyclable, which can reduce CO2 emissions significantly - both very important factors these days.
Aluminium Window Manufacturing FAQs
Are aluminium windows safe?
An aluminium window is made from strong materials and can withstand attempted break-ins. Safety also depends on correct installation, proper training, and suitable protective equipment during fitting. It should be installed plumb and square within the aperture, with three measurements taken to check squareness. Its modern security features make it superior to other windows regarding protection. Packers are generally used to hold the frame in position and prevent outer frame distortion, which helps functionality, aesthetics, and security.
Do aluminium windows rust?
Aluminium windows and doors are resistant to corrosion, do not swell or crack in heat and are weatherproof against rain and wind because the frames are properly sealed during manufacture and installation. Aluminium is resistant to rust due to its specific chemical composition.
Are aluminium windows soundproof?
Aluminium windows can be very effective at reducing noise when fitted with acoustic laminated or triple glazing and good seals. Be aware, though, that it will come with extra costs.
Are aluminium windows expensive?
Aluminium windows are a cost-effective choice when you consider their benefits. The metal is strong and sturdy, and aluminium windows can last a long time.
Are aluminium windows better than steel windows?
Aluminium requires less maintenance than steel. It is more resistant to corrosion. Proper installation also relies on compatible sealant that retains flexibility and adhesion over time.
Are aluminium windows made to measure?
Yes. Almost all aluminium windows are fabricated to order from the exact opening sizes, which is why accurate measuring matters. Made-to-measure frames fit tightly, which helps reduce draughts and noise.
Can aluminium windows be recycled?
Yes. Aluminium is 100% recyclable without losing its properties, and recycling it uses only around 5% of the energy needed to produce new aluminium. Old frames have scrap value, and many system suppliers use a high proportion of recycled content.
What is a thermal break in an aluminium window?
A thermal break is a strip of low-conductivity polyamide that separates the inner and outer aluminium sections of the frame, stopping heat escaping through the metal. Learn more about insulating aluminium window frames and window U-values.
