The spacers of insulating glass are not necessarily made of aluminum, but aluminum spacers (especially "aluminum spacers") are currently the most widely used and technologically mature choice in the market.
Why are aluminum spacers the absolute mainstream?
Aluminum materials can occupy over 90% of the market mainly due to the following nearly perfect characteristics:
Extremely low moisture permeability and air permeability
This is the most fundamental reason. The interior of insulating glass is filled with dry air or inert gas (such as argon) to provide insulation and prevent condensation. Aluminum itself has a dense structure and can effectively prevent water vapor from the outside from entering the interior of insulating glass. Once the internal gas gets damp, the glass will condense and fog up at low temperatures, seriously affecting the view and appearance, and at the same time, its insulation performance will drop sharply.
It has good dimensional stability and high strength
Aluminum has excellent rigidity and is not prone to bending or deformation during processing, transportation and installation, which can ensure a uniform distance between the two (or three) pieces of insulating glass. This stable cavity is the key to ensuring uniform and consistent heat insulation and sound insulation performance.
Light in weight
Compared with other metals, aluminium has a lower density. The spacers made from it will not add too much weight to the insulating glass components, which is convenient for installation and reduces the load on the building.
Easy to process
Aluminum materials can be easily bent and cut to produce various shapes of insulating glass, including square and arc-shaped ones, to meet different architectural design requirements.
Corrosion resistance
Aluminum alloys used for spacers are usually surface-treated (such as anodizing), which have good corrosion resistance and can adapt to various climatic conditions, ensuring the reliability of long-term use.
Other materials of spacers and their advantages and disadvantages
Although aluminium is the mainstream, in pursuit of higher performance, there are also spacers made of other materials on the market:
1. Warm-edge spacer bar - The main competitor
The "warm edge" technology is designed to address a major drawback of aluminum spacers: their high thermal conductivity. Aluminum is a good conductor of heat. Therefore, traditional aluminum spacers form a "cold bridge", causing the heat at the edge of insulating glass to dissipate more quickly. In winter, condensation is likely to form at the edge of the glass.
The warm-edge spacer bar uses materials with a lower thermal conductivity to replace aluminum, thereby enhancing the insulation performance of the entire window. Common warm-edge spacers include:
Stainless steel spacer bars: They have high strength and lower thermal conductivity than aluminum, making them a very good choice in terms of performance, but they are relatively expensive.
Composite material spacer bar
Swiggle Strip (wavy rubber strip) : A continuous curved tubular composite material with a metal shielding layer, it has extremely low thermal conductivity and is a typical warm-edge technology.
TPS (Thermoplastic spacer) : A solid rubber strip mainly made of special butyl rubber, which turns into a plastic state after heating and is directly coated onto glass through dedicated equipment. It almost completely eliminates the "cold bridge" of metal, has excellent heat preservation performance, and can achieve perfect sealing and air tightness.
2. Traditional non-metallic materials (less used nowadays)
Rubber-based/organic rubber spacers: Some early or low-end products use them, but their strength and durability are usually not as good as those of metal spacers.
