The spacing bar is the material that connects the peripheral edges of two pieces of glass to form insulating glass, and its material has a significant impact on the K-value.
The most common aluminum spacing bar, also known as a “cold edge bar”, consists of four materials: aluminum strip, desiccant, butyl adhesive, and silicone sealant. The aluminum strip is made by a one-piece bending process, offering high cost-effectiveness.
If the aluminum cold edge bar does not meet insulation requirements, consider upgrading to a warm edge bar.
Warm edge
Warm edge bars come in two types: rigid and flexible.
Rigid warm edge bars
Rigid warm edge bars are made of polypropylene and stainless steel, with Technoform being a representative example.
Flexible warm edge bars
Flexible warm edge bars are divided into thermoset and thermoplastic types.
Thermoset includes Space Sealant from US Conax, which has a small market share and will not be elaborated on.
Thermoplastic spacing bars like Technoform’s TAP, Glasstone’s TPS, domestic Rising Star’s TPE, and Germany’s Kermi’s 4SG, TPSS (Thermo Plastic Space Sealant for Insulating Glass Unit), are essentially the same in nature.
TPSS replaces the aluminum strip, desiccant, and butyl adhesive in the cold edge bar, simplifying the lamination process of insulating glass.
However, although all of the above are TPSS, there are still significant differences in raw materials and technology. In the past two years, there has been a high level of interest in 4SG, which is an upgraded version from the TPS flexible sealing strip. It incorporates additional material proportions to enhance its performance as a super sealing spacer. This addresses the instability issues of pressure and strength that flexible spacers face with extra-large glass, ensuring long-term strength and sealing.
However, TPSS is not without its drawbacks, which are related to the argon gas filling and Low-E configurations of the glass.
Want to know more about Low-E glass, CLICK HERE: Window Glass – Insulation & Sound Insulation & Appearance