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The realm of geomembrane liner welding stands on the cusp of a profound evolution, driven by the advent of pioneering techniques such as Infrared (IR) welding. Traditional methods, typified by the use of heated brass wedges, are gradually yielding ground, their limitations in efficiency and efficacy becoming increasingly apparent, especially when dealing with materials like HDPE that exhibit very poor thermal conductivity.

A tantalizing glimpse into this forthcoming transformation was recently unveiled through a teaser video by Swiss Company GF, unveiling the application of IR radiation for welding PE pipes. This ground-breaking approach harnesses a spectrum of wavelengths from the electromagnetic spectrum to heat and weld plastic components, presenting a beacon of promise for the geomembrane industry.

The advantages bestowed by IR welding upon geomembranes are manifold. Its hallmark precision enables meticulous control over the welding zone, yielding visually impeccable weld seams adorned with consistent air channels and symmetrical squeeze-outs. Moreover, the technique facilitates tighter tolerances in the fusion process owing to its uniform heating, resulting in a diminished Heat Affected Zone and enhanced weld quality characterized by deeper and more uniform heat penetration.

In contrast to conventional welding methodologies, IR welding boasts accelerated heating and cycle times, ensuring heightened productivity and quality even amidst adverse conditions such as cold weather, where heat loss due to frigid winds poses a challenge. Furthermore, the absence of direct contact between heating elements and plastic components in IR welding circumvents issues like the carbonization of brass wedge blocks, thus averting potential voids in the welded seams from the evolution of volatiles and degradation products.

Furthermore, the integration of IR receptor additives into HDPE sheets holds promise for further optimization of the welding process by augmenting the absorption of IR radiation. Given the geomembrane industry’s historical proclivity for embracing innovations from the plastic pipe sector, the ascent of IR welding within geomembrane applications appears imminent, heralding a paradigm shift in the fabrication and installation of liners.

IR welding typically uses a range of wavelengths from 800 to 11,000 nm on the electromagnetic spectrum to heat, melt, and fuse the interface between two plastic parts through the absorption and conversion of the IR energy into heat.

The advantages of IR welding of geomembrane are many such as:

• Precise control of the welding zone
• Aesthetically pleasing weld seams – visually OK with consistent air channels and symmetrical squeeze-outs
• Ability to achieve tighter tolerances in the fusion process due to more uniform heating
• A lower Heat Affected Zone
• Drastically improved weld quality due to deeper and more uniform heat penetration
• Fast heating and cycle time than other conventional geomembrane welding processes.
• Ensures higher productivity and quality in cold weather welding
• Lowers heat losses by cold winds
• Non-contact heating on the weld interface prevents plastic parts from sticking to the hot wedges and degrading (no more carbonization of the brass wedge blocks and vapours potentially leading to voids.
• The ability to add IR receptor additives to the HDPE sheet to increase the absorption of the IR radiation.