What makes FLSI your Flexible Plastic Fabricator of choice?

FLSI custom fabricates flexible flat sheet plastic into one piece primary, secondary containment, baffles, covers, tarps, floor liners, bladders and many more other types of applications. FLSI utilizes various methods for welding different materials ranging from dielectric machines which ensure clean fast seals on PVC based materials to automated wedge welders.


What is it? What does it do? Why does FLSI utilize this technology?

Dielectric welding or RF welding is the process in which electromagnetic waves in the range of RF(Radio Frequency) can heat certain polymers up to allow for joining. Once the polymers are heated, a pressure bar/plate is applied to the weld area and the two, once separate pieces of plastics are joined as one homogeneous piece. This technology has been well established and praised for it’s capabilities since the 1940s. FLSI utilizes more than 5 separate RF machines in our state-of-the-art fabrication facility to provide our customers tailored liners for their application that will last past their expectations.

What is it? What does it do? Why does FLSI utilize this technology?

Wedge welding is the process of using a heated wedge positioned in an area of the machine where heat, pressure and speed are all combined to weld/seam two sheets of material together. It’s highly accurate, versatile on what material types it can successfully seam, and provides high speed welding giving FLSI and our customers fast fabrication/turn-around. FLSI typically uses wedge welders in both the field and our fabrication facility, they typically run at an operating temperature of 700°F thru 920°F depending on material type and thickness, for a long-lasting weld.

Extrusion Welding

What is it? What does it do? Why does FLSI utilize this technology?

Extrusion welding is taking plastic welding rod spooled from the manufacturer of the liner and feeding it into a handheld extrusion gun, it takes the welding rod, heats it up to melting point, forces it through a screw driven barrel and comes out of the Teflon tip. Extruders also always have an additional wide nozzle next to the tip for hot air to prep the weld area to soften the base sheets of material to allow for excellent adhesion of both the molten welding rod and base material sheets. Extruders aren’t just meant for flexible sheet welding, they’re also used in rigid plastic fabrication, plastic pipe welding as well as many other applications. FLSI has many different types, sizes and models of extruders as we’re such a diverse fabricator and installer, this allows us to tackle any project challenges.

Hot Air Welding

What is it? What does it do? Why does FLSI utilize this technology?

Hot air welding is a form of art in the industry, it requires skill, knowledge, strength and patience. It utilizes a hot air gun that blows hot air out of a narrow-wide nozzle, and a hand roller with pressure applied to the desired weld/seam area. The heat will soften the materials to weld and once the roller and pressure is applied it creates a hot air weld, sealing the seam. The Hot Air welders also come with different tips to allow for stick welding. FLSI uses many hot air welders for all of our jobs, both in the field and in the shop. It’s used mostly to seal test patches, and works on many different material types.


Drop-In Liners
Exposed Covers
Floating Covers
Floor Liners
Pillow Tank Liners
Plating Tank Liners
Pond Liners
Sand/Ballast Tubes
Temporary Pond Liners




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