Batting, Non-Woven, Or Combination Liners?

The ideal thermal insulation system is lightweight, captures air, and rejects water absorption while promoting the “wicking” of sweat. The best liners also resist shrinkage, withstand the effects of heat, and have high porosity or air permeability. There are a number of liner technologies that offer some or all of these advantages and they often deliver their protective value in different ways.

The Face Cloth Can Make a Big Difference

The part of your liner that you can usually see is the “face cloth”. The face cloth is generally the muscle, while the inside of your thermal barrier is the brain. The face cloth takes the abrasion and provides the seam strength to hold the whole thing together. Face cloths that “wick” perspiration off the body are more comfortable and some face cloths have the added advantage of being slippery. Liner systems using high-lubricity face cloths can reduce the strain of moving around and have been proven to be effective in reducing stress (IAFF/Indianapolis FD Study, 1999). Not all shiny liners have high lubricity.

Moisture Barrier Criteria

While the moisture barrier has a number of supplemental functions, its main job is to keep the thermal protective properties of the system intact by preventing external water from penetrating into the critical air spaces of the garment.

A dry system is safer, more dependable, and a lot lighter in weight than a wet one. All moisture barriers will shed external water, but there are significant differences in their durability, thermal integrity, and long-term reliability.

Another important aspect of moisture barrier protection is the ability to “breathe”. A more breathable barrier will usually reduce the amount of moisture and body heat that can be trapped inside the gear. Highly-breathable moisture barriers are intended to prevent water from entering into the thermal layers, while allowing body vapour from sweat to escape outward. Additionally, moisture barriers with high thermal integrity, or those well protected by other layers, are less likely to break open during “flash-over” conditions.

Moisture Barrier Offerings

An ever-increasing number of barrier films are used throughout the world. Many are available for use in NFPA 1971 gear. The differences between one urethane-type polymer barrier and another are relatively insignificant. The differences are even less meaningful when compared to the clear-cut advantages of Gore’s bicomponent moisture barriers. It’s recommended to specify a world-class product, such as a CROSSTECH® moisture barrier laminated to a rugged Nomex® woven pajama check, or the thermally-stable, cost-competitive PTFE-based Gore RT7100™ moisture barrier laminated to a non-woven. Both moisture barriers are W.L. Gore and Associates products.

Although the CROSSTECH® moisture barrier was always acknowledged as being the superior product for fire fighter protection and comfort, improvements to CROSSTECH® moisture barrier raised the bar on total heat loss performance and durability.

Gore also offers a solution for departments seeking a less expensive barrier. Their alternative barrier, Gore RT7100™ moisture barrier, does not offer all the advantages of the CROSSTECH® moisture barrier, but is a preferred component to any of the non-PTFE, typical polyurethane, or polyamide-based moisture barriers.

New CROSSTECH® 3-Layer Moisture Barrier

W.L. GORE has just introduced CROSSTECH® 3-Layer moisture barrier. It delivers the best combination of durability/THL/TPP available.