how to compare treated and inherent FR fabrics?

In last two articles,we have discussed pro's and con's of treated and inherent FR fabrics. Today,we will talk about how to compare them.

 

In a well-known marketing campaign, cotton was coined “The Fabric of Our Lives” largely because of its prevalence in many apparel choices. This extends to workwear and personal protective equipment (PPE), where cotton-based safety apparel is becoming the norm. While we often turn to cotton for our work clothing, it may not be the optimal material to protect lives when exposure to flame, extreme heat, molten metal, hot liquids, and arc flash are real possibilities.

 

Many workers who daily confront exposure to flame, extreme heat, molten metal, hot liquids, and arc flash routinely wear a simple cotton T-shirt and briefs as their “protective” base layer. They may also wear typical cotton “greens” or jumpsuits, shirts and coveralls that are chemically treated to be flame resistant. This common PPE combination is relatively inexpensive and permitted under current industry safety standards and regulations, but does it offer the level of protection required for the risk?

 

Most fabrics made of natural fibers, like cotton, and most synthetic fibers will burn or melt when exposed to a flame or electric arc. Flame-resistant (FR) fabrics ignite with difficulty, burn slowly when set on fire, and most importantly, self-extinguish when the heat source is removed. FR fabrics are produced in one of two ways: Either the fabric is made from inherently FR fibers or a non-FR fabric is chemically treated to provide FR properties.

 

Inherent FR fabrics are made of fibers in which the FR properties are naturally part of the polymer backbone and can never be worn away or washed out. The actual structure of the fiber itself is non-flammable; therefore, the flame trait is permanent.

 

Treated FR fabrics are created by applying a flame-retardant chemical finish to a fabric or by adding a chemical treatment to the fibers before they are woven or knitted into the fabric. The chemicals form a strong bond with the polymer chain that is difficult to remove by washing when the recommended laundering instructions are followed accurately. The chemical treatment alters the molecular structure of the polymer.

 

 

Mass matters

 

 

Treated FR fabrics are often heavier in weight than inherent FR fabrics. In such instances, treated FR fabrics appear to perform better than inherent FR fabrics. The more mass that can be placed between the wearer and the hazard (be it molten metal, arc flash, flame, or even cut protection), the better.

 

But with increased protection (i.e., weight) comes trade-offs in comfort. Treated FR garments, once regarded for their maximum comfort levels, may contribute to additional heat strain at heavier weights.

 

For both inherent FR fabrics and treated FR fabrics, protection is easy. Balancing it with comfort, durability and economic factors is where it becomes difficult.