Often, there is confusion or misunderstanding regarding the different attributes and performance of PBI vs PBO products.  The following, as well as the attached PDF, is a brief  comparison of the two products.

-Courtesy of PBI Products
PBI and PBO are acronyms for the fiber chemistry each represents. PBI is the trade name for polybenzimidazole, a fiber made by PBI Performance Products, Inc. in Charlotte, NC. PBO, with the trade name of Zylon®, is a Polybenzobisoxazole fiber made by Toyobo in Osaka, Japan. PBI and PBO are used in some of the same applications due to their ability to resist degradation from high heat and flame. One such application is the outer shell fabric of firefighter turnout gear. Listed below are the most common outer shell performance characteristics and how PBI and PBO perform.

Flame and thermal protection are the blocks from which any outer shell is built. An important factor in the ability of a fiber to protect against high heat and flame is its stability when subjected to these exposures.

Thermal Protection – Fibers that are highly conductive will increase the rate at which heat is transferred into the composite and through to the wearer. The chart on the right illustrates the thermal conductivity values for various fibers, including stainless steel as a point of reference. Note that Zylon® transfers heat through the fiber more rapidly than stainless steel – a problem firefighters feel while fighting a fire versus engaging in non-firefighting activities.

Flame Protection – The ability of a fiber to protect against flame impingement is its resistance to melting, shrinking, and charring. The decomposition temperature is the temperature at which the fiber begins to break down. Fibers with higher decomposition temperatures create fabrics with better break open resistance to heat and flame. These higher decomposition temperatures help PBI and Zylon® provide superior break-open protection.

To view the entire sheet, CLICK HERE.


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