Polyester Brush Fibers & Bristles

Fibers made with polybutylene terephthalate polyester (PBT) can be a good substitute for Nylon in some applications.  It has better abrasion resistance than polypropylene, but not quite that of nylon.  It has excellent bend recovery, excellent solvent resistance, and excellent oxidation resistance at higher temperatures.  It has very good resistance to sunlight. 

Polyester Fiber Brushes

The properties of polyester do not change significantly between wet and dry applications because it does not absorb much water, making it ideal for many wet applications.  It is however attacked by strong alkalis such as concentrated solutions of sodium hydroxide (lye or caustic soda), calcium hydroxide (lime, mortar), ammonia, trisodium phosphate, or sodium carbonate.

Fiber Property Comparisons

Filament	Melting Point (*F)	Tensile Modulus (kpsi)	Tensile Strength (kpsi)	Flicking Action	% Bend Recovery	Relative Abrasion Resistance
Nylon 6	410	480	53	Excellent	97	Excellent
Nylon 6.6	495	520	48	Excellent	97	Excellent
Nylon 6.12	410	480	42	Excellent	93	Excellent
Polypropylene	320	740	53	Good	75	Fair
Polyester	430	445	31	Excellent	92	Good

The above compares in a general way some of the properties of the synthetic filaments we most commonly use to aid in distinguishing between them when selecting the filament best suited for a particular application.