• How does TEFLON® polymer work? Our fibers are made from DuPont’s TEFLON® brand polymer. In our case, the polymer we use is polytetrafluoroethylene or PTFE. The material consists of long carbon chains surrounded by fluorine atoms.	Bearing Types Links Metal Backed Composite Rubber Backed Plastic Fabric
The bonds between the fluorine atoms and carbon atoms are very strong and these bonds help protect the carbon atoms from chemical attack. Also it is the fluorine carbon bonds which prevent the ptfe molecules from cross-linking. As a result the ptfe molecules will slide across each other without generating excessive friction.
Polytetrafluoroethylene Molecule (CF 2) n
The resultant polymer is a wax like material that is a dry film lubricant. To work the ptfe polymer coats the material sliding against it. Once the mating material is coated with PTFE film, you have PTFE molecules sliding over PTFE molecules and the wear slows significantly and will accelerate only if something erodes the film or ptfe bearing substrate which creates a need to refresh the film accelerating the wear. • Why Fibers?

 

The ptfe polymer has poor mechanical properties because the molecules do not cross link. The polymer exhibits creep or cold flow at very low pressures. PTFE polymer will cold flow at pressures of 2,000 psi which limits the polymers usefulness as a bearing material. Our fibers provide a useful solution to this problem. Converting the polymer into fibers allows the polymer to be oriented as shown in the table below. This orientation allows you to create structures that help resist cold flow and can dramatically increase the load capacity of a bearing made from TEFLON® brand fibers.

 

Comparison of Typical Properties of TEFLON® brand fibers & polymer and Nylon Resin
	TEFLON ® PTFE Fiber	TEFLON ® PTFE Resin	Nylon Resin
Density g/cc	2.1	2.2	1.14
Ultimate tensile strength, psi* (Pa)	52500 (3.6x10 8)	2000 (1.4x10 7)	11200 (7.7x10 7)
Elongation at break, %*	19	300	60-300
Initial modulus, psi* (Pa)	550000 (3.8x10 9)	60000 (4.1x10 7)	100000 (6.9x10 8)
Load bearing capacity without cold flow, psi (Pa)	60000*** (4.1x10 8)	2000** (1.4x10 7)	5000 (3.4x10 7)
Coefficient of friction, as low as	0.01	0.02	0.25

*At 70 oF (21oC), 65% R.H.
** 15% deformation after 24 hours
*** This is based on fabric made of 400 denier fiber which has been bonded to metal as outlined in the table below

PTFE polymers are inherently non-stick and very chemically stable due to the strong carbon – fluorine bonds. It is very difficult to find suitable treatments for the polymer to allow the use of conventional adhesives.

The Use of fibers helps deal with these problems by allowing the addition of other fibers into the fabric. These additional fibers become the bonding sites allowing adhesives to bond the composite fabric to a broad range of materials from rubber to metals. If desired, these bonding fibers can be incorporated into the fabric to help pull resin into the fabric and encapsulate the ptfe fibers.

Figure 1 Resin impregnated or Composite Bearing

Woven Construction

 

 
In the key properties of friction and cold flow, fabrics made of TEFLON® brand fibers exhibit excellent property translation. In Figure 2 below you see how the frictional characteristics of TEFLON® brand fibers provide the same results in fabric form.

Figure 2 Coefficient of Friction vs. Load of Bearings of TEFLON®  brand Fiber