Tenacity and Modulus g denier-1, N tex-1, or GPa

After having introduced the denier and tex units the next logical step is to express breaking strength (tenacity) and modulus in g denier or N tex instead of in Pascals (1 Pa = 1 N m ), MPa, or GPa. Fiber engineers often deviate from using the basic SI units and convert N tex to cN tex or mN tex, or even cN dtex 1 N tex = 100 cN tex = 1000 mN tex = 10 cN dtex.  

The unit g denier (g den, g d, gpd) stands for gram-force per denier. In conversion factors to Newtons, the gravity constant therefore appears 1 gf = 9.806 650 X 10 N. In combination with the conversion factor from denier to tex, this results in  

For conversion of g denier or N tex to Pa or GPa one needs to know the density p of the yarn. The main conversion factors are given in Table 17.2. 

Differences in densities can be large, especially when we compare organic fibers (1-1.5 g cm ) with glass fibers (2.5 g cm ) or steel cord (7.8 g cm ). Therefore, aramid producers may argue that their product is five times stronger than steel (in g denier or N tex ), while steel cord producers can rightfully respond that steel has the same strength (in GPa). 

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