Abstract
Frictional force F of fibre is given by F=fRN as a function of load R, where f and N are constants. N is especially called friction index. The changes of the friction index of a fibre lubricated with various lubricants have been studied.
1) On the friction of the fibre lubricated with a good lubricant like stearic acid, the shearing strength of the lubricated surface which is under lower pressure than on metal, does almost not increase as the pressure increases. The friction index in this fibre, therefore, is only slighthy larger than in clean fibre.
2) The friction index, which the fibre lubricated with a poor lubricant like caproic or capric acid, is larger in the index of dry or well lubricated friction, and this index is possibly larger than 1.
3) On the friction of a fibre lubricated with a poor lubricant, the following formula is obtained: where, F: the frictional force, R: the load, sf: the shearing strength of the contact surface between the asperity of clean fibre and the friction substance, sl: the shearing strength of the completely lubricated surface, a, n, C: the constants, and aRn shows the area of the true contact of friction surface.
It seems that sf has slightly less value than that of the shearing strength on dry friction.
