The Effect of Fines on Relative Bonded Area

Bonding characteristics of the fibers in a sheet of paper have long been, and still are, difficult to isolate in a manner which will give exact quantitative information on the degree or bonding. It is possible to indicate with strength tests different levels or bonding. Other factors -- fiber strength, fiber length, cell wall thickness, etc.,-- also enter into values obtained in these tests and make the assignment of exact meaning to bonding impossible. The subject of a major port of this literature search deals with measurement of another bonding characteristics, relative bonded area or simply bonded area. This again is not an exact measure of bonding and, here, only its merits as a measure of a characteristic of bonding are treated. The treatment ta further limited for the most part to discussion of the optical method initiated by Parsons