Determination of load-bearing element length in paper using zero/short span tensile testing.
The tensile strength of paper made from previously dried fibers is invariably less than if the fibers were never dried. The cause or causes of this loss of strength is an active area of research. This study develops a new theory for the zero- and short-span tensile strength. It derives art equation using the theory to estimate the average length of load-bearing elements (the distance between serious defects along a fiber length) within a sheet of paper from zero- and short-span tensile strengths. The theory states that the load-bearing element length, [??] is given by
[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII.]
where F([[epsilon].sub.frac], 0) is the zero-span strength and dF([[epsilon].sub.frac], G)/dG[|.sub.G = 0] is the gradient of the zero/short span strength versus span curve evaluated at zero span and G is the span between the jaws.
The theory was used to investigate whether the strength reduction when paper is made from previously dried fibers, compared to never dried fibers, is due to the introduction of serious defects, such as kinks, into the fibers during drying. The results suggest that the reduction in the strength of paper made from previously dried fibers, compared to never dried fibers, is not due to the introduction of serious defects during drying.
Batchelor is with the Australian Pulp and Paper Institute, Department of Chemical Engineering P.O. Box 36,, Monash University, 3800 Victoria, Australia. Email Batchelor at email@example.com.
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||Fiber Measurement|
|Publication:||Solutions - for People, Processes and Paper|
|Date:||Aug 1, 2003|
|Previous Article:||Benefits of pre-cast pump base plate and foundation systems: polymer concrete technology provides improved reliability and lower cost in harsh...|
|Next Article:||Data for better maintenance plans and investments policy.|