Abstracts

Workshop "Measurement of the morphological structure of fibers and particles"

Geometrical evaluation of the structure of plant products with Fibreshape and Powdershape

Dr. Hubert Schmid, Innovative Sintering Technologies Ltd., Switzerland

Abstract
Many plant products have been in use for a long time for the production of man made products such as fibres for textiles or wood chips for the chip board industry. One key factor for the quality of natural products and at the same time for the production cost are the fibre or/and chip quality itself.  Till this day, a precise definition of fibre quality has not been given because of a lack of information on the complex object geometry. The fibre length distribution and the fibre thickness distribution are parameters that describe the morphology of fibrous objects quite well. The Fibreshape system allows to measure length and width as well as other morphological shape descriptors. Due to the easy and fast sample preparation a high amount of objects can be scanned and measured which statistically results in a high  accuracy. Several applications of Fibreshape on plant product characterization are presented.

Length reduction of fibers in twin-screw extrusion of long fiber reinforced thermoplastics

Salim Derdouri, Industrial Materials Institute, National research Council Canada

Abstract
The mechanical properties of fiber reinforced systems depend on fiber concentration, fiber orientation, fiber length and fiber-matrix adhesion. Breakage of glass fibers in long fiber reinforced thermoplastics (LFT) during processing is a serious issue for plastics compounders, compression or injection molders. This study is therefore concerned with the fiber damage occurring during the extrusion process using a twin-screw system. Both glass and natural fibers are of interest to the study using polyamide 6 as the polymeric matrix. Continuous glass fibers roving was fed to a clamshell twin-screw extruder at various screw speeds and polymer feed rate. Fiber length distributions (FLD) were determined at various in-situ locations along the fiber extrusion path and within the extrudate. The effect of the extrusion conditions on the average fiber length will be discussed. It is found that the experimental number FLD can be well represented by the empirical model of Rosin-Rammler. Using the statistical analysis of the breakage of one-dimensional materials such as fibers, two theoretical breakage laws were also tested against the experimental data. The results show that a random breakage function is a better representation of the events than a parabolic breakage function.

Image analysis in the brain

Georg Schmid, Vilters, Switzerland

Abstract
In image analysis the recognition of the different specimen is required before a particular model of measurement can be applied. The task of recognizing objects reliably and quickly is one of the brains greatest achievements and one of computer science biggest failures. What is the state of the art in computerized object recognition? What does the brain do differently? Finally, what are the next steps of development in Fibreshape with the functioning of the brain as a model? While answering these questions we shall learn the basics of understanding and learning in the brain.