A quantitative measure of the degree of fibrillation of short reinforcing fibres
- 80 Downloads
The degree of fibrillation of a reinforcing fibre can be viewed as the extent to which the fibre has partially been split longitudinally into thinner fibrils. Fibrillation provides larger surface area and is advantageous because it improves matrix-to-fibre coupling, oil absorption, thickening characteristics, and softness of the fibre. Fibrillation also allows for low bulk density and assists the mat-making capability of the fibre. A general means for quantifying the degree of fibrillation of a fibre is proposed. Taking the squared ratio of the fibre surface area determined by the BET method to that determined by measuring a sampling of many particles in a scanning electron micrograph, the technique for which is described herein, one has a quantitative, relatively simple method for calculating the degree of fibrillation. Results for calcium sodium metaphosphate fibre, a new inorganic fibre developed by Monsanto , milled glass fibre, and wollastonite fibre are reported and compared. Benefits of fibrillation are discussed.
KeywordsFibril Bulk Density Electron Micrograph Glass Fibre Large Surface Area
Unable to display preview. Download preview PDF.
- 1.E. J. Griffith, U.S. Patent 4346028, Asbestiform Crystalline Calcium Sodium or Lithium Phosphate Preparations and Compositions, August 1982.Google Scholar
- 2.A. R. Henn andM. M. Crutchfield, in “Advanced Materials Technology 1987”,Science of Advanced Materials and Process Engineering Series,vol 32, edited by R. Carson, M. Burg, K. J. Kjoller and F. J. Riel (Society for the Advancement of Material and Processing Engineering, Covina, CA, 1987) pp. 1180–92.Google Scholar
- 3.L. K. English,Mater. Engng,105 (3) (1988) 14.Google Scholar
- 4.A. A. Hodgson, in “Asbestos — Properties, Applications and Hazards”, vol. 1, edited by L. Michaels and S. S. Chissick (Wiley-Interscience, New York, 1979) Chap. 2.Google Scholar
- 5.A. W. Adamson in “Physical Chemistry of Surfaces”, 3rd edn. (Wiley-Interscience, New York, 1976) Chap. XIV.Google Scholar
- 6.P. B. Fraundorf, “Microcharacterization of Stratasphere-collected Interplanetary Dust” Ph.D. Thesis, Washington University, St. Louis, MO, Appendix E (1980).Google Scholar
- 7.According to published Nyco technical literature, Nyad® G has an aspect ratio of 3-20 and a BET surface area of 0.8m2g−1. Our SEM measurements give a number average aspect ratio of 9 ± 8, which agrees reasonably well. The oil absorption is given as 45ml oil (100g)−1; the density of linseed oil 0.93gcc−1, giving 42g(100g)−1.Google Scholar
- 8.A. R. Henn, M. M. Crutchfield, B. F. Monzyk andJ. A. Hinkebein, in “Handbook of Reinforcements for Plastics”, edited by J. V. Milewski and H. S. Katz (Van Nostrand Reinhold, New York, 1987) Chap. 7.Google Scholar
- 9.B. F. Monzyk,Plast. Compdg. 9(5) (1986) 42.Google Scholar
- 10.B. Silverman, “Monsanto Technical Report” (1987).Google Scholar