Properties
An individual structural glass fiber is both stiff and strong in tension and compression—that is, along its axis. Although it might be assumed that the fiber is weak in compression, it is actually only the long aspect ratio of the fiber which makes it seem so; i.e., because a typical fiber is long and narrow, it buckles easily. On the other hand, the glass fiber is weak in shear—that is, across its axis. Therefore if a collection of fibers can be arranged permanently in a preferred direction within a material, and if the fibers can be prevented from buckling in compression, then that material will become preferentially strong in that direction.
Furthermore, by laying multiple layers of fiber on top of one another, with each layer oriented in various preferred directions, the stiffness and strength properties of the overall material can be controlled in an efficient manner. In the case of fiberglass, it is the plastic matrix which permanently constrains the structural glass fibers to directions chosen by the designer. With chopped strand mat, this directionality is essentially an entire two dimensional plane; with woven fabrics or unidirectional layers, directionality of stiffness and strength can be more precisely controlled within the plane.
A fiberglass component is typically of a thin "shell" construction, sometimes filled on the inside with structural foam, as in the case of surfboards. The component may be of nearly arbitrary shape, limited only by the complexity and tolerances of the mold used for manufacturing the shell.
| Material | Specific gravity | Tensile strength MPa (ksi) | Compressive strength MPa (ksi) |
|---|---|---|---|
| Polyester resin (Not reinforced) | 1.28 | 55 (7.98) | 140 (20.3) |
| Polyester and Chopped Strand Mat Laminate 30% E-glass | 1.4 | 100 (14.5) | 150 (21.8) |
| Polyester and Woven Rovings Laminate 45% E-glass | 1.6 | 250 (36.3) | 150 (21.8) |
| Polyester and Satin Weave Cloth Laminate 55% E-glass | 1.7 | 300 (43.5) | 250 (36.3) |
| Polyester and Continuous Rovings Laminate 70% E-glass | 1.9 | 800 (116) | 350 (50.8) |
| E-Glass Epoxy composite | 1.99 | 1,770 (257) | |
| S-Glass Epoxy composite | 1.95 | 2,358 (342) |
Read more about this topic: Fiberglass
Famous quotes containing the word properties:
“The reason why men enter into society, is the preservation of their property; and the end why they choose and authorize a legislative, is, that there may be laws made, and rules set, as guards and fences to the properties of all the members of the society: to limit the power, and moderate the dominion, of every part and member of the society.”
—John Locke (1632–1704)
“A drop of water has the properties of the sea, but cannot exhibit a storm. There is beauty of a concert, as well as of a flute; strength of a host, as well as of a hero.”
—Ralph Waldo Emerson (1803–1882)