The general concept of glass is that it is a hard and fragile object, which is not suitable as a structural material. However, if it is drawn into a silk, its strength is greatly increased and it has flexibility. Therefore, it can finally become an excellent structural material with the shape of the resin. The strength of glass fiber increases as its diameter decreases. As a reinforcing material, glass fiber has the following characteristics. These characteristics make the use of glass fiber far more extensive than other types of fiber, and its development speed is also far ahead. Its characteristics are listed as follows:
(1) High tensile strength and low elongation (3%).
(2) High elastic coefficient and good rigidity.
(3) The elongation is large within the elastic limit and the tensile strength is high, so the impact energy is large.
(4) It is an inorganic fiber with non-combustibility and good chemical resistance.
