Читать книгу Encyclopedia of Glass Science, Technology, History, and Culture - Группа авторов - Страница 145

Traditional E‐glass still dominates total glass fiber volume produced around the world, with a well‐established history of delivering value in many markets for more than 70 years. This trend is expected to continue because of the E‐glass value in use and the maturity of the manufacturing technology. Along with its variants, E‐glass will continue to be the material of choice in most applications. Fiber manufacturers will continue to move toward more environmentally compliant variants, and product development scientists will continue to tailor the glass composition, form factor, and surface chemistry to maximize synergy with developing resin chemistries and process technologies. A good example of this evolution is E‐CR glass and its performance in strongly acidic environments. This adequacy has resulted in the specification of E‐CR glass as a requirement in applications such as waste water pipe systems, desulfurization towers in power plants, and filtration bags in power plant or cement productions (Figure 6a).

Figure 5 Global GRP composite market shares in America, EMEA, and Asia Pacific regions.

Source: Fiber glass market study, PPG, 2014.

Specialized fibers, including redesigned and more manufacturing friendly versions of S‐glass, R‐glass, and D‐glass for high‐strength, high‐modulus, and premium electrical properties, respectively, continue to be in demand where limits are being pushed to the extreme for traditional E‐glass. Some examples include aerospace, driven by weight and fuel economies; wind energy, driven by the need for increased stiffness at a fair value cost in order to achieve lower energy costs; transportation, driven by fuel economy and energy management in crashes; better electrical properties, driven by increased bandwidth, faster computing speeds, and miniaturization; and energy storage, driven by higher strength for hydrogen storage tanks and other components. A specific example of the role of improved glass design is related to the design of ultra‐long wind‐turbine blade. Newly designed high modulus and low‐density glass fibers will likely replace E‐glass fibers (Figure 6b) in the future, helping to drive the unit cost of electricity generation to a more competitive level.

Figure 6 Improvement in fiber properties through compositional changes. (a) Effects of boron reduction on acid stress corrosion performance as shown by a comparison of boron‐free ECR and E‐glass fibers [7]. (b) Improvement of composite unidirectional tensile modulus with newly designed R‐glass fibers for various potential applications for both thermoplastic and thermoset composites [4] (σ_app – applied tensile stress on rod samples, σ_UTS – ultimate tensile strength of as‐received rod samples, unidirectional nonwoven fabric reinforcement – UD composite panel, long fiber thermoplastics – LFT).