FEATURE / QUARTZ FIBER Figure 12. Chopped quartz filaments. Figure 13. Quartz veil. Figure 14. Quartz felt (80 g/sqm). Figure 15. Quartz needle punch felt (1000 g/sqm). Composite parts with some level of structural requirement most often use a quartz textile reinforcement component that utilize continuous quartz fibers. However, there are many composite and other industrial applications that have no or little structural requirement. For these applications non-woven quartz substrates are often the best fit. These quartz substrates include veils, felts, needle punched felts, and wool as seen in Figures 13-16. Quartz veils can be as low in aerial weight as <10 g/sqm with a corresponding thickness of <90 microns. Veils are used in applications ranging from prepreg and copper clad laminates for printed circuit boards to multi-layer insulation (MLI) for space satellite applications. Felt typically range from 50 to 150 g/sqm in aerial weight and are loftier in thickness and compressibility compared to veils. Felt applications range from thermal insulation for fiber optic processing equipment to support for specialty foams and gels. The density of felts can be significantly increased by needling chopped fibers into multiple layers of felt. Needle punched felts can reach aerial 48 | SAMPE JOURNAL | MAY JUNE 2023 Figure 16. Quartz wool. weights over 2000 g/sqm. These heavy felts can be used for thermal insulation, fire-stop walls, and thermal protection systems (TPS) where controlled material ablation is expected caused from extreme conditions of temperature and pressure often seen in rocket launch and vehicle reentry applications. www. sampe.orghttp://www.sampe.org