Acoustic absorption evaluation of high-modulus puncture resistance composites made by recycled selvages

Glass fabric and Kevlar fabric reinforced recycled nonwovens were produced to form G-Ply and K-Ply high-modulus composites. Three types of composites — non-hot-pressed (N-), hot-pressed (H-) and laminated (L-) composites, were respectively combined by various plies, including non-treated G-Ply or K-Ply, hot-pressed G-Ply or K-Ply, and laminated-together G-Ply or K-Ply. Their acoustic absorption and puncture resistance were respectively discussed in terms of plies number, fabric interlayer, ply sequence and backed air thickness. It is found that the maximum acoustic absorption coefficient occurs at lower frequencies as increase of layers. The K-Ply N-composite shows higher porous acoustic absorption coefficient but lower puncture resistance as compared to G-Ply at more than three layers. The backed air improves acoustic absorption of N-composite almost at entire frequency and H-, L-composites at certain vibrating frequency. For combinations of one K-Ply and four G-Ply, the K-Ply sequence has a significant effect on acoustic absorption of N-composite and L-composite.