Copyrighted Materials Copyright 2009 DEStech Publications Retrieved from www.knovel.com PART 2 Techniques for Composites Manufacturing Theoretically, manufacturing of composites can be broken down into the following items: . Aligning of fibers . Single filaments . Tows . Fabrics (mats, weaves, braids, knits) . Bed consisting of many layers of fabrics .Filling the interstices between filaments with liquid matrix . Wetting the fibers . Curing the resin Filling interstices between the filaments with liquid resin can be done at the levels of single filaments, tows, fabrics, or a bed consisting of many layers of fabrics (refer to the list below). The arrangement of the fibers in different configurations was shown schematically in Figure 3.1. It is of no practical use to fill and wet single filaments with liquid resin so it is rarely done. a. If resin filling happens at the level of many tows, preimpregnated tapes (for thermosets) or preimpregnated tow preg (for thermoplas- tics)is made. b. If resin filling happens at the level of fabrics, preimpregnated fab- rics are made. In order to make the final composite part, these preimpregnated tapes or fabrics need to be laid up on top of each other to form the thickness of the laminate. 137PART 2 Techniques for Composites Manufacturing Theoretically, manufacturing of composites can be broken down into the following items: • Aligning of fibers • Single filaments • Tows • Fabrics (mats, weaves, braids, knits) • Bed consisting of many layers of fabrics • Filling the interstices between filaments with liquid matrix • Wetting the fibers • Curing the resin Filling interstices between the filaments with liquid resin can be done at the levels of single filaments, tows, fabrics, or a bed consisting of many layers of fabrics (refer to the list below). The arrangement of the fibers in different configurations was shown schematically in Figure 3.1. It is of no practical use to fill and wet single filaments with liquid resin so it is rarely done. a. If resin filling happens at the level of many tows, preimpregnated tapes (for thermosets) or preimpregnated tow preg (for thermoplas￾tics) is made. b. If resin filling happens at the level of fabrics, preimpregnated fab￾rics are made. In order to make the final composite part, these preimpregnated tapes or fabrics need to be laid up on top of each other to form the thickness of the laminate. 137