Thermoplastic matrix composites

The term cocuring means that two parts that must be fastened together are cured simultaneously and in contact to achieve permanent bonding between them. The process applies equally to thermoset-matrix composite materials and to thermoplastic-matrix composite materials (except the cocuring of two thermoplastic-matrix parts is not, of course, permanent). 

Improvement in flexural strength due to silane treatments in glass liber thermoplastic matrix composites"... 

Friedrich K. (1985). Microstructural efficiency and fracture toughness of short fiber/thermoplastic matrix composites. Composites Sci. Technol. 22, 43-74. 

Table 7.1 Comparison of Thermosetting and Thermoplastic Matrix Composites...

The mechanism by which a thermoplastic matrix composite consolidates to form a laminate was attributed to autohesive bond formation between plies [13,18]. Autohesion, however, can... 

The interply bond strength for thermoplastic matrix composites has been shown to be dependent upon the processing parameters, pressure, temperature, and contact time. If the temperature distribution in the composite is nonuniform during processing, the ply interfaces will bond (or heal) at different rates. Thus, for a specified processing cycle, it is important to know precisely the temperature and degree of autohesive bonding at every point in the composite laminate in order to estimate the required process time. 

The process by which a thermoplastic matrix composite consolidates to form a laminated structure has been attributed to autohesive bond formation at the ply interfaces. Autohesive bond formation is controlled by two mechanisms (1) intimate contact at the ply interfaces, and (2) diffusion of the polymer chains across the interface (healing). The rate of autohesive bond formation and hence the speed of the composite consolidation process is directly related to the temperature-pressure-time processing cycle. 

Howes, J.C., Loos, A.C., Hinkley, J.A. In Advances in Thermoplastic Matrix Composite Materials, ASTM STP 1044 (1989) G.M. Newaz (Ed.). ASTM, Philadelphia... 

In the following sections, the basic modeling approaches for thermosetting and thermoplastic matrix composite cylinders will be summarized. Differences between the thermosetting and thermoplastic model approaches are highlighted. 

Consolidation and development of interlaminar bond strength for thermoplastic matrix composites have been modeled by two mechanisms intimate contact and autohesion. Intimate contact describes the process by which two irregular ply surfaces become smooth (Fig. 13.10). In areas in which the ply surfaces are in contact, autohesion occurs, and the long thermoplastic polymer chains diffuse across the ply boundaries. Filament winding with thermoplastic matrix materials is considered an on-line consolidation process in that local... 

Dara, P.H., Loos, A.C. Thermoplastic Matrix Composite Processing Model (1985) Blacksburg, Virginia, Center for Composite Materials and Structures, Virginia Polytechnic Institute and State University... 

Figure 14.4 Shape categories of components that might be formed from thermoplastic matrix composite materials...

Proceedings of the Fifth Industray/Government Review of Thermoplastic Matrix Composites (1988) Air Force Wright Aeronautical Laboratories, 8-11 Feb. 1988, San Diego... 

Thermoplastic matrix composites are generally employed where high-volume and economic considerations exist such as in the automotive and decorative paneling industries. Thermoplastic resin-based composites range from high-priced polyimide, polyethersul-fone, and polyetheretherketone to the more affordable nylon, acetal, and polycarbonate resins. Practically all thermoplastics are available in glass-reinforced grades. 

Another important application of thermoplastic fibers such as poly ether ether ketone (PEEK), Poly etherimide(PEI), and VectranM andHS (Vectranis the trade mark of Hoechst liquid crystalline polymer) is in making thermoplastic matrix composites. Commingled yams of the reinforcement and matrix such as quartz/PEEK, glass/PEI, Vectran HS/M are used to make the composites wherein the matrix yarn fuses to form the continuous phase of the composite. 

Similarly for the composites, a damage zone (or the process zone) dimension r can be incorporated into the fracture mechanics equation, Eq. 1. An extensive coverage of the damage or the energy dissipation zone for short fiber reinforced thermopla.stics can be found in Ref. 113. Equation 19, however, has also been used (114] to improve the linearity of the plots of (OfY) vs. 1/a, particularly for tough thermoplastic matrix composites. 

MaUick, P.K., 2010. Thermoplastics and thermoplastic—matrix composites for lightweight automotive structures. In Materials, Design and Manufaemring for Lightweight Vehicles. Woodhead Publishing Series in Composites Science and Engineering, pp. 174—207. 

PROPERTIES OF SPECIAL INTEREST Mostly synthesized as flexible semicrystalline thermoplastic, PBT has outstanding resilience and toughness. High toughness and resilience is due to improved chain flexibility derived from the four methylene units. Used in thermoplastic matrix composites for gears, machine parts, small pump housings, and insulators. 

---