Thermoplastics short-fiber-reinforced

Campbell, J.M. and Goettler, L.A., Proc. of PRI National Conference on Short-Fiber Reinforced Thermoplastics, Brunei University, Uxbridge, Middlesex, United Kingdom. Paper 14, 1985. 

Fig. 6.10. Schematics of the dependence of total fracture toughness, on fiber volume fraction of short fiber reinforced thermoplastic composites at different loading rates (a) static loading (b) dynamic...

Lauke B., Schultrich B. and Barthel R, (1985). Contribution to the micromechanical interpretation of fracture work of short-fiber reinforced thermoplastics. Composites Sci. Technol. 23, 21-35. 

Lauke B. and Schultrich B. (1986b). Fracture toughness of short fiber reinforced thermoplastics. Composites. Sci. Technol. 26, 37-57. 

Ramsleiner F. and Theysohn R. (1979). Tensile and impact strength of uni-directional short fiber reinforced thermoplastics. Composites 10, 111-119. 

Sato N., Kurauchi T.. Sato, S. and Kamigaito O. (1991). Microfailure behaviour of randomly dispersed short fiber reinforced thermoplastic composites obtained by direct SEM observation. J. Mater. Sci. 26. 3891-3898. 

Folkes, M. J., Short Fiber Reinforced Thermoplastics," Wiley, New York (1982). 

There are no standard test methods specific for discontinuous fiber (or short fiber) reinforced thermoplastics. It is also not clear whether a geometry-independent fracture parameter can be measured for these nonuniformly inhomogeneous materials. However in spite of these reservations there has been considerable work conducted towards characterizing short fiber composites for fracture toughness using the standard and other procedures outlined in the previous sections. The investigators have recognized that fracture mechanics data provide much more reliable information than the customary alternative tests for material selection and also a service performance indicator for components. 

A correlation between Kq and UTS has been shown by others, also for short fiber reinforced thermoplastics [69], and more generally for a variet of composite systems, embracing unidirectional. 0 90 woven and nonwoven, and random chopped fiber arrangements [118]. 

As previously discussed, fibers that form in situ should reduce the viscosity of the composite during processing conditions, if compared to short fiber reinforced thermoplastic. Moreover, it will be shown that the viscosity of the LCP and thermoplastic polymer will be resonably lower than the viscosity of the enginnering thermoplastic by itself, accordingly with the viscosity of deformable particles in viscous fluid. 

In an injection-molded short-fiber-reinforced thermoplastic, there is a distribution of fiber lengths. Not all fibers are oriented in one direction. Taking these factors into consideration, Bowyer and Bader (86) proposed the following equation to predict the theoretical strength of the short-fiber-reinforced composite ... 

Matsuoka, T., Takabatake, J., Inoue, Y. and Takahashi, H. (1990) Prediction of fiber orientation in injection molded parts of short-fiber-reinforced thermoplastics. Polym. Eng. Sci., 30, 957-966. 

A. Vaxman, M. Narkis, A. Siegmann and S. Kenig, Short fiber reinforced thermoplastics. II. Interrelation between fiber orientation and rheological properties of glass fiber-reinforced Noryl, Polymer Composites, 10, 78-83 (1989). 

Table 3.130. Effect of various factors on the fiber orientation during injection moulding of short-fiber-reinforced thermoplastics [1265]...

The fibres orientation with respect to the stress direction essentially influences the fracture mechanism, as it was proved for a composite with semicrystalline matrix, PET reinforced with short fibres, having the structural characteristics presented in Figure 3.496 [1267], It can be observed that different fibre orientation normally exists across the thickness of injection moulded plaques of short fiber reinforced thermoplastics. 

K.Friedrich, Fracture Mechanical Behaviour of Short Fiber Reinforced Thermoplastics, Fortsch.-Ber.VDI-Z, Reihe, (1984) 18. 

Short fiber-reinforced thermoplastics and long carbon fiber-reinforced plastics with matrices Nf 10 [148]... 

Short-fiber-reinforced thermoplastics also do not alter the transition characteristics of the plastics but also increase forces required to form the plastics. 

The theory, processes, and characterization of short fiber reinforced thermoplastics have been reviewed by De and White [31], Friedrich et al. [32], Summerscales [33], in an introductory text by Hull and Clyne [34], and in a handbook by Harper [35]. Natural fibers and composites have been reviewed by Wallenberger and Weston [36]. The introduction of new composite materials, called nanocomposites, has resulted in new materials that are being applied to various industrial applications. These materials have in common the use of very fine, submicrometer sized fillers, generally at a very low concentration, which form novel materials with interesting morphology and properties. Nanocomposites have been discussed in a range of texts including two focused on polymer-clay nanocomposites by Pinnavaia and Beall [37] and Utracki [38]. 

Long fiber-reinforced thermoplastics (LFT) are a relatively new class of fiber-reinforced materials in the field of composites. According to the fiber length, they take an intermediate position between injection molded short fiber-reinforced thermoplastics (SFT) and compression molded glass mat-reinforced thermoplastics (GMT). However, LFT show better mechanical properties and even new property combinations compared to the corresponding SFT and GMT composites (Table 1). 

Folkes MJ (1982) Short fiber reinforced thermoplastics. Wiley, New York... 

In steady slit extrusion of short fiber reinforced thermoplastic composites, the formation of a skin-core of fibers oriented in the thickness direction has been observed, with fibers axis along the flow direction and parallel to the walls in the skin region, irrespective of the entrance geometry. Different fiber orientation distributions in the core region are however obtained by using different entrance geometries. ... 

A. Larsen. Injection molding of short fiber reinforced thermoplastics in a centergated mold. Polym. Compos., 21 (1), 51-64, 2000. 

C. Vajrasthira, T. Amomsakchai, S. B.-Limcharoen. Fiber-matrix interactions in aramid-short-fiber-reinforced thermoplastic polyurethane composites.. Appl. Polym. Sci., 87,1059-1067,2003. 

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