Long fiber reinforced thermoplastics

Fig. 11.30 Effect of preheating 50% by weight E-glass fiber-filled polyamide pulltruded pellets on fiber lengths at the screw tip of a 300-ton 23.86-oz reciprocating injection molding machine. [Reprinted by permission from C. G. Gogos, C. K. Yoon, and J. Brizzolara, Injection Molding Process Development for Long Fiber Reinforced Thermoplastics, SPE ANTEC Tech. Papers, 40, 384 (1994).]...

C. G. Gogos, C. K. Yoon, and J. Brizzolara, Injection Molding Process Development for Long Fiber Reinforced Thermoplastics, SPE ANTEC Tech. Papers, 40, 384 (1994). 

The first all-around automobile application of composite leaf-springs was made in the Sherpa 200 series van and mini buses built by Freight Rover. These fiber-reinforced plastic (FRP) components for high stress, high-temperature uses were developed by GKN. ICl s Verton, a long-fiber reinforced thermoplastic is also suitable for such applications. 

Direct Long Fiber-Reinforced Thermoplastic Process (Overview)... 

Interim storage of the fiber composite material is realized in a heat accumulator, from which it is discharged in cycles by a ram, chopped into molding compound units by a cutter at the end of the accumulator, and transported on a discharge belt. The plasticized material produced in this way is transferred into a compression mold, then formed into a structural component in an extrasion process. The finishing steps are the same as in other CM methods used for long fiber-reinforced thermoplastics. 

Table 1 compares their opportunities and risks. Fig. 1 shows the frontend plastic element in an LFT-D version (direct long fiber-reinforced thermoplastics). For detailed descriptions see [5, 11]). 

Long fiber-reinforced thermoplastics are becoming increasingly important as materials, in the automotive sector in particular. The light construction aspect of... 

Trdster S, Geiger O, Henning F, Eyerer P (2004) Added value for long-fiber reinforced thermoplastic components by in-line-compounding in the LFT-D-ILC process. SPE Paper 1121, ANTEC 2004, Chicago, IL... 

Zhuang, H., Ren, P., Zong, Y, and Dai, G.C. (2008) Relationship between fiber degradation and residence time distribution in the processing of long fiber reinforced thermoplastics. Eiqmss Pdym. Lett., 2 (8), 560-568. 

Celstran, Long fiber-reinforced thermoplastics, Ticona... 

The impregnated tows can be used for many applications which are generally subdivided into those where the fiber reinforcement is continuous (e.g. filament winding or pultrusion) and those where the tow is cut and the unidirectionally reinforced peUets (discontinuous long fiber reinforced thermoplastics) are then further processed into parts (e.g. in extrusion or injection molding). 

Fig. 5. Twintex (Vetrotex) long fiber reinforced thermoplastic (LFRT) fabric—made by commingling woven fiber glass with polypropylene fibers—is preformed for manufacture of automotive bumper beams. Courtesy of Plastic Omnium, Paris.

Compounding of long fiber reinforced thermoplastics (LFRTs) is very different from compounding short fiber or particle filled composites. Long fibers enhance properties such as impact strength and are finding great utility in a number of applications in the automotive, industrial, and sports markets. Most of these products use PP or polyamide (PA), but poly(ethylene tere-phthalate) (PET) and other resins are also used. 

F. W. J. van Hattum, J. H. van Breugel (2001) Innovative processing and properties of long fiber reinforced thermoplastics. Proc. 22 SAM PE Europe Int. Conf.., Paris, France, p. 207. 

Long Fiber-Reinforced Thermoplastic Composites in Automotive Applications... 

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). 

Tapio Harmia - Managing Director, FACT GmbH, Germany. He received his Doctoral degree in the area of long fiber-reinforced thermoplastics from the Kaiserslautern University of Technology, Institute for Composite Materials Ltd. 

IVW), Germany, in 1996. Dr. Harmia has over 30 publications and several patents in the field of composite materials. He has been involved in the development of new methods in the manufacturing of long fiber-reinforced thermoplastics. His current research interests are in the area of mechanical properties and tailoring of properties of composite materials. Dr. Harmia is the founder of FACT GmbH and has successfully managed the company since 1998. 

Mathias Lindner - Head of R D, FACT GmbH, Germany. Mr. Lindner got his degree in Mechanical Engineering in 1997. He has been active in several research subjects in the field of long fiber-reinforced thermoplastics. His interests are especially in the field of mechanical properties of composite materials, as well as in the manufacturing methods of long fiber-reinforced thermoplastics. He holds several patents in the field of composite materials. 

Chevali, V.S., Dean, D.R., Janowski, G.M. Effect of environmental weathering on flexural creep behavior of long fiber-reinforced thermoplastic composites. Polym. Degrad. Stab. 95, 2628-2640 (2010)... 

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