Process thermoplastic pultrusion

Different TP pultrusion processes are used. As an example Thermoplastic Pultrusion Technologies (TPT), Yorktown, VA, USA, uses a hot-melt injection process for pultruding RP thermoplastic. Unlike TS pultruded profiles, TP profiles can be postformed and reshaped. Higher continuous use temperatures are possible with some TP matrices, and line speeds are faster with raw materials usually costing less. 

Dow, using Fulcrum thermoplastic composites technology and Isoplast thermoplastic polyurethanes, have developed a new thermoplastic pultrusion process. 

T Asai, T Ohara, T Tanaka, S Hashizume. Method of Manufacturing Continuous Fiber-Reinforced Thermoplastic Prepregs. U.S. Patent 5529652, June 25, 1996. J-M Charrier, PJ Bates, D Guillon, G Zanella. The Effect of Pin Shape on Spreading Roving Filaments for a Thermoplastic Pultrusion Process. 45th Annual Conference, Composites Institute, SPI, Washington DC, 1990, 18-A, pp 1-4. 

Gibson and coworkers [2] emphasized that the preheating section of their thermoplastic pultrusion process was of crucial importance to a successful operation. Besides the results achieved with CF/PEEK tapes, these authors presented a wide range of interlaminar shear strength (ILSS) data for pultrudates from glass fiber (GF)/polyamide 12 (PA12) tapes. 

Astrom, B.T. and Pipes, R.B. (1991) Correlation between modelling and experiments for a thermoplastic pultrusion process. Proceedings of the Vlllth International Conference on Composite Materials, ICCM-VIll (eds S.W. Tsai and G.S. Springer), Honolulu, Hawaii, USA, July 15-19, Section 13-A-1-13-A-10. 

The investigation of pulling forces during the thermoplastic pultrusion process has been widely neglected in research, although it is an important... 

Some disadvantages exist in the traditional thermosetting and thermoplastic pultrusion processes due to the limitation in different major aspects of the processes. However, studies conducted in various key features and problem areas, as listed in Table 12.1, of pultrusion process have resulted in better understanding and major advancements in the process. 

Various optimization studies on thermosetting as well as thermoplastic pultrusion parameters were conducted (Chew, 2004 Joshi et al, 2003 Kyaw, 2003 Li, 2001 Tat, 2006 Zaw, 2003) using the same FE/NCV method developed by Joshi and Lam (2001). Chew (2004) worked on cooling optimization in thermoplastic pultrusion whereas Tat (2006) studied the impact of mounting locations for the feedback thermocouples controlling heater temperatures. It was observed that if the thermocouples sense either the maximum or the minimum temperature on a hot die surface, the power input to the heater will be rather uneven and the process may not completely optimize. Joshi et al. (2003) looked for improved pultudate quality with the... 

Pultrusion is mainly used to process glass-, aramide-, carbon fiber rovings with a wide variety of thermoset matrices such as polyester-, vinylester- and epoxy-resins [10]. The processing speed can be up to 5 m/min. In addition, thermoplastic matrix based composite pultrusion has been developed over the last 20 years. Due to the higher viscosity of thermoplastics in compaxison to thermosets, the processing speed is about ten times slower in terms of thermoplastic pultrusion [11]. 

B. T. Astrom (1992) Development and application of a process model for thermoplastic pultrusion. Compos. Manuf. 3,189. 

Composite processing uses specialized methods. For thermoplastics, glass mat thermoplastic (GMT) is the main method but prepreg, lay-up, tape winding, pultrusion are also used to produce composites. SMC/BMC are the main processes for thermosets but lay-up is currently used for large parts and prepregs are used for high-tech parts. 

The ring opening polymerization of cyclic monomers that yield thermoplastic polymers of interest in composite processing is reviewed. In addition, the chemistry, kinetics, and rheology of the ring opening polymerization of caprolactam to nylon 6 are presented. Finally, the rheo-kinetics modelsfor polycaprolactam are applied to the composite process of reaction injection pultrusion. 

Among the more common thermoplastics from ring opening polymerization of interest in composite processing are polylactams, polyethers, polyacetals, and polycycloolefins. It has also been shown that polycarbonates can be produced from cyclic carbonates [22], Anionic ring opening polymerization of caprolactam to nylon 6 is uniquely suited to form a thermoplastic matrix for fiber-reinforced composites, specifically by the reaction injection pultrusion process [23-25]. The fast reaction kinetics with no by-products and the crystalline... 

The characteristics of the three most common thermoset resin systems used in pultrusion are compiled in Table 11.2 [3]. It is noteworthy that unreinforced polyesters and vinylesters shrink 7-9% upon crosslinking, whereas epoxies shrink much less and tend to adhere to the die. These epoxy characteristics translate into processing difficulties, reduced processing speed, and inferior component surface finish. It is normal practice to use resin additives to improve processability, mechanical properties, electrical properties, shrinkage, environmental resistance, temperature tolerance, fire tolerance, color, cost, and volatile evaporation. It is normally the resin, or rather its reactivity, that determines the pulling speed. Typical pulling speeds for polyesters tend to be on the order of 10-20 mm/s, whereas speeds may exceed lOOmm/s under certain circumstances. Apart from the resins characterized in Table 11.2, several other thermosets, such as phenolics, acrylics, and polyurethanes, have been tried, as have several thermoplastics (as will be discussed in Sec. 11.2.6). 

Recendy, storm doors have been constmcted of advanced thermoplastic composites. Stampable, glass-mat reinforced polypropylene sheet is used to create a high strength outer skin. These compression molded skins are welded together using a friction or ultrasonic process then injection molded with a polyurethane foam core to produce an insulated structure. New technology for window frames incorporate the pultrusion of frame channels to produce a thermoset composite channel that can be filled with fiber glass for further insulation enhancement (12,31,33,34,48,49,54—56,60—67). 

This paper will describe briefly the pultrusion process developed and built locally, its reliability or performance, the quality of prepreg combined with the controlling parameters and finally the preliminary results on its usage as laminates and reinforcement in thermoplastic composites. 

Pultrusion process development of a graphite reinforced PEI thermoplastic composite. 4tb annual Conf. of Reinforced... 

Special types of glass fiber for specific processes (Chapters 4 and 5), such as sheet molding compound (SMC), pultrusion, and reinforcement of thermoplastics, is a marked trend in current development. Examples follow ... 

If the filaments are not wound onto a mandrel but simply gathered into relatively large bundles and led slowly into a heated consolidation zone, emerging from a die partly or completely cured, the primitive essentials of pultrusion are present (Fig. 2.3(b)). This process began as the thermosetting resin equivalent of extrusion, that is, it was a continuous operation for manufacturing profiles, such as rod and channels. The method has been extended to fibre reinforced thermoplastics. 

LFT-G are produced by means of pultrusion. In a variant of the pultrusion process, endless fibers are drawn through a thermoplastic melt then partially or completely impregnated, depending on the production process, by means of a mold. Fig. 35. In another variant, mixtures of glass filaments and polymer filaments are used for pultrusion, so-called hybrid fibers. 

CAS 21645-51-2 EINECS/ELINCS 244-492-7 Uses Flame retardant, smoke suppressanL processing aid, water resist, aid, antistat for wire/cable, elec, insulators, printed circuit boards, potting resins, molded and extruded polyolefins, flooring compds., conveyor belting, fabric coatings, polyester and aciylic pultrusion compds., thermosetting resins (BMC, SMC), PVC, EVA, EPDM, XLPE, EEA, thermoplastic elastomers, silicone rubber, NR, SR, acrylic resins, unsat. polyesters... 

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