Melt impregnation

It is very important to maximise the chlorination of the furnace charge components. If nonchlorinated residue accumulates, it noticeably increases the resistance in the furnace (because the melt impregnates the unreacted residue), impairs the distribution of chlorine in the furnace and causes other serious problems. 

Rampone E., Piccardo G. B., Vannucci R., Bottazzi P., and Zanetti A. (1994) Melt impregnation in ophiolitic peridotites an ion microprobe study of clinopyroxene and plagioclase. Min. Mag. 58A, 756-757. 

Special methods of incorporation slurry process in which polymer powder and fibers are suspended in water followed by dewatering and wet sheet formation similar to paper manufacture technology melt impregnation of fiber bundles in equipment containing fluidized bed zone and heating zone followed by extrusion through die filler encapsulation is faster than blend compatibilization therefore filler must be added to compatibilized blend " compatibilizers were used with glass beads to improve mechanical properties of composite ... 

One example of pre-impregnation is melt impregnation, in which roving is pultruded through a resin melt and over cylindrical pins. The pins are designed to spread the fibre bundle or tow, and to entrain a film of liquid resin which becomes drawn into the tow. Another approach is solvent impregnation, which can only be used with soluble thermoplastics. The... 

Recently, new compounding methods have been investigated to produce long, natural fiber-reinforced thermoplastic pellets and improve composite mechanical properties [31, 32]. For example, pellets have been formed by melt impregnation of continuous natural fiber yarns by pultrusion followed by cooling and chopping. Another method involves commingling of continuous forms of natural and synthetic fibers that are then heated, consolidated, and chopped. 

Figure 9.23 Illustration of stampable glass fiber mat-reinforoed polypropylene sheet by (a) melt impregnation and (b) wet/paper machine process. (From Ref. 173, with permission.)...

P Peltonen, K Lahteenkorva, EJ Paakkonen, PK Jarvela, P Tormala. The influence of melt impregnation parameters on the degree of impregnation of a polypropylene/ glass fibre prepreg. J Thermoplastic Composite Materials 5 318-343, 1992. 

The substrate, for example a woven or nonwoven fabric, serves as support carrier to the end product, while the coating seals it. In the melt impregnation process, the polymer melt is extruded into a thin smooth film, laid down onto the substrate. The impregnation of the latter is achieved by pressure. The product is then cooled and wound up by a winder. An impermeable polymer film can also be formed between two textile fabrics. Besides sealing, the film also takes the role of an adhesive layer between the two fabrics. 

Figure 1 Dry-laid melt impregnation techniques of GMT sheet manufacturing.

The main advantage of this technique is that the introduction of the thermoplastic matrix occurs via simple melting. This has led to the development of various types of melt impregnation techniques, which are surveyed below. 

The restriction in output of the above-mentioned melt impregnation techniques is governed by the time during which the effective impregnation... 

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