Cooling melt impregnation

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. 

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. 

Epilation is required for permanent hair removal. The most effective epilation process is electrolysis or a similar procedure. Epilation can also be achieved by pulling the fibers out of the skin. Eor this purpose, wax mixtures (rosia and beeswax) are blended with Hpids, for example, oleyl oleate, which melt at a suitable temperature (about 50—55°C). The mixture is appHed to the site (a cloth tape may be melted iato the mass) and after cooling is rapidly pulled off the skin. A similar process can be carried out with a tape impregnated with an aggressive adhesive. 

Expandable PS beads are a material devised to accommodate the transportation drawbacks of foams. Foams take up a lot of room, but not much weight, so a truck or boxcar cannot be used very efficiently. Expandable PS beads can be readily turned into foam at their destination. The beads are impregnated with a volatile liquid like pentane as they are extruded, chopped, and cooled. Later, on site, the beads are heated in small batches with steam. The vaporization temperature of the pentane is just below the melting point of the PS beads. As the beads soften, the pentane flashes (volatilizes) and causes the PS to foam. The polymer is then ready for molding. Coffee cups, ice chests, life preservers, buoys, and floats are often fabricated this way. 

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