Polymer waste pulverization

Pulverization of multicomponent polymer waste. [Data from Khait, E. Riddick, E. G, US Patent 6,494,390, Dec. 17,2002.]... 

Ohama, Y., Demura, T. and Satoh, T. (1994) Basic Properties of Polymer-Modified Motrars Containing FRP Powder Made by Pulverization of Waste FRP Products. Journal of the College of Engineering of Nihon University, Series A, Vol. 35. pp. 33 -0. 

Polyurethane is a very common crosslinked polymer and many materials produced from it end up as waste. Given the quantity of material, recycling is a major problem. Cryogenic pulverization systems have been developed which can process PU foam to particles smaller than 1 mm (preferably <100 pm)/ " These particles are homogenized with polyol and then reacted with isocyanates to produce foam. This foam with 5% pulverized PU foam has a density equivalent to a similar foam produced without the recycled material. A further increase in filler content causes a density increase. Pulverized PU foam particles were also tried as a filler in natural rubber vulcanizates with good results. Figure 12.10 shows the effect of PU... 

Khait, K., Recycling of post-consumer plastic waste via new solid-state shear extrasion pulverization process, Proceedings Polymer Processing Society and American Instimte of Chemical Engineers joint meeting, Chicago, 11-14 Nov 1996. 

The pulverization techniques for rubbers are also being developed based on the concept of polymer pulverization originally proposed for plastics. The process manufactures polymer powder using a twin-screw extruder imposing compressive shear on the polymer at specific temperatures that depend on the polymer (Enikolopian, 1985). Based on this method, the solid-state shear extmsion pulverization method of rubber waste is also proposed (Khait and Torkelson, 1999 Khait, 1994). The obtained rubber particles were fluffy and exhibited unique elongated shape. 

In the same line of recycling plastic waste without the aid of compatibilizers, the family of homogenization and sohd-state pulverization processes can be found (Daren 1998 DubmUe D Orhcel 1993 La Mantia et al. 1996 Khait et al. 1999 Khait et al. 2001) essentially based on the fractionation of plastic waste into fine particles and formation of cross-polymers induced by shear activated reactions that... 

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