Thermopressing

FIGURE 6.5 Reprocessing of polyurethane waste by thermopressing. (After Muller, P. and Reiss, R., Die Makromol. Chem., Macromol. Symp., 57, 175, 1992. With permission.)... 

The history of the material has also a high impact on the reaction rate. A high water content of the material reduces the reaction time. Thermopressing at 260°C of water saturated PET leads to a primarily hydrolysis and shortening of the ehain length. The subsequent hydrolysis in nonaqueous solution of NaOH in glycol at 170°C reduced the reaction time to one quarter [31]. 

Some patents have reported that the introduction of fibers and/or inorganic fillers is interesting for improving mechanical properties of starch materials (Andersen et al., 1998 Andersen and Hodson, 1995, 2001). Other studies have shown that it is possible to obtain food packaging from mixtures of starch, fibers, water, and other additives by thermopressing or baking (Carr et al., 2006 Schmidt and Laurindo, 2010), and these products could be an alternative to the use of expanded polystyrene foams (Vercelheze et al 2012). 

Schmidt, V. C. R. and Laurindo, J. B. 2010. Characterization of foams obtained from cassava starch, cellulose fibres and dolomitic limestone by a thermopressing process. Brazilian Archives of Biology and Technology 53 185-192. 

Id Fig. 60 llie ex[ rimental data for the effective area of two honeycomb packings made of sheets of thermopressed sintered porous FVC [64] are presented. The packing is specially designol to operate at extremely low liquid superficial velocity. 

Description of the structured packing with boundary layer turbulizers The usage of thermopressed plates for honeycomb packings allows to press on there walls special turtnilizers of the mass transfer boundaiy layer [148-156] for intensification of tibe h and mass transfer processes. A packing block wi such a construction is presented in Fig. 6S. 

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