Drying difference

Oven drying difference in weight between ambient temperature and 102°C. 

Table 1,7 Examples of drying different plastics (courtesy of Spirex Corp.)...

Examples of major plastic families Thermoplastic thermal properties are compared to aluminum and steel General properties of thermoplastic General properties of thermoset plastic General properties of reinforced thermoplastic General properties of reinforced thermoset plastic Examples of drying different plastics (courtesy of Spirex Corp.)... 

While the equilibrium thermodynamic approaches of Meier (1969,1970, 1971) and Inoue et al (1970a,h) predict that particular compositions will have particular fine structures, several investigators have shown that materials cast from different solvents and subsequently dried differ from each other and from materials prepared from the melt. As an example, let us examine the effects of the following solvents on a typical styrene-butadiene-styrene block copolymer benzene/heptane 90/10 tetrahydro-furan/methyl ethyl ketone 90/10, and carbon tetrachloride (Beecher et al, 1969). The particular compositions were chosen to give selective solvating behavior. While benzene dissolves both blocks, the heptane component, which evaporates last, swells only the butadiene block. Tetrahydrofuran is also a mutual solvent it evaporates first, leaving methyl ethyl ketone, which swells only the polystyrene block. Pure carbon tetrachloride is a mutual solvent. (Examples of swelling crystalline block copolymers are considered in Chapter 6.)... 

In this first example, paracetamol was recrystallized separately in three different types of solvents (ethanol, water and dioxane) with different boiling points, molecular weights, dielectric constants and paracetamol solubilising power. After the crystallization process, crystals were separated by filtration under vacuum and washed with the same crystallization solvent. Each batch was divided into four fractions to be dried differently. 

Accelerated drying for smaller kiln charges. The ability to dry different species and dimensions at the same time allows for greater production and scheduling flexibility. The RFV kilns can also be used for pasteurization and fixation of preservatives. 

Finally, since during drying different parts of the support in contact with different quantities of water are submitted to different temperatures, the reactions between precursor and support may be not uniform. As a consequence, the number of seeds on which particles nucleate may not be the same along the axis of the pellet, resulting in differences in particle size inside the extrudate [17]. This explains why often drying is optimized on the basis of trial and error, rather than by using models. 

If, however, a nonhygroscopic polymer is compoimded with a hygroscopic pigment or additive, the resultant compound will be hygroscopic and may need to be dried differently. For more detail on drying nonhygroscopic polymers, refer to Sec. 7.15.1. 

Figure 7.48 A central material drying-distribution system includes one or more dryers, serving multiple hoppers, dedicated to drying different materials. A manifold system allows dried material to be conveyed wherever it is needed.

Derivation of Equation for Through Circulation Drying. Different forms of Eqs. 

For uniformity of the RM content see the remarks on shielding in Section B.l. Besides the DR data the plots 2, 3, and 4 in Figure 2 show a change of slope at - 0.6%/h. This change indicates that a certain amount of water was not frozen and is now vacuum dried (different example in fig. 1.73.3 in [5]). 

Fig. 20.21 Competition of polymerization and drying—different studies of a single droplet being injected in a spray dryer. Showing the drop sizes and mean drop temperatures or mass fraction of acrylic acid over time if drops with a diameter of 10 pm (at top left and right), 100 pm (at bottom left) and 1000 pm (at bottom right) are calculated by the use of (20.35)-(20.38)...

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