Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Williams plastimeter

ISO 732324 specifies a parallel plate test based on the Williams plastimeter with plates 4 cm in diameter. The test piece is 2.00 0.02 cm3 in volume and can conveniently be a cylinder 16 mm diameter and 10 mm thick. As discussed above, a close tolerance on volume is necessary for this type of plastimeter. The test piece is preheated for 15 min (the temperature of test is usually 70°C or 100°C) and compressed under a force of 49N. The thickness of the compressed test piece is measured in mm and this value multiplied by 100 quoted as the plasticity number. The preferred time of application of the force is 3 min. The correction to the standard in 2003 was to change the tolerance on the force from 0.05N to 0.5N. [Pg.69]

Many workers have studied and published correlations between various types of plastimeter, often to show that they do not agree and to illustrate the superiority of the instrument which supposedly agrees best with processing behaviour. Several comparisons are included in the literature already noted and other examples are shown in Figure 6.6. Figure 6.6a shows the relatively close correlation obtained between two compression instruments, the Wallace rapid and Williams plastimeters, for materials of similar flow characteristics (plasticised natural rubber). When such rubbers are compared on two basically different instruments (compression and extrusion) the... [Pg.80]

Figure 6-6. Correlations between readings of various plastimeters. Rapid = Wallace rapid, compression, disk type Williams = compression, plate type Extrusion = Griffiths (1926) ... Figure 6-6. Correlations between readings of various plastimeters. Rapid = Wallace rapid, compression, disk type Williams = compression, plate type Extrusion = Griffiths (1926) ...

See other pages where Williams plastimeter is mentioned: [Pg.216]    [Pg.216]   
See also in sourсe #XX -- [ Pg.67 , Pg.69 , Pg.80 , Pg.81 , Pg.82 ]




SEARCH



Plastimeters

© 2024 chempedia.info