Elongation values

Process details may be summarized powder sizes are fine (usually < 20 Ilm) low (generally < 69 MPa (10,000 psi)) injection pressure low (ca I49°C) mol ding temperature shrinkage (molded part to finished size) typically 20% final part densities are usually 95—98% + of maximum pore-free density and ductility is exceptionally high, elongation values are > 30%. 

Properties of Typical Commercial LCPs. Table 17 presents data on three significant, commercially available LCPs (238). Elongation values have been quoted for HX-2000 as 0.6%, for Xydar G-930 as 1.6%, and for Xydar G-540 as 1.5%. Eurther details can be obtained from the manufacturers. 

Titanium alloys should be melted and cast under carefully controlled and optimum conditions. The higher elongation values of titanium castings reflect the superior ductihty of titanium. Ductile clasp arms of titanium castings can withstand relatively large bending adjustments without fracture. 

The modulus (or tensile stress) at various elongations is the load at the elongation divided by the original cross-section. This is expressed in terms of force per unit area (MPa). The normally used elongation values are 50%, 100%, 200%, and 300%. 

FIGURE 3.2 Elongation values from commercial fluoropolymers (ASTM D638). (From Scheirs, J., in Modem Fluoropolymers, Scheirs, J., Ed., John Wiley Sons, New York, 1997. With permission.)... 

The experimental ranges of strain rates (or strains) are summarized in Table 2 for the various types of experiments. Time-temperatiire superposition was successfully applied on the various steady shear flow and transient shear flow data. The shift factors were foimd to be exactly the same as those obtained for the dynamic data in the linear viscoelastic domain. Moreover, these were found to be also applicable in the case of entrance pressure losses leading to an implicit appUcation to elongational values. 

For most elastomers the ultimate tensile and elongation values were found to be quantitatively related by simple linear equations to the volume fraction of the rubber swelled In mixtures of gasoline and ethanol or MTBE. They were also found to be related to each other by simple logarithmic relatlonshlps. 

The addition of EPDM to HDPE (Table 11.9) increases low-temperature flexibility it also helps maintain high strength with high elongation values at room temperature [Brooks, 1983]. The pres-... 

This value was excluded from the model calculations, because the film formed with much difficulty and the elongation value was not considered reliable. 

MR = High temperature release 20 = 50 ii,m B = Both sides adherable L = Low gloss 3 = Medium tensile and elongation values... 

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