TMA probes

Alternatively, Ramis and Salla (1997) define gelation of a polyester resin via Figure 3.56 as the point at which a submerged TMA probe becomes embedded ( stuck ) in the resin. 

Figure 6 TMA probe types (left-right) compression, penetration, tension, volumetric...

Table 6.1. TMA probes and deformation modes for specific apphcations Parameter Probe/deformation mode...

Sample probe—in order to measure dimensional changes of samples under stress or strain, various types of sample probes are used. TMA probes and deformation modes for specific applications are shown in Figure 2.19. 

Figure 2.19 Various types of TMA probes J, expansKW mode II, compression mode III, bending mode IV, strctc ing mode...

Thermomechanical analysis (TMA) provides a convenient and more reproducible, scientific approach to gel time measurement. Using a specific TMA probe configuration (parallel plate rheometer), TMA-measured dimensional changes can be converted to gel time and viscoelastic values. 

The CTE in x and y direction can also be measured by TMA, although care must be taken during the preparation of the sample to avoid any influence of reinforcement material on the TMA probe. The results are strongly dependent on the properties of the reinforcement fabric. 

Figure 4.34. Penetration by a rounded-nose TMA probe versus temperature (compressive load 15 g on a maximum 3-mm-diameter probe, helium purge) into a UV-enriched PC layer compared to the neat polycarbonate layer [from Bair (1997) reproduced with permission from Elsevier],...

What is, on the basis of the expansivities listed in Fig. 6.2, the best material for the TMA probe connector (connections between probe and LVDT, see Figs. 6.2 and 6.5) ... 

A typical TMA thermal curve is shown in Figure 7-21. Here a fused silica rod is used as a compression probe. The probe is placed onto the sample, and the thermal expansion or contraction is recorded as a function of temperature. The polymer used in the test contains a chemical blowing agent. Over the first 60 0, the TMA probe is slightly pushed up by the expansion of the polymer solid. As the... 

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