5. Induced release

5.1 Thermostimulated rupture

When the temperature is raised, the crystallized oil melts and its density increases. The pressure then exerted on the rigid shell is sufficient to break it, allowing the oil to flow out of the shell (figure 8 ). Rupture takes place through the appearance of a propagating fracture, irrespective of the nature of the oil and the size of the capsules. By increasing the temperature quasi-statically (0.5°C/min), the shell rupture temperature can be determined. This corresponds to the melting temperature of the oil, irrespective of shell size. However, if the temperature increase is rapid (> 5°C/min), inertia effects appear:...