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--- en:materialdaten:dichtedaten_bzw._spezifisches_volumen [2025/01/13 16:47] – neelest
+++ en:materialdaten:dichtedaten_bzw._spezifisches_volumen [2026/09/17 10:09] (aktuell) – gelöscht - Externe Bearbeitung (Unbekanntes Datum) 127.0.0.1
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-======Density data or specific volume======
-===== Input dialogue =====
-The rheological data of the material is entered in the ‘Density’ tab:
-  * **Solids density**: The density of the compact solid
-  * **Bulk density**: The bulk density of the granulate or flakes. Is inevitably lower than the solid density
-  * **Calculation type**: Optionally density function (with 3 parameters) or volume function (with 2 parameters). See below for details.
-{{ :materialdaten:rex171_mat_en_003.png?nolink |}}
-===== Theoretical basics =====
-Both the density and the specific volume as well as the glass transition or crystalline
-melting point can be determined from the pvT-diagrams.
-{{ :materialdaten:abb_pvt_diagramm_en.svg?600 |}}
-The crystallite melting temperature $T_K$ is defined by the inflection point of the specific volume function in the pvT diagram. The glass transition temperature $T_G$ can be determined as the intersection of the tangents at the upper and lower course of the volume function.
-==== Density function ====
-The density function requires the three input values
-  * **Specific density** $\rho_0$: Corresponds to the density extrapolated to 0 °C (by default for a pressure of 100 bar)
-  * **Slope of the density function** $\rho_m$: Corresponds (for positive value) to the **decrease** in density per 1 °C
-  * **Compressibility value** $\kappa$: Describes the pressure dependence of the density
-The temperature-dependent density of the melt can be described by the following linear equation
-\[ρ = ρ_0 - ρ_m \cdot T\]
-If only one density value is available, make sure that this value corresponds to the mass temperature in the process and that the gradient $\rho_m$ is zero. Otherwise, the value $ρ_0$ at $0 °C$ should be entered with the corresponding temperature dependence $\rho_m$.
-The compressibility factor $\kappa$ influences the density as a function of the pressure:
-$$ \kappa = - \frac{1}{V} \frac{dV}{dp} $$
-$$\text{with}$$
-$$\frac{dV}{V} = - \frac{d \rho}{\rho}$$
-$$\text{is}$$
-$$\frac{\Delta \rho}{\rho} = \kappa \cdot \Delta p$$
-The value kappa can be imported directly from PAM or entered manually. If the value 0 is set for kappa, the density is calculated without taking the pressure into account.
-==== Volume function ====
-The function of the specific volume as the reciprocal of the density contains only two parameters:
-\[v = v_0 + v_m \cdot T\]
-The two characteristic values $v_0$ and $v_m$ can also be determined from the pvT diagram, whereby the data must be determined at an average pressure corresponding to the process. \\
-The modelling of the specific volume cannot take pressure dependency into account.
-===Further topics===
-  * [[en:materialdaten:datenbankanbindung_an_pam|]]
-  * [[en:materialdaten:allgemeineangaben|]]
-  * [[en:materialdaten:rheologische_materialdaten|]]
-  * [[en:materialdaten:thermodynamische_daten|]]
-  * [[en:materialdaten:dichtedaten_bzw._spezifisches_volumen|]]
-  * [[en:materialdaten:tribologische_daten|]]
-  * [[en:materialdaten:technologische_daten|]]
-  * [[en:materialdaten:molekulargewicht|]]
-  * [[en:materialdaten:faserabbau|]]
-  * [[en:materialdaten:eingabe_von_mischungen|]]