Oluschinski: Created page with "{{Language_sel|LANG=ger|ARTIKEL=Schmelze-Volumenfließrate}} {{PSM_Infobox}} Melt volume-flow rate (MVR) (Author: Prof. Dr. H.-J- Radusch) FORCETOC ==Measurement of melt-volume flow rate (MVR)== The melt-volume flow rate (MVR = melt-volume flow rate or, conversely, MVI = melt volume index) is used to characterise the flow behaviour of a thermoplastic material. Melt index testers are u..."

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Created page with "{{Language_sel|LANG=ger|ARTIKEL=Schmelze-Volumenfließrate}} {{PSM_Infobox}} Melt volume-flow rate (MVR) (Author: Prof. Dr. H.-J- Radusch) __FORCETOC__ ==Measurement of melt-volume flow rate (MVR)== The melt-volume flow rate (MVR = melt-volume flow rate or, conversely, MVI = melt volume index) is used to characterise the flow behaviour of a thermoplastic material. Melt index testers are u..."

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{{Language_sel|LANG=ger|ARTIKEL=Schmelze-Volumenfließrate}}
{{PSM_Infobox}}
Melt volume-flow rate (MVR) (Author: Prof. Dr. H.-J- Radusch)
__FORCETOC__

==Measurement of melt-volume flow rate (MVR)==

The melt-volume flow rate (MVR = melt-volume flow rate or, conversely, MVI = melt volume index) is used to characterise the flow behaviour of a [[Thermoplastic Material|thermoplastic material]]. Melt index testers are used to determine the melt volume flow rate, as they are also used to determine the [[Melt Mass-Flow Rate|melt mass-flow rate]] (MFR).

==Equation for determining the MVR value==

The melt-volume flow rate MVR indicates the volume extruded from the capillary in 10 minutes. The MVR value is given in cm3 (10 min)-1 and calculated according to the equation:

{|
|-
|width="20px"|
|width="500px" | <math> MVR=\frac{\pi\cdot r^2\cdot l\cdot t_{ref}}{t}=\frac {427\cdot l}{t}</math>
|}

mit
{|
|-
|''r''
|width="15px" |
|piston radius
|-
|''l''
|
|piston travel distance
|-
|''t''ref
|
|600 s
|-
|''t''
|
|measurement time
|
|}

The determination of the melt index is standardised in ISO 1133 [2] and ASTM D 1238 [3].

The test conditions must be specified for each [[Material Value|characteristic value]] determined.

==Information content and comparability of the MVR value==

The melt index value represents only one value indirectly proportional to [[Shear Viscosity|viscosity]] at a relatively low shear rate. Due to the simple measurement principle, there is no direct comparability with viscosity values measured on high-pressure [Capillary Rheometer|capillary rheometers]] [1]. Viscosity values measured using a melt indexing machine can differ by up to 30 % compared to corrected, actual values measured using high-pressure [[Capillary Rheometer|capillary rheometers]] [4].

'''Acknowledgement'''

The editors of the lexicon would like to thank Prof. Dr. Hans-Joachim Radusch, [https://www.uni-halle.de/?lang=en Martin-Luther-Universität Halle-Wittenberg] and [[Polymer Service GmbH Merseburg]] for this guest contribution.

==See also==

* [[Melt Mass-Flow Rate|Melt mass-flow rate]]
* [[Moulding Compound Test|Moulding compound test]]
* [[Glowing Hot-Wire Test|Glowing hot-wire test]]
* [[Capillary Rheometer|Capillary rheometer]]

'''References'''

{|
|-valign="top"
|[1]
|[[Radusch, Hans-Joachim|Radusch, H.-J.]]: Determining Process-Related Properties. In: [[Grellmann, Wolfgang|Grellmann, W.]], [[Seidler, Sabine|Seidler, S.]] (Eds.): Polymer Testing. Carl Hanser, Munich (2022) 3. Edition, pp. 62–64 (ISBN 978-1-56990-806-8; e-Book 978-1-56990-807-5; see [[AMK-Büchersammlung|AMK-Library]] under A 22)
|-valign="top"
|[2]
|ISO 1133: Plastics – Determination of the Melt Mass-flow Rate (MFR) and Melt Volume-flow Rate (MVR) of Thermoplastics
: Part 1 (2022-06): Standard Method
: Part 2 (2011-12): Method for Materials Sensitive to Time-temperature History and/or Moisture
|-valign="top"
|[3]
|ASTM D 1238a (2023): Standard Test Method for Melt Flow Rates of Thermoplastics by Extrusion Plastometer
|-valign="top"
|[4]
|Schramm, G.: Einführung in die Rheologie und Rheometrie. Gebrüder Haake, Karlsruhe (2nd Edition 2004) ([https://www.polymerservice-merseburg.de/fileadmin/inhalte/psm/veroeffentlichungen/Rheologie_Inhaltsverzeichnis.pdf Content as pdf])
|}

[[Category:Process-related Properties]]
[[Category:Guest Contributions]]

Melt Volume-Flow Rate - Revision history