How do you find melt density?
Dividing the mass from the MFR test by the volume from the MVR test gives you the melt density. Alternately, you can use an MFR tester to measure the melt density of a material.
What is the difference between MFR and MVR?
While the MFR is given as a mass per unit time, such as grams/10 minutes, MVR is reported as a volume per unit time, such as cm3/10 minutes or, regrettably, inches3/10 minutes.
How do I convert MVR to MFI?
MFI is the flow of extrudate expressed in g/10 mins, whereas the MVR (melt volume flow rate) is the volume of extrudate which flows and is expressed as cm3 /10 mins. Multiplying the MVR with the melt density will give the MFI.
What is the melt density of polypropylene?
0.855 g/cm3
Polypropylene
| Names | |
|---|---|
| Chemical formula | (C3H6)n |
| Density | 0.855 g/cm3, amorphous 0.946 g/cm3, crystalline |
| Melting point | 130 to 171 °C (266 to 340 °F; 403 to 444 K) |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
What is MVR in plastics?
The Melt Flow Rate is a measure of the ease of flow of melted plastic and represents a typical index for Quality Control of thermoplastics. An alternative quantity is the volume flow expressed (SI units) in cm3/10min, called Melt Volume-Flow Rate or MVR.
How is melt flow rate calculated?
A weight specified for the material is applied to a plunger and the molten material is forced through the die. A timed extrudate is collected and weighed. Melt flow rate values are calculated in g/10 min. melt flow rate = g/10 min.
What is melt volume?
Therefore, for the viscosity commonly the MVR (melt volume-flow rate) is used. This value describes how much mass of a polymer is flowing during 10 minutes at a specific temperature and pressure (mostly 2,16 kg or 5 kg) through a given capillary.
How do you calculate melt flow?
What is MFI of LDPE?
1. LDPE has an MFI of 0.3 ± 0.05 g/10 min; however, PLA has an MFI of 5.9 ± 0.08 g/10 min which are very close to values found for non-extruded pellets. This measurement was undertaken to check any degradation of polymers when being extruded.
What is melt mass flow rate?
The Melt Mass-Flow Rate is a one number indication of the viscosity of a polymer in the melt phase. It is defined as the mass of polymer in grams flowing per 10 minutes through a capillary of specific diameter and length by a pressure applied via a range of standard weights at specified temperature.
What is the thermal conductivity of PVC?
Thermal Conductivity of Unfilled Plastics (W/mK) 1
| Plastic Type | Commercial Name | Thermal Conductivity (W/mK |
|---|---|---|
| Polysulfone | 0.26 | |
| Polyurethane | PUR | 0.29 |
| Polyvinylchloride | PVC | 0.12 – 0.25 |
| Polyvinylidene fluoride | Kynan | 0.1 – 0.25 |
How is the density of a polymer melt measured?
The density of a polymer melt can be measured by densymeters, pycnometers and mass flow meters. The most commonly used densymeters and mass flow meters are based on the principle of vibrating tubes, for example Coriolis flow meters [11].
Why is solid density vs melt density important?
It is important because the fundamental principle of solid density vs. melt density needs to be understood so that you can then understand two other very important topics related to plastics:
How to calculate the melt density of an amorphous material?
As a general guideline, you can estimate the melt density for an amorphous material by using 90% of the solid density, and for a semi-crystalline material by using 80% of the solid density.
How is the mass melt flow rate calculated?
The mass melt flow rate from Method A is calculated using the mass of the extrudate (s), as shown in the equation below: where (g) is the mass in grams of material, collected over time (sec). In order to convert the unit of MFR to g/10 min the value “600” is used. Volumetric displacement measurement of MVR using a Dynisco LMI5500.