.mvr-calculator-container {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 600px;
margin: 20px auto;
padding: 30px;
background-color: #f9fbfd;
border: 1px solid #e1e4e8;
border-radius: 8px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.mvr-header {
text-align: center;
margin-bottom: 25px;
color: #2c3e50;
}
.mvr-input-group {
margin-bottom: 20px;
}
.mvr-input-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #4a5568;
}
.mvr-input-group input {
width: 100%;
padding: 12px;
border: 1px solid #cbd5e0;
border-radius: 6px;
font-size: 16px;
box-sizing: border-box;
transition: border-color 0.2s;
}
.mvr-input-group input:focus {
border-color: #3182ce;
outline: none;
box-shadow: 0 0 0 3px rgba(49, 130, 206, 0.1);
}
.mvr-input-note {
font-size: 12px;
color: #718096;
margin-top: 5px;
}
.mvr-btn {
width: 100%;
padding: 14px;
background-color: #3182ce;
color: white;
border: none;
border-radius: 6px;
font-size: 16px;
font-weight: 600;
cursor: pointer;
transition: background-color 0.2s;
}
.mvr-btn:hover {
background-color: #2b6cb0;
}
.mvr-results {
margin-top: 25px;
padding: 20px;
background-color: #ffffff;
border: 1px solid #e2e8f0;
border-radius: 6px;
display: none;
}
.mvr-result-row {
display: flex;
justify-content: space-between;
align-items: center;
margin-bottom: 12px;
padding-bottom: 12px;
border-bottom: 1px solid #edf2f7;
}
.mvr-result-row:last-child {
border-bottom: none;
margin-bottom: 0;
padding-bottom: 0;
}
.mvr-result-label {
font-weight: 500;
color: #4a5568;
}
.mvr-result-value {
font-weight: 700;
font-size: 18px;
color: #2d3748;
}
.mvr-unit {
font-size: 14px;
color: #718096;
margin-left: 5px;
}
.error-msg {
color: #e53e3e;
font-size: 14px;
text-align: center;
margin-top: 10px;
display: none;
}
function calculateMVR() {
// Get DOM elements
var massInput = document.getElementById('cutMass');
var timeInput = document.getElementById('cutTime');
var densityInput = document.getElementById('meltDensity');
var errorDiv = document.getElementById('errorMsg');
var resultsDiv = document.getElementById('mvrResults');
// Get values
var m = parseFloat(massInput.value);
var t = parseFloat(timeInput.value);
var rho = parseFloat(densityInput.value);
// Validation
if (isNaN(m) || isNaN(t) || isNaN(rho) || m <= 0 || t <= 0 || rho <= 0) {
errorDiv.style.display = 'block';
resultsDiv.style.display = 'none';
return;
}
errorDiv.style.display = 'none';
// Calculations
// 1. Calculate Mass Flow Rate in g/s
var massFlowPerSecond = m / t;
// 2. Calculate MFR (Melt Mass-Flow Rate) in g/10min
// MFR = (Mass / Time) * 600 seconds
var mfr = massFlowPerSecond * 600;
// 3. Calculate Volumetric Flow Rate in cm³/s
// Volume = Mass / Density
var volFlowPerSecond = massFlowPerSecond / rho;
// 4. Calculate MVR (Melt Volume Rate) in cm³/10min
// MVR = (Volume / Time) * 600 seconds = MFR / Density
var mvr = volFlowPerSecond * 600;
// Display Results
document.getElementById('resultMVR').innerText = mvr.toFixed(2);
document.getElementById('resultMFR').innerText = mfr.toFixed(2);
document.getElementById('resultFlow').innerText = volFlowPerSecond.toFixed(3);
resultsDiv.style.display = 'block';
}
Melt Volume Rate (MVR) Calculator
The weight of the polymer strand cut (grams).
Time elapsed during the cut (seconds).
Density of the polymer at test temperature (g/cm³).
Please enter valid positive numbers for all fields.
Melt Volume Rate (MVR):
0.00 cm³/10min
Melt Mass-Flow Rate (MFR):
0.00 g/10min
Volumetric Flow Rate:
0.000 cm³/s
Understanding Melt Volume Rate (MVR)
The Melt Volume-flow Rate (MVR) is a critical rheological property used in the plastics industry to characterize the flow behavior of a polymer melt. While Melt Mass-flow Rate (MFR or MFI) measures the weight of polymer extruded over a specific time, MVR measures the volume extruded.
Formulas Used
This calculator determines MVR based on the standard relationship between mass, density, and volume during an extrusion plastometer test (commonly known as the Melt Flow Index test). The logic follows ISO 1133 and ASTM D1238 standards:
- MFR (g/10min): Calculated by taking the mass of the cut ($m$) divided by the cut time ($t$) in seconds, multiplied by 600 (to convert seconds to 10 minutes).
Formula: $$ MFR = \frac{m \times 600}{t} $$ - MVR (cm³/10min): Calculated by dividing the MFR by the melt density ($\rho$) of the polymer at the specific test temperature.
Formula: $$ MVR = \frac{MFR}{\rho} $$
Why Measure MVR?
MVR is often preferred over MFR in injection molding simulations and mold filling calculations because molds are filled by volume, not weight.
- Material Comparison: Allows comparison of flow properties between materials with different densities (e.g., filled vs. unfilled grades).
- Processing Quality: High variations in MVR can indicate degradation of the polymer or moisture contamination during processing.
- Unit Conversion: Provides a bridge between the lab data (typically weight-based) and engineering requirements (volume-based).
Typical Melt Density Values
To calculate MVR accurately, you must know the melt density at the testing temperature, which is lower than the solid density (room temperature density). Approximate values for common polymers:
- Polypropylene (PP): ~0.74 – 0.77 g/cm³
- Polyethylene (PE): ~0.76 – 0.80 g/cm³
- Polystyrene (PS): ~0.94 – 0.97 g/cm³
- Nylon 6 (PA6): ~0.96 – 0.98 g/cm³
Note: Always consult your specific material datasheet for precise melt density values.