XPS PRO-DENSITY CALCULATOR
XPS PRO-DENSITY
CALCULATOR
Sample Preparation Guide
- Cut specimen cleanly using a hot wire or fine-tooth bandsaw (avoid ragged saw dust).
- For Core Density, slice off top and bottom calibration skins completely.
- For Overall Density, leave the extruded surface skins intact.
What is Expansion Ratio?
It compares solid Polystyrene density (~1050 kg/m3) to your final foam density. A 35x ratio means the polymer expanded 35 times its original solid volume.
Gas Void Fraction (Porosity)?
This is the percentage of the foam volume that consists of trapped blowing agent gas. High porosity (>96%) provides superior thermal insulation while requiring stable cell walls for compressive strength.
Target Deviation Explained
Shows how far your current sample is from the ideal QC target. A positive value (+) means the foam is heavier than target (consumes extra resin). A negative value (-) means it is lighter (risk of cell collapse or shrinkage).
About This XPS Density Calculator
The XPS Pro-Density Calculator is a specialized quality control (QC) instrument built for process engineers and production operators in the Extruded Polystyrene (XPS) foam industry. Accurate verification of apparent foam density in accordance with ASTM D1622 and ISO 845 standards is essential for maintaining structural compressive strength and long-term thermal insulation performance (R-value).
By monitoring the polymer expansion ratio, closed-cell gas void fraction (porosity), and target midpoint deviation in real time, extrusion teams can fine-tune blowing agent dosing, die lip pressure, and secondary extruder cooling profiles. Proper density control streamlines extrusion troubleshooting and prevents costly raw resin over-consumption.
