ISO 8394-2:2017

Overview

ISO 8394-2:2017 specifies a laboratory method to determine the extrudability of sealants independently of their packaging. Part 2 of the series defines the use of a standardized pneumatic apparatus to extrude conditioned sealant under controlled conditions and measure the extrusion mass or volume. The method provides repeatable extrusion-rate results useful for quality control, product comparison and specification.

Key topics and technical requirements

• Principle: fill a standardized cylinder, extrude sealant under defined pressure/time, weigh the extrudate. Results reported as mass/min or converted to volume/min using density.
• Conditioning: test specimen and apparatus conditioned at the test temperature for a minimum of 12 h. Default temperature (23 ± 2) °C; other allowed temperatures (5 ± 2) °C or (35 ± 2) °C or agreement between parties.
• Apparatus: regulated enclosure; pneumatic apparatus with cylinder volumes 250 ml or 400 ml; orifice diameters 2 mm to 10 mm; compressed air up to 700 kPa. Measurement tools: stopwatch (0.1 s) and balance (0.1 g).
• Test procedure:
  • Single-component sealants: three extrusion tests, one apparatus per test; extrude for 30 s at (300 ± 10) kPa (default) or agreed pressure.
  • Multi-component sealants: perform extrusions at three pot-life times (quarter, middle, third quarter), using three apparatuses at each time (total nine tests) and plot mean extrusion rate vs time to assess viscosity increase.
• Expression of results: E (g/min) = m × 60 / t. Convert to mL/min using density where required.
• Reporting: include reference to ISO 8394-2, lab name/date, sealant identification (chemical family, colour, batch), conditioning temperature, cylinder volume, orifice diameter, extrusion pressure/time, individual and mean results, density (if used), and any deviations from the standard.

Applications and users

• Quality control and acceptance testing by sealant manufacturers, independent testing laboratories, and construction materials QC teams.
• Product development and R&D teams evaluating extrusion behavior for tooling, application methods (manual or pneumatic guns), and workability.
• Specifications writers, architects, and contractors who require objective, comparable extrusion data for procurement and performance criteria.
• Useful where extrudability independent of packaging is critical (e.g., cartridges vs sausages vs bulk).

Related standards

• ISO 6927 - Sealant vocabulary (referenced for terms)
• Bibliography items referenced in ISO 8394-2: ISO 228‑1, ISO 2009, ISO 2338
• Other parts of the ISO 8394 series address complementary aspects of sealant testing (see ISO website).

Keywords: ISO 8394-2:2017, extrudability, sealants, standardized apparatus, extrusion rate, sealant testing, building and civil engineering.