ISO 12115:1997

Overview

ISO 12115:1997 specifies laboratory methods to determine the flowability, maturation and shelf life of fibre‑reinforced thermosetting moulding compounds and prepregs. It defines two complementary test methods - a room‑temperature, unconstrained flow test (Method I) and a production‑condition moulding test (Method II) - to evaluate how a compound fills a mould and how its handling properties change with age. The standard is primarily applied to unsaturated polyester (UP)‑based materials but is applicable to all fibre‑reinforced thermosetting moulding compounds (SMC, BMC, DMC) and prepregs.

Key Topics and Requirements

• Definitions: Clear terms for flowability, maturation, matured state, shelf life and elementary unit are given to ensure consistent interpretation.
• Two test methods:
  • Method I (room temperature): An unconstrained specimen is loaded by a punch and the punch displacement is recorded (test loads include 390 N, 1 000 N and 2 000 N; punch descent speed ~1.5 mm/s). Tests are run at 23 °C ± 2 °C. Results characterise instantaneous flowability and non‑Newtonian flow behaviour over time (e.g., punch sink after 15 s and 45 s).
  • Method II (moulding conditions): A specimen is moulded in a heated shear‑edge mould under press conditions; mould closing speed ~3.5 mm/s and forces up to 310 kN are measured. Filling time is controlled (nominal 10 s ± 5 s) and pressure at centre and ends of the cavity is recorded to assess filling behaviour.
• Apparatus & sensors: Specifications for punch/platen geometry, displacement indicators, hydraulic press, pressure sensors (e.g., piezoelectric), and data recording are provided.
• Sampling & conditioning: Guidance for representative sampling of sheet or bulk compounds, storage precautions, and conditioning (e.g., 1 h at 23 °C ± 1 °C) prior to testing.
• Test specimens & procedure: Instructions for specimen preparation for both SMC and bulk compounds, number of specimens (minimum three), and how to express and report results.

Applications and Users

ISO 12115 is used for:

• Quality control and incoming inspection of SMC, BMC, DMC and prepregs.
• Product development and formulation screening to compare flow behaviour and maturation rates.
• Determination of shelf life and handling limits for production planning and logistics.
• Process engineers, composite material formulators, test laboratories, R&D teams, and procurement/specification writers in automotive, marine, electrical and general composites industries.

Keywords: ISO 12115, fibre‑reinforced plastics, thermosetting moulding compounds, prepregs, flowability test, maturation, shelf life, SMC, BMC, DMC, quality control.

Related Standards

• ISO 472 - Plastics - Vocabulary (terminology used).
• ISO 8605 / ISO 8606 - Specifications for SMC, BMC and prepregs.
• ISO 12114 - Determination of curing behaviour (relevant when shelf life depends on cure characteristics).