ISO 2386:2019

Overview

ISO 2386:2019 specifies a standardized laboratory method for determining the moisture content of packed cork - including virgin cork, raw reproduction cork, burnt cork, boiled reproduction cork and raw cork waste. The method is gravimetric: measuring mass before and after controlled drying and calculating the moisture loss as a percentage of the initial mass. ISO 2386:2019 ensures repeatable, comparable moisture measurements for quality control and lot acceptance.

Key topics and technical requirements

• Scope: Applies to packed cork types listed above (virgin, reproduction, burnt, boiled, waste).
• Principle: Mass determination, drying under specified conditions, reweighing and calculation of moisture loss.
• Test specimens: Three specimens taken at random from the laboratory sample; each specimen ~400 g.
• Apparatus essentials:
  • Balance with resolution of at least 0.5 g.
  • Ventilated drying oven set to (103 ± 2) °C.
  • Open containers and desiccators with an efficient desiccant (e.g., silica gel).
• Procedure highlights:
  • Pre-dry containers at (103 ± 2) °C for 30 min, cool 30 min in desiccator, weigh container (m1).
  • Place specimen in container and weigh (m2).
  • Dry sets at (103 ± 2) °C for at least 1 hour, cool 30 min, weigh (repeat drying and weighing until constant mass: two consecutive weighings within 0.5 g) to obtain m3.
  • Round masses to the nearest 0.5 g per the standard.
• Calculation: Moisture content (%) = (m2 − m3) / (m2 − m1) × 100.
• Result reporting: Average the three specimen results and round to the nearest integer. Test report must identify the sample, include result, reference ISO 2386:2019, note any non‑specified operating details and incidents.

Applications and users

ISO 2386:2019 is practical for:

• Cork producers and processors performing quality control and drying-process monitoring.
• Laboratory technicians in materials testing labs measuring moisture content for lot acceptance.
• Manufacturers using cork as an input (e.g., wine stoppers, flooring, composites) who require consistent moisture specifications for processing and storage.
• Importers/exporters and certification bodies needing a standardized method to verify consignments.

Benefits include improved consistency in product performance, reduced processing defects linked to improper moisture, and clearer acceptance criteria for traded cork lots.

Related standards

• ISO 633: Cork - Vocabulary (referenced for terminology used in this method).
• General ISO/IEC Directives apply to document development and use.

Keywords: ISO 2386, packed cork, moisture content determination, cork testing, drying oven 103°C, balance 0.5 g, virgin cork, cork waste, quality control.