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.
