Overview
EN 26591-2:1992 (identical with ISO 6591-2:1985) defines the description and method of measurement for empty sacks made from thermoplastic flexible film. The standard specifies how to describe plastic sacks by type and dimensional designation, the measurement equipment and procedure, sampling requirements, calculation and reporting of results. It is intended for use with plastic sacks as referenced in ISO 6590-2.
Key topics and technical requirements
- Scope and purpose: Method for measuring and expressing dimensions of empty thermoplastic flexible-film sacks (plastic sacks).
- Dimensional designation: Sacks are described by successive indication of type and dimensions using up to eight figures (for example b/e/a/c or b/a/v/f/i depending on sack type). Common dimension symbols:
- b = width, a = length, e = gusset width, c = bottom width
- v = valve width, f = valve length, i = valve sleeve length, n = heat-seal distance
- Types covered: Open-mouth heat-sealed, open-mouth pasted, gusseted, valved (heat-sealed or pasted) and hexagonal/rectangular bottoms - with standard diagrammatic designations for each.
- Valve position: Defined relative to front-side print (top/bottom, left/right) to standardize valve location descriptions.
- Measurement equipment: Simple ruler or instrument graduated in millimetres, capable of 1 mm accuracy.
- Sampling: Follow ISO 7023; take at least 10 sample sacks for measurement.
- Procedure: Lay sack flat, smooth wrinkles, measure specified dimensions at indicated points, measure at least 10 sacks to 1 mm accuracy.
- Calculation and expression: Report the arithmetic mean of determinations, expressed in millimetres to the nearest millimetre.
- Test report: Must include sample identification, reference to this standard, results (nearest mm), any unusual observations, and any optional operations or influences that may have affected results.
Applications and who uses it
- Packaging manufacturers and converters for specifying and verifying sack dimensions during production.
- Quality control and testing laboratories performing dimensional checks and issuing test reports.
- Procurement and specification writers who need unambiguous dimensional designations for purchasing and tender documents.
- Standards bodies and regulatory authorities that reference consistent measurement procedures for trade and compliance.
- Designers and engineers developing packaging for bulk and industrial goods where valve location and sack geometry affect filling and handling.
Related standards
- ISO 6591-1: measurement method for empty paper sacks (related part)
- ISO 6590-2: vocabulary and types - sacks made from thermoplastic flexible film
- ISO 7023: sampling method for empty sacks for testing
- CEN adoption: EN 26591-2:1992 (SIST EN 26591-2:1999 national adoption)
Keywords: EN 26591-2:1992, ISO 6591-2:1985, packaging, sacks, plastic sacks, thermoplastic flexible film, dimensions, method of measurement, sampling, test report.