ISO 6591-2:1985

Overview

ISO 6591-2:1985 is an international standard published by the International Organization for Standardization (ISO) that defines the description and method of measurement for empty sacks made from thermoplastic flexible film. This part of ISO 6591 specifically focuses on plastic sacks used in packaging, outlining a standardized system for characterizing sack types and their dimensions through an eight-figure designation. The standard also details sampling, equipment, measurement procedures, result calculation, and reporting formats to ensure consistent evaluation of empty plastic sacks.

The standard facilitates clear communication of sack specifications across manufacturers, suppliers, and users worldwide, improving quality control and compatibility in packaging applications.

Key Topics

• Scope and Application
  Applicable to plastic sacks made of thermoplastic flexible films as defined in ISO 6590/2. It primarily concerns empty sacks used for packaging.

• Sack Types and Dimensional Designation
  Sacks are classified based on type including:

  • Open-mouth heat sealed flat sacks
  • Open-mouth heat sealed gusseted sacks
  • Open-mouth pasted flat hexagonal bottom sacks
  • Valved heat sealed and pasted sacks with various configurations

  These sacks are described using parameters such as sack length, width, gusset width, bottom width, valve width, and valve sleeve length.

• Definitions
  The standard provides precise definitions for crucial sack dimensions:

  • Length of sack
  • Width of sack
  • Width of gusset or bottom
  • Length and width of valves and valve sleeves
  • Heat seal distances

• Valve Positioning
  Valve orientations on valved sacks are specified as top or bottom, and left or right when viewed from above with the front-side print upright. This allows for repeatable and standardized descriptions.

• Measurement Methodology
  Measurement equipment includes rulers or instruments graduated in millimeters with ±1 mm accuracy.
  Sampling requires at least 10 sacks following ISO 7023 procedures to ensure representative results.
  Sacks are laid flat on a horizontal surface, wrinkles smoothed, and measurements performed at designated points.
  Results are averaged and expressed in millimeters rounded to the nearest whole number.

• Test Reporting Requirements
  Test reports must include:

  • Identification information of the samples
  • Reference to ISO 6591-2:1985
  • Measured dimensional results
  • Any irregular observations or deviations during testing
  • Notes on optional operations or unusual conditions that may affect results

Applications

ISO 6591-2:1985 is essential for manufacturers, quality inspectors, and packaging engineers involved in the production or specification of plastic sacks used across industries such as:

• Agriculture (grain, seed packaging)
• Chemical and pharmaceutical industries (bulk powders, granules)
• Food packaging (flour, sugar sacks)
• Industrial packaging for chemicals, minerals, or construction materials

By adopting this standard, organizations ensure uniform sack dimension reporting, reducing ambiguity and enhancing interoperability between packaging suppliers and users.

Consistent dimensional measurement supports:

• Quality control and conformity assessments
• Procurement and specification clarity
• Optimized packaging system design
• Regulatory compliance related to packaging dimensions

Related Standards

• ISO 6590/2 - Packaging - Sacks - Vocabulary and types - Part 2: Sacks made from thermoplastic flexible film
  Provides terminology and classification of sacks relevant to ISO 6591-2.

• ISO 7023 - Packaging - Sacks - Method of sampling empty sacks for testing
  Specifies sampling procedures referenced in ISO 6591-2 to obtain representative sack samples.

• ISO 6591-1
  Covers measurement methods for empty paper sacks, complementing the plastic sack-focused ISO 6591-2.

By implementing ISO 6591-2:1985, packaging professionals benefit from a globally recognized benchmark for the precise description and measurement of empty thermoplastic film sacks, facilitating quality assurance, standardization, and enhanced supply chain coordination.