ISO 7213:2021

Overview

ISO 7213:2021 is an internationally recognized standard that specifies the method for sampling pulps for testing purposes. It ensures that gross samples taken from pulp lots delivered in bales or rolls are truly representative of the entire lot. This standard is essential for quality control and testing in the pulp industry, except when determining saleable mass, for which related ISO standards, ISO 801-1 and ISO 801-2, apply. However, gross samples obtained for saleable mass testing can also be used to assess other pulp properties.

The key objective of ISO 7213:2021 is to provide a reliable sampling procedure to obtain a consistent gross sample for various testing needs such as strength, purity, chemical, and physical properties of pulp.

Key Topics

• Scope and Applicability Applies to all types of pulp delivered in bales or rolls, covering sampling for testing purposes but excluding the determination of saleable mass.

• Sampling Principles Sample bales or rolls are chosen randomly and proportionally from the lot to ensure representativeness. Specimens of equal size are taken from each selected bale and combined to form a gross sample.

• Sample Size and Selection The number of sample bales or rolls to be taken depends on the total lot size with a recommended minimum number based on the square root of the lot size, but never exceeding 32 samples regardless of lot size.

• Sampling Procedures by Pulp Form

  • Sheet form: Select one sheet randomly from each bale, avoiding the top/bottom five sheets and edges.
  • Flash-dried pulps in slabs: Use test discs or pieces broken from internal corners, excluding outside surfaces.
  • Pulps in rolls: Remove outer layers and sample from inner layers, avoiding edges.
  • Combined units: Sample bales taken from top and bottom without dismantling units.

• Sample Handling Protect the gross sample from contamination, sunlight, heat, and moisture. Use non-metallic tools when testing for trace metals to avoid contamination.

• Documentation and Reporting Sampling reports must include lot identification, number and IDs of sampled bales, sampling location and date, quantity information, and any deviations from the prescribed procedure.

Applications

• Quality Testing in Paper and Pulp Industry ISO 7213:2021 supports laboratory testing of pulp properties such as fiber characteristics, chemical composition, and contamination levels, helping producers, buyers, and regulators ensure pulp lot consistency and quality.

• Industrial Sampling for Compliance The standard provides a uniform, traceable method for sampling pulp lots, facilitating compliance with contractual specifications and regulatory requirements.

• Support for Further Analysis Gross samples obtained can be used for diverse analyses other than saleable mass, including strength testing, moisture content, chemical treatments, and contaminant detection.

Related Standards

• ISO 801-1: Pulps - Determination of saleable mass in lots - Part 1: Pulp baled in sheet form Addresses the sampling and testing specifically for saleable mass in sheet-form pulps.

• ISO 801-2: Pulps - Determination of saleable mass in lots - Part 2: Pulps baled in slabs Focuses on saleable mass testing for pulps baled as slabs or flash-dried forms.

• ISO/IEC Directives Outline editorial and procedural rules governing the development and maintenance of ISO standards including ISO 7213:2021.

Keywords: ISO 7213:2021, pulp sampling, gross sample, pulp testing, quality control, pulp industry standard, sampling procedure, pulp bales, pulp rolls, industrial standards, pulp quality, international standards for pulp.