ISO 15360-3:2024

Overview

ISO 15360-3:2024 – Recycled pulps - Estimation of stickies and plastics - Part 3: Determination and identification by applying near-infrared measurement sets out a standardized method for detecting and identifying sticky and non-tacky polymeric contaminants in recycled pulps and paper using near-infrared (NIR) analysis. This international standard is key for the pulp and paper industry, helping to quantify and classify contaminants such as adhesives and plastics that impact recyclability and final product quality. The standard is applicable to processed samples in laboratory or industrial settings, supporting sustainable paper recycling and quality assurance.

Key Topics

• Stickies and Plastics in Recycling:
  Stickies, or tacky substances, are a major concern in recycled pulp operations as they can disrupt machinery and degrade paper quality. Non-tacky polymeric contaminants (commonly referred to as plastics) further complicate recycling processes and product specifications.

• Near-Infrared (NIR) Measurement:
  The standard utilizes hyperspectral NIR imaging to detect and chemically identify contaminants within recycled pulp or paper sheets. NIR spectroscopy allows for rapid, non-destructive measurement, differentiating between various polymers based on their spectral signatures.

• Contaminant Classification:
  The method distinguishes between stickies (typical adhesive residues like PVAc, EVA, and acrylates), non-tacky polymers (polyethylene, PET, polystyrene, etc.), and unidentified substances. Classification is based on chemical composition, not just adhesive properties as in older methods.

• Sample Preparation and Analysis:
  The procedure covers both pulp samples (often formed into laboratory handsheets) and finished paper, with guidelines for ensuring suitable sample thickness and area for accurate NIR analysis. The sampling and handsheet formation techniques referenced must comply with related ISO standards.

• Measurement and Calculation:
  The standard prescribes how to record, calculate, and report contaminant quantities by area and number per kilogram, including breakdowns by size class, enabling precise monitoring and process control.

Applications

• Recycling Facility Quality Control:
  Paper mills and recycling operations can use this method for routine assessment of recycled pulp and paper batches, ensuring that contaminant levels meet production and regulatory thresholds and do not disrupt downstream processing.

• Product Compliance and Certification:
  The standardized measurement allows manufacturers and suppliers to document the cleanliness of recycled pulp, facilitating compliance with buyer specifications and environmental standards.

• Process Optimization:
  By identifying the types and quantities of stickies and plastics, facilities can adjust deinking, cleaning, and screening processes to improve product quality, reduce downtime, and maximize yield.

• Research and Development:
  The method supports innovation in recycled product development by enabling comparative assessment of various collection, cleaning, and pulping techniques with respect to contaminant removal and control.

Related Standards

Consider referencing these ISO standards for a complete approach to testing and validating recycled pulp:

• ISO 15360-1: Recycled pulps - Estimation of stickies and plastics - Part 1: Visual method
• ISO 15360-2: Recycled pulps - Estimation of stickies and plastics - Part 2: Image analysis method
• ISO 216: Writing paper and printed matter - Trimmed sizes
• ISO 534: Paper and board - Determination of thickness, density, and specific volume
• ISO 536: Paper and board - Determination of grammage
• ISO 4119: Pulps - Determination of stock concentration
• ISO 5263-2: Pulps - Laboratory wet disintegration
• ISO 5269-1/-2: Pulps - Preparation of laboratory sheets

By following ISO 15360-3:2024, stakeholders in the recycled paper supply chain can achieve more consistent, reliable identification and quantification of stickies and plastics, supporting cleaner recycling streams and higher-quality end products.