ISO 15360-2:2015

Overview - ISO 15360-2:2015 (Recycled pulps, Image analysis method)

ISO 15360-2:2015 specifies an image analysis method to estimate Stickies and Plastics in all grades of recycled pulp. It complements ISO 15360‑1 (visual method) by replacing manual visualization and counting with automated image detection and analysis. The method estimates tacky particles that are retained on a laboratory screen (commonly 100 μm or 150 μm slit aperture) under defined temperature and pressure conditions - it does not necessarily measure the total amount of all stickies/plastics present in a sample.

Key topics and technical requirements

• Principle: screening of disintegrated pulp, transfer of retained material to filter paper, marking/highlighting of Stickies and Plastics, and automated measurement by image analysis.
• Two marking methods for Stickies: metallic powder (white) or coating particles pulled from a special coated paper. Plastics are highlighted after dyeing and hiding Stickies with black silicon carbide.
• Image analyser system specs:
  • Detects entire filter area (20 cm diameter or larger).
  • Image detector (scanner or camera) with ≥256 grey levels and physical pixel resolution < 50 μm/pixel.
  • Illuminant concentrated in visible range (380–750 nm); preferred 45° ± 5° incident angle and illumination uniformity within ±4%.
  • Software using a centre‑surround filter (nominal 1.0 mm) and a detection threshold of 10% contrast (per calibration chart).
• Equipment flexibility: permits different laboratory screening devices and slit sizes due to variability of recycled pulp stickies/plastics.
• Key apparatus: disintegrator, laboratory screening equipment, Büchner funnel or Rapid‑Köthen sheet former, white/black filter paper, heated press (95 kPa ±5 kPa at 94 °C ±4 °C for 10 min), oven (105 °C ±2 °C).
• Outputs: number and area of Stickies/Plastics, area distribution histograms and reporting formats.

Applications - practical value

• Routine quality control and monitoring in pulp and paper recycling operations.
• Process troubleshooting and optimization (deinking, screening, washing).
• Supplier audits and incoming recycled pulp acceptance testing.
• Research and development (evaluating decontamination, additives, screening technologies).
• Reducing machine breaks and improving runnability by tracking problematic stickies/plastics.

Who should use this standard

• Pulp & paper laboratory technicians and QC managers
• Recycling plant process engineers
• Equipment and image‑analysis system manufacturers
• R&D and environmental compliance teams concerned with recycled fiber contaminants

Related standards

• ISO 15360‑1 (Visual method) - complementary procedures
• ISO 5263 (disintegration), ISO 5269‑2 (sheet forming), ISO 638, ISO 4119, ISO 7213 - referenced test‑prep and sampling standards

Keywords: ISO 15360-2:2015, recycled pulp, stickies, plastics, image analysis method, laboratory screening, pulp quality control, image analyser.