ISO 5636

Introducing ISO 5636 – Industrial Physics

ISO 5636 is the international standard series for determining the air permeance and air resistance of paper and paperboard. These tests measure how easily air passes through a sheet under controlled pressure, providing essential insight into fibre structure, formation, porosity, and coating performance.

Air permeance is a critical property for printing papers, packaging grades, specialty papers, and filtration materials — influencing ink holdout, barrier performance, drying behaviour, and overall sheet quality.

What ISO 5636 Covers

ISO 5636 consists of multiple parts, each defining a different method for measuring air permeance or air resistance. Across the series, the standard specifies:

• Controlled pressure differentials
• Defined measurement geometries
• Calibrated airflow restrictors
• Conditioning requirements for temperature and humidity
• Reporting results in µm/(Pa·s) or Gurley seconds, depending on the method

The methods apply to:

• Printing and writing papers
• Packaging grades
• Coated and uncoated papers
• Porous and semi‑porous specialty papers
• Paperboard

ISO 5636 ensures consistent, comparable porosity measurements across laboratories and production environments.

Where ISO 5636 Is Used

This standard is widely used across the paper and packaging supply chain:

• Paper mills and coating operations
• Printing‑grade producers
• Packaging‑board manufacturers
• Filtration‑paper producers
• Quality‑control laboratories
• R&D and formulation teams

It supports both routine production monitoring and comparative evaluation of sheet structure.

Why Air‑Permeance Testing Matters

Understanding air permeance is essential for:

• Ensuring printability and ink holdout
• Optimising coating absorption and barrier performance
• Controlling drying behaviour and sheet formation
• Predicting press performance and converting behaviour
• Meeting industry and customer specifications

Air‑permeance testing is a foundational structural metric for paper and board.

Testing solutions for ISO 5636

Three products from the Featured Products section align with ISO 5636’s focus on airflow‑based porosity and permeance measurement:

Profile Plus Porosity

A high‑precision porosity‑measurement module engineered for accurate airflow‑based evaluation of paper and board. Ideal for ISO 5636 testing, it delivers stable, repeatable results across a wide range of porosity levels and paper structures.

Profile Plus Porosity – Calibrated Air‑Flow Restrictor (High Range)

A high‑range restrictor designed for testing more porous or open‑structured papers. This calibrated module extends the measurement capability of Profile Plus Porosity systems while maintaining ISO‑aligned accuracy.

Profile Plus Porosity – Calibrated Air‑Flow Restrictor (Low Range)

A low‑range restrictor for fine, dense, or highly coated papers where low air‑permeance values must be measured with precision. Perfect for premium printing grades and barrier‑coated materials.

Your Global Test and Measurement Partner for ISO 5636

Industrial Physics supports paper manufacturers, converters, and laboratories with the tools and expertise needed to evaluate porosity and air permeance in line with ISO 5636. From airflow‑based porosity testing to full physical‑property analysis, we help ensure your materials meet demanding print and performance standards.