December 2025: Updated Standard for Internal Bond Strength in Paper and Board

The paper and board industry saw a significant enhancement in December 2025 with the publication of a revised standard that directly impacts print quality, product durability, and manufacturing consistency. The latest edition—ISO 16260:2025—addresses the determination of internal bond strength, a vital property for anyone involved in converting, printing, or designing paper-based materials. This article explores the core updates, technical requirements, and what these changes mean for quality and compliance across the sector.

Overview / Introduction

Paper technology continues to evolve, driving innovations in packaging, printing, and specialty applications. International standards play a pivotal role in ensuring that products meet consistent quality metrics across the globe. The recently published ISO 16260:2025 reflects the industry's ongoing commitment to robust testing and material performance. Whether you are a quality manager, compliance officer, engineer, or researcher, understanding these updates will help you optimize product reliability and comply with market expectations.

In this article, you'll gain a thorough understanding of the scope, technical changes, compliance implications, and implementation best practices associated with the new standard for internal bond strength in paper and board.

Detailed Standards Coverage

ISO 16260:2025 - Internal Bond Strength of Paper and Board

Paper and board – Determination of internal bond strength

ISO 16260:2025 specifies a robust method for measuring the energy required to delaminate a paper or board sample—essentially testing the material’s resistance to splitting in the "Z" (thickness) direction. This is particularly important for products that are subject to impacts, impulses, or shock loads during processing, printing, or end-use.

The test utilizes a precision pendulum device, which simulates rapid impacts to the sheet—replicating the dynamic stresses materials face in real-world conditions. By adhering double-sided tape to both surfaces of a test sample and applying a sudden force, the method quantifies the internal bond strength based on the energy required for delamination.

Scope and Application

• Suitable for both single- and multi-ply papers and boards, including those coated or laminated with synthetic polymer films
• Critical for materials exposed to rapid Z-direction stress during printing and packaging processes
• Not recommended for structurally fragile or highly porous materials where tape adhesive migration could compromise test results

Key Requirements and Specifications

• Apparatus: Includes a test assembly preparation device, pendulum, metal anvil, aluminum platen, and double-sided adhesive tape
• Sample Preparation: Standardized sample dimensions (25.4 mm x 25.4 mm) and precise pressure cycles are specified
• Calibration: Mandates regular device calibration with verification protocols detailed in annexes
• Testing Procedure: Involves adhering tape, assembling the test piece, releasing the pendulum, and recording the absorbed energy
• Results Expression: Mean, standard deviation, and data on device type used (analog vs. digital) are required in reporting

Notable Changes in the 2025 Revision

• Updated device types: Clarified differences and compensation requirements for analog and digital testers
• Addition of new Annex B for device verification
• Revised preparation and calibration processes for increased accuracy
• New requirements for documenting tester type and reporting both compensated and uncompensated values when using digital devices
• Editorial improvements and expanded precision data

Who Should Comply

• Paper product manufacturers, especially in packaging, printing, and converting
• Quality assurance and production engineers
• Testing labs and R&D institutions working with paper and board
• Organizations producing coated or laminated paper products

Practical Implications

• Enhanced predictive capability for "real world" sheet performance under load
• Improved quality control during production and conversion
• Better consistency in test results across analog and digital testing devices
• Increased customer confidence for applications where bond strength is critical

Key highlights:

• Covers both single- and multi-ply, coated, and laminated paper boards
• Addresses both analog and digital device measurement methods and reporting
• Stronger focus on calibration, device verification, and reporting transparency

Access the full standard: View ISO 16260:2025 on iTeh Standards

Industry Impact & Compliance

ISO 16260:2025 sets a new benchmark for quality in the paper and board sector. For producers and converters, compliance is not only about meeting customer expectations but also about minimizing the risk of product failure in demanding applications. Regulatory agencies and major clients often require evidence of rigorous internal bond testing—making adherence to the latest version essential for continued market access.

Compliance Considerations and Timelines

• Organizations should audit current bond strength testing protocols and equipment
• Align preparation, testing, and reporting methods with ISO 16260:2025
• Update or recalibrate analog and digital ply bond devices as per the new device verification requirements
• Document tester type and all compensations in test reports, as specified
• Train quality control staff and lab technicians on new procedures
• Most regulatory requirements will expect prompt adoption; transition periods may vary by country or region

Benefits of Adopting ISO 16260:2025

• Increased reliability and reproducibility of test results
• Enhanced material and product quality control
• Greater confidence for buyers and end-users, particularly in high-stakes applications like packaging, graphic papers, and specialty boards
• Easier comparability of results with suppliers or customers globally
• Reduced costs related to product returns or performance failures

Risks of Non-Compliance

• Increased production defects due to undetected internal weaknesses
• Difficulty in meeting client or regulatory requirements for critical applications
• Potential loss of business to more compliant competitors
• Higher liability exposure in cases of product failure

Technical Insights

Common Requirements Across Standards

• Use of specified apparatus and adherence to defined test piece dimensions
• Routine device calibration and precise pressure application for sample preparation
• Thorough documentation in test reports, including machine types and any measurement compensations
• Clear division between analog and digital tester methodologies
• Repeatability and reproducibility addressed in annexes for laboratory confidence

Implementation Best Practices

1. Review equipment specifications: Ensure your pendulum devices (analog or digital) match the updated standard requirements
2. Establish calibration intervals: Set regular calibration schedules and maintain verification logs to ensure ongoing compliance
3. Standardize operator training: Educate lab technicians on differences between device types, compensation factors, and new sample handling procedures
4. Update documentation templates: Incorporate revised reporting requirements, including tester type and both compensated/uncompensated values
5. Integrate into quality management systems: Regularly audit compliance to ISO 16260:2025 as part of ISO 9001 or similar frameworks

Testing and Certification Considerations

• Accredited labs should review their testing protocols for conformity with the latest procedure and device compensation instructions
• Certification bodies will expect evidence of updated methods and reporting for initial or surveillance audits

Conclusion / Next Steps

With the release of ISO 16260:2025, the paper and board industry benefits from a clearer, more technically rigorous protocol for measuring internal bond strength. This reflects global advancements in quality expectations for printed, packaged, and converted paper products.

Key takeaways:

• Ensure immediate review of testing practices and compliance for ongoing quality assurance
• Update equipment and train staff as required
• Include the new reporting criteria for analog and digital testers in all documentation

Recommendations:

• Procurement and compliance teams should reference ISO 16260:2025 in all relevant RFQs and supplier assessments
• Quality managers should integrate the new standard into internal SOPs and training materials
• R&D and testing labs should validate equipment and methods to match the revised procedures

Stay proactive:

• Regularly visit iTeh Standards for updates and guidance on international specifications
• Download or purchase the full text for in-depth implementation support

Explore ISO 16260:2025 and other paper and board standards at iTeh Standards