ISO 11093-6:2005 Overview
ISO 11093-6:2005 is an international standard published by the International Organization for Standardization (ISO) that specifies a reliable, repeatable three-point bending test method for determining the bending strength of cylindrical paperboard cores. This standard applies specifically to cores with an internal diameter ranging from 50 mm to 300 mm, a minimum wall thickness of 5 mm, and a minimum test length (span) of 1100 mm. It covers the procedures, apparatus, and reporting requirements essential for assessing the mechanical integrity of paper and board cores used widely in packaging and other industries.
The standard provides a fundamental test methodology wherein the paperboard core sample is treated as a beam subjected to a central load, supported at two ends, until fracture. The result helps manufacturers, converters, and quality assurance professionals ensure that cores meet specified mechanical strength requirements, thereby optimizing product performance and reducing waste.
Key Topics
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Scope and Applicability
ISO 11093-6 applies to cylindrical paperboard cores satisfying specific dimensional criteria, focusing on bending strength as an indicator of core robustness.
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Test Principle
The core sample is placed horizontally on two prism-shaped supports and loaded vertically at the midpoint until failure. This setup simulates bending stress conditions.
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Test Apparatus
- Compression testing machine calibrated according to ISO 7500-1
- Two prism supports each with 120° angled faces and rounded edges
- A loading prism to apply the bending force, ensuring uniform contact and accurate force application
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Sampling and Preparation
Samples should be representative of the batch and conditioned under standardized atmospheric conditions per ISO 11093-1 and ISO 11093-2. At least three specimens with lengths exceeding the test span by 100 mm are required for valid results.
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Test Execution
Load is applied centrally at a constant speed of 25 ± 2.5 mm/min until the core fractures. The maximum load registered corresponds to the bending strength in kilonewtons.
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Reporting
Test reports must include complete sample identification, test conditions, individual and average bending strength values, and any deviations from the standard procedure.
Practical Applications
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Quality Control in Core Manufacturing
Producers of paper and board cores utilize ISO 11093-6 to verify product strength, ensuring cores withstand handling and operational stresses during winding, storage, and transport.
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Material Selection and Design Optimization
R&D teams apply this standard to compare materials and core designs, facilitating decisions to enhance durability and reduce material costs without compromising performance.
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Performance Assessment in Packaging and Converting
End-users and converters employ the method to ensure cores meet mechanical specifications critical for safe and efficient reel handling and processing.
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Supplier Compliance and Contract Specification
ISO 11093-6 provides a basis for contractual agreements between buyers and suppliers, establishing consistent testing criteria for bending strength of paperboard cores.
Related Standards
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ISO 11093 Series
- Part 1: Sampling
- Part 2: Conditioning of Samples
- Part 3: Water Content Determination
- Part 4: Dimensional Measurements
- Part 5: Rotation Characteristic Determination
- Part 7: Determination of Flexural Modulus by Three-Point Method
- Part 8: Frequency and Flexural Modulus by Experimental Modal Analysis
- Part 9: Flat Crush Resistance Determination
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ISO 7500-1
- Calibration and verification of uniaxial static testing machines, essential for ensuring accuracy of force measurements during bending tests.
By adhering to ISO 11093-6:2005, industry stakeholders can achieve standardized, reliable measurements of core bending strength, contributing to improved product quality, reduced production risks, and enhanced operational efficiency in paper and board applications.
Keywords: ISO 11093-6, paperboard core testing, bending strength, three-point bending test, core mechanical properties, paper and board standards, core quality control, cylindrical core strength, compression testing machine, ISO paperboard standards.
Open preview (PDF)Paper and board — Testing of cores — Part 6: Determination of bending strength by the three-point method