Overview
ASTM D2176-16(2021) is the globally recognized standard test method for determining the folding endurance of paper and plastics films using the M.I.T. Tester. Developed and maintained by ASTM International, this standard provides a consistent procedure to evaluate a material’s ability to withstand repeated bending, folding, or creasing. Folding endurance is a critical property for materials exposed to flexing during their service life, helping manufacturers assess strength, durability, and the effects of aging on paper and plastic film products.
Key Topics
- Folding Endurance: Measures the number of double folds a paper or plastics film can withstand before breaking, using an M.I.T.-type folding apparatus.
- Sample Preparation: Specifies requirements for specimen dimensions, directionality (machine and cross direction), and conditioning prior to testing, ensuring reliable and comparable test results.
- Apparatus Requirements: Details construction and calibration requirements for the M.I.T. tester, including adjustable tension, folding head geometry, and control of testing temperature.
- Testing Procedure: Outlines step-by-step instructions for performing the test, including proper handling, folding cycle settings, and recording results.
- Data Reporting: Provides guidance for documenting fold numbers, test conditions, sample orientation, statistical calculations, and any deviations from standard conditions.
- Significance and Use: Emphasizes the value of folding endurance data for quality control, product research, and assessing the degradation of materials through aging.
Applications
The ASTM D2176-16(2021) standard test method is vital in various industries that rely on the mechanical integrity of paper and flexible films, including:
- Paper Manufacturing: Used in the production of writing, printing, packaging, and specialty papers to ensure durability and suitability for end use.
- Plastics and Flexible Packaging: Assesses the resilience of films and laminates used in bags, wraps, and other products subject to repeated bending, which directly influences usability and lifespan.
- Archival Materials: Evaluates aging effects on documents, maps, and records, helping conservators and libraries make informed choices for preservation and storage.
- Quality Control and Research: Enables manufacturers and laboratories to benchmark different formulations and aging processes, supporting continuous improvement and product development.
Related Standards
ASTM D2176-16(2021) references and aligns with several other key standards and terminology documents to ensure uniformity and comparability across different testing scenarios:
- ASTM D643 - Standard Test Method for Folding Endurance of Paper by the Schopper Tester (Withdrawn 2010).
- ASTM D685 - Practice for Conditioning Paper and Paper Products for Testing.
- ASTM D1968 - Terminology Relating to Paper and Paper Products.
- ASTM E122 - Practice for Calculating Sample Size to Estimate the Average for a Characteristic of a Lot or Process.
These related standards support accurate sampling, consistent terminology, and appropriate specimen conditioning, further strengthening the reliability of folding endurance measurements.
Practical Value
Implementing ASTM D2176-16(2021) helps ensure product quality, regulatory compliance, and customer satisfaction by:
- Providing a standardized method for comparing folding endurance across different materials and vendors.
- Facilitating the identification of material defects or changes in material properties due to manufacturing variations or environmental exposure.
- Supporting claims related to product durability, longevity, and suitability for specific applications.
For producers, converters, and end users focused on the mechanical performance of papers and films, folding endurance testing is a cornerstone of material evaluation and product assurance.
Keywords: folding endurance, M.I.T. tester, ASTM D2176, paper testing, plastics film testing, material durability, quality control, aging of materials, flexing resistance