Overview
ISO 177:2016 is an international standard published by the International Organization for Standardization (ISO) that specifies a standardized method to determine the migration of plasticizers from plastics. Plasticizers are additives commonly used in polymer materials to enhance flexibility and workability. This standard addresses the critical issue of how plasticizers migrate from plastics into other materials or plastics when in close contact, including organic surface coatings such as lacquers.
Understanding plasticizer migration is vital for assessing the durability, safety, and performance of plastic products, especially films and sheets, in various applications. ISO 177:2016 outlines procedures to evaluate the tendency of these materials to lose plasticizers and provides a reliable testing framework for materials engineering and quality control.
Key Topics
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Migration Determination Method: The standard defines how to measure the loss of plasticizers by weighing test specimens (plastic sheets or films) before and after exposure to absorbing sheets under controlled temperature and pressure conditions.
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Test Specimens: Plastic samples are shaped into standardized discs or plates, ensuring surface smoothness for effective contact. Special provisions are made for coated materials and composite specimens.
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Absorbent Discs: Sheets with affinity for plasticizers-such as reference rubber, polyethylene, or polyvinyl acetate without plasticizers-are used to absorb migrating plasticizers. The standard allows using materials relevant to the actual application environment for more tailored results.
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Test Conditions: The migration test is typically performed at 70 °C ± 2 °C, with options to adjust between 50 °C and 85 °C based on the material's service temperature. Specimens are maintained in contact with absorbent discs under a 5 kg load inside an air-circulating oven.
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Measurement & Calculation: After exposure (commonly 24 hours, with intervals up to 30 days), the mass loss of the plastic specimens and mass gain of absorbent discs are measured to quantify migration, reported as average changes in grams.
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Considerations: The standard notes potential confounding factors such as migration of other volatile constituents and simultaneous material exchange between test pieces and absorbents.
Applications
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Quality Control in Plastics Manufacturing: ISO 177:2016 enables manufacturers to verify that plasticized materials meet performance and safety requirements by assessing plasticizer retention under simulated use conditions.
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Material Development and Research: This standard supports formulation studies by quantifying plasticizer migration from resins and composite materials at various concentrations.
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Regulatory Compliance and Safety: Understanding plasticizer migration helps ensure compliance with regulations, particularly for products in close contact with food, medical devices, or sensitive surfaces.
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Surface Coating Evaluation: The method is applicable in the testing of plastics that contact organic surface coatings such as varnishes, important in packaging and automotive industries.
Related Standards
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ISO 291: Specifies standard atmospheres for conditioning and testing plastics, relevant for specimen preparation in ISO 177.
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ISO 293: Defines compression moulding of thermoplastic test specimens, used for producing samples tested under ISO 177.
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ISO 294 Series (Parts 1 and 3): Covers injection moulding procedures for plastic test specimens, ensuring consistent sample quality for migration assessment.
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ISO 4649: Details abrasion resistance testing of rubber, referenced for selecting rubber-based absorbent materials in the migration test.
Keywords: ISO 177:2016, plasticizer migration, plastics testing, plastic films, plastic sheets, migration determination, plastic additives, material testing standards, plasticizer loss, absorbent materials, plastics quality control, polymer testing, standard test method, plastic coatings, migration rate.
