Overview
SIST EN 4913:2026 is a European Standard developed by CEN for the aerospace sector, guiding the use of regrinds and recycled materials in thermoplastic parts. Its main objective is to facilitate greater sustainability in aerospace manufacturing without compromising performance or quality. The standard outlines requirements for the inclusion of regrinds and recycled thermoplastics, excluding reinforced thermoplastic materials such as short fibre-reinforced plastics due to their unique processing needs and material properties. Guidance in SIST EN 4913:2026 pertains to aerospace components produced by standard thermoplastic manufacturing methods, such as injection moulding, extrusion, and blow moulding.
Key Topics
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Regrinds in Thermoplastics:
The standard defines regrind as reprocessed scrap material from the same grade of virgin thermoplastic used in the production process. It limits the use of regrind to no more than 25% by weight in aerospace thermoplastic parts unless specific verifications prove suitability for higher proportions.
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Recycled Plastic Materials:
The document covers requirements for recycled thermoplastic materials, focusing on traceability and maintaining batch integrity. For recycled materials, rigorous evaluation is needed to ensure consistent material properties.
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Material Traceability and Quality:
SIST EN 4913:2026 places strong emphasis on traceability, specifying that only qualified and specified materials are to be used. Adequate documentation is required to track both regrind and recycled materials throughout the manufacturing process.
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Testing and Validation:
The standard requires essential tests-such as tensile strength, tensile modulus, Charpy impact resistance, and differential scanning calorimetry-especially when higher regrind contents are involved. Flammability testing is also mandated where regulations apply.
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Exclusions:
The guidance does not apply to thermoplastics reinforced with fibres or similar reinforcements, as these materials have distinct degradation and structural characteristics demanding more stringent controls.
Applications
SIST EN 4913:2026 is relevant for:
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Aerospace Component Manufacturers:
Applicable to companies producing fuselage, interior parts, panels, ducts, and other thermoplastic components for aircraft using processes like injection moulding, extrusion, or blow moulding.
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Sustainability Programs:
Supports aerospace companies’ environmental objectives by enabling validated incorporation of regrinds and recycled polymers, reducing waste and reliance on virgin materials.
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Quality and Compliance Teams:
Provides a reference for maintaining material performance and documentation integrity when incorporating recycled materials into supply chains.
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Material Suppliers and Processors:
Helps material suppliers define acceptable regrind and recycled content levels to supply compliant thermoplastic grades for aerospace applications.
Related Standards
For comprehensive compliance and best practices, SIST EN 4913:2026 references and complements several internationally recognized standards, including:
- EN 9103 - Aerospace series - Quality management systems - Variation management of key characteristics
- EN 10204 - Metallic products - Types of inspection documents (focus on traceability through certificates)
- ISO 179-1 - Plastics - Determination of Charpy impact properties
- ISO 472 - Plastics - Vocabulary
- ISO 527-2 - Plastics - Determination of tensile properties (testing for moulding and extrusion plastics)
- ISO 11357-1 - Plastics - Differential scanning calorimetry (DSC) - General principles
- CS-25 - Certification Specifications for Large Aeroplanes (especially flammability requirements)
SIST EN 4913:2026 serves as a critical guideline in adopting sustainable materials practices in aerospace, ensuring high-performing, reliable, and compliant thermoplastic parts through responsible recycling and quality assurance.