What Is Recycled Polyethylene Terephthalate (PET) Testing?
Recycled Polyethylene Terephthalate (PET) Testing involves a comprehensive suite of analytical procedures aimed at meticulously assessing the quality, purity, characteristics, and conformity of PET materials recovered from post-consumer and post-industrial waste, most commonly bottles and packaging.
Why Is Recycled Polyethylene Terephthalate (PET) Testing Important?
This crucial testing ensures that recycled PET (rPET) meets stringent industry standards, such as those detailed in UNE-EN 15348, and is suitable for its diverse end-uses, including new food-grade packaging (bottle-to-bottle), fibres for textiles, strapping, and thermoformed sheets.
Applus+ Laboratories holds ENAC accreditation (LE 1680) for polymer testing, demonstrating our unwavering commitment to quality assurance and precision in the characterisation of recycled materials. We are also COFRAC And NADCAP for melt temperature and density measurement.
What Compulsory Recycled Polyethylene Terephthalate (PET) Testing Do We Perform?
Our expert services evaluate the critical physical, chemical, thermal, and rheological properties that govern the successful processing and application of recycled PET. We offer in sample preparation from various forms of rPET, including the capability to perform extrusion and injection moulding to produce standardised test specimens. This ensures that test results are both accurate and truly representative of your rPET recyclates.
Our Recycled PET testing capabilities are carefully aligned with the characterisation requirements outlined in UNE-EN 15348 and other relevant international standards.
Core Recycled PET Characterisation (Aligned with UNE-EN 15348)
These tests focus on the fundamental attributes of the recycled PET material, often considered mandatory for baseline quality assessment and batch consistency, whether for flakes or pellets.
Visual and Physical Characteristics:
- Colour Analysis: Performed via visual inspection for flakes and instrumentally using colorimetry (in accordance with EN ISO/CIE 11664-4) with spectrophotometer analysis for pellets. This ensures colour consistency and meets specific aesthetic or functional requirements for rPET products, including Delta E calculations.
- Shape Evaluation: Visual assessment to characterise the form of flakes or pellets.
- Water Content Determination (Moisture Analysis): Measured according to UNE EN 15348 Annex B, typically using the Karl Fisher method. Precise moisture analysis in a temperature-controlled environment is critical as PET is hygroscopic and excess moisture can degrade the material during melt processing.
- Volumetric Density (Bulk Density): Determined for pellets according to standards like EN ISO 60 or ASTM D1895 (Method C). This provides information on the packing characteristics of the material.
- Particle Size Distribution & Pellet Size:
- For flakes: Analysis of small particle content (fines) as per UNE EN 15348 Annex A and determination of maximum particle size via sieving analysis.
- For pellets (granza): Assessment of pellet size, often by weighing 100 granules or counting the number of granules in 1g.
Contamination Analysis:
- PVC and Polyolefin Content: Assessed as per UNE EN 15348 Annex C, ISO 12418-2, or Annex D. Techniques like Pyro-GC-MS can be employed. Identifying and quantifying these common contaminants is crucial for processing stability and final product quality.
- Other Visible Contaminants: Including ferrous and non-ferrous metals, labels from PET bottles, and other foreign materials, assessed according to UNE EN 15348 Annex C or ISO 12418-2. ICP analysis can be used for specific metal detection.
Processability and Thermal Properties:
- Melt Mass-Flow Rate (MFR) / Melt Volume-Flow Rate (MVR): Performed according to EN ISO 1133-2. This measures the flow characteristics of molten PET, an indicator of its average molecular weight and processability. (ENAC accredited for this test).
- Melting Temperature (Tm) / Melting Point: Determined using Differential Scanning Calorimetry (DSC) as per EN ISO 11357-3. This confirms the material as PET and provides information for setting processing temperatures.
Further Recommended Testing for Comprehensive PET Evaluation
This suite of tests provides a deeper understanding of the recycled PET's properties, often recommended for specific applications (especially food contact) or more stringent quality and regulatory requirements.
Advanced Physical & Mechanical Properties:
- Density: Determined according to EN ISO 1183-1 (COFRAC/NADCAP accredited method available).
- Intrinsic Viscosity (IV): Measured according to standards like ISO 1628-5. IV is a key indicator of PET's molecular weight and is critical for predicting its mechanical performance, especially for bottle-grade rPET.
- Hardness Testing: Performed according to ISO 868 (Shore D) (COFRAC/ENAC accredited method available).
- Tensile Properties: (Though not explicitly listed as mandatory in the provided PET document's table, this is a common and important test for mechanical performance characterisation, similar to PP/PE).
Composition, Purity & Stability:
- Ash Content: Measured according to EN ISO 3451-5 to determine the amount of inorganic residue.
- Thermal Stability (e.g., DSC analysis for degradation): To assess how the material withstands processing temperatures without significant degradation.
- Identification of Other Residuals/Contaminants: Using techniques like Infrared Spectroscopy (IR), X-Ray Fluorescence (XRF), DSC, GC-MS, or UPLC-MS for a broader screening of potential contaminants or additives.
- Alkalinity: Assessed as per UNE EN 15348 Annex E.
- Filtration Test: According to UNE EN 15348 Annex F or EN ISO 23900-5 to assess the level of non-melting particulate contamination.
Safety for Specific Applications (e.g., Food Contact):
- Migration Studies: Essential for food contact applications to ensure that no substances migrate from the rPET into food at levels exceeding regulatory limits.
- NIAS (Non-Intentionally Added Substances) Screening: Identifying and quantifying substances that may be present in the recycled PET as a result of previous use or the recycling process itself.
What Are the Benefits of Recycled Polyethylene Terephthalate (PET) Testing?
Engaging in Recycled Polyethylene Terephthalate (PET) Testing with Applus+ Laboratories offers significant and multifaceted advantages for your business and products:
- Ensure Product Quality & Regulatory Compliance: Verifying rPET properties upholds high material and product quality, crucial for customer satisfaction and, especially for food contact, consumer safety.
- Enhance Market Acceptance and Brand Reputation: Providing certified test reports for your recycled PET significantly boosts its credibility and transparency. This makes your rPET a more attractive and trustworthy material for converters and brand owners, strengthening your market position.
- Support Circular Economy and Sustainability Commitments: By rigorously testing and validating the quality of recycled PET, your organisation actively contributes to a robust circular economy. This reduces reliance on virgin plastics, conserves resources, minimises plastic waste, and promotes the use of sustainable materials.
- Optimise Processing and Reduce Production Issues: Understanding the precise characteristics of your rPET, such as IV, moisture content, and MFR, allows for better control and optimisation of manufacturing processes, leading to reduced waste, improved efficiency, and consistent product output.
Why Choose Applus+ Laboratories for Recycled Polyethylene Terephthalate (PET) Testing?
Choosing Applus+ Laboratories for your Recycled Polyethylene Terephthalate (PET) testing needs means partnering with a globally recognised leader in materials testing, inspection, and certification. We offer important advantages:
- Recognised Expertise in Polymers: We have extensive hands-on experience with polymer science and recycled materials, giving us practical insight into their real-world behaviour and properties.
- Integrated Testing & Certification: Streamlined rPET testing and certification from a single, expert team, simplifying regulatory navigation, especially for food-contact materials.
- Accurate & Reliable Data: Meticulous PET testing with stringent quality control, ENAC and specific method accreditations, delivering dependable data for informed decisions on your rPET.
- Advanced Capabilities & Expertise: State-of-the-art equipment and specialist knowledge for tackling recycled PET challenges, including contamination and NIAS screening.
- Client-Focused Solutions: Customised testing plans tailored to your unique recycled PET requirements, material challenges, and end-application needs.
- Global Recognition & Market Access: Internationally respected reports and certifications, enhancing your recycled PET products' market standing and facilitating trade.
By partnering with Applus+ Laboratories, you gain access to world-class testing facilities, profound expert insights, and an unwavering commitment to helping you achieve your quality, safety, compliance, and sustainability goals for recycled Polyethylene Terephthalate.