Polymer Recycling

Material Characterization for Sustainable Plastic Cycles and High-Quality Recyclates

Plastic recycling is an essential part of a sustainable circular economy. Recycling polymer materials reduces resource consumption, lowers CO₂ emissions, and allows valuable materials to be reused in new products.

However, the quality of recycled materials depends largely on their composition, thermal stability, and aging history. Modern analytical methods provide important information about material purity, polymer composition, additives, and degradation processes. This allows recycling processes to be optimized and high-quality secondary raw materials to be produced.

LINSEIS’s material characterization solutions enable the reliable analysis and evaluation of recycled materials, polymer blends, and recycling streams

Typical Challenges with Recycled Materials

Relevant Questions

  • How does a polymer change as a result of repeated processing?
  • What are the thermal properties of recycled material?
  • What is the purity level of a recycled material?
  • What additives or foreign substances are present?
  • How does aging affect reusability?
  • What types of polymers are found in a material stream?
  • How does thermal stability change after recycling?
  • How many times can a material be recycled?
  • How do recycling processes affect material quality?
  • How can high-quality recycled materials be produced?


Relevant Material and Process Parameters

Parameter
Meaning
Melting temperatureIdentification of polymer types
Glass transition temperatureEvaluation of Material Condition and Aging
Heat CapacityCharacterization of Thermal Properties
Mass LossDetection of additives and impurities
Thermal StabilityEvaluation of Processability
Ash ContentDetermination of inorganic constituents
Oxidation StabilityAssessment of Aging and Service Life
Moisture ContentImpact on Processing and Quality
CrystallinityEffect on Mechanical Properties
Polymer CompositionQuality Control of Recycled Materials

Test Methods for Thermal Insulation Materials

Differential Scanning Calorimetry (DSC)

DSC enables the identification of polymers and the study of thermal transitions in recycled materials.

Analysis of

  • Melting temperatures
  • Glass transitions
  • Crystallinity
  • Material Aging

Typical Applications

  • PE Recyclates
  • PP Recyclates
  • PET Recycling
  • Polymer blends

Thermogravimetry (TGA)

The TGA analyzes thermal stability, additives, and residues in recycled materials.

Analysis of

  • Mass loss
  • Additive content
  • Fillers
  • Ash content

Typical Applications

  • Plastic waste
  • Recycled materials
  • Composite Materials
  • Recycling streams

Simultaneous Thermal Analysis (STA)

STA combines TGA and DSC to provide a comprehensive analysis of recycled materials.

Analysis of

  • Thermal Stability
  • Melting processes
  • Aging Behavior
  • Material Composition

Typical Applications

  • Recycled materials
  • Polymer compounds
  • Engineering Plastics
  • Multi-component materials

Gas Analysis (EGA)

Coupled gas analysis identifies volatile components and decomposition products.

Analysis of

  • Outgassing
  • Additives
  • Contaminations
  • Decomposition products

Typical Applications

  • Plastic Recycling
  • Quality Control
  • Pollutant Analyses
  • Research and Development

Recommended Measurement Instruments for Polymer Recycling

Case Study: Analysis of a Recycled Polymer

Thermal Stability of PET/PBS Recyclates After Composting

This practical example shows how the Linseis TGA L83 is used to investigate the thermal degradation behavior of PET/PBS recyclates. By comparing samples before and after composting, changes in thermal stability can be evaluated, and the potential effects of biodegradable impurities on the quality of recycled plastics can be investigated.

Why Material Analysis Is Crucial for Plastic Recycling

Recycling processes place high demands on quality assurance and material evaluation. Even minor changes in the polymer structure can affect the processability and performance of recycled materials.

The combination of modern measurement methods makes it possible to:

  • Identification of Polymer Types
  • Analysis of Aging and Degradation Processes
  • Assessment of Material Purity
  • Determination of Thermal Properties
  • Optimization of Recycling Processes
  • Quality Assurance for Recycled Materials

Applications – Polymers

FAQ – Recycling

Why is material characterization important in polymer recycling?

Material characterization provides important information about the composition, aging, and quality of recycled materials. This allows for the determination of appropriate processing parameters and the production of high-quality recycled materials.

DSC, TGA, STA, and coupled gas analyses are among the most important methods. They enable the identification of polymers as well as the assessment of aging, purity, and thermal stability.

Thermal analysis methods such as DSC make it possible to identify plastics based on their characteristic melting and glass transition temperatures. This allows materials to be reliably classified and separated.

Multiple processing cycles can lead to chain degradation, oxidation, and changes in the material structure. This can affect mechanical properties, thermal stability, and processability.

Additives affect the processing, stability, and service life of plastics. Analyzing their content is important for evaluating the quality and suitability of recycled materials for new applications.

Thermal stability determines whether a recycled material can be reprocessed without excessive material degradation. It is therefore a key quality parameter in plastics recycling.