Evaluation of thermal stability, melt-state behavior, and material phase transitions.

1) Thermogravimetric Analysis (TGA)

Thermal stability and compositional analysis

• Measures weight changes of polymers as a function of temperature or time.
• Used to evaluate thermal stability, decomposition behavior, and the content of fillers or moisture.
• Essential for assessing degradation resistance and formulation stability.

Applications: formulation development, quality control, additive performance.
Case study: quantification of the organic polymer fraction and inorganic fillers in multiphase polymer compounds.

2) Differential Scanning Calorimetry (DSC)

Thermal transitions and phase behavior.

• Determines the heat flow associated with transitions in polymeric materials.
• Used to measure glass transition (Tg), melting (Tm), crystallization, and curing reactions.
• Essential for understanding processing windows.

Applications: formulation development, quality control, determination of characteristic temperatures (Tg, Tm, Tc).
Case study: identification of unknown polymer blends through characteristic melting and glass transition temperatures, enabling differentiation between PE, PP, and PET fractions in recycled materials.

3) UL94 Flammability Test: HB (horizontal burning), V (vertical burning), HBF (horizontal burning of foamed materials)

• Evaluates polymer combustion behavior and self-extinguishing properties.
• Used to assess fire performance.
• Essential for materials used in electrical and automotive applications.

Applications: fire resistance certification and material approval.
Case study: evaluation of flame retardant efficiency in polyolefin compounds formulated with different synergistic additive systems.

Identification of molecular structure, functional groups, and polymer–additive interactions.

1) Selective Solvent Extraction

• Separates polymer fractions or additives using specific solvents.
• Used to investigate crosslinking degree, soluble fraction content, and chemical composition in complex or unknown polymer matrices.
• Key technique for identifying individual polymer species and verifying formulation purity.

Applications: compositional analysis and determination of soluble and insoluble fractions.
Case study: identification of polymer fractions and insoluble fillers in multicomponent or recycled mixtures through selective dissolution and residue analysis.

2) Gel Content (ASTM D2765)

• Determines the insoluble fraction of a polymer through solvent extraction.
• Used to evaluate the degree of crosslinking in crosslinked polymers (e.g., XLPE, elastomers).
• Essential for verifying the effectiveness of the crosslinking process and the stability of the three-dimensional network.

Applications: crosslinking degree control and compliance verification for crosslinked materials.
Case study: comparison of gel content in XLPE cables to correlate crosslinking degree with mechanical performance and thermal resistance.

3) ICP-OES (Inductively Coupled Plasma – Optical Emission Spectroscopy)

• Determines elemental composition through plasma spectroscopic analysis.
• Used to quantify metals, inorganic fillers, catalytic residues, or contaminants.
• Key technique for compositional analysis and purity control of polymer materials.

Applications: quantification of metallic elements and verification of filler or additive content.
Case study: determination of calcium and magnesium content in polyolefin compounds filled with calcium carbonate to validate the declared formulation.

4) Infrared Spectroscopy (IR)

• Analyzes infrared absorption to identify functional groups in polymers, both in bulk and on surfaces (FTIR-ATR).
• Used to identify polymer types through characteristic absorption peaks and to detect chemical modifications or degradation.
• Key technique to confirm molecular structure and evaluate compositional variations.

Applications: polymer identification and degradation monitoring.
Case study: verification of polymer identity in blends and detection of oxidation-induced carbonyl peaks in aged polyolefins.

5) Raman Spectroscopy

• Detects molecular vibrations for precise chemical fingerprinting.
• Used to identify polymers with weak IR activity or interference from fillers or pigments, and to analyze pure carbon structures such as graphite or carbon black.
• Key technique for characterization of polymer blends, filled systems, and conductive compounds.

Applications: polymer identification and analysis of carbonaceous phases.
Case study: identification of carbon structures and transient reaction intermediates invisible to conventional IR analysis.

6) UV–Vis Spectroscopy

• Measures optical absorption of polymer films or solutions.
• Used to analyze chromophoric groups and stabilizer performance within polymer matrices.
• Key for studying photo-oxidative degradation, additive interactions, and color stability in optical or outdoor applications.

Applications: evaluation of photostability, additive efficiency, and optical aging in polymer films and blends.
Case study: quantitative determination of optical tracer additives and evaluation of polymer transparency.

7) Colorimeter (CIELab, CIEXYZ, CIELabCh)

• Quantifies color coordinates.
• Used to monitor color variation, yellowing, and surface oxidation.
• Essential to ensure color uniformity and visual quality.

Applications: color control and surface appearance evaluation.
Case study: quality control of polymer coloration, enabling precise identification of color codes and detection of slight chromatic deviations during production.

8) Gloss Measurement (Surface Gloss)

• Quantifies surface reflectivity and appearance.
• Used to monitor surface uniformity and finish quality.
• Important for aesthetic evaluation and coating control.

Applications: surface finish analysis.
Case study: gloss evaluation in PC/ABS samples.

9) SEM – Scanning Electron Microscopy

• Analyzes surface morphology and material microstructure at high resolution.
• Used to evaluate filler dispersion, matrix–reinforcement adhesion, defects, and fracture surfaces.
• Key technique to correlate mechanical performance with microscopic structure.

Applications: morphological analysis of polymers, composites, and post-fracture surfaces.
Case study: observation of filler dispersion in polyolefin compounds.

Essential analyses for understanding viscosity, material stability, and extrusion behavior.

1) Co-Rotating Twin-Screw Extruder – Pilot Scale (Prism)

• Simulates industrial compounding and reactive extrusion.
• Used to optimize formulation, mixing, and process parameters.
• Ideal for scale-up and testing new polymer blends from 5 to 100 kg.

Applications: process development and formulation optimization.

2) Single-Screw Extruder – Lab Scale (Brabender)

• Processes small quantities of polymers under controlled conditions.
• Used to evaluate melt flow behavior and processing stability.
• Useful for defining extrusion temperature profiles and material performance.
• Extrusion evaluation also possible using flat die heads.

Applications: extrusion testing and processing studies.

3) Batch Mixer – Laboratory Scale (Brabender)

• Mixes polymers, fillers, and additives under controlled shear and temperature conditions.
• Used to test compatibility, dispersion, and formulation stability.
• Key tool for preliminary compounding and additive evaluation.

Applications: premixing, formulation development, torque measurement.

4) Melt Flow Index (MFI) Analysis

Certified test validated through the European RVEP circuit (RVEP 250220 – Excellent Performance), ensuring high data reliability and reproducibility.

• Measures polymer flow under a predefined load and temperature.
• Used to evaluate viscosity, processability, and batch consistency.
• Essential for rapid comparison of polymer grades and blends.

Applications: quality control and evaluation of melt behavior.
Case study: measurement used to evaluate differences in melt fluidity between polymer samples and detect process-induced degradation through variations in flow behavior.
MFI tests can be performed according to the following standards: Internal method, ISO 1133-1:2022, ISO 1133-2:2022, ASTM D1238.

5) Preparation of Standard Test Specimens

(injection molding press and compression press)

• Produces standardized polymer specimens under controlled pressure and temperature.
• Used to prepare samples for mechanical and thermal testing.
• Crucial for reproducibility and accurate performance evaluation.

Applications: specimen preparation and quality control.
Specimens can be produced according to the following standards: Izod impact: ISO 180 / ASTM D256, Hot Set Test: IEC 60811-507, Tear Test: ISO 34 (methods A and B), Tensile Test: ISO 527, Flexural Test: ISO 178

6) 3D Printer with Pellet Extruder

• Converts polymer pellets directly into 3D-printed parts.
• Used to evaluate printability, layer adhesion, and material consistency.
• Key tool for rapid prototyping and evaluation of recycled materials.

Applications: material safety certification and approval.
Case study: evaluation of printing performance of recycled polymers with different additive systems.

SPINPET performs evaluation of mechanical properties of thermoplastics, thermosets, and composites, according to international standards as well as experimental formulations outside standard specifications.

1) Tensile (ISO 527), Flexural (ISO 178) and Tear Test (ISO 34, Methods A and B)

• Measures strength, stiffness, elongation of polymers, and tear resistance.
• Used to evaluate mechanical performance and formulation effects.
• Key for product validation and comparative testing.

Applications: evaluation of mechanical properties.

2) Izod Impact Test (ISO 180 / ASTM D256)

• Measures the energy absorbed by a specimen during impact.
• Used to classify materials as brittle or ductile.
• Essential for evaluating toughness and reliability under sudden stress.

Applications: impact resistance testing.

3) Hot Set Test (IEC 60811-507)

• Determines elongation under load at elevated temperature.
• Used for crosslinked materials and thermoplastic elastomers.
• Important for predicting deformation behavior at high temperatures.

Applications: thermal resistance and dimensional stability.

4) Tensile Test Correlated to ESCR (Internal Method)

• Rapid optimized test based on stress–strain analysis, used to compare and screen compounds before performing standardized ESCR tests.
• Enables correlation of mechanical parameters with expected ESCR behavior.
• Screening method preceding longer and more expensive standardized ESCR tests.

Applications: preliminary selection of polyolefin compounds and formulation optimization.
Case study: rapid exclusion of formulations with poor stress–strain performance statistically correlated with low ESCR values, focusing standardized tests only on promising materials.

5) HDT (ISO 75) and VICAT (ISO 306)

• Determine the behavior of polymer materials subjected simultaneously to increasing temperature and mechanical load.
• Essential for defining thermal service limits of thermoplastics and engineering compounds.

Applications: quality control and verification of deformation resistance under load at elevated temperature.

6) Shore Hardness A/D (ISO 868)

• Measures surface hardness and elasticity of polymers.
• Used to classify rubbers, elastomers, and soft plastics.
• Crucial for ensuring mechanical reliability and tactile properties.

Applications: hardness and elasticity evaluation.
Case study: comparison of hardness among TPU formulations containing different plasticizer levels.

7) Viscosity Determination

• Determines viscosity by measuring resistance to flow under controlled conditions.
• Useful for evaluating consistency between production batches.

Applications: viscosity determination.
Case study: evaluation of viscosity differences between production batches or competitor materials.

8) Density Determination

• Determines polymer density by immersion in water or other liquids.
• Used to detect filler content and material homogeneity.
• Key parameter for verifying formulation consistency and quality.

Applications: quality control and material verification.
Case study: tracking density variations in polyolefin compounds with different filler loadings.

9) Environmental Stress Crack Resistance (ESCR) – ASTM D2561

• Evaluates resistance to crack formation and propagation in polyethylene containers subjected to mechanical stress in the presence of surfactants.
• Used to simulate real operating conditions where the material is exposed simultaneously to load and chemically aggressive environments.
• Essential for qualifying materials used in bottles, jerrycans, and blow-molded containers.

Applications: validation of HDPE grades for chemical and detergent packaging.
Case study: comparison between different HDPE grades for blow-molded containers, highlighting significant differences in failure time under stress in surfactant environments.

1) MONOWAVE 400 R Microwave Reactor (max power 900 W) – Laboratory Scale

• Performs polymerization, depolymerization, and modification reactions under microwave heating.
• Used to achieve rapid and uniform heating and precise control of reaction parameters.
• Key tool for studying reactions at laboratory scale.

Applications: polymer synthesis, extractions, and chemical modification.
Case study: used for polymer depolymerization and real-time monitoring of reaction kinetics.

2) ETHOS X Microwave Reactor (max power 1800 W) – Pilot Scale

• Performs polymerization and modification reactions under microwave heating.
• Equipped with 12 L vessels.
• Used for scale-up of polymer synthesis and modification, ensuring homogeneous heating, efficient mixing, and reliable control of reaction parameters at larger volumes.
• Essential for transferring formulations and processes from laboratory scale to pilot or pre-industrial scale.

Applications: polymer synthesis, extraction, chemical modification, and depolymerization.
Case study: used for scale-up of polymer depolymerization, enabling validation of reaction kinetics and process reproducibility under industrially relevant conditions.

COMPLIANCE TESTING AND COMBINED ANALYTICAL METHODS

1) UNI 10667 – Characterization of Recycled Polymer Materials

SPINPET performs the main analyses required by the standard, applying certified protocols for polyolefins:

• UNI 10667-2 and UNI 10667-3 for polyethylene (PE) and polypropylene (PP)
• UNI 10667-7 for PET
• UNI 10667-10 for polystyrene (PS)
• UNI 10667-14 and UNI 10667-16 for blends and complex materials such as POMIX

2) Cellulose/Polymer Ratio Quantification Test

Different processing, sampling, and analytical techniques can be combined to obtain a complete and reliable quantification of cellulose/polymer-based composites. This integrated approach overcomes the limitations of individual techniques, ensuring a rigorous physico-chemical characterization of the material.

• Quartering and grinding: ensure a homogeneous and representative sample.
• Extrusion: homogenizes and uniformly distributes the polymeric mixture.
• TGA: measures weight loss as a function of temperature, enabling discrimination between the different components based on their degradation temperatures.

3) Quantitative and Qualitative Determination of Complex Matrices

Material characterization through a structured and multidisciplinary analytical approach that combines multiple techniques for the characterization of multimaterial systems, aimed at generating a reliable, application-oriented technical data sheet.

• Selective Extraction and DSC: separate the components and identify polymers (PE, PP, PET) through their characteristic thermal transitions.
• TGA: quantifies the fractions by measuring mass loss as a function of temperature.

The result is a precise compositional profile of the material.