Introduction
Recycled plastics must meet specific material properties in order to be used in industrial applications. In this case, a regranulate examined did not show the required mechanical properties. The aim of the analysis was to quantification of foreign substances in the recyclate by means of chemical and thermal characterization.
analysis and results
1. Material determination using FTIR spectroscopy
- The main component of the recyclate is High-Impact Polystyrene (HIPS).
- traces of polyolefins were identified which indicate contamination of the material.
2. Thermal analysis using differential scanning calorimetry (DSC)
- melting peaks of polyethylene (PE) and polypropylene (PP) were proven.
- Calculated shares: 2% PE, 4% PP.
3. Determination of the inorganic content by thermogravimetric analysis (TGA)
- The Ash or filler content is 12%, which indicates a high proportion of inorganic components.
Conclusion
The recyclate examined contains 6 % foreign polyolefins (PE and PP) and 12 % inorganic fillersThese foreign substances influence the mechanical properties of the material and are the cause of the inadequate performance of the regranulate.
Suggestions
To achieve the desired material properties, a Mixing in a ratio of 1:3 with pure material or new goods recommended. This reduces the amount of foreign matter and improves the mechanical properties of the final product.
Figures: Comparative FTIR spectroscopy (left) and DSC analysis (right).
Black: HIPS reference material; blue: contaminated plastic sample.