DSC of Recycled Sheets, said to be PE-HD
Sample
Noticeably brittle and distorted sheets, said to be made of PE-HD
Conditions
Measuring Cell: DSC20
Pan: Aluminum standard 40 ul, pierced lid
Sample Preparation: Disk cut from material (6.8 mg)
DSC measurement: Heating from 30 to 200°C at 10 K/min
Atmosphere: Nitrogen, 50 cm3/min
Evaluation
The heat of fusion determined for the PP peak (14.3 J/g) allows the approximate content of PP to be calculated. If the heat of fusion of pure PP is taken to be 60 J/g (typical for polypropylene), then the content is given by:
Content=ΔH/ΔHpp*100%, i.e. 23.9%
Interpretation
The melting curve clearly shows that the material is a blend of PE-HD (peak temperature of 135°C) and PP (peak temperature of 163°C) and not pure PE.
Conclusion
DSC proves that the material does not match the quality agreed upon. The supplier therefore replaced the sheets free of charge.
DSC of Recycled Sheets, said to be PE-HD | Thermal Analysis Application No.HB207 | Application published in METTLER TOLEDO TA Application Handbook Thermoplastics