What is PSU natural?
PSU natural is an amorphous, transparent high-performance thermoplastic with a glass transition temperature of 190 °C. It combines high heat deflection temperature and dimensional stability with good hydrolysis resistance – PSU can be steam sterilised – and a lower tendency to stress cracking than polycarbonate.
Technical data
| Property | Value | Test method |
|---|---|---|
| General Properties | ||
| Density | 1.24 g/cm³ | DIN EN ISO 1183-1 |
| Water absorption | 0.200 % | DIN EN ISO 62 |
| Flammability (Thickness 3 mm / 6 mm) | HB/V0 | UL 94 |
| Mechanical Properties | ||
| Yield stress | 80 MPa | DIN EN ISO 527 |
| Elongation at break | 15 % | DIN EN ISO 527 |
| Tensile modulus of elasticity | 2,600 MPa | DIN EN ISO 527 |
| Notched impact strength | 6.0 kJ/m² | DIN EN ISO 179 |
| Ball indentation hardness | 155 MPa | DIN EN ISO 2039-1 |
| Shore hardness | 85 scale D | DIN EN ISO 868 |
| Thermal Properties | ||
| Thermal conductivity | 0.26 W/(m·K) | DIN 52612-1 |
| Thermal capacity | 1.10 kJ/(kg·K) | DIN 52612 |
| Coefficient of linear thermal expansion | 55 ·10⁻⁶/K | DIN 53752 |
| Service temperature, long term | -50 to 160 °C | Average |
| Service temperature, short term (max.) | 180 °C | Average |
| Heat deflection temperature | 175 °C | DIN EN ISO 75, Verf. A, HDT |
| Glass transition temperature | 190 °C | ISO 11357-2 |
| Electrical Properties | ||
| Dielectric strength | 30 kV/mm | IEC 60243-1 |
PSU natural vs. PPSU MG compared directly
| Property | PSU natural | PPSU MG |
|---|---|---|
| Density | 1.24 g/cm³ | 1.29 g/cm³ |
| Water absorption | 0.200 % | 0.6 % |
| Yield stress | 80 MPa | 77 MPa |
| Elongation at break | 15 % | 30 % |
| Tensile modulus of elasticity | 2,600 MPa | 2500 MPa |
| Notched impact strength | 6.0 kJ/m² | 10 kJ/m² |
| Thermal conductivity | 0.26 W/(m·K) | 0.35 W/(m·K) |
| Service temperature, long term | -50 to 160 °C | -50 to 180 °C |
| Service temperature, short term (max.) | 180 °C | 210 °C |
| Heat deflection temperature | 175 °C | 205 °C |
| Glass transition temperature | 190 °C | 220 °C |
| Dielectric strength | 30 kV/mm | 15 kV/mm |
PSU natural in detail
1What is PSU natural?+
PSU natural is an amorphous, transparent high-performance thermoplastic with a glass transition temperature of 190 °C. It combines high heat deflection temperature and dimensional stability with good hydrolysis resistance – PSU can be steam sterilised – and a lower tendency to stress cracking than polycarbonate. PSU natural offers a yield stress of 80 MPa and a tensile modulus of 2,600 MPa, largely retained over a wide temperature range up to the continuous service temperature of 160 °C. The material is resistant to hot water, steam, dilute acids and alkalis, microwave-safe, an excellent electrical insulator and self-extinguishing at 6 mm thickness (UL 94 V0). The yellowish transparency allows sight components. As an amorphous material, PSU is sensitive to stress cracking in contact with ketones, esters and chlorinated hydrocarbons and has only limited UV resistance; the heat deflection temperature is below that of PES and PPSU.
2How does Liedtke machine PSU natural?+
PSU natural can be machined well using all conventional cutting methods; sharp tools and good cooling via chip removal avoid heat build-up and stress cracking. Cooling lubricants must be compatible with the amorphous material – if in doubt, machine dry or with compressed air. For tight tolerances and thick-walled parts, we recommend intermediate annealing to relieve machining stresses.
3When should I choose PSU natural?+
PSU natural is used wherever components are exposed to hot water, steam or repeated sterilisation and must remain dimensionally stable and transparent – for example in medical technology, the electrical industry and food technology.
- Sterilisable components and instrument parts
- Sight glasses, filter housings and media-carrying components
- Insulating and functional parts for electrical engineering
4What determines the price of a PSU natural part?+
PSU natural is calculated individually based on drawing or sample. The part price is determined mainly by the semi-finished form and dimensions, material utilisation and offcuts, machining effort and batch size. We are happy to provide binding prices on request.
5When is PSU natural not the right choice?+
The limits of the material are equally important:
- Sensitive to stress cracking with some solvents
- Limited UV resistance
- Lower heat deflection temperature than PES and PPSU
6Advantages and disadvantages of PSU natural+
An honest assessment:
- Advantage: High heat deflection temperature (HDT 175 °C), continuous service up to 160 °C
- Advantage: Hydrolysis resistant, steam sterilisable, microwave-safe
- Advantage: High dimensional stability, transparent
- Advantage: Very good electrical insulating properties
- Disadvantage: Sensitive to stress cracking with some solvents
- Disadvantage: Limited UV resistance
- Disadvantage: Lower heat deflection temperature than PES and PPSU
Typical properties
- High heat deflection temperature
- High transparency
- Good hydrolysis resistance, steam sterilisable
- High dimensional stability
Typical industries
- Medical Technology
- Electrical Industry
- Food Industry
Downloads for PSU natural
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