SynTherm® – Insulating Materials SynTherm® YT56 (metastar® YT56)

SynTherm® YT56 is a synthetic medium density electro-insulation paper constructed of a calendered, aromatic polyamide fibride flock composition.

SynTherm® YT56 is a Class H (180 °C) insulating material. Its mechanical, thermal and electrical properties are between SynTherm® YT510 and SynTherm® YT511.

Temperatures over 200 °C only slightly influence its electrical properties. The good mechanical properties can be extrapolated to significantly higher temperatures. SynTherm® YT56 is also suitable for use at temperatures to -190 °C due to its polymer-structure.

It has a high short-term dielectric strength. SynTherm® YT56 is compatible with all classes of common resins, varnishes, adhesives as well as transformer liquids, lubricants, and cooling agents. Common solvents may lead to slight reversible moisture expansion. SynTherm® YT56 has low flammability (UL 94V-0) and very high resistance to beta and gamma radiation.

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SynTherm® YT56 is designed for cost critical applications which require a moderate mechanical and electrical strength. Application ranges from phase insulation in AC and DC motors to layer insulation in wet and dry transformers and chokes, even exposed to beta and gamma radiation.


  • Insulating material class H (180 °C)
  • UL listed (RTI mech. + electr. 210 °C)
  • UL file no. E358562
  • RoHS compliant acc. to 2011/65/EU

Delivery forms

Film thickness in μm:
130, 180, 300, 510

SynTherm® YT56 is available:
- in tapes: depending on material thickness on request beginning at 6mm (thin material)
- in rolls:   1000 mm

- depth approx. 1 - 12 mm, distance approx. 1 - 10 mm
- 10 mm up to 240 mm tape-width, thickness on request


Calandered, aromatic polyamide fibride flock composition

Technical data

Property Unit of measure         Test method 
Nominal thickness  μm  130 180 300 510  
Typical thickness  µm  130 180 300 500 GB/T451.3-2002
Specific weight  g/m²  86 125 245 342 GB/T451.2-2002
Tensile strength longitudinal  N/cm  100 155 300 320 GB/T12914-2008
Tensile strength transversal  N/cm  40 60 145 150 GB/T12914-2008
Elongation at break longitudinal  8 9 12 11 GB/T12914-2008
Elongation at break transversal  8.5 9.5 13 11.5 GB/T12914-2008
Elmendorf tear strength longitudinal  1.5 2.5 5.5 11.5 GB/T455-2002
Elmendorf tear strength transversal  3.5 5 7 14.5 GB/T455-2002
Property Unit of measure         Test method 
Nominal thickness  μm  130 180 300 510  
Field intensity  kV/mm  11 11 15 13 GB/T1408.1-2006