Toray Lumirror S56 PET Film is a heat stabilized, standard-transparency film at 75, 100, and 125 micron, and its headline number is how little it moves in the oven
Heat is where most polyester films misbehave, and Toray Lumirror S56 PET Film is built around that single weakness. Its datasheet lists MD shrinkage well under half a percent at 150°C, a fraction of what a standard film shows.
Reading the Shrinkage Figures
- MD shrinkage after 30 minutes at 150°C: about 0.45 to 0.5 percent (ASTM D1204)
- TD shrinkage under the same conditions: about 0.16 to 0.20 percent (ASTM D1204)
The standard grade in this range, Toray Lumirror S10 PET Film, lists MD shrinkage of roughly 0.9 to 1.0 percent at similar thicknesses, about double. Lower shrinkage means better dimensional stability, which matters whenever the film goes through soldering, drying, or curing steps.
The datasheet adds that the heat shrinkage is well balanced to avoid curling, and that the film is slightly hazy for good handling. Balanced shrinkage matters because a film that shrinks much more in one direction than the other tends to curl after heating (a general explanation, not from this datasheet).
Where It Is Used
The datasheet recommends S56 for all applications that require low heat shrinkage PET film, and names flyback transformer (FBT) and flexible print circuit (FPC) in particular. Both involve heat during manufacture and depend on layers staying in register. Suitability depends on your own process, so test samples first.
The Other Numbers
- Thickness: 75, 100, and 125 um
- Tensile strength: about 190 to 220 MPa, easing with thickness (ASTM D882)
- Elongation at break: about 165 to 185 percent (ASTM D882)
- Breakdown voltage: about 14.9 kV at 75 um, 17.3 kV at 100 um, and 19.7 kV at 125 um (ASTM D149)
- Volume resistivity at 20°C: about 5E+17 ohm-cm
- UL746B RTI: 105°C electrical, 105°C mechanical
Breakdown voltage is the voltage at which the film fails electrically, so a higher number means stronger insulation. It rises steadily with thickness, which is the lever to pull if a design needs more margin. RTI is a UL rating related to the temperature a material can withstand in long-term use, and for a specific end product the current UL listing should be confirmed.
How It Differs from Neighboring Grades
- S10 shares S56’s UL rating and has similar breakdown voltage at 75 to 125 um, but shrinks about twice as much in MD.
- X10S carries a higher thermal rating (140°C electrical) and low oligomer, but shrinks more in the thin grades, about 2.4 percent in MD at 75 um. If minimal movement matters more than top temperature rating, S56 is the one to read first.
What the Datasheet Does Not Say
- The values are typical data under specific test conditions and are not limiting specifications, as the datasheet itself notes.
- No haze value, light transmittance, surface tension, or thickness tolerance is listed, and the dissipation factor has no figures in the text available here.
- Some numbers are approximate ranges. Please check the official datasheet for the exact value at your thickness.
Quick Answers
What thicknesses does the datasheet cover?
75, 100, and 125 um.
Which applications are named?
Flyback transformer (FBT) and flexible print circuit (FPC), and any use needing low heat shrinkage PET film.
Can I buy Toray Lumirror S56 PET Film from Jinlu Film?
Yes. Jinlu Film supplies Toray Lumirror S56 PET Film. If you prefer a comparable-specification alternative, including domestic options, we can offer those as well, together with datasheets and samples so you can test them on your own line.
More PET Film Guides
- Toray Lumirror E60 PET Film: a soft white film for D2T2 printers
- Toray Lumirror S28 PET Film: a high-grade S10 with a uniform surface
- Toray Lumirror X21 PET Film: an anti-static white film for displays
- Toray Lumirror X20 PET Film: a brilliant white film for display and tape
Sourcing Low Shrinkage Film
Jinlu Film supplies Toray Lumirror S56 PET Film, along with comparable heat stabilized polyester film grades, including domestic alternatives, for transformer and flexible circuit applications. Tell us your process temperature, thickness, and insulation needs, and contact us for technical data, samples, or a factory quote.
Source: Toray’s publicly available Lumirror S56 technical data sheet (typical values). Please refer to the latest official version. Lumirror, Toray, and related names are trademarks of their respective owners. This article is an independent explanation for reference only.
