Understanding Heat Setting, Dimensional Stability, and Why Low Shrinkage Matters for Converting Processes
Product Overview
When engineers specify BOPET (Biaxially Oriented Polyethylene Terephthalate) film, they look at tensile strength, optical clarity, and thickness. But one of the most critical metrics is often misunderstood: BOPET Film Thermal Shrinkage. If a film shrinks too much when exposed to heat, it can cause severe registration errors during printing, curling in laminated structures, or even machinery jams. Understanding how thermal shrinkage percentage is controlled and measured is essential for maintaining high yields in your production line.
What is Thermal Shrinkage?
Thermal shrinkage is the percentage of dimensional change a film undergoes when exposed to a specific temperature for a set period. For BOPET film, this is typically measured at 150°C for 30 minutes. Because the film is stretched in two directions during manufacturing, it naturally wants to return to its original unstretched state when heated. The “heat setting” process at the factory locks the molecular structure to minimize this movement.
Why Low Shrinkage is Crucial for Buyers
- Print Registration: If the film shrinks during the drying phase of printing, the colors will not align correctly.
- Lamination Quality: High shrinkage can cause the final laminated pouch to curl or delaminate.
- Dimensional Stability: For electronic components or die-cutting, the film must remain flat and stable under high heat.
MD vs TD Shrinkage
It is important to note that BOPET has two shrinkage directions: Machine Direction (MD) and Transverse Direction (TD). Often, MD shrinkage is slightly higher than TD. A high-quality BOPET film should have balanced and strictly controlled shrinkage in both directions to ensure predictable processing.
Technical Characteristics
The following values represent the typical capabilities of our low-shrinkage BOPET film:
- Material: Biaxially Oriented Polyethylene Terephthalate
- Thickness Range: 12 μm up to 500 μm
- Tensile Strength: MD 133 to 271 MPa
- Thermal Shrinkage at 150°C, 30min: MD 0.9% to 1.5% / TD 0.1% to 0.6%
- Breakdown Voltage (Insulation Grades): up to 39.6 kV
- Certifications: RoHS, REACH, UL746B (RTI 105°C)
Why Choose Jinlu Film as Your Supplier
Jinlu Film is a leading BOPET Film Manufacturer and Factory. We use advanced heat-setting lines to guarantee exceptionally low and consistent BOPET Film Thermal Shrinkage. If you are dealing with tight printing tolerances or high-temperature laminations, our Low Shrinkage BOPET film will keep your production running smoothly.
Contact us today for a factory quote, technical data, or a sample of BOPET Film.
