BOPP Film Thickness Measurement
Online X-ray Measurement and Control for BOPP Film Lines
Online X-ray measurement and automatic thickness control for BOPP (biaxially oriented polypropylene) film lines. SCANTECH measures the true thickness of your BOPP film across the full web width, on both the cast sheet and the final film, to reduce give-away, stabilize your profile and start production faster.
Why BOPP film thickness measurement matters
BOPP films are stretched in two directions, first in the machine direction (MDO) and then in the transverse direction (TDO). Any thickness variation in the cast sheet is multiplied by the stretching process and ends up in the final film. Accurate, continuous BOPP film thickness measurement is the key to:
- Less raw material: a tighter profile lets you run closer to the target thickness and reduce give-away.
- Better roll quality: a flat profile avoids gauge bands, wrinkles and winding defects on BOPP rolls.
- Fewer film breaks: a precise edge profile is essential for the tenter clips.
- Faster start-up: with automatic die control, stable production can usually be reached in less than 30 minutes.
Online X-ray thickness gauge for BOPP lines
SCANTECH scanners use X-ray sensors to measure BOPP film thickness online, without a radioactive source. The X-ray technology offers very high spatial resolution and a fast sensor, for a high-fidelity profile right up to the film edge.
What we measure on BOPP lines:
- True thickness
- TDO stretch profile
- Edge profile
- Porosity
- Fillers: CaCO3, TiO2, BaSO4
Two scanners for complete BOPP process control
For BOPP lines, SCANTECH recommends two scanners: one on the cast section, to measure the thick cast sheet before stretching, and one on the film section, to measure the final BOPP film after the TDO. This setup provides complete and reliable mapping of the profile to the die, faster, tighter and more stable control, and a clear view of the stability of the whole process.
Automatic die control for BOPP film
Thickness measurement is only half of the job. SCANTECH controls your automatic die to correct the profile in real time:
- Auto mapping of the profile to the die
- APC (Auto Profile Control)
- Melt flow model and cascade control
- Bolt controller: power and temperature, up to 360 bolts
See our biax film solution for automatic dies. Manual die? SCANTECH also offers measurement solutions for biax lines with manual dies.
Scanners for wide BOPP lines
SCANTECH scanners are adapted to the widest BOPP lines: the widest scanner supplied for biax is 12.5 m, on a BOPP line. SCANTECH systems are installed on hundreds of biax lines (BOPP, BOPET, BOPA, BOPE…). Discover the SHF3 visual inspection scanner.
FAQ – BOPP film thickness measurement
What is the typical thickness of BOPP film?
Most BOPP packaging films are between 15 and 50 µm. The cast sheet before stretching is much thicker, which is why SCANTECH recommends measuring both the cast and the film sections.
Which technology is best for BOPP film thickness measurement?
SCANTECH uses X-ray sensors: they measure online, without a radioactive source, with a very high spatial resolution that gives an accurate edge profile, which is critical to avoid clip-outs in the tenter.
Can you measure voided or pigmented BOPP?
Yes. SCANTECH measures porosity and fillers (CaCO3, TiO2, BaSO4) in addition to thickness.
How wide can a BOPP line be?
The widest scanner SCANTECH has supplied for biax is 12.5 m, on a BOPP line.
Do I need one or two scanners on my BOPP line?
SCANTECH recommends two scanners (cast and film) for complete mapping of the profile to the die and faster, more stable control.
Can SCANTECH control my automatic die?
Yes. SCANTECH's bolt controller controls up to 360 bolts, with auto mapping and Auto Profile Control. Stable production can usually be launched in less than 30 minutes.
