Easy Made Surface Pressure Evaluation
The ability to measure surface pressures and pressure distributions with the unique Fuji pressure sensitive film has been available for more than 30 years. The measurement range covers surface pressures from 0.05 to 300 MPa.
The measurement method is quite simple: the films are placed between the components to be measured. After loading a red imprint of the image will appear on the film, where the colour intensity is a measure of the surface pressure.
The FujiFilm Prescale can be used almost in all sorts of measurements of surface pressure, or simply to show the pressure distribution. The films may be used both in air and in water. The tests usually have two different objectives: to check the uniformity of surface pressure or measure the pressure at dedicated points.
The following list provides only a preliminary overview of the versatility of the films and helps to identify similarities to specific measurements.
- Pressure distribution between pressed surfaces, valves, gears, pumps, hydraulic cylinders for the design of seals, gaskets or to verify the machine assembly
- Pressure distribution under heavy equipment and supports or the testy of tyre profiles
- Pressure contacts and pressure patterns on brakes, clutches, injection moulds, roll pressure or rollers in print machines
- Quality control of sealings like sterile packagings, blisters or bags and cartons in the food industry
A qualitative overview of the pressure distribution is already given by inspection of the printed image. The areas with high intensity of red indicate a high surface pressure, while the areas that experienced little or no red colour indicate a lower pressure. For many applications, this qualitative statement is sufficient.
A quantification of the pressure from the printed images is possible at different levels of accuracy.
The user manual that accompanies each package of Fuji Prescale Film presents two different calibration curves for different types of load cycles – short load contact and continuous load. One is for a 5 seconds load cycle only, the other for constant pressure for 2 minutes. These are examples of applications for short-term and in long-term applications.
The different colours at continuous load and short-term exposure is due to the continuous rupture and to a small extent when the micro-capsules are at constant load, so that the same load at a longer period of action leads to a slightly darker result. Fuji guarantees an accuracy of about 10%.
Computerized Analysis of the Results
The Fuji-FDP-8010E software delivers a wide range of evaluation opportunities in conjunction with the scanner from EPSON.
For intensity measurement, the FUJI-print images have to be scanned. The setting of the flatbed scanner is made via a supplied calibration card to adjust the greyscale. In order to measure the scanned footprint with the different red intensities, the program relies on the given calibration curves per film, equal to the manual.
The measured values allow a digital, one-off or planar imaging computation. The program offers various possibilities, such as false colour or 3D representation of the surface pressure.
Using this Windows-based image-processing program, the applications for the FujiFilm Prescale have been significantly expanded.
Accuracy: +/- 10%, measured at 23°C, 65 % rel. humidity (RH)
Resolution: 0.1 mm
Rec. temperature: 20°C to 35°C, for temperatures >80°C we offer a Thermo-Protective-Film
Rec. humidity: 35 % RH to 80 % RH
Film thickness: 1 layer 110 µm, 2 layers 90 µm each
Fuji Digital Analysis System FDP-8010E
Package: Software, A4 scanner cover, calibration card
Resolution: 200 dpi
PC: min. Pentium III, 1 GHz, 512 MB
MS-Windows: MS-Window 7. 8