Frequently Asked Questions about FUJIFILM Prescale 4LW (0.05–0.2 MPa) Pressure Measurement Film:

General Questions

1. What is FUJIFILM Prescale 4LW and how does it work?

Prescale 4LW is a dual-layer pressure-sensitive film designed to measure extremely low contact pressures from 0.05 to 0.2 MPa. When sandwiched between two surfaces under load, micro-encapsulated dye in the A layer bursts and reacts with the developer layer C, producing a red stain. The stain intensity directly correlates with local pressure. After removal, you compare the color density against FUJIFILM’s calibration chart or scan it with a densitometer to quantify the pressure distribution.

2. What measurement range does 4LW cover?

Prescale 4LW accurately maps contact pressures between 0.05 MPa and 0.2 MPa, making it ideal for applications such as delicate assembly joints, soft-material compression tests, and low-pressure laminating processes.

Analysis and Usage

3. How do I calculate pressure from applied force?

To convert applied force to pressure in MPa:

Measure the force in kgf or newtons (N).

Determine the contact area in cm² or mm².

Apply the appropriate formula:

or

After performing the test, overlay your scanned film image on the calibration chart or process it via software to generate precise point-by-point pressure values.

4. What equipment or software is required to read results?

A densitometer or calibrated film scanner optimized for detecting red optical density.

Image analysis software capable of converting optical density maps into pressure data.

The official FUJIFILM 4LW calibration chart or digital reference file.

Film Variants and Customization

5. What film formats are available?

FUJIFILM Prescale films come in several formats:

Rolls: 320 mm wide × 3 m long (4LW only in roll form).

Pre-cut demo sheets for trial evaluations.

Single-layer (for specific applications) and dual-layer (standard) configurations.

You can manually cut the 4LW roll to custom shapes and sizes as needed.

6. What is the film thickness?

Dye-bearing layer (Film A): 95 ± 10 µm

Developer layer (Film C): 85 ± 15 µm

Total thickness: approximately 180 µm

Handling and Storage

7. Can the film be reused?

No. Prescale 4LW is strictly single-use. Once the microcapsules have ruptured and produced a stain, the film cannot revert to its original state or provide a second measurement.

8. How should I store and handle the film?

Store in its sealed pouch at ≤ 30 °C, away from direct sunlight and high humidity.

Keep the film in a dry, dark environment until just before use.

Handle only with clean, lint-free gloves to avoid contamination.

Do not expose the film to solvents, oils, or cleaning agents.

Selection and Ordering

9. How do I choose the correct Prescale film for my application?

Consider these factors:

The pressure range you need to measure (0.05–0.2 MPa → 4LW).

The surface geometry (flat vs. contoured).

Desired format (roll vs. sheet).

Resolution and sensitivity requirements.

Consult the FUJIFILM Prescale product catalog or contact QTE Technologies (qtetech.com/en) to confirm the best film series for your needs.

10. Are sample/demo films available?

Yes. Many FUJIFILM distributors offer small demo sheets so you can validate performance before committing to larger roll quantities.

Troubleshooting

11. Why did I get no color change after testing?

Applied force was below 0.05 MPa.

Film orientation was reversed (developer side must face the dye layer).

Film sensitivity has degraded (expired film or improper storage).

12. Why is the color non-uniform or too faint?

Surface contaminants (dust, oil) prevented uniform contact.

Applied pressure exceeded or fell outside the film’s range.

Film was creased, folded, or unevenly loaded during setup.

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