QTY-32 Paint Film Bend Tester User Manual
This English user manual covers the intended use, specifications, operating procedure, result inspection, precautions, and storage of the FMF QTY-32 Paint Film Bend Tester.
English PDF manual
PDF, 4 pages, approximately 9 KB
Download the FMF QTY-32 Paint Film Bend Tester user manual (PDF)
QTY-32 Intended Use
The QTY-32 determines the flexibility of paint and clear-varnish films. It evaluates whether a coating cracks or detaches from a metal panel when the panel is bent around a cylindrical mandrel under specified conditions. The source manual states compliance with GB 6742.
Operating Principle
Coating films differ in their ability to elongate with the substrate when bent over mandrels of different radii. Film flexibility is evaluated by observing whether the coating cracks or detaches at each bend radius.
Technical Specifications
| Item | Specification |
|---|---|
| Mandrel diameters | 2, 3, 4, 5, 6, 8, 10, 12, 16, 18, 20, 25, and 32 mm |
| Handle adjustment range | Greater than 17 mm |
| Permissible gap | 0.1 mm when the specimen is pressed against the mandrel |
| Standard specimen | Tinplate panel, 120 x 50 x 0.3 mm, or a thinner specimen |
| Special specimen | A custom instrument is required for a 1.0 mm thick specimen; consult the equipment supplier |
| Test environment | 23 +/- 2 degrees C and 50 +/- 5% relative humidity |
How to Use the QTY-32 Bend Tester
- Prepare the specimen as required by the applicable product standard: sample, coat, dry, and measure it.
- Place the tester at the edge of a sturdy laboratory bench so the adjusting handle can move freely and the specimen can be inserted.
- Select a suitable mandrel. Insert it into the openings in the tester base and spindle, then tighten the locknut by hand.
- Turn the adjusting handwheel to lower the support plate. Insert the specimen with the coated side facing downward between the mandrel and adjusting handle. Clamp it with the retaining screw and pressure bar.
- Raise the support plate until the specimen is in close contact with the mandrel.
- Lower the adjusting handle to its lowest position. Adjust the pressure-spindle knob so the pressure spindle presses the specimen firmly against the mandrel.
- Raise the adjusting handle smoothly through 180 degrees within 1 to 2 seconds. Do not jerk the handle upward.
- Lower the support plate, release the bent specimen from the mandrel, and remove it.
Inspecting and Recording the Result
- Inspect the specimen immediately after bending.
- Use normal vision, or a 10x magnifying glass when required by the product standard, to check for cracking or detachment from the substrate.
- Disregard coating within 10 mm of the panel edges.
- If a magnifying glass is used, record this fact.
- Test progressively smaller mandrels, from large to small, until the coating cracks or detaches. Repeat the same mandrel diameter using a new specimen to confirm the result.
- Record the mandrel diameter at which cracking or detachment first occurs. If the smallest mandrel causes no damage, record the smallest diameter and state that no damage occurred.
Precautions and Storage
- A sheet of thin paper may be placed over the coated face before testing to help prevent coating damage during bending.
- For an aluminum-panel specimen, position its long edge parallel to the rolling direction.
- If the tester will not be used for an extended period, coat all mandrels with anhydrous petroleum jelly.
QTY-32 Manual FAQ
Which mandrel diameters are included in the manual?
The manual lists 13 mandrel diameters from 2 mm to 32 mm.
How quickly should the specimen be bent?
Raise the adjusting handle smoothly through 180 degrees within 1 to 2 seconds.
How should a no-damage result be recorded?
If the smallest mandrel causes no cracking or detachment, record its diameter and state that no damage occurred during bending.