How does Purson QFZ-II paint film adhesion tester test paint film adhesion?

Pushen QFZ-II Paint Film Adhesion Tester is used to test the adhesion of the paint film to the surface of the object to be coated. It is a desktop manual paint film adhesion tester.

Structural principle

This instrument is a desktop manual and is divided into five parts.

1. The hand transmission part is due to the wheel, the toothed belt, and the toothed belt wheel. Composed of helical gear transmission and drawing head, when the hand wheel is turned, the worktable moves left and right, and the needle is drawing a circle at the same time.

2. The drawing head part is composed of the following two components;

a. The double-headed square screw is used to adjust the machine head up and down.

b. It is composed of a head jacket and an eccentric head core and can be rotated to adjust the drawing diameter.

3. The workbench is equipped with a movable half nut connected to the lead screw at one end to drive the workbench to move back and forth. There are four nuts and two pressure plates on the workbench for pressing and releasing the test piece.

4. The machine base part is used to support the workbench and tracing head, etc.

Instructions

1) Prepare the template according to the specified requirements.

2 ) It is better to check the steel needle and replace it with a new steel needle at the beginning of use (the needle tip is about 3mm away from the work surface).

3 ) Adjust the eccentric position of the needle point according to the required drawing diameter, and then tighten it with screws.

4 ) Install the prepared sample on the workbench with the painted side up and press it tightly with a pressure plate.

5 ) Add weights on the weight plate according to the regulations.

6 ) Lift the movable half nut to move the table to the outer end, then lower the movable half nut.

7 ) Fluctuate the pressure rod to make the needle tip contact with the membrane surface.

8 ) Shake the hand wheel, the steel needle will draw a spiral pattern on the sample plate, and the adhesion of the coating film can be judged according to the pattern.

9 ) Take out the model, remove the paint film on the scratches with a paint brush, check the scratches with a four-fold magnifying glass and grade them.

Take the upper side of the scratches on the model as the inspection target, and mark seven parts 1, 2, 3, 4, 5, 6, and 7 in sequence. Correspondingly divided into seven levels. Check the completeness of the paint film of each part in order. If more than 70% of the lattice of a certain part is intact, it is considered that the part is intact, otherwise it should be considered damaged. For example, if the paint film of part 1 is intact and the adhesion is very good, it is rated as the first grade; if the paint film of part 1 is damaged and the part 2 is intact, the adhesion is next, and it is rated as the second grade. And so on, grade seven is the worst adhesion.

The result is subject to the same level of at least two samples.

Maintenance, storage and transportation

1. The sliding part should be oiled frequently (No. 20 engine oil and vaseline) to prevent rust.

2. Before the measurement work, the oil hole and the guide rail of the instrument should be lubricated, and the instrument should be placed flat for use .

3. Be careful not to collide with the rigid needle when moving the workbench.

4. Generally , a steel needle has to be replaced after being used for 5 times.

5. During the test , the needle needs to pierce the bottom of the coating film, and the exposed board surface shall prevail according to the drawn figure.

6. This instrument is not suitable for wood or plastic samples.

7. After the instrument has been used, it should be cleaned and properly covered to prevent dust . Moisture-proof.

8. When not in use for a long time and transported, it should be wrapped in a plastic bag with a built-in desiccant and a protective wooden box outside, filled with soft wood to avoid vibration and affect the use of the paint film adhesion tester .