First, the scope of application
Paint film bending tester is mainly used for the determination of paint and varnish coating
flexibility, is a measure of the performance of the coating one of the main indicators for the
choice of paint varieties, the application has a great reference value.
Paint film bending tester is the evaluation of paint, varnish and related products coating,
under standard conditions around the cylindrical shaft bending resistance or cracking from
the metal plate on the performance of special equipment, in line with GB6742 national standards.
Second:
1. Working principle:
Bending radius of the different properties of the substrate is also different, depending on the
coating at different bending radius of the crack or stripping the situation, and determine the
flexibility of the coating film.
2. The main parameters:
The diameter of the film bending test shaft is 2, 3, 4, 5, 6, 8, 10, 12, 16, 20, 25 and 32 mm,
respectively.
Rotary handle adjustment should be greater than 17mm, with the test bar to allow the gap
when the gap is 0.05mm.
The height of the support plate should be greater than 17mm, with the test bar to allow the
gap when the gap is 0.1mm.
The instrument is suitable for the following thickness of 1.0mm model.
Third, use and operation
1. According to product standards require sampling, coating, drying and thickness measurement.
2. Place the paint tester on the edge of the test bench so that the adjustment handle can
operate freely and insert the model.
3. Select a suitable shaft bar according to the product requirements. Insert the tester base
and shaft rod holes and fasten them with manual nuts.
4. Turn the adjustment handwheel pallet to insert the coated film face down between the
shaft bar and the adjustment handle and press with the fastening screw and the presser
on the pallet.
5. Turn the adjustment handwheel to lift the pallet so that the model is attached to the shaft bar.
6. Turn the adjustment handle to the lowest position, adjust the knob on the handle of the
clamping shaft, so that the compression shaft close the model.
7. Raise the adjustment handle and lift it 180 ° smoothly in 1-2 seconds. The model on
the shaft is also bent 180 °.
8. Turn the adjustment handwheel, lower the pallet, and let the curved pattern remove
the shaft bar and remove it.
9. Sample testing
After bending, do not remove the model from the instrument and check the model
immediately. Check whether the coating is cracked or peeled from the base plate
(excluding the board less than 10mm coating) with normal vision or with a 10x
magnifying glass according to the product standard. Need to use a magnifying glass.
So as to avoid misunderstanding with the normal vision results.
10. Obtain the operating procedure that first causes damage to the shaft diameter
According to the above operation, in order (from large to small) to test the smaller
diameter of the axis until the film cracking or trough off the bottom plate, and then in a
new block on a block with the same diameter to repeat the operation to prove this result,
The shaft diameter at which the coating film was first cracked or peeled was recorded.
If the minimum diameter of the shaft can not damage the coating, the film is recorded on
the smallest diameter of the shaft, bending will not be destroyed.
11. Test environment and conditions
For the results to be correct, the test should be carried out at a temperature of 23 ± 2 ° C
and a relative temperature of 50 ± 5%.
Fourth, the use of attention
1. In order to prevent the coating during the bending operation, in the model of the coating
surface can be attached to a thin paper, and then inserted between the pallet and adjust
the handle between the test.
2. If the 10% magnifying glass observation results should be noted.
3. The shaft rods with the smallest diameter do not crack or peel off, and in this case the
diameter of the shaft bar should also be indicated.
4. If the aluminum plate its long side should be parallel to the direction of rolling.
5. Paint film bending tester long-term use, all shaft should be coated with anhydrous Vaseline.