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GB/T 1731-1993《Determination of film flexibility》

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Home> Standard> GB/T 1731-1993《Determination of film flexibility》

Flexibility tester is used to determine the flexibility of the paint film, and the flexibility of the paint film is expressed by the minimum diameter of the shaft rod that does not cause the damage of the paint film

Number: GB/T 1731-1993Name: Determination of film flexibilityStatus: Abolish

Theme content and scope of application

This standard specifies the method for measuring the flexibility of a paint film using a flexibility tester and expresses the flexibility of the paint film in terms of the minimum rod diameter that does not cause damage to the paint film.

Reference Standard

GB 1727 General preparation method of paint film

GB 1764 Paint film thickness determination method

GB 3186 Sampling of coating products

Materials and Instruments

1. The bottom plate should be flat and without distortion, and the board surface should be free of any visible cracks and wrinkles. Unless otherwise specified, the bottom plate shall be 120mm×25mm×0.2~0.3mm tinplate plate.

2.4x magnifying glass

3. Flexibility tester

As shown in the figure, the flexibility tester consists of 7 steel shaft rods with different diameters fixed on the base. The dimensions of each shaft rod are as follows:

Shaft rod 1 is 35mm long and φ15±0.05mm in diameter;

Shaft rod 2 is 35mm long and φ10±0.05mm in diameter;

Shaft rod 3 is 35mm long and φ5±0.05mm in diameter;

Shaft rod 4 is 35mm long and φ4±0.05mm in diameter;

Shaft rod 5 35mm×10mm×3±0.1mm, radius of curvature 1.5±0.1mm;

Shaft rod 6 35mm×10mm×2±0.1mm, radius of curvature 1±0.1mm;

Shaft rod 7 35mm×10mm×1±0.1mm, radius of curvature 0.5±0.1mm;

After the flexibility tester is assembled, the verticality tolerance of each shaft rod and the installation plane shall not be greater than 0.1mm.

Flexibility tester

sampling

Unless otherwise specified, it shall be carried out in accordance with the provisions of GB 3186.

Base plate preparation and painting

Prepare the paint film on the tinplate according to the regulations of GB 1727.

Drying of test panels

Unless otherwise specified, the sample should be dried according to the drying time specified in the product standard and then conditioned according to the specified constant temperature and humidity conditions and time.

Steps

Unless otherwise specified, the test shall be conducted under the constant temperature and humidity conditions specified in GB 1727.

Use both hands to place the paint film of the test panel upward, press it tightly on the shaft rod with a specified diameter, and use the power of the two thumbs to bend the test plate around the shaft rod inward. After bending, the two thumbs should be symmetrical to the center line of the shaft rod.

After bending, use a magnifying glass to observe the paint film. Check whether the paint film has cracks, peeling or other damage.

experiment report

The test report should include the following content:

a. The model and name of the product under test;

b. Indicate the adoption of this national standard (GB/T 1731);

c. Any difference from the content specified in this national standard;

d.Test results;

e. Test date.

Additional information

This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China.

This standard is under the jurisdiction of the National Coatings and Pigments Standardization Technical Committee.

This standard is drafted by Shenyang Paint Factory.

The main drafter of this standard is Yu Tonglan.

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