Overview
QHY type Buchholz Crowd tester is a professional testing instrument under HuiNuo brand, which is suitable for the anti-indentation test of single-layer or multi-layer films of Paints and varnish. The instrument forms Crowd by pressing the film under specified conditions, and expresses the anti-indentation performance of the film as a function of the reciprocal of the Crowd length. The larger the performance value, the better the anti-indentation performance of the film.
Features
1. Cutting device and payload weight are accurate, 1000 +/- 5g and 500 +/- 5g respectively.
2. Equipped with a reading Microscope with 20x magnification and an Illuminant with an incident angle greater than 60 ° to ensure clear images.
3. Microscope accuracy, up to 0.1mm, to ensure the accuracy of measurement results.
4. Structural design professional, composed of rectangular metal blocks, hard tool steel sharp blade metal wheels and two pointed feet to ensure the mass of the Cuan.
Principle
The instrument applies pressure to the film surface under specified conditions by means of its Caller device (a rectangular metal block with a specific weight and a hard steel blade wheel). The film deforms plastically under pressure, forming a Caller. Microscope measurement of the Caller length and calculation of the film's indentation resistance as the inverse of the Caller length (100/L) is used to evaluate the film's resistance to indentation deformation.
Applications
Paints film, varnish film single or multi-layer film anti-indentation performance test
Standards
GB3186、GB9275—88
Steps
1. Prepare the test plate: Make sure that the test plate substrate is hard, flat and free of distortion, the paint film is uniform, smooth and clean, and the thickness is maintained at least 10 μm under the test load. Sampling and test plate production are carried out according to GB3186 and GB9275-88 respectively.
2. Environment control: unless otherwise specified, the test shall be carried out at a temperature of 23 +/- 2 ° C and a relative humidity of (50 +/- 5) %.
3. Place the Crowder: Place the paint film of the test plate up on a stable table, gently place the Crowder in an appropriate position (first make the foot of the device touch the test plate, and then carefully put down the Crowder), place it for 30 +/- 1s and then lift it (first lift the Crowder, then lift the foot of the device).
4. Cedar measurement: within 35 +/- 5s after removing the Cedar, measure the length of the Cedar image with a reading Microscope, accurate to 0.1mm, and record the result.
5. Sexual repeability and calculation: Perform 5 tests in different parts of the same test plate to calculate the arithmetic average of the length of the Cedar.
6. Result evaluation: After revising the average value, look up the table or calculate the indentation resistance through the formula 100/L (L is the length of Cedar, in mm).
Notice
* The test plate substrate must be hard, flat and not deformed under the test load.
* During the test, the paint film should mainly exhibit plastic deformation rather than resilience deformation.
The film thickness should be sufficient to ensure that it remains at least 10 micrometers under the load of the Crane device.
When placing and lifting the crest, it is necessary to operate in sequence to avoid affecting the formation of the crest.
* Clearance measurement must be completed within the specified time window (35 +/- 5s after removal of the Clearance).
To ensure representative results, at least five trials should be performed on the same panel and averaged.
