Inspection of powder spraying products

Inspection of powder spraying products

1. Check conditions

L Arctic daylight or indoor high-efficiency dual-light fluorescent lamp (illuminance 1000 lumens)

L Sight distance: Class A plane is 300MM, Class B plane is 500MM, Class C plane is 1000MM, and speed eye scanning is 3 m/min.

2. Inspection standard:

L All surfaces shall be exposed and peeled off without scratches, blisters, wrinkles, pinholes and powder accumulation.

L film thickness: outdoor powder 60-120; Indoor powder 50-100; Spray painting is generally 40-70 (film thickness meter 1 point is measured five times, and the average value is taken, and then the average value is taken at four corners and five points in the middle of the whole surface).

3. Production of painted color plates

L A: When baking, make two color plates for each furnace for testing (one for testing and one for archiving). Indicate the powder number, curing conditions and time after being discharged from the furnace, and sign it by QE.

L B: the color sample is stored for two years, and the humidity is 70 15% at room temperature, without direct ambient light.

4. Performance requirements

1 NDT

L film thickness test

L brightness test: glossmeter is qualified with an incident angle of 60 degrees and an error of 5%. Some customers require gloss ≥90%.

L Color difference test: one color difference is 0.8, others are less than 1, or compared with color samples.

2 destructive testing

L Hundred-grid test: Draw a line every 1mm in the area of1100m2 (the depth must be bottomed out) and cross 100 grid. Stick 3M#600 transparent tape 10 ~ 13mm or compatible tape in the test area.

L bending test: the color plate is qualified when it is bent at r=t 180 degrees or repeated for 90 degrees, and the coating does not fall off;

L Hardness test: the pencil is pushed at a 45-degree angle with the front ruler 1kg 15-30mm, and the eraser is qualified if it doesn't leak the bottom after being removed, with slight traces allowed; Or the hardness of the pencil is higher than h, cut the pencil tip into a right angle, apply a force of 1KG to the test surface along the direction of 45 degrees, and draw a straight line of 8CM on the paint surface. There should be no damage or scratches on the surface, and slight paint marks are allowed. .

Reference room temperature hardness: more than 3H.

L Anti-dissolution test: dip a cotton swab with 99.8% absolute alcohol and pull it back 50 times with a force of 1KG. The coating should not change color, swell or peel off, but the gloss changes slightly; Or wet clean solvent (95% industrial alcohol) with clean cotton cloth; Wipe the test surface back and forth with a force of 500 grams for 50 times. The test surface shall not change color, paint, float or lose luster, and the luster may change slightly.

L Impact test: A 500g weight with a cross-sectional area of 1/4 falls freely from 500m, and the coating is qualified without shedding or cracking. There is also a falling ball experiment: a falling ball experiment (using a solid ball with a diameter of 1.5CM and a hollow rod with a length of 1.5M to test the strength and adhesion of the paint). Or on the QCJ paint film impactor (1Kg weight falls freely at a height of 500mm to impact, and there can be no cracks and plastic spraying layer falling off).

L Wear resistance test: brush with sponge for 5000 times, with the hard surface of the material not exposed, plus a load of 30mm wide and 500g, with a distance of 55mm, and brush back and forth for 60 times/minute; It's still Great Wall Rubber 500g. Push it back and forth for 50 times without leaking.

Moisture resistance: The coating shall be left in an environment with 60℃ and 90% relative humidity for 240 hours, and the surface of the coating shall be normal.

L boiling water resistance, soaking 1hr, no abnormality;

L Fading resistance: use ultraviolet lamp with wavelength of 2800 A ~ 3000 A, 15W. After continuous irradiation at a distance of 25cm for 72 hours, compared with the control sample, the test surface should not have leg color, paint peeling, floating or tarnishing.

L alkali-resistant 5% NaOH, no change for 240 hours;

L Acid resistance of 3% HCl, unchanged for 240 hours;

L solvent-resistant xylene, unchanged for 24 hours;

L pollution-resistant lipstick, no abnormality at room temperature for 24 hours;

L heat resistance: 180℃ x l hr color difference e

L Corrosion resistance: salt spray resistance 1000hr unchanged; Humid heat resistance remains unchanged for 500 hours; Or salt water spray shall be free of bubbles and rust (5% salt water at 35 degrees Celsius for 400 hours).