1. Standardizing the paint process inspection operation, so that the quality inspection personnel can work according to the basis.

2. Scope of application: all in-plant coating products, including powder coating. Process inspection for liquid coating and outsourcing.

3. Frequency of sampling inspection: 2 PCS of the first piece were tested, and 1PCS were recorded; Process 4PCS/HR, record 2PCS.

ASTM D412-0 Inspection of Baking Paint Process in an Enterprise

Iv. Inspection contents:

4.1 Test before processing:

4.1.1 Check the process card and material label of the previous process. If there is no process card or the record of the process card is incomplete or the process is not completed or there is no material label or the label is not clear, it will be treated as unqualified products.

4.1.2 Conduct sampling inspection on the pre-treated materials, mainly check the appearance of the factory products for scratches. Deformation. Distortion. Welding slag. Desoldering, breakage, etc. Make detailed records if necessary.

4.2 Pre-treatment test:

4.2.1 Degreasing: Use alkaline solution degreasing, degreasing time is not less than 3 minutes.

4.2.2 Cleaning: clean water is used.

4.2.3 Pickling: the acid solution removes the embroidery, and the surface of the workpiece is shiny without embroidery spots after pickling.

ASTM D412-0 Inspection of Baking Paint Process in an Enterprise

4.2.4 Neutralization: alkaline solution is neutralized.

4.2.5 Cleaning: clean with clean water.

4.2.6 Skin film: phosphate skin film treatment, the surface is dark gray after treatment.

4.2.7 Cleaning: clean with clean water.

4.2.8 Drying: drying furnace for drying treatment, generally 120~150℃ drying.

ASTM D412-0 Inspection of Baking Paint Process in an Enterprise

Notes:

1. The concentration of pretreatment liquid shall be checked regularly by the production unit. For the specific standard, please refer to the SOP operation instruction.

2. Surface requirements of workpiece after pre-treatment: no cracking. Embroider spot. Edge. Weld evenly. No welding slag. No distortion. Concave and convex points and other bad conditions are qualified, the surface is dark gray after pre-treatment.

4.3 Baking Paint:

4.3.1 Appearance: If the coating surface is free of whitening, yelping, paint dropping, pinholes, sand grains, wrinkled orange peel, blistering, scratches, embroidery spots, hanging spots, and wool thorns, it is qualified. Please refer to < Appearance Standard > for details.

4.3.2 Adhesion test: Please refer to “Paint Development Test Standard” for details.

Standard: according to the scratch method, according to the standard requirements for scratch and then use 3M adhesive paper in the spacing of 1MM for the horizontal and vertical square of 10 square compaction, to 180° horizontal direction tear adhesive paper, visual inspection and statistics of the number of good lattice, lattice integrity rate of 90% for qualified.

4.3.3 Gloss:

1. Coating: 3-9 (using 60 degrees gloss tester test). Use A clean cloth to wipe the product to be tested, and then place the calibrated gloss meter on the product and press the measurement key. The data displayed on the display screen is gloss.

ASTM D412-0 Inspection of Baking Paint Process in an Enterprise

2. Heat at 600 F for 4 hours, not below weber’s minimum requirements.

4.3.4 Film thickness: The film thickness of key parts shall be controlled to prevent the ignition caused by too thick coating.

1. Single coating: 2.0-4.0mils

2. Coating: 2.0-4.0mils

3. Maximum total coating thickness: 8mils

4.3.5 Texture: Compare the product with the standard sample provided by Weber and visually check whether there is a big difference in texture.

4.3.6 Impact resistance test: (in accordance with ASTMD2794)

1. According to Weber test standard 80in/lb, put the color board on the base of the impacter, the coating is facing down, and the impact head falls freely from the predetermined height. After the test, check whether the protrusion point of the impact part is cracked, if it is not cracked, it is qualified, otherwise it is not qualified.

ASTM D412-0 Inspection of Baking Paint Process in an Enterprise

4.3.7 Hardness Test:

1. First place the coated pencil instrument on a flat workbench, insert the sharpened pencil into the hole of the instrument, then place the adjustment block on the lower part of the instrument body, insert the pencil into the interior until the pencil lead touches the workbench, turn the locking screw, and turn the instrument over 90°.

2. Put the hardness tester loaded with the pencil on the measured surface of the product, and push forward at a constant speed of about 1mm per second (the force or the edge of the end of the pencil lead is broken or the film is damaged by plow). Starting from the hardest (6H) pencil, plow five marks of 3mm long for each grade until the pencil without plow damage is found. The hardness of the pencil represents the hardness of the measured film.

3.Weber minimum hardness must reach 2H.

4.3.8 Elasticity: After the coating surface is bent at 180° diameter of 1/8, if there is no loss of adhesion or surface crack, it is qualified; otherwise, it is unqualified.

4.3.9 Color: There is no obvious color difference in the control color board.

ASTM D412-0 Inspection of Baking Paint Process in an Enterprise

4.3.10 Record: It is not necessary to record each pre-treatment process, but it is necessary to record the relevant inspection before pre-treatment in detail, and record the results after baking according to the sampling and record requirements.

Film thickness requirements Schedule: