Suzuki SIS N5101 Painting Parts Inspection Standards

The standard “Suzuki SIS N5101 Painting parts inspection standards” developed by Suzuki, a Japanese automotive manufacturer, under Suzuki engineering standards, describes the inspection method for paint film applied to the base metal sheet to prevent corrosion and improve appearance. However, this standard does not apply to the following films:

• Dye film for vacuum evaporation cultivation
• Dye film for fluorescence or directional reflection
• Heat resistant paint film
• Soundproof paint film
• Paint film for insulation

Effective surfaces in this standard refer to:

• Surface that can be seen in a normal posture in use
• Surface that will easily wear or scratch
• Surface that will affect its function by corrosion formation, change or peeling of the paint film

The inspection area should be free from direct sunlight, heat, gas, steam, dust, which will adversely affect the test, without any specification, and still should be ventilated very little. If the painted surface is dirty, it should be cleaned with a waste cloth (if it is dirty with oil or grease, it should be used harmlessly). The materials, tools, reagents used for inspection should be in accordance with Japanese industrial standards. The parts used for inspection should be sampled from the finished products produced according to the specified coating specification (base preparation, pretreatment, coating process, coating method, thickness of paint film). The inspection should be carried out on the parts set for the hours specified in the table after drying.

Appearance inspection: Color, gloss, defect (scratch), indentation, ground mark on the base metal sheet, particles (mixture of foreign matter), bubble and the like should be checked with the naked eye under the following conditions:

• Back color: Achromatic (gray at or near N8721 according to JIS Z 5 standard).
• Lighting: Light - light transmitted through ground (frosted) glass or diffused daylight.
• Light intensity: 300LX or more on the effective surface.
• Distance: 50cm distance (30cm for orange peel of class SS ground surface).

Visual inspection should be carried out with special emphasis on the parts that are conspicuous when assembled as a completed vehicle. If necessary, limit samples should be prepared by agreement between the persons concerned.

This standard describes the following test methods used in paint film examination:

• Corrosion resistance test: A cross scratch is made on the effective surface of the test specimen with a cutting blade. The scratch depth should reach the base metal of the test specimen. The neutral salt spray test specified in JIS Z 2371 is carried out for the hours specified in the table. The test specimen is left in the room for 2 hours after being washed in water. A piece of cellophane adhesive tape or equivalent specified in JIS Z 1522 is firmly attached to the scratch. The tape is immediately peeled off and the end of the tape is held at right angles to the painted surface. The part not wider than 12 mm on each side and the part with a total width of 3 mm on both sides along the scratch are checked for corrosion formation, blistering, peeling and softening of the paint film. This test is not performed on paint film for temporary corrosion protection and temporary decoration.
• Air resistance test: This method is an accelerated air resistance test with carbon arc. The test should be carried out for the hours specified in the table. Foreign substances are removed. Rust, cracks, bubbles and peeling formations are examined. If discoloration occurs after lightly polishing the painted surface with solid wax, color differences and gloss retention rate are checked. This test is not performed on parts that do not require undercoating, primary corrosion protection coating and good appearance.
• Water resistance test: It should be carried out under the conditions specified in the table. The test sample is taken after immersion in distilled water or deionized water. The test sample is left in the room for 1 hour. It is checked for bubbles, peeling, cracks on the effective surface, change in gloss and softening of the paint film.
• Moisture resistance test: It should be carried out in a bubble box under the conditions specified in the table. The test sample is left in the room for 2 hours. It is checked whether there is a bubble, peeling, cracks on the effective surface, change in gloss and softening of the paint film.
• Oil resistance test: It should be carried out under the conditions specified in the table. After immersion in oil, the test sample is taken. The oil stain is wiped with absorbent cotton soaked in gasoline. The test sample is left in the room for 1 hour. It is checked whether there is any bubble, peeling, crack and discoloration on the effective surface, and softening of the paint film. This test is carried out on special parts, and the test oil (Suzuki gear oil, Suzuki CCIS oil and Suzuki designated brake fluid) is determined by agreement between the relevant parties.
• Gasoline resistance test: The test sample is immersed in normal gasoline at room temperature for the time specified in the table. The test sample is left in the room for more than 2 hours. The effective surface is checked for bubbles, peeling, cracks and gloss, color change, softening of the paint film.
• Alkali resistance test: It is carried out under the conditions specified in the table. After water washing, the test sample is left in the air for 1 hour. The effective surface is checked for bubbles, peeling, cracks and softening of the paint film. This test is carried out only on the necessary parts.
• Acid resistance test: It is carried out under the conditions specified in the table. After water washing, the test sample is left in the air for 1 hour. The effective surface is checked for swelling, peeling, cracking and softening of the paint film. This test is carried out only on the necessary parts.

This standard also describes the following test methods:

• Pencil hardness test
• gloss test
• Adhesion test
• Impact resistance test
• Paint film thickness test

Our organization, which has been trying to support businesses from every sector with its testing, measurement, analysis and evaluation studies carried out in a wide range for years, has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. In this context, testing services in accordance with the "Suzuki SIS N5101 Painting parts inspection standards" standard are also provided to businesses.