How does the metal logo detect if the paint is falling off?-A

To detect whether the Engraved Round Metal Logo has lost its paint, it is necessary to combine physical testing, chemical reagent testing, instrumental analysis and environmental simulation testing and other multi-dimensional methods, the following specific testing programme:

Firts.Paint falling off basic physical test

Visual inspection

Tools: Magnifying glass (5-10 times), standard light source box (D65 light source).

Steps: Observe the surface of the logo under uniform light and check whether there is any visible paint flaking, cracks or bubbles.

Criteria: The surface should be free of visible paint layer defects, and there should be no paint layer build-up or peeling off on the engraved edges.

Adhesion Test

Method:Hundred grams test: Use a scribing knife to scribe 1mm x 1mm 10 x 10 squares on the paint surface, use 3M No. 600 tape to tear vertically and observe the peeling off of the paint layer.

Scratch test: Scratch with a hardness tester (e.g. pencil hardness tester) at a pressure of 750g, the paint layer should be free from peeling.

Standard: Paint layer shedding area ≤5% in 100-frame test, no flaking in scratch test.

Abrasion Test

Tools: Taber 5135 abrasion tester, CS-10 grinding wheel, 500g weight.

Steps: Observe the paint layer wear after 500 rotations.

Criteria: No obvious abrasion of the paint layer, no exposed substrate in the engraved area.

Second.Paint falling off chemical reagent test

Solvent wipe

Reagent: Isopropyl alcohol (99%), MEK (Methyl Ethyl Ketone).

Steps: Dip a cotton ball into the reagent and wipe it on the paint surface 50 times with 500g pressure.

Criteria: No dissolution, softening or peeling of the paint layer.

Corrosion Resistance Test

Method:Salt spray test: 5% NaCl solution, 35°C for 48 hours.

Sweat test: Artificial sweat (pH 4.7-7.8), 35°C for 24 hours.

Standard: no blistering, corrosion or discolouration of the paint layer, adhesion degradation ≤ 1 level.

Third. Paint falling off instrumental analysis

Thickness measurement

Tool: XRF fluorescence thickness gauge or eddy current thickness gauge.

Standard: the thickness of the paint layer should meet the design requirements (such as 20-30μm), error ≤ ± 10%.

Composition analysis

Tools: FTIR (Fourier Transform Infrared Spectroscopy), SEM-EDS (Scanning Electron Microscope Energy Spectroscopy).

Purpose: To confirm the way of combining the composition of the paint layer with the substrate, and to exclude the risk of peeling off due to incompatible composition.