| Project Overview

During vehicle operation, the body surface coating is inevitably subjected to impacts from gravel, stones, and various other particulate matter. The resistance of the body coating to gravel impact directly affects the vehicle’s appearance, corrosion resistance, and overall service life. Therefore, accurately evaluating the gravel impact resistance of automotive body coatings is an important means of improving coating quality. Gravel impact testing is applicable to adhesion failure tests of exterior coatings, interlayer adhesion failure tests within coating systems, brittle thickness of hard glass materials, optimal coating thickness for flaking resistance, as well as flaking, collision, and abrasion resistance tests of plastics and glass.

| Instrument Features

1. The test spray gun can be freely and quickly replaced to meet the requirements of VDA and SAE standards.

2. Touchscreen settings make the testing process convenient and straightforward.

3. The flat-panel test sample holder can be set at 45°, 54°, or 90°, while irregular samples can be tested using a 3D test chamber.

4. A large-capacity compressed air reservoir ensures constant pressure and flow rate, while the pressure can be adjusted via a regulating valve at the spray gun.

| Technical Specifications

1. Equipment Dimensions (W × D × H): 1600 × 500 × 1250 mm

2. Spray Gun Types: SAE spray gun assembly, VDA spray gun assembly

3. Pressure Control System: 0–10 Bar, with an accuracy of ±0.5% of the final stabilized value

4. Gravel impact duration: 0–30 seconds (adjustable)

5. Configuration: SAE 90° impact chamber, SAE 45° impact chamber, SAE spray gun assembly, VDA 90° impact chamber, VDA 54° impact chamber, VDA spray gun assembly

6. Test temperature range: –30 ℃ to ambient temperature

| Types of Gravel

| Evaluation Method (SAE Standard)

1. Test procedure based on standards: SAE J400, ASTM D3170.

2. Apply adhesive tape to the coated surface of the sample, press evenly to ensure full contact without air bubbles, and then peel it upward.

3. Repeat step 2 until the damaged coating has completely detached.

4. Accurately count and evaluate: (Grade according to Table 1 and Table 2; record failure modes according to Table 3).