The core differences between high-quality aluminum composite panels and low-quality products are reflected in five dimensions: aluminum substrate, PE core material, bonding strength, surface coating, and physical properties. Consumers need to make a comprehensive judgment based on appearance inspection, physical testing, and brand endorsement to avoid choosing only at a low price, which may lead to a doubling of the cost of later removal and reinstallation and repair.
1. The core structure and quality of aluminum composite panels
Aluminum composite panels are composed of four parts: aluminum alloy sheet + PE core material + adhesive layer + coating. The quality difference is reflected in each link. The cross-section of high-quality panels is clearly layered and uniform, while the core material of low-quality panels has bubbles or layers.
2. Comparison of the quality of the five core materials
1) Comparison of the quality of aluminum plate substrates
• High-quality aluminum composite panels:
Use high-purity aluminum alloy (such as 3000/5000 series), the thickness of the aluminum layer meets the national standard (external wall ≥ 0.5mm, internal wall ≥ 0.2mm). The aluminum surface is flat, without impurities or oxidation spots.
Recommended reference: Observe the cross section of the aluminum layer to be uniform silver-white, without stratification or impurities.
• Inferior aluminum composite panels:
Use recycled aluminum or mixed impurity aluminum, the aluminum layer thickness is insufficient (such as only 0.1-0.3mm). The aluminum surface is rough, and oxidation, black spots or scratches may appear.
Typical characteristics: The aluminum layer is easy to break when bending, and the cross section is gray or has bubbles.
| Item | High-quality aluminum composite panel | Low-quality aluminum composite panel |
| Material | 3003/5005 aviation-grade aluminum alloy | Recycled aluminum or doped with other metals |
| Thickness | 0.5mm±0.02 (actual measurement meets the standard) | False mark 0.5mm (actual measurement is only 0.3-0.4mm) |
| Surface | Smooth and scratch-free (even reflection) | Visible particles/wave patterns (scattered reflection) |
| Ductility | No fracture after bending 180° (picture shows bending test) | Cracks after bending 90° |
Feature description:
- The thickness of high-quality panels measured with a micrometer meets the standard, while the thickness of low-quality panels does not meet the standard
- The surface coating of low-quality panels falls off obviously in the bending test
2) Comparison of core material composition
• High-quality aluminum composite panel:
The core material is high-density polyethylene (HDPE) or flame-retardant PE, without impurity filling. The core material is translucent milky white, flexible, and can rebound without breaking after bending.
Burning test: No black residue remains after complete combustion, and no odor.
• Inferior aluminum composite panel:
The core material is doped with cheap fillers such as calcium carbonate and stone powder, with low density and brittleness. The core material is easy to break when bending, and black particles remain after burning and release a pungent smell.
| Item | High-quality aluminum composite panel | Low-quality aluminum composite panel |
| Material | High-density polyethylene (HDPE) | Recycled plastic + calcium carbonate filling |
| Odor | No irritating odor | Pungent plastic smell after heating |
| Flame retardancy | B1 flame retardant (open flame does not spread) | Flammable and produces black smoke |
| Cross section | Milky white uniform and dense | Gray black contains impurities/bubbles |
Experimental comparison suggestions:
- Combustion test: High-quality panels extinguish themselves when away from fire, while low-quality panels continue to burn
- The enlarged cross section shows that the low-quality core material has honeycomb holes
3) Bonding strength comparison
| Test method | Performance of high-quality boards | Performance of low-quality boards |
| Peel test | 500N or more of tensile force required for delamination (tensile machine data shown) | Can be torn apart manually (delamination diagram) |
| Boiling test | No debonding after 4 hours of boiling at 100℃ | Bubbling separation occurs after 1 hour |
Key differences:
- Low-quality boards use low-quality polymer films, which are prone to failure in high temperature and high humidity environments
- The cross-sectional enlarged image shows that the bonding layer of high-quality boards is continuous and uniform
4) Surface coating comparison
• High-quality aluminum composite panel:
Using fluorocarbon coating (PVDF), the weather resistance is more than 20 years, the color is uniform and there is no missing coating. Wipe with butanone 200 times without revealing the bottom.
Image features: The surface is smooth like a mirror and the reflection is uniform.
• Low-quality aluminum composite panel:
Using low-end polyester (PE) or acrylic paint, it is easy to fade and powder. The bottom is exposed after 50 wipes, and there is obvious color difference after 1-2 years of outdoor use.
Typical performance: The surface has orange peel texture or granularity.
| Index | High-quality board | Low-quality board |
| Coating type | PVDF fluorocarbon coating (above 25μm) | Polyester paint (below 15μm) |
| Weather resistance | No obvious fading in 10 years | Powdering and peeling in 2 years |
| Adhesion | No peeling after 100-grid test) | Paint film peels off in pieces after scratching |
| Glossiness | 60° angle measurement ≥90GU | ≤70GU (dim surface reflection) |
Identification tips:
- Scratch test with a coin: high-quality board has no obvious scratches, low-quality board reveals the base color
- UV aging test comparison chart shows that the low-quality board is seriously discolored
5) Physical performance comparison
Test items High-quality aluminum composite board Low-quality aluminum composite board Reference basis
Bending strength Aluminum layer breaks when bent 180°, core material intact Aluminum layer and core material break at the same time when bent 90°
Fireproof grade B1 (flame-retardant core material) No clear grade, releases toxic gas when exposed to fire
Temperature difference resistance -40℃~80℃ No deformation Bubbling at high temperature, embrittlement at low temperature
Sound insulation effect 25-30dB noise reduction Almost no sound insulation function
| Test items | High-quality board | Low-quality board |
| Wind pressure resistance | Passed the 9-level typhoon test | Board surface deformed under strong wind |
| Sound insulation | 28dB (professional test report) | ≤20dB |
| Flatness | Gap measured by 2m ruler ≤1mm | Unevenness visible to the naked eye |
| Environmental protection | Passed SGS heavy metal test | Lead and chromium content exceeded the standard |
Price and cost analysis
- Cost distribution of high-quality panels: aluminum 55% > coating 20% > core material 15% > glue 10%
- Cost compression of low-quality panels: recycled aluminum 30% > filler 40% > low-quality glue 15% > thin coating 15%
- Market price difference: High-quality panels Price $9-35/㎡vs low-quality panels $3-8/㎡
Comparison of engineering application results Installation and use performance
1. Construction adaptability
• High-quality products:
Can be slotted, punched, and processed in an arc shape, with no cracks on the edges
• Low-quality products:
During processing, the aluminum skin is separated from the core material, and there are many burrs on the edges, which require a lot of glue repair.
2. Long-term durability
• High-quality aluminum composite panels:
No fading or delamination after more than 10 years of outdoor use, with wind pressure resistance of more than 5000Pa.
• Low-quality aluminum composite panels:
After 2-3 years, the panel surface will bulge, the aluminum skin will peel off, and the core material will absorb water and expand, causing overall deformation
Case 1: High-quality panel curtain wall (10-year-old building)
- No obvious fading and deformation
- No cracks at the joints
Case 2: Low-quality panel canopy
- Powdering of the coating causes water seepage
- The core material absorbs water and expands, causing bulging
3. Purchase identification guide (illustration of key inspection points) Price and brand reference
Category High-quality aluminum composite panel Low-quality aluminum composite panel
Price $9-35/㎡ $3-8 yuan/㎡ (unknown brand)
Warranty Provide 10-year warranty and test report No formal warranty, refuse to provide report
Brand Alucobond, Alpolic, HUABOND. No brand or counterfeit OEM
Suggested purchase tips:
1. Thickness detection: Use a micrometer to measure the thickness of the aluminum layer Use a caliper to measure the thickness of the aluminum layer and compare whether the advertised parameters are consistent.
2. Combustion test: Take a sample of the core material and burn it to observe the smoke and provide SGS test report and fireproof certification (such as GB8624-2012 B1 grade)
3. Brand identification: such as Alucobond®, Alpolic®, HUABOND®
4. Priority selection: Products from the same batch to avoid color difference problems
Through the above comparison, it can be seen that high-quality aluminum composite panels are completely superior to inferior products in terms of durability, safety and appearance.
It is recommended to give priority to products from well-known brands and verify the quality through professional testing methods to avoid high removal, replacement and maintenance costs in the later stage due to low-price purchases.