Aluminum composite panel performance test

1.The necessity of detection of aluminum plastic plate:

Aluminum-plastic composite panels are widely used in various architectural decorations and even in buses and subways due to their advantages of light material, good flatness, uniform color, convenient processing and installation and so on. However, nowadays the market is mixed with high-quality products and inferior products, it is inevitable that there will be some undesirable business men to fill with inferior goods. So, how do we choose qualified aluminum-plastic panels? This requires our aluminum-plastic panels to be tested and meet the relevant requirements. Only the aluminum-plastic panels that meet the requirements can be assured to buy.

2.The standard of detection

China Standard: GB/T 17748-2008 “Aluminum-plastic composite panel for building curtain wall”，GB/T 22412-2008 “Ordinary decorative aluminum-plastic composite board”
American Standard: AAMA, ASTM Standard
European Standards: EN, ISO, BS Standards, QUALICOAT Regulations
International Standard: SGS

3.How to test aluminium composite panel in domestic?

(1) Firstly, describe the test environment briefly

a.Before the test, the sample should be placed in the standard environment specified in GB/T 2918 for 24 hours. Except for special regulations, tests should also be conducted under these conditions.

b.Preparation of test pieces: When preparing the specimen, consideration should be given to the consistency of product decorative surface performance in vertical and horizontal directions.In addition to the performance of the decorative surface, the other requirements of the product on the vertical, horizontal ，front sides and back sides are also consistent.

c.The location of the specimen shall be within 50mm from the product side, and the size and quantity of the specimen shall be agreed upon by both parties

(2) Domestic testing methods take our company as an example

From our company’s test report, we can see that the main tests in China are: Appearance quality, sheet thickness, aluminum thickness, coating thickness, surface pencil hardness, coating gloss deviation, coating flexibility, coating adhesion, impact resistance, coating hydrochloric acid resistance, coating oil resistance, bending strength, peel strength. And each performance has corresponding requirements, as shown in the figure below:

After reading these pictures, you will find that the performance of Aluminobond aluminum-plastic composite board not only meets domestic requirements, most of the performance is much higher than the national standards, which is also one of the main reasons why Aluminobond aluminum plastic board has strong competitiveness both at home and abroad.

(3) Terms and definitions

a.wave

Non-decorative wavy lines or bumps on the product’s decorative surface.

b.spot

Partial defect of product decorative surface layer.

c.bubble

Partial bulge of aluminum or decorative surface.

d.Coating flexibility

The flexibility of the coating refers to the minimum number of wrappings when coating surface of the coated aluminum material facing outward and bent 180° around it and the coating is free from cracking or detachment.

(4) Requirements of relevant materials

a.Aluminum

Curtain wall panels shall use 3333 series, 5333 series or other series of aluminum alloys with better performance in corrosion resistance and better mechanical properties, whose material properties should meet the requirements of GB/T 3880.2.

b.coating

The coating material of curtain wall board is suitable to use fluorocarbon resin with excellent weatherability, or other material with comparable or better properties.

Note 1: The most widely used is polyvinylidene fluoride fluorocarbon resin (PVDF) with excellent weatherability. However, pure PVDF resin is not suitable for direct coating on aluminum materials, it is necessary to add some other materials as appropriate to change its coating performance, which constitutes what is commonly referred to as 70% fluorocarbon resin.

Note 2: 70% fluorocarbon resin refers to PVDF accounted for 70% of the resin raw materials among the production of aluminum plastic plate coating used in the paint of various raw materials. Because there are pigments and other components in the paint, and there is usually a layer of non-fluorocarbon resin primer under the fluorocarbon resin coating, the final content of PVDF in the aluminum-plastic composite coating is about 25% to 45%.

c. core materials

More than 80% of raw materials used for curtain wall core materials are inorganic materials.

(5) Testing method

a.The thickness of the aluminum

The aluminum material removed from the sample was used as a test piece. Measure the thickness of aluminum with a thickness measuring instrument with a minimum score of 0.001mm (not including coating thickness, etc.). Measurements should be made in enough places, but at least five parts including four corners and center should be measured on each test piece. Take the minimum and arithmetic mean of all measured values as the test result.

b.The thickness of the coating

Coating thickness refers to the total thickness of the coating. The thickness of coating should be made in enough places, but at least five parts including four corners and center should be measured on each test piece. Take the minimum and arithmetic mean of all measured values as the test result.

c.Surface pencil hardness

In accordance with the provisions of GB/T 6739, the surface of the specimen should be free of furrow and scratch after the test.

Take the minimum of all the measured values as the test results.

d.Coating gloss deviation

In accordance with GB/T 9754, the glossiness value shall be measured in sufficient places on the specimen, at least five parts including four corners and a center shall be measured on each specimen. During the test, the production direction of the specimen should be consistent.

The difference between the maximum value and the minimum value in all the measured values is used as the test result.

Here we will focus on the issue that everyone is very concerned about: peel strength. There are several factors that affect the peel strength of aluminum-plastic composite panels:

a.The quality of aluminum foil itself

b.Pre-treatment of aluminum plates

c.Selection of core material

d.Selection of polymer membrane

e. The peeling strength of aluminum-plastic plates has a lot to do with production equipment

f. co-extrusion process

4.Aluminum plastic board SGS test

SGS is a global leader in inspection, verification, testing and certification. It is a globally recognized benchmark for quality and integrity. SGS can perform a variety of physical, chemical and metallurgical analyses, including destructive and non-destructive tests.

(1) the following figure is the SGS report of our company:

(2) main project details and methods of using SGS to detect aluminum plastic sheet:

a.chemical resistance

Anti-chemical corrosion means to avoid the direct oxidation and reduction reaction between metal and the substance in contact and to be lost by oxidation. The test result and method are as follows:

b.Pencil Hardness

Pencil hardness is a test method and measurement system for calibrating the hardness of a coating film. According to industry standards, the hardness of pencil refills is divided into 13 levels. It goes from the hardest 6H down to 5H,4H,3H, 2H, H, and then it goes through the HB, which is soft and hard moderate, and then it goes from B,2B to 6B, which is the softest. The test result and method are as follows: