Reasons why the surface of honeycomb aluminum foil cannot be bonded with the adhesive

Reasons why the surface of honeycomb aluminum foil cannot be bonded with the adhesive

Aluminum honeycomb panels have good performance in use. They have good strength and good impact resistance. They can be well designed in use. Therefore, they are widely used at present.

Aluminum honeycomb core materials only need to use aluminum foil to achieve different ways of bonding, and then form honeycombs of different specifications by stretching. The performance of the core material is directly related to the thickness of the aluminum foil and the size of the cells. The aluminum honeycomb core material can be compounded with the aluminum sheet skin material to form an aluminum honeycomb panel.

3004 honeycomb aluminum foil

In the manufacturing process of aluminum honeycomb cores, the quality requirements of aluminum foil are very high:

First, the aluminum foil needs to be 3003/3004/5052 and other products with high strength and durability, and avoid using 1100 pure aluminum foil to manufacture aluminum honeycomb cores.

Secondly, the surface of the aluminum foil needs to be degreased and passivated so that the adhesive can bond the adjacent aluminum foils well.

Common Problems

The adhesive cannot bond the aluminum foil on both sides, or the bonding of the aluminum foil does not achieve the desired effect.

Methods for judging aluminum foil quality problems

After the honeycomb aluminum foil has gone through the degreasing and passivation process, the surface of the aluminum foil will become rougher, but it is difficult to detect with the naked eye. We can use a dyne pen for testing

Dyne value test

The above is the dyne value of the aluminum foil we tested with a dyne pen. The value that the dyne pen can draw a complete line is the maximum dyne value of the aluminum foil surface;

The higher the value, the higher the surface adhesion and the better the bonding effect.

Cause Analysis

1. Oil stains on the surface of aluminum foil

During the rolling process of aluminum foil, rolling oil will remain on the surface of aluminum foil during the rolling process and has not been completely removed

2. Passivation process problems

Passivation process: The purpose of the passivation process is to make the surface of aluminum foil rough so that adhesive can be attached and provide a better focus point when stretching aluminum foil

Passivation process materials: silane, trivalent chromium, hexavalent chromium, etc.

Passivation process problems: Passivation liquid fails. Passivation liquid also has a certain service life. After a certain period of use, the concentration and effect of the passivation liquid will not be as good as before, resulting in ineffective passivation of the aluminum foil surface;

Aluminum honeycomb core

How to avoid the above problems

• 1. Use relatively clean industrial pure water to clean the rolling oil on the surface of aluminum foil to avoid impurities in the water that may cause incomplete cleaning;
• 2. Replace the passivation liquid regularly to ensure the passivation effect;