The brittleness of aluminum profiles has always been a factor that has troubled the normal operation of some profile companies. The brittleness of profiles has affected the market share and user reputation of these profile companies more or less in terms of cross-sectional appearance and the degree of approval of door and window assembly plants.

The brittleness of aluminum profiles is basically fully reflected in the physical and mechanical properties of the products. Its main features are: collapsing and cold punching when cutting. There are many reasons for the poor physical and mechanical properties of profile products, which are mainly manifested as the following:

1. The formula and mixing process are unreasonable

1. Too much filler

2. Type and quantity of impact modifier added

3. Too much or too little stabilizer

4. Too much external lubricant

5. The order of hot mix addition, temperature setting and curing time also have decisive factors for the performance of the profile

Second, the extrusion process is unreasonable

1. Excessive or insufficient plasticization of materials

2. Insufficient head pressure

3. The low molecular components in the product are not discharged

4. The screw torque is too low

5. The traction speed does not match the extrusion speed

3. Unreasonable mold design

1. The section design of the die is unreasonable, especially the distribution of internal ribs and the treatment of the angle of the interface. This will cause the existence of stress concentration, which needs to improve the design and eliminate the right angle and acute angle at the interface.

2. Insufficient die pressure. The pressure at the die head is directly determined by the compression ratio of the die, especially the length of the straight section of the die. If the compression ratio of the die is too small or the straight section is too short, the product will not be dense and affect the physical properties. On the one hand, the change of die head pressure can be adjusted by changing the length of the straight section of the die head

On the other hand, in the die design stage, different compression ratios can be selected to change the extrusion pressure, but it must be noted that the head compression ratio should be compatible with the compression ratio of the extruder screw; the extrusion process parameters can also be adjusted by changing the formula , Increase the perforated plate to change the size of the melt pressure.

3. For the performance degradation caused by poor shunt rib confluence, the length of the rib and the outer surface, the length of the rib and rib confluence, or the compression ratio should be increased to solve.

4. The die output is not uniform, resulting in inconsistent wall thickness or inconsistent density. This also caused a difference in the mechanical properties between the two sides of the profile. In the experiment, we sometimes passed the cold punching side and failed, which just proved this point. As for non-standard profiles such as thin walls, I won't say more here.

5. The cooling rate of the mold. The temperature of the cooling water often does not attract enough attention. The function of the cooling water is to cool and set the macromolecular chain stretched in time to achieve the purpose of use.