Causes and prevention measures for tail shrinkage in the extrusion process of aluminum profiles

The reason for the formation of the compression tail core
Tail shrinkage is a unique waste product in the extrusion production process of aluminum alloy profiles. Specifically, it is divided into hollow tail reduction and annular tail reduction. Hollow tail shrinkage is due to the formation of hollow funnel tail reduction due to the oil stain on the extrusion gasket and the fact that too little extrusion residue is left, resulting in a serious shortage of metal supply; The annular tail shrinkage is mainly due to the insufficient supply of metal in the deformation area at the end of the extrusion process of the aluminum profile, which forces the metal to flow transversely along the periphery of the extrusion gasket, and the colder and oil-stained metal at the edge and side surface are refluxed and involved in the product. Annular tail shrinkage is generally in the cross-section of the tail end of the product, mostly in the shape of a continuous or discontinuous ring.

The solution of extrusion and compressing the tail wrap
Key measures to prevent tail shrinkage:
1) Reduce the temperature difference between the aluminum ingot and the tool temperature, or use low-temperature extrusion.
2) Ensure that the surface of the ingot is clean and heated evenly.
3) It is forbidden to apply oil on the extrusion gasket or wipe the extrusion pad with an oilcloth.
4) Improve the surface finish of the mold and the extrusion cylinder, and clean the extrusion cylinder in time.
5) Reduce the extrusion speed towards the end of the extrusion process.
6) Lubrication extrusion and reverse extrusion are adopted.
7) Leave the residual material and cut the tail according to the regulations, or increase the thickness of the residual material appropriately.