The weld of the aluminum tube is unqualified

The aluminum tube produces layered shrinkage, which may be due to:

The extruded material is too short.

The extruded gasket has lubricant which needs to be removed.

The ingots inherently have layers or bubbles, and the quality of the ingots needs to be improved.

The weld of the aluminum tube is unqualified, which may be because there is oil or dust on the surface of the ingot that needs to be cleaned.

The extrusion temperature is too low.

The residual material is too short or the residual material is not cleaned up completely.

The mold design is unreasonable, the static pressure of the mold cavity is insufficient or uneven, and the mold needs to be redesigned.

Extrusion speed is too fast or uneven.