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Causes and preventive measures for shrinkage of industrial aluminum extrusion process
- 2019-10-08-

The tail shrinkage is a unique waste product in the extrusion process of industrial aluminum profiles . Specifically divided into hollow tail and ring tail. Hollow shrinkage is due to the oil on the extrusion gasket and the excessive residue of the extrusion material, resulting in a serious shortage of metal supply and other reasons to form a hollow funnel-shaped tail; the annular shrinkage is mainly due to the end of the aluminum extrusion process Insufficient supply of metal in the deformation zone forces the metal to traverse along the periphery of the extrusion gasket, causing the edges and side surfaces to be cold, and the oil-stained metal is reflowed and wound into the product. The annular tail is generally on the cross section of the end of the product, and is mostly in the shape of a continuous or discontinuous ring. Manufacturing industrial aluminum profiles According to the operation plan, select the mold that meets the plan, flat die: 460 ° C - 480 ° C B. Split mode: 480 ° C - 500 ° C. The residence time of the mold in the furnace is not more than 8 hours, the mold loading process should be fast and fast, and the mold should be prevented from cooling.

To properly use the extrusion gasket, protect the extrusion gasket from scratches. When the extrusion gasket wears too much and becomes rounded, the new gasket should be replaced in time when the cylinder is not clean. Every time you squeeze, you should pay special attention to whether the gasket has been placed properly to prevent equipment accidents caused by the extrusion gasket not being placed. During the extrusion process of industrial aluminum, attention should be paid to the change of hydraulic oil temperature: when the oil temperature rises to about 45-50 °C, the pressing force will drop greatly, and the pressing opportunity becomes weak. At this time, stop the machine and try to put the oil. The temperature drops and then it can be squeezed again. The tonnage (ton) of industrial aluminum extrusion press is 60010001650, and the number of ingots per die is 100-15060-8040-80. In order to prevent the gas and dirty flow in the dead zone from being squeezed into the aluminum profile and to prevent the extrusion rod from being damaged, the limit of the pressure limit is not allowed to be too thick, and the book is not allowed to be passed, and the pressure control is 15-30 mm thick. 6063 extruded aluminum profile T6 quenching is forced air cooling, T5 is naturally cooled, and the profile can not be cooled to below 170 °C at a speed of less than 80 °C / min. 6061 extruded profiles are quenched by strong wind, water mist or direct water cooling, and the temperature should be reduced to below 200 °C in 2-3 minutes.

The main measures to prevent tailing:

1) Reduce the temperature difference between the aluminum ingot and the tool, or use low temperature extrusion.

2) Ensure that the surface of the ingot is clean and heated evenly.

3) Do not apply oil on the extrusion pad or wipe the pad with a tarpaulin.

4) Improve the surface finish of the mold and the extrusion cylinder, and clean the extrusion cylinder in time.

5) Reduce the extrusion speed at the end of the extrusion process.

6) Lubrication extrusion and reverse extrusion.

7) Retain the residual material and cut the tail as required, or increase the thickness of the residual material as appropriate