Extrusion of large caps caused by aluminum extrusion die issues

The main cap caused by extrusion mold is generally caused by uneven die surface leading to unclean shear, and the aluminum gradually adheres outward, the following are several reasons why extrusion mold may lead to extrusion big hat:

1. The end face of the extrusion die is uneven or has a defect, so that there is a gap on the locking surface, and the aluminum channel flows. The mold defect should be repaired in time, and the die surface must be milled.

2. If the external circle of the feeding cavity is too large (the die spacing is too short), the locking area of the die barrel will be small------ the distance between the external circle of the feeding cavity and the wall of the cylinder is normally left 10mm on one side, and the limit is not less than 5mm. When using such an extrusion die for production, the up, down, left, and right centers must be aligned to prevent the die spacing from deviating again.

3. The extrusion mold has no milling water port, the mold closure surface is too large, the pressure value per unit area is small--- less than the outlet pressure, and the die surface is not clean after running aluminum and gluing aluminum, resulting in uneven die surface. This kind of big hat is difficult to clean. Note that the cylinder surface should be properly oiled and no longer stick to the aluminum, the aluminum on the die surface can be sheared off many times, and the indentation of the cylinder on the die surface can be oiled, so that the die surface runs aluminum and does not stick to the mold, and is cut off. Even if there is an occasional flash, it is a success.

4. The size of the water port of the extrusion mold is smaller than the size of the cylinder working surface, and the closing area of the cylinder die is small, and it is also vulnerable to the cylinder working surface. Note that when the small machine mold is modified to a large machine, the diameter of the mold water port is the same as the diameter of the large cylinder working surface.

5. The thickness of the extrusion die is not enough, and the extrusion cylinder is stressed on the mold sleeve. The thickness of the mold and mold sleeve should conform to the principle of the first 3 and the last 1, that is, the mold diversion surface should protrude the die sleeve by 1mm. ------ die sleeve is never directly subjected to extrusion pressure, otherwise, the die sleeve is fragile and easy to deform.

6. The gap between the die sleeve and the mold is too large, and the aluminum adhesion in the gap leads to unclean shear and uneven die surface. This situation is generally common in molds modified from small machines.

7. The extrusion ratio is too high, the outlet resistance is greater than the extrusion force, the locking surface is uneven, and the aluminum flows out of the locking surface. In this case, most of the stuffy car phenomenon will occur, and the rod temperature, mold temperature, and cylinder temperature can be appropriately increased. If necessary, the mold cover or even the gasket can be heated before being put on the machine for production, and at the same time, the length of the rod can be appropriately shortened and the fixed size can be reduced. When the aluminum rod is too short, it can be stamped and produced without blindly increasing the rod temperature, and the rod temperature is also easy to cap, which also limits the increase in speed.