Main reasons:
1) When the homogenization treatment on the surface of the ingot is not effective, there are a certain number of hard metal particles in the ingot. When the metal flows through the work belt during the extrusion process, these floating objects or hard metal particles adhere to cause damages to or on the surface of the work belt, and ultimately scratches on the surface of the profile;
Solutions:
3) Use soft felt to isolate the profile from the auxiliary tools to minimize contact damage between the profiles and auxiliary tools;
4) Handle with care during production and try to avoid dragging or flipping profiles at will;
5) Place the profiles reasonably in the material frame and try to avoid friction with each other.
Main reasons:
Due to unreasonable mold design or manufacturing errors, improper extrusion process, misalignment of the mold and extrusion barrel, unreasonable lubrication, etc., the flow velocity correlation at each point in the metal flow is too large, resulting in internal stress and deformation of the profile.
Solutions:
2) Carry out the extrusion process correctly and set the extrusion temperature and extrusion speed reasonably;
3) Ensure the neutrality of the equipment;
4) Use moderate traction force and strictly control the amount of stretching and straightening of the profile.