Why does the profile break off when pulled apart in the forming die? How should it be solved?

Why does the profile break off when pulled apart in the forming die? How should it be solved?

The main reasons for the fracture of profiles in the forming die include:
①The mismatch between the traction speed and the extrusion speed leads to poor tensile strength. When the traction speed is too fast, the profile in the first section of the dry forming die may not have fully hardened yet, resulting in poor tensile strength and being easily broken. When the traction speed is too slow, the profile坯extruded from the die head is prone to accumulate at the inlet end face of the forming die, causing mold sticking, and the profile is more likely to be broken；
②The cooling performance of the forming die is poor. When the cooling capacity of the forming die cooling system is insufficient, the profile坯 entering the forming die cannot be cooled in time and cannot be rapidly hardened, thus being more likely to be elongated or even broken. When the cooling of the forming die is uneven, the parts of the profile that have not been cooled in time on the surface of the forming die are prone to be torn, and the friction resistance increases, making the profile more likely to be broken；
③The discharge of the die hole is uneven. Due to the failure to achieve uniform extrusion, the traction force on the entire profile is not uniform. The traction force mainly concentrates at the slow-discharging parts, making the profile more likely to be broken；
④The formulation is unreasonable. For example, if the content of fillers such as calcium carbonate is too high, or if the impact modifier is applied improperly, the material will have poor toughness and become brittle, which also makes the profile more likely to be broken；
⑤The extrusion temperature is too low, and the material is poorly plasticized, which can also cause the profile to be broken. The solutions mainly include：
①Adjust the traction speed and extrusion speed to be appropriate, generally requiring the traction speed to be slightly higher than the extrusion speed to ensure the appropriate tensile force on the profile；
②Strengthen the cooling performance of the forming die cooling system to ensure uniform cooling；
③Clean the die hole to ensure uniform discharge；
④ Adjust the formulation and add appropriate impact modifiers to improve the impact toughness of the material and control the appropriate filler dosage.
Top
Inquiry
Inquiry