When producing medium-sized profiles and encountering bending issues, how can one determine if it is caused by uneven material discharge from the die head?

When producing medium-sized profiles and encountering bending issues, how can one determine if it is caused by uneven material discharge from the die head?

Uneven material discharge from the die is one of the common causes of profile bending. Generally, under the condition that the profile is cooled sufficiently in the forming system and the traction resistance is balanced, uneven material discharge from the die will cause the profile to bend towards the side with slower discharge. The determination of the uniformity of material discharge from the die mainly relies on two indicators: "difference in discharge speed" and "difference in profile wall thickness". 
① "Determination of difference in discharge speed": After the profile is extruded normally, use a special chisel to quickly cut 4-5 pieces of well-plasticized profiles about 20mm long at the die outlet for measurement. If the length error of each side of the profile (taking the average value of each piece) does not exceed 10%, it is considered that the discharge speed uniformity of the profile is in line with the requirements; otherwise, the discharge speed of the die needs to be adjusted; 

② "Determination of difference in profile wall thickness": Continue to analyze and measure the above several slices. If the thicknesses of the outer wall, inner ribs, etc. (due to the effect of mold ejection expansion, this thickness is not equivalent to the mold lip gap) correspond to the proportion relationship and the proportion relationship of the thicknesses of each part of the outer wall, inner ribs, etc. on the product cross-section diagram are basically consistent - the error does not exceed 10%, it is considered that the extruded profile thickness error meets the requirements; otherwise, the difference in profile wall thickness needs to be adjusted.