How to analyze the quality problems in the extrusion molding production of polypropylene strapping?

How to analyze the quality problems in the extrusion molding production of polypropylene strapping by the packaging steel belt manufacturer?
　　 (1) The width dimension error of the strip blank before stretching is large
　　①The water temperature and liquid level in the cooling water tank fluctuate.
　　②The working speed of the screw is unstable, which makes the melt volume of the extrusion molding die unstable. Unstable screw rotation speed may be affected by the slippage of the transmission belt.
　　③ Excessive impurities at the filter screen block the uneven extrusion volume of the melt.
　　 (2) The width dimension error of the packing tape after stretching is large
　　①The temperature of the water in the stretching tank fluctuates greatly.
　　②The rotation speed of the front and back stretching traction rollers is unstable or the rotation speed of a group of traction rollers is unstable.
　　③The pressure of the pulling and stretching roller on the belt is insufficient, which causes the belt to slip on the surface of the roller.
　　 (3) The finished package has cracks
　　① The filter screen is broken or the number of filter screens is too small.
　　②There are coke particles of decomposing material in the molding die.
　　③The working surface of the driving roller is not clean or smooth.
　　 (4) The finished packing belt has large curvature
　　①The installation position of each working drive shaft on the production line is incorrect, and the center line between the rollers is not parallel or horizontal.
　　②The unbalanced pressure of the traction and stretching rollers on the belt (refers to the uneven lateral pressure of the upper roller to the lower roller in a group of traction and stretching rollers).
　　③The belt does not run in a straight line when running in the auxiliary machine, and the running direction oscillates left and right.
　　（5）The finished pattern of packing belt is not clear
　　①There is foreign matter or residual material on the surface of the embossing roller.
　　②The horizontal (width) pressure of the upper and lower pattern rollers on the belt is uneven.
　　③The center line of the upper and lower pattern rollers is not on a vertical plane when embossing.
　　④The temperature of the belt body is inconsistent at the embossing place.