What are the reasons that affect the tolerance of Automotive Wiring Harness Protection Sleeve?

Any product has a tolerance when it is produced. This tolerance is related to many factors. Nothing can be said to be exactly the same. As long as it is an item, as long as it is produced, there must be a tolerance. Similarly, the following is a brief introduction to some of the main reasons that affect the tolerance of Automotive Wiring Harness Protection Sleeve.

1. The influence of the head temperature
Under the same extrusion conditions, if the temperature of the machine head is too low, the inner diameter of the extruded Automotive Wiring Harness Protection Sleeve will become larger, and the wall thickness of the Braided Sleeve will become thinner; but when the extrusion temperature is higher, the Automotive Wiring Harness Protection Sleeve The inner diameter of the sleeve will become smaller, otherwise the wall thickness of the Braided Sleeve will become thicker.
Second, the influence of screw speed and traction speed
At the same temperature, the diameter and wall thickness of the extruded Automotive Wiring Harness Protection Sleeve have a great relationship with the screw speed and pulling speed. As the extrusion speed increases, the inner diameter of the Automotive Wiring Harness Protection Sleeve will become larger and the tube wall will become thinner. This change will be more obvious when the temperature of the die is lower. This is mainly because as the extrusion speed increases, although the viscosity of the material decreases with the increase of the shear stress, due to the high processing pressure of the Cable Sleeve melt, the viscosity also increases with the increase of the extrusion pressure, at this time the fluidity of the material depends largely on the external heating temperature.
3. The influence of melting point and fluidity
The flow properties of materials are closely related to temperature:
① When the temperature of the machine head decreases, the surface viscosity of the material increases and the fluidity becomes poor. Forced extrusion increases the pressure of the machine head, and the released tube embryo will produce elastic recovery due to the release of stress, and its expansion degree is also the same as The previous pressure is directly proportional, and at the same time, the fluidity of the material becomes poor so that the material is extruded less, resulting in a larger inner diameter of the Braided Sleeve and a thinner wall thickness.
② When the temperature of the machine head rises, the surface viscosity of the material decreases and the fluidity is better. The flow performance of the extruded material in the machine head is improved, the pressure of the machine head is reduced accordingly, and the elastic recovery of the molded tube is also reduced due to the stress, the inner diameter of the extrusion is reduced, and then the extrusion volume of the material increases with the improvement of the flow performance. Increase to thicken the Braided Sleeve wall.