What are the causes of errors in PET Self Wrap Braided Sleeve?

The factors causing errors in PET Self wrap braided sleeve include subjective factors and objective factors. But the main factor is subjective. Let`s take a look at the influence of three major factors: machine head temperature, melting point and fluidity of extruded materials, different screw speeds and traction speeds:

1. Due to the influence of machine head temperature. Under the same extrusion conditions, if the machine head temperature is too low, the inner diameter of the extruded silicone casing becomes larger, and the wall thickness of the Open Type Braided Sleeve becomes thinner; when the extrusion temperature is higher, the inner diameter of the Open Type Braided Sleeve becomes smaller. becomes smaller, the wall thickness of the Open Type Braided Sleeve becomes thicker.
2. Due to the influence of the melting point and fluidity of the extruded material. The flow properties of materials are closely related to temperature. As the temperature increases, the apparent viscosity of materials decreases and the flow properties are good. When the temperature of the machine head decreases, the apparent viscosity of the material is higher and the flow performance is poor. Forced extrusion increases the pressure on the machine head and the tube embryo that leaves the mold undergoes elastic recovery due to the relief of stress, and its expansion level is also the same as the one it was previously subjected to. Directly proportional to pressure.
At the same time, the poor fluidity of the material causes less material extrusion, causing the inner diameter of the Open Type Braided Sleeve to become larger and the wall thickness to become thinner. As the temperature gradually increases, the flow performance of the extruded material in the die is improved, the pressure of the die is reduced, the elastic recovery amount of the die-leaving tube blank is correspondingly reduced due to stress, and the extrusion inner diameter is reduced; on the other hand, , the amount of material extruded increases with the improvement of flow properties, making the wall of the Open Type Braided Sleeve thicker.
3. The influence of different screw speeds and traction speeds. At the same temperature, the diameter and wall thickness of the extruded silicone casing have a great relationship with the screw speed and traction speed. As the extrusion speed increases, the inner diameter of the silicone casing will become larger and the pipe wall will become thinner, the lower the machine head temperature, the more obvious this change will be. This is mainly because as the extrusion speed increases, although the viscosity of the material decreases with the increase of shear stress (shear strength), due to the high processing pressure of silicone melt, as the extrusion pressure increases, its viscosity also decreases. improved.