pvc plastic products will also have insufficient stability when the stabilizer is added in the same amount and formula system. The reasons are also divided into two categories:
1. Material factors,
2. Extrusion equipment factors, high-quality continuous production of plastic products cannot be done alone with a good material formula system and high-configuration extrusion equipment. The stability of the extrusion equipment, die runner, pressure and screw plasticizing capacity, shearing capacity, pressure are required, and at the same time it must be matched and adapted to its material formula system, interlocking and interacting with each other.
A simple summary of the main points of PVC plastic products processing is: under the condition of ensuring stability, plasticization balance, lubrication balance, and the addition of relative modifiers. However, the balance point is difficult to grasp and there are many influencing factors.
We focus on discussing the factors that lead to insufficient stability: the plasticizing factor of the main part of the extrusion machinery, the screw has too strong plasticizing capacity, and the plasticizing capacity is too strong, which will inevitably lead to excessive shearing force, and high-strength shearing force will form materials. Increased shear heat and frictional heat will accelerate the thermal decomposition of the resin.
1) It is the first choice to supplement the external slip agent with good release properties in the later stage.
2) Increasing the speed of the screw of the main engine shortens the residence time of the material in the barrel cavity.
3) Appropriately supplement the amount of stabilizer added while increasing the temperature of the die head to facilitate the smooth extrusion of the material.
4) Lower the extrusion temperature in the 1-3 zone of the barrel.