What are the reasons for the brittle extrusion of PVC pipes

 What are the reasons for the brittle extrusion of PVC pipes in terms of raw                                  material formula? What are the solutions?

                                       (pvc pipe production line )

What are the reasons for the brittle extrusion of PVC pipes in terms of raw material formula?

① Too much filler;

② The type and amount of impact modifier selected. Generally, the impact strength of ACR is about 30% higher than that of CPE. When modified with CPE, when the amount is less than 8 parts by mass, the pipe will often become brittle;

③ Too much or too little stabilizer. When the amount of stabilizer is too much, it will delay the plasticization time of the material, so that the material is not yet plasticized when it exits the mold. The molecules in the formula system cannot be completely fused, and the intermolecular structure is not strong. When the dosage is too small, it will cause the relatively low molecular weight substances in the formula system to degrade or decompose, causing damage to the stability of the intermolecular structure of each component. Using too much or too little stabilizer can easily cause the strength of the pipe to decrease and make the pipe brittle;

④Excessive dosage of external lubricant. The external lubricant has poor compatibility with the resin, resulting in poor compactness and poor plasticization of the pipe, resulting in poor impact performance and making the pipe brittle.

The main solutions as following :

① Reduce the amount of filler. Ultra-fine lightweight activated calcium carbonate or even nanoscale calcium carbonate is often used, which not only increases rigidity and filling, but also has a modifying effect. The general dosage is controlled at 20 to 50 parts by mass. Try to use as little heavy calcium carbonate as possible. Since the particle shape of heavy calcium carbonate itself is irregular and the particle size is relatively coarse, it has poor compatibility with the PVC resin body. Adding a large amount will have adverse effects on the color appearance and performance of the pipe. ;

② Use an appropriate amount of impact modifier, and try to use a variety of impact modifiers in combination to improve the effect of impact modification;

③ Use a reasonable stabilizing system and try to use composite heat stabilizers to improve the heat stabilization effect and reduce the amount of heat stabilizer;

④Choose appropriate external lubricant and minimize the amount of lubricant used