The size of polymer and the width of molecular have a great influence. It can affect the stress, strength, gloss and shrinkage.

The raw material of PVC must be pure. Because the foreign matter not only cause quality defect, but also affects the appearance. While it cause even cause downtime.

The raw materials of PVC hose should be dry to reduce the content of moisture. Especially the materials that are easy to absorb moisture. Besides dry, you should prevent it from absorb wet in the use. Because that can affect the clear. Besides, it can cause stripe and other problem.

The particle size of the raw material is uniform. Then screen the powder in the raw material. While this is to prevent uneven heat and reduce the gloss of the PVC tube.

Be careful when change material. The the same resin and additives may be different due to  areas and batch numbers. Thus when change it, it is necessary to test and solve problems in time.

Strictly control the amount of recycled materials added. The higher the proportion of recycled materials mixed, the greater the impact on the quality of flexible PVC pipe. Besides, the times that use that will also cause bad effect.