Production principle and theory of the pvc-o pipe:

1, the tensile orientation mechanism of polymer materials

The tensile orientation process of polymer materials is the process of the molecules from disordered arrangement to ordered arrangement under the action of external forces under the temperature condition between the glass transition temperature and the melting temperature (generally near the softening point). Due to the orderly arrangement of the polymer molecular chain, the material changes from isotropy to anisotropy; that is, the strength of the material along the molecular orientation direction is greatly increased, and the strength perpendicular to the tensile direction is greatly reduced, that is, the strength perpendicular to the tensile direction is superimposed on the strength along the molecular orientation direction through the tensile orientation of the material. Biaxial tensile is the material through biaxial tensile, the strength perpendicular to the biaxial tensile surface superimposed on the strength of the tensile surface direction, thereby increasing the strength of the material in the direction of the tensile surface. The tensile orientation plan of polymer materials must be carried out between the glass transition temperature and the melting temperature; if it is lower than the glass transition temperature, the molecular chain is in a frozen state, and the stretching under this temperature condition will only cause the material to be damaged by forced stretching. If the temperature is higher than the melting temperature, the molecular chain can move freely, and the stretched molecular chain cannot realize the orientation effect. Only between the glass transition temperature and the melting temperature, preferably near the softening point of the material, can the most effective molecular orientation be achieved and maintained.

2. Ratio and drawing rate

Stretch orientation, in popular terms, is to straighten the curly molecular chain and arrange it in the direction of the stretch. When the tensile ratio is properly increased, the degree of molecular orientation is increased, and the strength of the material is also increased. However, excessive increases in the tensile ratio will lead to the destruction of the material; in popular terms, that is, the molecular chain of the material is broken, and the material is damaged. In addition, if the stretching temperature is too high and the stretching rate is too low, the molecular chain will relax during the stretching process; that is, the molecular chain has enough time and ability to return to the original curly state during the stretching process so that the degree of orientation is reduced. Therefore, in order to obtain an ideal degree of orientation, a reasonable tensile temperature, and a faster tensile rate should be formulated, and the temperature of the material after stretching should be reduced to below the glass transition temperature in time.

3. Biaxial stretching of PVC-U pipe

PVC is an amorphous plastic because the chlorine in the molecule has a large polarity, it is rigid, the glass transition temperature is high, and there is no clear melting point. Compared with other crystalline polyolefin pipes, this kind of pipe is more suitable for biaxial tensile orientation. PVC pipe is easy to use uniaxial tensile orientation during the molding process. PVC pipe is easy to carry out uniaxial tensile orientation in the molding process, that is, axial tensile orientation, as long as the speed ratio of pipe traction and extrusion can be increased to achieve this orientation. However, this axial tensile orientation is meaningless for the performance of the pipe because although it increases the strength of the pipe orientation through the tensile orientation, it reduces the radial (that is, annular) strength of the pipe, which is very harmful to plastic pipes, especially water supply pipes, because it will greatly reduce the hydraulic blasting strength of the pipe. This is also the reason why the quality standard of the pipe should stipulate that the longitudinal shrinkage rate of the pipe must be less than or equal to 5%. The ideal tensile orientation should be bidirectional, that is, biaxial tensile orientation, through which both the axial strength of the pipe and the radial (that is, circumferential) strength of the pipe are increased. In other words, the overall performance of the pipe is improved through the biaxial tensile orientation. On the basis of greatly increasing the strength of the pipe material and the original hydraulic blasting strength of the pipe, the method of reducing the wall thickness saves raw materials and reduces the cost of the product.

Product performance:

1, PVC-O pipe with excellent impact resistance

2, ultra-high strength: the wall thickness of the pipe is only half of that of the ordinary PVC-U pipe, but the strength reaches 4 times.

3, with excellent flexibility

In the direction of pipe diameter, it can withstand deformation up to 100% of the pipe diameter. When the pipe is extruded, the pipe can be quickly restored to its original shape, thus minimizing the risk of damage caused by sand extrusion or mechanical impact during construction. At the same time, the excellent toughness of the pipe makes it extremely suitable for the laying of S-shaped pipelines.

4, with good resistance to low-temperature brittleness

Even in a cold environment of -25 ° C, its ability to absorb shock has not significantly changed, thus expanding the use area of the pipe and extending the window of pipeline construction.

5, with excellent cracking resistance.

The pipe is not sensitive to the notch, and the mesh pipe wall structure can effectively prevent the extension of cracks and scratches, and the damage point caused by the outside world will not expand. The phenomenon of fast cracking and slow cracking of the pipeline is eliminated, which greatly ensures the safety of the pipe network and prolongs the service life of the product.

6, with excellent water hammer resistance

The wave speed of the pipe is much lower than that of the traditional pipe, which is four times lower than that of the cast iron pipe, which means that the water hammer formed by the change of water pressure and water quantity is reduced, thus reducing or even eliminating the possibility of tube explosion when opening and closing the water network; At the same time, when the water network is running, it also protects the various components of the water network.

7, with convenient connectivity

The pipe adopts flexible connection, which is not only simple and fast for construction and installation, but also ensures that the joint will not shift after the installation of the pipeline, and the pipeline has good water tightness, less leakage, and the precious water resources are effectively transported.

8, with environmental protection and energy-saving

The pipe wall is only half of the traditional plastic pipe, and the inner diameter and water transmission section area are increased. At the same time, the excellent production equipment and technology of Taiji Blue tube make its inner wall much smoother than the metal pipe, which not only reduces the loss of water head but also makes the sediment in the pipeline is difficult to adhere to the inner wall. This means that the Taiji blue tube with the same outer diameter can increase the water flow rate by 15-40% compared with the traditional pipe.