阅读说明：本技术 一种聚偏氟乙烯柔性复合高压管加工工艺 (Processing technology of polyvinylidene fluoride flexible composite high-pressure pipe ) 是由 高雄 于 2020-05-23 设计创作，主要内容包括：本发明公开了一种聚偏氟乙烯柔性复合高压管加工工艺,涉及柔性复合管技术领域。其技术要点是：包括以下步骤：步骤一,进料,将聚偏氟乙烯原料颗粒加入挤出机的进料斗中；步骤二,挤出,所述挤出机的速度为1-10m/min,螺杆转速50-100r/min,所述挤出机分为机筒加热段、过渡段、机头注模段,所述机筒加热段分为四段加热温度均为215-225℃,所述过渡段温度为220-230℃,所述机头注模段分为注模一、注模二、注模三、注模四、注模五温度分别为215-225℃、215-225℃、225-235℃、225-235℃、230-240℃。步骤三,成型,所述聚偏氟乙烯经过挤出机的机头注模段后通过口模挤出再进入真空定型机中冷却定型形成内层管；步骤四,缠绕增强层,步骤五,包覆层包覆。本发明具有提高柔性复合管的力学性能的优点。(The invention discloses a processing technology of a polyvinylidene fluoride flexible composite high-pressure pipe, and relates to the technical field of flexible composite pipes. The technical key points are as follows: the method comprises the following steps: feeding, namely adding polyvinylidene fluoride raw material particles into a feed hopper of an extruder; and step two, extruding, wherein the speed of the extruder is 1-10m/min, the screw rotation speed is 50-100r/min, the extruder is divided into a barrel heating section, a transition section and a machine head injection section, the heating temperature of the barrel heating section is 215-225 ℃ in four sections, the temperature of the transition section is 220-230 ℃, and the temperature of the machine head injection section is 215-225 ℃, 225-235 ℃ and 230-240 ℃ respectively. Step three, molding, namely extruding the polyvinylidene fluoride through a die after passing through a head injection section of an extruder, and then cooling and molding the polyvinylidene fluoride in a vacuum molding machine to form an inner-layer pipe; and step four, winding the enhancement layer, and step five, coating by a coating layer. The invention has the advantage of improving the mechanical property of the flexible composite pipe.)

1. A processing technology of a polyvinylidene fluoride flexible composite high-pressure pipe is characterized by comprising the following steps:

feeding, namely adding polyvinylidene fluoride raw material particles into a feed hopper of an extruder;

step two, extruding, wherein the speed of the extruder is 1-10m/min, the screw rotation speed is 50-100r/min, the extruder is divided into a barrel heating section, a transition section and a machine head injection section, the heating temperature of the barrel heating section is 215-225 ℃ in four sections, the temperature of the transition section is 220-230 ℃, the temperature of the machine head injection section is 215-225 ℃ in one injection mold, 215-225 ℃ in two injection molds, 225-235 ℃ in four injection molds and 230-240 ℃ in five injection molds;

step three, molding, namely extruding the polyvinylidene fluoride through a die after passing through a head injection section of an extruder, and then cooling and molding the polyvinylidene fluoride in a vacuum molding machine to form an inner-layer pipe;

winding a reinforcing layer, namely winding 2-8 layers of industrial polyester filaments on the outer side of the inner-layer tube in a crossed manner, wherein the number of the industrial filaments in each layer is 50-78, and the specification of the industrial polyester filaments is 17000-19800D;

and step five, coating the coating layer, namely adding the raw material of the coating layer into a hopper of a plastic coating machine, passing the raw material through an extruder of the plastic coating machine, enabling an inner layer pipe wound with the enhancement layer to pass through a mold of the plastic coating machine, melting the raw material by the plastic coating machine, then coating the raw material on the outer side of the enhancement layer to form an outer layer pipe, wherein the temperature of the extruder of the plastic coating machine is 180-210 ℃.

2. The processing technology of the polyvinylidene fluoride flexible composite high-pressure pipe as claimed in claim 1, wherein in the second step, the temperature of the heating section of the machine barrel is 219-221 ℃.

3. The processing technology of the polyvinylidene fluoride flexible composite high-pressure pipe as claimed in claim 2, wherein the temperature of the transition section is 224-226 ℃.

4. The processing technology of polyvinylidene fluoride flexible composite high-pressure pipe as claimed in claim 3, wherein the injection molding temperature is 219-.

5. The polyvinylidene fluoride flexible composite high-pressure pipe processing process according to claim 1, wherein in the second step, the speed of the extruder is 2-3 m/min.

6. The polyvinylidene fluoride flexible composite high-pressure pipe processing technology according to claim 5, wherein the screw rotation speed is 62-67 r/min.

7. The processing technology of the polyvinylidene fluoride flexible composite high-pressure pipe according to claim 1, wherein in the fourth step, 4 layers of industrial polyester filaments are wound on the outer side of the inner-layer pipe, and the number of each layer of industrial filaments is 75-78.

8. The processing technology of the polyvinylidene fluoride flexible composite high-pressure pipe as claimed in claim 7, wherein in the fourth step, the specification of the terylene industrial filament is 19500-.

Technical Field

The invention relates to the technical field of flexible composite pipes, in particular to a processing technology of a polyvinylidene fluoride flexible composite high-pressure pipe.

Background

With the rapid development of industries such as petroleum and natural gas, coal, water conservancy and the like, more and more conveying pipelines are applied to various pipeline fields such as petroleum and the like which need to convey substances at higher pressure. Most of the materials passing through the conveying pipeline have certain corrosiveness, so that the original metal pipeline is always subjected to severe corrosion. In order to alleviate the corrosion problem of the pipeline, most of the existing conveying pipelines are flexible composite pipes.

Flexible composite pipes generally comprise an inner liner, an intermediate reinforcement layer, and a coating layer. The inner liner is as the direct part with the contact of transportation medium of flexible composite pipe, and polyvinylidene fluoride is as a semi-crystalline high polymer, and by wide application as the inner liner in accessories such as the pipeline of petrochemical equipment, when interior heavy layer adopted single polyvinylidene fluoride material shaping, because polyvinylidene fluoride's uniqueness, if adopt ordinary forming process can reduce the performance of final flexible composite high-pressure pipe.

Disclosure of Invention

Aiming at the defects in the prior art, the first purpose of the invention is to provide a polyvinylidene fluoride flexible composite high-pressure pipe processing technology which can improve the mechanical property of a flexible composite pipe.

In order to achieve the purpose, the invention provides the following technical scheme:

a processing technology of a polyvinylidene fluoride flexible composite high-pressure pipe comprises the following steps:

feeding, namely adding polyvinylidene fluoride raw material particles into a feed hopper of an extruder;

and step two, extruding, wherein the speed of the extruder is 1-10m/min, the screw rotation speed is 50-100r/min, the extruder is divided into a barrel heating section, a transition section and a machine head injection section, the heating temperature of the barrel heating section is 215-225 ℃ in four sections, the temperature of the transition section is 220-230 ℃, and the temperature of the machine head injection section is 215-225 ℃, 225-235 ℃ and 230-240 ℃ respectively.

Step three, molding, namely extruding the polyvinylidene fluoride through a die after passing through a head injection section of an extruder, and then cooling and molding the polyvinylidene fluoride in a vacuum molding machine to form an inner-layer pipe;

winding a reinforcing layer, namely winding 2-8 layers of industrial polyester filaments on the outer side of the inner-layer tube in a crossed manner, wherein the number of the industrial filaments in each layer is 50-78, and the specification of the industrial polyester filaments is 17000-19800D;

and step five, coating the coating layer, namely adding the raw material of the coating layer into a hopper of a plastic coating machine, passing the raw material through an extruder of the plastic coating machine, enabling an inner layer pipe wound with the enhancement layer to pass through a mold of the plastic coating machine, melting the raw material by the plastic coating machine, then coating the raw material on the outer side of the enhancement layer to form an outer layer pipe, wherein the temperature of the extruder of the plastic coating machine is 180-210 ℃.

By adopting the technical scheme, the plasticity of the polyvinylidene fluoride can be influenced to a great extent by the temperature of the polyvinylidene fluoride in the process of heating and melting the polyvinylidene fluoride to extrusion molding and the temperature of the polyvinylidene fluoride in different periods in the whole extrusion process, when the temperature is too high, the plasticity of the polyvinylidene fluoride can be damaged, and when the temperature is not enough, the plasticity of the polyvinylidene fluoride is difficult to fully exert. Therefore, through increasing more heating electricity, multipoint dispersion heating is carried out, the temperature is controlled at multiple points, the temperature of the polyvinylidene fluoride at different positions in different periods is regulated, and the temperature difference in the same heating point control range is reduced within the heating range of each heating point in multiple sections. Meanwhile, temperature regulation and control are carried out according to different states and shapes of polyvinylidene fluoride at different positions, polyvinylidene fluoride is heated in a heating section of a machine barrel only to change granular solid state of the polyvinylidene fluoride into molten flowable state, the originally molten flowable polyvinylidene fluoride is injected into a die of a die head injection molding section through a transition section, the polyvinylidene fluoride is still in the molten state, but the polyvinylidene fluoride is changed into a specific shape from an original group, the filtering section has a special transition effect and the die head injection molding section is formed, the states of the polyvinylidene fluoride in the whole process are different, and different temperatures are required to be set respectively to enable the effects of the polyvinylidene fluoride to be fully exerted. The temperature of the machine head injection molding section is gradually increased from the transition section to the outlet end of the extruder, so that the plasticity of the polyvinylidene fluoride is further improved, and the mechanical property of the final product is improved. By winding the reinforcing layer, the final product meets the required pressure resistance requirement.

More preferably, in the second step, the temperature of the barrel heating section is 219-.

By adopting the technical scheme, the temperature of the heating section of the machine barrel is optimized, the plasticity of the polyvinylidene fluoride can be obviously improved, particularly, the ring stiffness of the inner-layer pipe is obviously improved, the capacity of resisting external load of a final product is improved, the deformation of the final product after external pressure is reduced, and the stable property of the final product in the using process is stabilized.

More preferably, the temperature of the transition section is 224-226 ℃.

By adopting the technical scheme, the temperature of the transition section is optimized, and the longitudinal retraction rate of the inner-layer pipe can be obviously reduced, so that the shrinkage deformation of the final product in the using process is reduced, and the property of the final product is stabilized.

Further preferably, the injection molding I, the injection molding II, the injection molding III, the injection molding IV and the injection molding V are respectively at the temperatures of 219-.

By adopting the technical scheme, the temperature of the injection molding section of the machine head is optimized, the roughness of the inner wall of the inner pipe can be obviously reduced, the friction force between the pipe and the transported fluid is reduced, the transportation efficiency is improved, the abrasion of the inner pipe is reduced, the service life of the inner pipe is prolonged, the residue of the transported fluid on the inner wall of the inner pipe is reduced, the smoothness of the fluid flowing is improved, the pressure of the fluid on the inner pipe is reduced, the pressure born by the inner pipe is reduced, and the service life of the inner pipe is prolonged.

More preferably, in the second step 5, the speed of the extruder is 2 to 3 m/min.

By adopting the technical scheme, the speed of the extruder is optimized, and the longitudinal retraction rate of the inner-layer pipe can be obviously reduced, so that the shrinkage deformation of the final product in the using process is reduced, and the property stability of the final product is stabilized.

More preferably, the rotating speed of the screw of 6 is 62-67 r/min.

By adopting the technical scheme, the ring stiffness of the inner-layer pipe can be improved by optimizing the rotating speed of the screw, the capacity of resisting external load of a final product is improved, the deformation of the final product after external pressure is reduced, and the stability of the property of the final product in the using process is stabilized.

More preferably, in the fourth step, 4 layers of industrial polyester filaments are wound on the outer side of the inner-layer tube, and the number of the industrial filaments in each layer is 75-78.

By adopting the technical scheme, under the condition that the specifications of the industrial polyester filaments are consistent, the pressure resistance of the final product is obviously improved by four layers of 75-80 industrial polyester filaments in each layer, and if the number of layers and the number of filaments in each layer are continuously increased, the pressure resistance of the final product is extremely small in change.

More preferably, in the fourth step, the specification of the industrial polyester filament is 19500-19800D.

By adopting the technical scheme, the weight of 9000 meters of the industrial polyester filaments is preferably selected, so that the deformation resistance of 75-80 polyester filaments after crossing together is enhanced, and the pressure resistance of the final product is further improved.

In summary, compared with the prior art, the invention has the following beneficial effects:

(1) temperature regulation and control are carried out according to different states and shapes of polyvinylidene fluoride at different positions, so that the polyvinylidene fluoride exerts the best plasticity, the plasticity of the inner-layer pipe is improved, and the mechanical property of a final product is improved;

(2) the temperature of the heating section of the machine barrel and the rotating speed of the screw of the extruder are optimized to jointly improve the ring rigidity of the inner-layer pipe;

(3) the temperature of the injection molding section of the machine head is optimized, so that the roughness of the inner wall of the inner-layer pipe is obviously reduced, and the performance of the inner-layer pipe is improved;

(4) the specification and the number of the industrial polyester filaments are optimized, and the pressure resistance of the final product is improved.

Detailed Description

The present invention will be described in detail with reference to examples.