New PFA lining production process application and processing equipment

Abstract

The invention discloses a novel PFA lining production process application and processing equipment, which belongs to the technical field of electromagnetic flowmeter lining processing, and specifically comprises the following steps: step 1, before injection molding, PFA raw materials need to be placed in a drying box for drying, so as to remove moisture and volatiles in PFA; step 2, the dried PFA raw materials are added into the barrel of an injection molding machine, a heating device on the barrel is started to heat the PFA raw materials in the barrel, and then a screw is started to rotate in the barrel to convey the PFA raw materials forward, and the plasticization process of the PFA raw materials is completed under the cooperation of the screw and the barrel; step 3, the molten PFA raw materials are injected into the mold cavity of a lining mold through a nozzle on an injection molding machine; step 4, the PFA raw materials are cooled and solidified in the mold cavity to form a final PFA electromagnetic flowmeter lining; the production process of the invention is simple, and the purposes of cost saving, efficiency improvement, emission reduction and automation can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of electromagnetic flowmeter lining processing, and in particular relates to a novel PFA lining production process application and processing equipment. Background Art

[0002] The lining of the electromagnetic flowmeter is one of its key components, which is mainly used to isolate the measuring tube from the fluid to prevent corrosion and wear while ensuring measurement accuracy.

[0003] The traditional PTFE lining process is to pull the PTFE tube into the electromagnetic flowmeter conduit through a tube pulling device, which is a tight lining process, and then heat the exposed PTFE tube to make it transparent, and then use a hydraulic device and a mold to flanging it, and then corrode the PTFE tube to make its surface rough, and then use AB resin glue to apply it, and finally add a tooling splint and put it in an oven for more than 12 hours, and then polish it after completion.

[0004] Now considering that the above process steps are complicated, costly, wasteful of raw materials, and serious environmental pollution, it is necessary to provide a PFA lining production process application and processing equipment to solve the above technical problems. Summary of the invention

[0005] In order to solve the problems raised in the above background technology, the present invention provides a novel PFA lining production process application and processing equipment, which has the characteristics of simple production process, and can achieve the purpose of cost saving, efficiency improvement, emission reduction and automation.

[0006] To achieve the above object, the present invention provides the following technical solution: A new PFA lining production process application comprises the following steps: Step 1: Before injection molding, the PFA raw material needs to be placed in a drying oven for drying to remove moisture and volatiles in the PFA; Step 2: Add the dried PFA raw material into the barrel of the injection molding machine, start the heating device on the barrel to heat the PFA raw material in the barrel, and then start the screw to rotate in the barrel to transport the PFA raw material forward. The plasticization process of the PFA raw material is completed under the cooperation of the screw and the barrel. Step 3, injecting the molten PFA raw material into the mold cavity of the lining mold through the nozzle on the injection molding machine; Step 4: The PFA raw material is cooled and solidified in the mold cavity to form the final PFA electromagnetic flowmeter lining.

[0007] Preferably, the drying time of the drying box is 3-4 hours.

[0008] Preferably, the drying temperature in the drying box is 150°C-200°C.

[0009] Preferably, the temperature of the upper barrel of the injection molding machine is 300°C-400°C, and the temperature of the upper nozzle of the injection molding machine is 380°C-390°C.

[0010] Preferably, the aspect ratio of the screw on the injection molding machine is 20:1-25:1, and the compression ratio of the screw on the injection molding machine is 2:1-3:1.

[0011] Preferably, the injection pressure of the injection molding machine is 100MPa-200MPa.

[0012] Preferably, the temperature of the lining mold is 150°C-200°C.

[0013] Preferably, it comprises a drying machine, an injection molding machine and a lining mold, wherein an injection molding cavity is arranged in the lining mold, and an injection molding nozzle connected with the injection molding cavity is arranged in the middle of the lining mold.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention adopts the process of injection molding the lining by an injection molding machine. The lining mold is mainly designed according to the electromagnetic flowmeter, and then the electromagnetic flowmeter pipe fittings are put into the mold for injection molding. Generally, a pipe fitting can be demolded within 2-3 minutes. After demolding, it is directly a finished lining product without secondary processing, avoiding the cumbersome problems of traditional processes, and can achieve the purposes of cost saving, efficiency improvement, emission reduction and automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a schematic diagram of the production process structure of the present invention; DETAILED DESCRIPTION The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] Example See also Figure 1 , this embodiment provides the following technical solution: the application of a new PFA lining production process includes the following steps: Step 1: Before injection molding, the PFA raw material needs to be placed in a drying oven for drying to remove moisture and volatiles in the PFA; Step 2: Add the dried PFA raw material into the barrel of the injection molding machine, start the heating device on the barrel to heat the PFA raw material in the barrel, and then start the screw to rotate in the barrel to transport the PFA raw material forward. The plasticization process of the PFA raw material is completed under the cooperation of the screw and the barrel. Step 3, injecting the molten PFA raw material into the mold cavity of the lining mold through the nozzle on the injection molding machine; Step 4: The PFA raw material is cooled and solidified in the mold cavity to form the final PFA electromagnetic flowmeter lining.

[0017] The lining is molded by an injection molding machine. The lining mold is designed mainly according to the electromagnetic flowmeter. The electromagnetic flowmeter pipe fittings are placed in the mold and the injection molding is started. Generally, a pipe fitting can be demoulded within 2-3 minutes. After demoulding, it is directly a finished lining product without secondary processing, avoiding the cumbersome problems of traditional processes, and achieving the goals of cost saving, efficiency improvement, emission reduction and automation.

[0018] The difference between PTFE lining and new PFA lining: In terms of never opening the edges: conventional polytetrafluoroethylene linings cannot fundamentally solve the problem of opening the edges no matter what adhesive is used, especially when the lining is subjected to large mechanical stress, drastic temperature changes or long-term use, it is more likely to open the edges; the new PFA lining, due to its own design structure, relies on physical embedded connection and will not be affected by changes in the external environment, fundamentally solving the global problem of opening the edges of the lining.

[0019] Appearance: The surface of the PTFE lining is relatively smooth, but there may be some subtle textures, and the color is generally white, and there may even be internal unevenness due to factors such as steel pipes; while the new PFA lining has a more uniform and smooth appearance, a brighter color, and due to the consistency of the lining mold, there will be no internal unevenness of the lining.

[0020] Temperature resistance: Due to the process and material itself, the long-term use temperature of the polytetrafluoroethylene lining is at most 110°C; while the new PFA lining can at least increase it by 10 to 20°C.

[0021] Flow field stability helps high-precision standardized production: PTFE lining can provide a certain degree of flow field stability, but in some production processes with extremely high precision requirements, the stability of the flow field may be affected by the slight unevenness of the lining, especially the bulging inside the pipe caused by welding; the new PFA lining can provide a more stable flow field due to its more uniform structure and better surface smoothness, which is more helpful for high-precision standardized production. Because PFA lining is molded, in some processes that require precise control of fluid flow, the new PFA lining can ensure that the fluid flows more smoothly and evenly, thereby improving production accuracy and quality.

[0022] Strong anti-permeability: The polytetrafluoroethylene lining has good anti-permeability and can effectively prevent the penetration of chemical substances; while the new PFA lining has stronger anti-permeability and can better resist the penetration of various corrosive media, thereby extending the service life of the equipment and reducing maintenance costs. This is crucial for some production processes with extremely high requirements for sealing, and can ensure the safety and stability of the production process. Creep resistance: The new PFA lining has better creep resistance than PTFE. While maintaining many excellent properties of PTFE, PFA improves the creep resistance of the material by improving the molecular structure. Under the same stress and time conditions, the creep deformation of PFA is relatively small, and it can better maintain dimensional stability, which is of great help to the electromagnetic flowmeter, especially the sealing at the electrode and the stability of the flow field.

[0023] Cracking at the flange: Traditional PTFE tubes often crack and break at the flange due to stress, temperature and other factors. The PFA structure avoids the above situation due to different processes.

[0024] Cost-effectiveness: Compared with traditional PFA, the price of the new process is several times that of the new process, and its production cycle is greatly shortened.

[0025] In some embodiments, the drying time of the drying box is 3-4 hours, and the drying temperature in the drying box is 150°C-200°C, which can better remove moisture and volatiles and avoid defects such as bubbles and cracks in the manufactured lining.

[0026] The temperature of the upper barrel of the injection molding machine is 300℃-400℃, the temperature of the upper nozzle of the injection molding machine is 380℃-390℃, and the temperature of the lining mold is 150℃-200℃, which helps to improve the surface quality and dimensional stability of the product.

[0027] The length-to-diameter ratio of the screw on the injection molding machine is 20:1-25:1, and the compression ratio of the screw on the injection molding machine is 2:1-3:1, which can ensure that the PFA material can be evenly plasticized and injected.

[0028] The injection pressure of the injection molding machine is 100MPa-200MPa, and the injection speed should not be too fast to avoid excessive stress in the product, resulting in deformation or cracking.

[0029] The processing equipment of the new PFA lining includes a drying machine, an injection molding machine and a lining mold. An injection molding cavity is arranged in the lining mold. An injection molding nozzle connected with the injection molding cavity is arranged in the middle of the lining mold. By arranging the injection molding nozzle in the middle of the lining mold, the traditional method of injection molding from the end of the lining mold is changed, the injection molding efficiency of the lining is improved, the injection molding pressure inside the injection molding cavity is reduced, and the injection molding effect of the lining is improved.

[0030] The working principle of the present invention is as follows: when in use, firstly put the PFA raw material into a drying box for drying, heat the temperature of the drying box to between 150°C and 200°C, and allow the drying box to dry the PFA raw material for 3-4 hours to remove moisture and volatiles in the PFA; Add the dried PFA raw material into the barrel of the injection molding machine, start the heating device on the barrel, heat the barrel to 300℃-400℃, heat the PFA raw material in the barrel, and then start the screw to rotate in the barrel to transport the PFA raw material forward. At the same time, heat the nozzle temperature on the injection molding machine to 380℃-390℃, and complete the plasticization process of the PFA raw material with the cooperation of the screw and the barrel; The molten PFA raw material is connected to the injection nozzle on the lining mold through the nozzle on the injection molding machine, and the molten original PFA raw material is injected into the mold cavity of the lining mold. After the injection is completed, the PFA raw material is cooled and solidified in the mold cavity to form the final PFA electromagnetic flowmeter lining. After cooling, the PFA electromagnetic flowmeter lining is demolded, and there is no need for secondary processing of the PFA electromagnetic flowmeter lining.

[0031] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Application of new PFA lining production process, characterized by: The steps include: Step 1: Before injection molding, the PFA raw material needs to be placed in a drying oven for drying to remove moisture and volatiles in the PFA; Step 2: Add the dried PFA raw material into the barrel of the injection molding machine, start the heating device on the barrel to heat the PFA raw material in the barrel, and then start the screw to rotate in the barrel to transport the PFA raw material forward. The plasticization process of the PFA raw material is completed under the cooperation of the screw and the barrel. Step 3, injecting the molten PFA raw material into the mold cavity of the lining mold through the nozzle on the injection molding machine; Step 4: The PFA raw material is cooled and solidified in the mold cavity to form the final PFA electromagnetic flowmeter lining.

2. The application of the new PFA lining production process according to claim 1 is characterized in that: The drying time of the drying box is 3-4 hours.

3. The application of the new PFA lining production process according to claim 1 is characterized in that: The drying temperature in the drying box is 150°C-200°C.

4. The application of the new PFA lining production process according to claim 1 is characterized in that: The temperature of the upper barrel of the injection molding machine is 300°C-400°C, and the temperature of the upper nozzle of the injection molding machine is 380°C-390°C.

5. The application of the new PFA lining production process according to claim 1 is characterized in that: The aspect ratio of the screw on the injection molding machine is 20:1-25:1, and the compression ratio of the screw on the injection molding machine is 2:1-3:

1.

6. The application of the new PFA lining production process according to claim 1 is characterized by: The injection pressure of the injection molding machine is 100MPa-200MPa.

7. The application of the new PFA lining production process according to claim 1 is characterized by: The temperature of the lining mold is 150°C-200°C.

8. New PFA lining processing equipment, characterized by: The invention comprises a drying machine, an injection molding machine and a lining mold. An injection molding cavity is arranged in the lining mold, and an injection molding nozzle which is connected with the injection molding cavity is arranged in the middle of the lining mold.

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