A one-step molding method for plastic reinforced pipes

Abstract

The present invention relates to a one-step molding processing method for a plastic reinforced pipe, and belongs to the technical field of pipe processing. In order to solve the problem of poor quality in existing pipe processing, a one-step molding processing method for a plastic reinforced pipe is provided, which comprises wrapping continuous fibers around the core tube of a molding device through a winding machine to form a fiber reinforcement layer; under the traction of a traction machine, the fiber reinforcement layer continuously passes through a mold cavity and moves forward into a vacuum sizing box; a fixed air plug is provided inside, and the outer peripheral edge of the air plug elastically acts on the inner wall of the fiber reinforcement layer; under traction, the mold cavity is continuously moved forward, and then molten plastic material is injected into the mold cavity, and compositely molded with the fiber reinforcement layer that continuously passes through to form a pipe blank; air introduced into the pipe blank forms pressure to support the pipe blank under the blocking action of the air plug; and after sizing and cooling, the pipe blank is cut to obtain the corresponding plastic reinforced pipe. This can achieve the effects of improving processing efficiency and effective sizing.

Description

Technical Field

[0001] The invention relates to a one-step molding processing method for a plastic reinforced pipe, belonging to the technical field of pipe processing. Background Art

[0002] Plastic reinforced pipes are usually reinforced by setting reinforcing fiber materials inside the pipe to achieve the reinforcement function. They generally include a three-layer structure: an inner layer, a reinforcement layer, and an outer layer. During the production process, continuous reinforcing fibers are wound on the core pipe of the pipe processing equipment to form a cylindrical reinforcement layer. The tube is then composited with the molten plastic material injected into the mold cavity of the forming mold to form a tube blank. The tube blank then enters a vacuum sizing box for sizing and cooling, and then enters cutting and other processes to obtain the final plastic reinforced pipe. However, in the current processing of continuous reinforced plastic pipes, during the sizing and cooling forming process in the vacuum sizing box, the vacuum effect in the vacuum sizing box is used to utilize the vacuum adsorption effect of the vacuum sizing sleeve to expand and deform the pipe, and tightly adhere to the inner wall of the vacuum sizing sleeve to achieve the sizing function; however, since in the continuous processing of the pipe, when the pipe blank enters the vacuum sizing box at the beginning, the plastic material of the pipe blank is still in the insufficient cooling stage, so there will be a partial sagging phenomenon during the processing; and this phenomenon also exists when the pipe blank just enters the channel inlet of the above-mentioned vacuum sizing box, and the sizing is only performed at the sizing sleeve by external vacuum adsorption, but since the interior of the pipe blank is empty and relatively unsupported, there is a risk of internal sagging, which easily leads to insufficient fit between the pipe and the inner wall of the sizing sleeve, resulting in low dimensional accuracy and low wall thickness uniformity of the pipe, which will lead to defects in poor sizing quality during the processing and affect the final pipe quality. Summary of the Invention

[0003] In view of the above defects in the prior art, the present invention provides a one-step molding processing method for plastic reinforced pipes, which solves the problem of how to improve the sizing quality of pipes and the efficiency of pipe processing, and to achieve good product quality.

[0004] The object of the present invention is achieved by the following technical solution: a processing method for one-step molding of a plastic reinforced pipe, the method comprising the following steps:

[0005] A. Wrap the continuous fiber around the core tube of the forming equipment through a winding machine to form a cylindrical fiber reinforcement layer;

[0006] B. Under the traction of a traction machine, the fiber reinforced layer continuously passes through the mold cavity of the forming mold and moves forward into the vacuum sizing box;

[0007] C. A fixed air plug is provided inside the fiber-reinforced layer in the vacuum sizing box, wherein the outer peripheral edge of the air plug elastically acts on the circumferential inner wall of the fiber-reinforced layer to form an air path blockage;

[0008] D. continuously moving the fiber-reinforced layer forward under the traction of the traction machine, injecting molten plastic material into the mold cavity of the forming mold, and composite-molding the molten plastic material and the continuously passing fiber-reinforced layer in the mold cavity to form a tube blank;

[0009] E. The tube blank continuously moves forward and enters the passage of the vacuum sizing box. The outer peripheral edge of the air plug elastically acts on the circumferential inner wall of the tube blank. The air entering the tube blank forms a certain pressure under the blocking effect of the air plug to support the tube blank from the inside. After the tube blanks continuously passing through the vacuum sizing box are sized and cooled, they enter the subsequent cutting process to obtain corresponding plastic reinforced pipes.

[0010] After the fiber reinforced layer is pulled into the vacuum sizing box under the action of the traction machine and passes through the vacuum sizing box under the traction of the traction machine, an air plug is provided inside the corresponding fiber reinforced layer in the vacuum sizing box, which can block the internal channel of the fiber reinforced layer. Then, in the process of subsequent pipe processing to form a tube blank, the molten plastic material melt is continuously injected into the forming mold and compounded with the fiber reinforced layer continuously passing through the mold cavity to form a corresponding tube blank, and the tube blank continuously enters the subsequent vacuum sizing box, so that the outer peripheral edge of the internal air plug will elastically act on the inner wall surface of the above-mentioned tube blank to form a blockage, so that the gas introduced from the inside of the corresponding tube blank can form a certain pressure inside the tube blank under the action of the air plug. Force, the inside will always be able to maintain pressure, support the tube blank from the inside, play the effect of supporting the round outward, and can also effectively prevent the inner wall from collapsing, etc., better guarantee the internal tube diameter, at the same time, in the process of cooling in the vacuum sizing box, the internal collapse will not occur before the tube blank is completely cooled, and it can also effectively realize the pressure support effect of internal ventilation combined with the vacuum negative pressure adsorption function of the original vacuum sizing sleeve of the vacuum sizing box, and the function of sizing the tube blank with the dual effect of internal and external cooperation, which has the advantages of high sizing quality, and ensures the uniformity of the thickness of the tube wall, and has a high degree of continuous production, which can not only ensure the improvement of the processing efficiency of plastic reinforced pipes, but also achieve high-quality cooling and sizing effects, and meet the quality requirements of products.

[0011] In the above-mentioned one-step molding processing method of the plastic reinforced pipe, preferably, the air plug in step C is provided inside the fiber reinforced layer by the following method:

[0012] a. After step B, the traction of the traction machine is paused to stop the fiber reinforcement layer from moving forward, and the fibers of the fiber reinforcement layer between the vacuum sizing box and the forming die are separated to allow communication with the interior;

[0013] b. Then, extend the other end of the flexible drawstring tied to the air plug into the opened portion and tie it to the outlet end of the forming mold, place the air plug into the interior of the fiber reinforced layer, and elastically apply the outer peripheral edge of the air plug to the circumferential inner wall of the fiber reinforced layer;

[0014] c. Continue to turn on the traction machine to make the fiber reinforced layer move forward continuously under the action of traction and drive the air plug to move forward synchronously, so that the air plug enters the channel of the vacuum sizing box until the flexible pull rope is tensioned and then stops moving forward to be fixed.

[0015] By operating at the fiber reinforced layer between the vacuum sizing box and the forming mold, an opening is first opened to enable communication with the interior of the fiber reinforced layer, which is equivalent to providing an operable opening, and then the other end of the flexible pull rope with one end tied to the air plug is extended into the opened opening and tied to the outlet end of the forming mold for fixation, which is equivalent to fixing the flexible pull rope to the forming mold from the inside of the fiber reinforced layer; then, the elastic air plug is placed into the interior of the fiber reinforced layer through the opening, and the elastic action of the air plug on the inner wall of the fiber reinforced layer has a certain friction force. In the process of continuous forward movement of the fiber reinforced layer, the friction between them can drive the air plug placed therein to move forward synchronously, so that the air plug can be effectively and quickly brought to the corresponding position inside the channel of the vacuum sizing box, which has the advantage of convenient operation, and there is no need to make large-scale changes to the existing vacuum sizing box, and the original The production line is conducive to controlling production costs. At the same time, since it is connected to the air plug by a flexible pull rope, when the air plug moves forward to a certain distance synchronously with the fiber reinforced layer, that is, when the flexible pull rope is in a tensioned state, under the tension of the flexible pull rope, the air plug will no longer move forward with the fiber reinforced layer and stop at this position to form a positioning, and the air plug is fixed by the connected flexible pull rope. The friction between the air plug and the inner wall of the fiber reinforced layer due to the elastic effect will not affect the continuous forward movement of the fiber reinforced layer. In this way, the elastic effect of the air plug on the inner surface of the fiber reinforced layer is used to effectively block the inside of the fiber reinforced layer, thereby achieving the advantage of rapid placement. Moreover, such a structural design has the advantage of high continuous process in the subsequent pipeline processing. After the fiber reinforced layer is arranged in the early stage, the pipeline processing can be directly carried out, which can ensure that the gas entering the interior is blocked during the pipeline processing, thereby achieving the effect of gas path blocking. In addition, by using a flexible pull rope to connect the air plug, there is no need to pre-set the air plug in the vacuum sizing box, and it is more convenient and effective to pull the fiber reinforcement layer through the channel of the vacuum sizing box, which has the advantage of convenient operation. At the same time, the flexible pull rope is extended to enter the vacuum sizing box, so that the air plug can enter a deeper position in the vacuum sizing box and be farther away from the forming mold. This can increase the overall pressure holding length, and then the pipe blank entering the vacuum sizing box can fit well on the inner wall of the vacuum sizing sleeve, which can better improve the sizing quality and ensure the advantages of high pipe size accuracy and uniform pipe wall thickness.

[0016] In the above-mentioned processing method for one-time molding of plastic reinforced pipes, preferably, before the air plug in step b is placed into the interior of the fiber reinforced layer, the air plug is first placed in a plastic guide tube, and the outer peripheral edge of the air plug elastically acts on the circumferential inner wall of the plastic guide tube, and then the plastic guide tube with the air plug is placed into the fiber reinforced layer from the separated part, and the plastic guide tube matches the inner wall surface of the fiber reinforced layer.

[0017] Since the fiber reinforced layer is in a tensioned state during the continuous forward movement, the air plug arranged therein will be tilted or deformed during the movement, which will cause the air plug to have a poor effect in blocking the air path after the flexible pull rope is tensioned and positioned. Therefore, a plastic guide tube is first provided to place the air plug in the plastic guide tube. During the forward movement of the fiber reinforced layer, the plastic guide tube is driven to move forward synchronously, and the plastic guide tube synchronously drives the air plug forward to the corresponding position in the vacuum sizing box. The plastic guide tube can be used to protect the air plug, which is more conducive to the air plug being able to directly act elastically on the inner wall after being separated from the plastic guide tube after the subsequent flexible pull rope is tensioned, and the outer peripheral edge of the air plug can be kept completely on the inner wall as much as possible, eliminating the defects such as tilting and deformation that may be caused by the air plug during the early movement, which is more conducive to achieving the effect of blocking the internal channel and can also better improve the service life of the air plug. As a further preferred embodiment, when the flexible drawstring is tensioned in step c, the fiber-reinforced layer continues to move forward, driving the plastic guide tube forward. The air plug stops moving forward under the tension of the flexible drawstring. After the air plug is released from the plastic guide tube, its outer edge elastically acts on the circumferential inner wall of the fiber-reinforced layer. The tension of the flexible drawstring during tensioning allows the air plug to be positioned and fixed at a corresponding position within the chamber. Specifically, the length of the flexible drawstring can be directly adjusted to control the specific position of the air plug within the vacuum sizing chamber, resulting in a highly convenient operation.

[0018] In the above-mentioned one-step molding processing method of the plastic reinforced pipe, preferably, in step c, before the plastic guide tube with the air plug enters the channel inlet of the vacuum sizing box, the following steps are further included:

[0019] When the fiber reinforced layer moves forward and drives the plastic guide tube to move forward to the channel entrance of the vacuum sizing box, the traction of the traction machine is first paused to stop the fiber reinforced layer from moving forward, and then the fiber reinforced layer is retreated a certain distance to become relaxed;

[0020] The plastic guide tube with the air plug in the fiber reinforced layer is sent into the channel inlet of the vacuum sizing box, and then the traction machine is turned on to traction to make the fiber reinforced layer continue to move forward.

[0021] Since the fiber reinforced layer is in a tensioned state during the process of pulling the fiber reinforced layer forward, the plastic guide tube placed therein will be partially deformed due to extrusion during the movement, which will affect the plastic guide tube from entering the inlet of the vacuum sizing box during the movement. Through the above operation, after stopping the traction and retreating the tensioned fiber reinforced layer a certain distance, the fiber reinforced layer can be restored to a relaxed state, which can reset the plastic guide tube. After the plastic guide tube is placed in the inlet of the vacuum sizing box, it can better achieve the goal of driving the plastic guide tube into the vacuum sizing box when the continuous fiber reinforced layer enters the vacuum sizing box, thereby driving the air plug located therein to enter the corresponding position in the vacuum sizing box, which is also conducive to the convenience of operation.

[0022] In the above-mentioned one-step molding method for plastic reinforced pipes, preferably, after placing the plastic guide tube with the air plug into the inlet of the passage of the vacuum sizing box, the method further includes moving the vacuum sizing box toward the forming die, closer to the outlet of the forming die. By bringing the two closer together, the pipe blanks exiting the outlet of the forming die can be more quickly introduced into the vacuum sizing box during the pipe processing process, reducing the time the pipe blanks are exposed to air. This also effectively avoids the lack of external retention and positioning of the outer diameter of the pipe blanks due to external exposure, allowing the pipe blanks to be substantially completely located within the vacuum sizing box, further facilitating pipe forming and achieving the effect of substantially complete sizing and cooling of the pipe blanks within the vacuum sizing box.

[0023] In the above-mentioned one-step molding method for plastic reinforced pipes, preferably, after the flexible drawstring is tightened in step C and the air plug stops moving forward, the air plug is located at a position corresponding to the vacuum sizing sleeve in the vacuum sizing box. This allows the tube blank to be effectively sized both inside and outside after entering the vacuum sizing box. The vacuum adsorption on the outside of the tube blank and the internal gas flow provide support for the inside of the tube blank, effectively achieving dual sizing. Simultaneously, through sufficient and complete cooling within the vacuum sizing box, both cooling and sizing of the pipe are achieved, resulting in a good sizing effect and better product quality assurance.

[0024] In the above-mentioned one-step molding method for a plastic reinforced pipe, preferably, the gas plug in step b comprises a circular elastic sealing sheet, the outer edge of which elastically acts on the inner wall of the fiber-reinforced layer. This has a good elastic effect, can better block the gas path inside the pipe blank, and achieves the advantage of effective internal support during the pipe processing.

[0025] In the above-mentioned one-step molding processing method of the plastic reinforced pipe, the fiber reinforced layer in step A is obtained by the following method:

[0026] An axial fiber layer is formed by wrapping a number of continuous fibers distributed axially along the core tube on the circumferential surface of the core tube of the forming equipment, and a winding fiber layer is formed by continuously winding along the circumferential direction of the outer tube outside the axial fiber layer. The axial fiber layer and the winding fiber layer together form the fiber reinforcement layer.

[0027] In the above-mentioned processing method for one-time molding of plastic reinforced pipes, preferably, the injection of the molten plastic material melt in step D includes the simultaneous injection of a molten inner layer plastic material and a molten outer layer plastic material, so that the inner layer plastic material and the outer layer plastic material are simultaneously injected into the mold cavity of the molding mold and compositely molded with the passed fiber reinforcement layer in one step to form a pipe blank.

[0028] In summary, the present invention has the following advantages compared with the prior art:

[0029] 1. An air plug is first provided inside the continuously entering fiber reinforced layer, and the outer peripheral edge of the air plug elastically acts on the inner wall, and then the molten plastic material melt is subsequently injected to perform the integrated pipe molding process. This can effectively support the tube blank from the inside during the processing, thereby achieving the dual effects of sizing and cooling the tube blank from the inside and combining the original external vacuum adsorption effect of the vacuum sizing box, which can not only ensure the improvement of processing efficiency, but also achieve effective sizing effect, meet the high quality requirements of the product, and have the advantages of high product dimensional accuracy and uniform thickness.

[0030] 2. It is connected to the air plug through a flexible pull rope. When the air plug moves forward to a certain distance synchronously with the fiber reinforced layer, under the strong pulling force of the flexible line, the air plug will no longer move forward with the fiber reinforced layer and stop at this position to form a positioning. In this way, the elastic effect of the air plug is utilized to effectively block the inner surface of the fiber reinforced layer, thereby blocking the inside of the fiber reinforced layer, achieving the advantage of fast operation, and having the advantage of good blocking effect on the gas entering the interior. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the process structure of the molding equipment in the processing method of the plastic reinforced pipe one-step molding of the present invention.

[0032] Figure 2 It is a partially enlarged structural schematic diagram of the placement of the gas plug in the one-step molding processing method of the plastic reinforced pipe of the present invention.

[0033] Figure 3 yes Figure 2 Schematic diagram of the partially enlarged structure when the flexible pull rope is tensioned after the air plug is placed.

[0034] Figure 4It is a partially enlarged structural schematic diagram of another type of gas plug placement in the one-step molding processing method of the plastic reinforced pipe of the present invention.

[0035] Figure 5 yes Figure 4 Schematic diagram of the partially enlarged structure when the flexible pull rope is tensioned after the air plug is placed.

[0036] In the figure, 1. fiber reinforcement layer; 2. traction machine; 3. forming mold; 4. vacuum sizing box; 41. vacuum sizing sleeve; 5. air plug; 51. elastic sealing sheet; 6. flexible pull rope; 7. plastic guide tube; 8. winding machine; 9. cutting machine. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be further specifically described below through specific embodiments and drawings, but the present invention is not limited to these embodiments.

[0038] Example 1

[0039] Combine Figure 1 As shown, the processing method for one-time molding of the plastic reinforced pipe mainly includes corresponding processes in the pipe molding equipment, specifically the processing process of the fiber reinforcement layer 1, the tube blank molding process, the vacuum cooling and shaping process, the pulling process and the cutting process. Under the traction action of the traction machine 2 located after the vacuum cooling and shaping process of the vacuum sizing box, the fiber reinforcement layer 1 is continuously pulled forward and composited with the injected molten plastic material melt in the mold cavity of the molding mold 3 to form a tube blank. After the tube blank continuously passes through the vacuum sizing box 4 for cooling and shaping, it enters the cutting process under the traction action of the traction machine 2 for cutting to obtain a plastic reinforced pipe of corresponding length.

[0040] The specific processing method can be obtained by the following method.

[0041] Combine Figure 1-Figure 3 As shown, the glass fiber on the unwinding device is continuously pulled out, so that the above-mentioned continuous glass fiber is wrapped around the core tube of the forming device through the winding machine 8 to form a cylindrical fiber reinforcement layer 1, which is equivalent to forming a tubular fiber reinforcement layer 1;

[0042] Under the traction action of the traction machine 2 in the subsequent process of the forming equipment, the front end of the above-mentioned fiber reinforced layer 1 can be pulled by the traction tube, and the traction machine 2 pulls the above-mentioned traction tube to drive the fiber reinforced layer 1 to move forward continuously, so that the continuous fiber reinforced layer 1 moves forward along the axial direction of the core tube into the mold cavity of the forming mold 3 and continuously passes through the mold cavity of the above-mentioned forming mold 3 and is pulled out from the outlet of the corresponding forming mold 3 into the vacuum sizing box 4, so that the fiber reinforced layer 1 can completely pass through the channel of the vacuum sizing box 3 before entering the next step;

[0043] A fixed air plug 5 is provided inside the fiber reinforced layer 1 located in the vacuum sizing box 4, so that the outer peripheral edge of the air plug 5 elastically acts on the circumferential inner wall of the fiber reinforced layer 1 to form an air path blockage. The air plug 5 can be effectively placed in the fiber reinforced layer 1 so that the air plug 5 can slide relative to the fiber reinforced layer 1. This can achieve the effect of blocking the interior to form the air path blockage without affecting the fiber reinforced layer 1 or the subsequent continuous forward movement of the tube blank during the pipe forming process.

[0044] The fiber reinforced layer 1 is continuously moved forward under the traction of the traction machine 2. The air plug 5 is positioned so as to remain stationary and to be able to slide relative to the fiber reinforced layer 2. After the fiber reinforced layer 1 is continuously moved forward, the fiber reinforced layer 1 pulled out from the outlet of the forming mold 3 is neatly arranged. The pulled fiber reinforced layer 1 on the side of the traction machine 2 is removed, and the fiber reinforced layer 1 is continuously pulled forward. After the forming mold 3 is closed, molten plastic material is injected into the mold cavity of the forming mold 3. The molten plastic material and the continuously passing fiber reinforced layer 1 are compositely molded into a tube blank in the mold cavity at one time. The molding temperature can be controlled and adjusted according to actual needs. The molten plastic material can be processed and melted using the required plastic material according to the actual needs of the tube.

[0045] After forming in the forming die 3, the tube blank is pulled out from its outlet and continuously moved forward into the passage of the vacuum sizing box 4. At this time, since the above-mentioned air plug is fixed, the outer peripheral edge of the above-mentioned air plug 5 elastically acts on the circumferential inner wall of the continuously entering tube blank during the forward movement of the tube blank, so that the air entering the tube blank forms a certain pressure under the blocking effect of the air plug 5, thereby supporting the tube blank from the inside. At the same time, the vacuum sizing sleeve 41 of the vacuum sizing box 4 itself uses vacuum negative pressure to absorb and size the tube blank from the outside. Under the cooling effect of the cooling water in the vacuum sizing box 4, the continuously passing tube blanks are cooled and shaped, and then sized and cooled in the vacuum sizing box 4. After the previously used traction tube is used up, when the formed pipe enters the traction process of the traction machine 2, the above-mentioned traction tube can be removed, and the entering pipe is directly driven forward by the traction machine 2. Under the traction effect of the traction machine 2, it enters the subsequent cutting process, where it is cut into a fixed length pipe by the cutting machine 9 according to the required pipe length to obtain the corresponding plastic reinforced pipe.

[0046] The above-mentioned air can be introduced through the air inlet passage provided in the core mold in the forming mold 3, and the air outlet of the air inlet passage is located on the end face of the core mold close to the vacuum sizing box 4, and the air discharged from the air outlet is filled into the interior of the tube blank. Under the blocking effect of the air plug 5, the required air pressure is formed inside, and the internal pressure requirement is maintained as needed, so as to achieve the function of supporting the interior of the tube blank.

[0047] As a more preferred embodiment, the air plug 5 is preferably provided inside the fiber reinforced layer 1 by the following method:

[0048] Combine Figure 2 After the fiber-reinforced layer 1 is continuously pulled into the vacuum sizing box 4 and moves forward out of the vacuum sizing box 4 after a certain distance, the traction of the traction machine 2 is first paused to stop the fiber-reinforced layer 1 from moving forward. Then, the fibers are pushed apart at the fiber-reinforced layer 1 between the vacuum sizing box 4 and the forming mold 3 to form an opening that can communicate with the interior of the fiber-reinforced layer 2; this is equivalent to pushing apart the surface position of the fiber-reinforced layer 1 in the radial direction to form an opening for the subsequent operation of inserting the air plug 5; the fibers here can be made of fiber materials such as glass fibers.

[0049] Then, the other end of the flexible drawstring 6, which is tied to the air plug 5, is extended into the opened portion and tied to the outlet of the forming mold 3. It is preferable to provide a structure for tying the flexible drawstring 6 at the outlet, such as a through hole or a hook. The outer tube of the corresponding mold core is further formed with the above-mentioned through hole or hook for tying the above-mentioned flexible drawstring 6. This ensures that the whole is located inside during processing. Then, the air plug 5 is placed into the fiber reinforced layer 1 through the above-mentioned opening, and the outer peripheral edge of the air plug 5 elastically acts on the circumferential inner wall of the fiber reinforced layer 1; forming a blocking function for the internal channel. It is preferable to tie the above-mentioned flexible drawstring 6 to the middle position of the air plug 5, which is conducive to balance and maintains the overall stability. After the air plug 5 is placed, the opened opening on the fiber reinforced layer 1 can be tidied to make the opening as complete as possible; this can make subsequent operations more convenient and facilitate forward movement. In addition, since the operation is performed on the fiber reinforced layer 1 exposed to the outside, the convenience of operation can also be better improved.

[0050] Combine Figure 3 After the air plug 5 is placed, the traction machine 2 is turned on again, causing the fiber-reinforced layer 1 to continue to move forward under the action of the traction force, driving the internal air plug 5 forward synchronously, so that the air plug 5 enters the channel of the vacuum sizing box 4 until the flexible pull rope 6 is tensioned, and then stops moving forward to be fixed. This is equivalent to when the flexible pull rope 6 is in a tensioned state, using the tension of the flexible pull rope 6 to pull the air plug 6 to position and fix it, while the air plug 6 elastically acts on the inner wall to form a blockage of the internal channel. The air plug 6 can slide between the inner wall of the fiber-reinforced layer 1, so as not to affect the overall continuity of the pipeline processing.

[0051] A further implementation plan, combined with Figure 4 and Figure 5Before inserting the air plug 5 into the fiber-reinforced layer 1, it is preferable to first insert the air plug 5 into a plastic guide tube 7, with the outer edge of the air plug 5 elastically acting on the circumferential inner wall of the plastic guide tube 7. The plastic guide tube 7 with the air plug 5 is then inserted into the fiber-reinforced layer 1 through the separation, with the plastic guide tube 7 matching the inner wall surface of the fiber-reinforced layer 1. This is equivalent to ensuring that the outer diameter of the plastic guide tube 7 matches the inner diameter of the fiber-reinforced layer 1, allowing the plastic guide tube 7 to be inserted into the fiber-reinforced layer 1 and generating friction therebetween, effectively driving the plastic guide tube 7 forward as the fiber-reinforced layer 1 moves forward. The length of the plastic guide tube 7 can be selected as needed to protect the air plug 5 during forward movement and improve the air plug's blocking effect within the fiber-reinforced layer 1. The length of the plastic guide tube 7 is preferably 10-20 cm.

[0052] It is best that when the above-mentioned flexible pull rope 6 is in a tensioned state, the fiber reinforced layer 1 continues to move forward to drive the plastic guide tube 7 forward, and the air plug 5 stops moving forward under the tension of the flexible pull rope 6, the air plug 5 is separated from the plastic guide tube 7, and the outer edge of the air plug 5 elastically acts on the circumferential inner wall of the fiber reinforced layer 1.

[0053] In a further preferred embodiment, the flexible drawstring 6 is made of a uniform material such as a steel wire rope or a braided wire rope. By utilizing the characteristics of the flexible drawstring 6, the air plug 5 can be placed more effectively and conveniently from outside the vacuum sizing chamber 4 to be placed inside the fiber-reinforced layer 1. Furthermore, the remaining clearance of the flexible drawstring 6 can be utilized to move the fiber-reinforced layer 1 forward, driving the air plug 5 into the vacuum sizing chamber 4. The tension of the tightened flexible drawstring 6 allows the air plug 5 to be conveniently and quickly inserted into the chamber, while also providing the advantages of positioning and securing the air plug 5.

[0054] In a further embodiment, in the process of the traction machine 2 pulling the fiber reinforced layer 1 forward, before driving the plastic guide tube 7 with the air plug 5 into the channel inlet of the vacuum sizing box 4, the following operation process is also included:

[0055] When the fiber reinforced layer 1 moves forward and drives the plastic guide tube 7 to move forward to the channel entrance of the vacuum sizing box 4, the traction of the traction machine 2 is first stopped to stop the fiber reinforced layer 1 from moving forward, and then the fiber reinforced layer 1 is retreated a certain distance to relax.

[0056] Then, the plastic guide tube 7 with the air plug 5 in the fiber reinforced layer 1 is sent into the channel inlet of the vacuum sizing box 4. After the plastic guide tube 7 with the air plug 5 is completely placed in the channel of the vacuum sizing box 4, the traction machine 2 is turned on to traction so that the fiber reinforced layer 1 continues to move forward.

[0057] After the flexible drawstring 6 is tightened and the air plug 5 stops moving forward, the pull of the flexible drawstring 6 effectively stops the air plug 5 from moving forward, positioning the air plug 5 at the position corresponding to the vacuum sizing sleeve 41 within the vacuum sizing chamber 4. This means that the air plug 5 enters the passageway of the vacuum sizing chamber 4 and positions itself between the areas of the vacuum sizing sleeve 41. This allows for better sizing during the pipe forming process, through the combined effects of vacuum suction on the outside of the tube and air pressure support within.

[0058] In a preferred embodiment, the air plug 5 preferably includes a circular elastic sealing sheet 51, the outer peripheral edge of which elastically acts on the inner wall of the fiber-reinforced layer 1. This effectively blocks the internal passage. In a further embodiment, two elastic sealing sheets 51 can be sleeved on the connecting shaft. The two elastic sealing sheets 51 are spaced apart along the axial direction of the connecting shaft, and two elastic sealing sheets 41 are sleeved on the connecting shaft for fixation. Each elastic sealing sheet 51 is clamped and fixed by two clips, so that the outer diameter of the elastic sealing sheet 41 is larger than that of the clip, and the elastic sealing sheet 51 and the clip are coaxially arranged. This can maintain a certain deformation range for the elastic sealing sheet 51, and the use of two spaced-apart arrangements can improve the sealing stability. The elastic sealing sheet 51 can be made of elastic rubber material. The flexible pull cord 6 can be fixed to the fixing hole on the connecting shaft for connection, which can further improve stability. The outer diameter of the elastic sealing sheet 51 is preferably slightly larger than the inner diameter requirement of the tube blank during processing, which can not only effectively block the internal channel, but also effectively improve the continuity of the processing process and avoid interference.

[0059] In a further embodiment, the aforementioned injection of the molten plastic material melt can be injected all at once, as needed, to form plastic material layers on the inner and outer surfaces of the fiber-reinforced layer 1, resulting in a multi-layer pipe structure. Of course, as another processing method, the injection of the molten plastic material melt can also include the simultaneous injection of molten inner and outer plastic materials, depending on the pipe processing requirements. The inner and outer plastic materials are then simultaneously injected into the mold cavity of the molding die 3 and compositely molded with the passing fiber-reinforced layer 1 all at once to form the corresponding pipe blank. This results in the corresponding plastic material being formed on both the inner and outer surfaces of the fiber-reinforced layer 1, resulting in a multi-layer plastic-reinforced pipe structure.

[0060] As a more specific embodiment, the fiber reinforced layer 1 can be obtained by the following method:

[0061] An axial fiber layer is formed by wrapping a number of continuous fibers distributed axially along the core tube on the circumferential surface of the core tube of the forming equipment through a winding machine 8, and a winding fiber layer is formed by continuously winding along the circumferential direction of the outer tube outside the axial fiber layer. The axial fiber layer and the winding fiber layer together form the fiber reinforced layer 1.

[0062] The quality of the obtained plastic reinforced pipes was tested accordingly, and the results showed that they all met the required quality requirements, and the pipe sizing effect was good, the thickness of the pipe wall was uniform, and there was no uneven thickness problem.

[0063] Example 2

[0064] The specific processing method of this embodiment is basically the same as that of the first embodiment, except that the specific method of providing a fixable air plug 5 inside the fiber-reinforced layer 1 in the vacuum sizing box 4 is different. Specifically, the air plug 5 is provided inside the fiber-reinforced layer 1 by the following method:

[0065] After the fiber reinforced layer 1 is continuously pulled into the vacuum sizing box 4, and after a certain distance, the fiber reinforced layer 1 can be moved forward out of the vacuum sizing box 4, the traction of the traction machine 2 is first paused to stop the fiber reinforced layer 1 from moving forward, and then the fiber reinforced layer 1 is directly cut at the fiber reinforced layer 1 between the vacuum sizing box 4 and the forming mold 3, and then the flexible pull rope 6 is directly tied to the open end of the forming mold 3 from the fracture of the fiber reinforced layer 1, and then the air plug 5 or the plastic guide tube 7 with the air plug 5 is placed into the interior of the fiber reinforced layer 1 from the fracture, and then the traction tube is re-pulled to the circumferential position of the fracture of the fiber reinforced layer 1, and the traction machine 2 is turned on to re-pull the fiber reinforced layer 1 forward. The other operations are consistent with the first embodiment and will not be repeated here.

[0066] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

[0067] Although the present invention has been described in detail and certain specific embodiments have been cited, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

Claims

1. A one-step molding method for a plastic reinforced pipe, characterized in that: The method comprises the following steps: A. Wrapping the continuous fiber around the core tube of the forming device through a winding machine (8) to form a cylindrical fiber reinforcement layer (1); B. Under the traction of the traction machine (2), the fiber reinforcement layer (1) continuously passes through the mold cavity of the forming mold (3) and moves forward into the vacuum sizing box (4); C. A fixed air plug (5) is provided inside the fiber-reinforced layer (1) located in the vacuum sizing box (4), wherein the outer peripheral edge of the air plug (5) elastically acts on the circumferential inner wall of the fiber-reinforced layer (1) to form an air path blockage; the air plug (5) is provided inside the fiber-reinforced layer (1) by the following method: a. After step B, the traction of the traction machine (2) is first stopped to stop the fiber-reinforced layer (1) from moving forward, and the fibers of the fiber-reinforced layer (1) between the vacuum sizing box (4) and the forming mold (3) are separated or cut to enable communication with the interior; b. Then, the other end of the flexible drawstring (6) with one end tied to the gas plug (5) is extended into the opened part or the broken part and tied to the outlet end of the forming mold (3), and the gas plug (5) is placed inside the fiber reinforced layer (1), and the outer peripheral edge of the gas plug (5) elastically acts on the circumferential inner wall of the fiber reinforced layer (1); c. Continue to turn on the traction machine (2) so that the fiber reinforcement layer (1) moves forward continuously under the action of the traction force and drives the air plug (5) to move forward synchronously, so that the air plug (5) enters the channel of the vacuum sizing box (4) until the flexible pull rope (6) is tightened and stops moving forward to be fixed; D. The fiber-reinforced layer (1) is continuously moved forward under the traction of the traction machine (2), and then a molten plastic material melt is injected into the mold cavity of the molding die (3), and the molten plastic material melt and the continuously passing fiber-reinforced layer (1) are composite-molded in the mold cavity to form a tube blank; E. The tube blank continuously moves forward and enters the passage of the vacuum sizing box (4). The outer peripheral edge of the air plug (5) elastically acts on the circumferential inner wall of the tube blank. The air introduced into the tube blank forms a certain pressure under the blocking action of the air plug (5) to support the inner wall of the tube blank from the inside. After the tube blank continuously passes through the vacuum sizing box (4), it is sized and cooled, and then enters the subsequent cutting process to obtain the corresponding plastic reinforced pipe.

2. The one-step molding processing method of the plastic reinforced pipe according to claim 1 is characterized in that: Before the air plug (5) is placed into the interior of the fiber reinforced layer (1) in step b, the air plug (5) is first placed in a plastic guide tube (7), and the outer peripheral edge of the air plug (5) elastically acts on the circumferential inner wall of the plastic guide tube (7), and then the plastic guide tube (7) with the air plug (5) is placed into the fiber reinforced layer (1) from the opened position, and the plastic guide tube (7) matches the inner wall surface of the fiber reinforced layer (1).

3. The one-step molding method of a plastic reinforced pipe according to claim 2, characterized in that: When the flexible pull rope (6) is in a tensioned state in step c, the fiber reinforced layer (1) continues to move forward, driving the plastic guide tube (7) to move forward, and the air plug (5) stops moving forward under the pulling force of the flexible pull rope (6). After the air plug (5) is separated from the plastic guide tube (7), the outer peripheral edge of the air plug (5) elastically acts on the circumferential inner wall of the fiber reinforced layer (1).

4. The one-step molding method for plastic reinforced pipes according to claim 3, characterized in that: Before the plastic guide tube (7) with the air plug (5) enters the channel inlet of the vacuum sizing box (4) in step c, the following steps are also included: When the fiber reinforced layer (1) moves forward and drives the plastic guide tube (7) to move forward to the channel entrance of the vacuum sizing box (4), the traction of the traction machine (2) is first suspended to stop the fiber reinforced layer (1) from moving forward, and then the fiber reinforced layer (1) is retreated a certain distance to become relaxed; The plastic guide tube (7) with the air plug (5) in the fiber-reinforced layer (1) is fed into the channel inlet of the vacuum sizing box (4), and then the traction machine (2) is turned on to traction the fiber-reinforced layer (1) so that the fiber-reinforced layer (1) continues to move forward.

5. The one-step molding method for a plastic reinforced pipe according to any one of claims 2 to 4, characterized in that: After placing the plastic guide tube (7) with the air plug (5) into the inlet of the channel of the vacuum sizing box (4), the method further includes moving the vacuum sizing box (4) toward the side of the forming mold (3) close to the outlet end of the forming mold (3).

6. The one-step molding method for a plastic reinforced pipe according to any one of claims 2 to 4, characterized in that: After the flexible pull rope (6) is tightened in step C and the air plug (5) stops moving forward, the air plug (5) is located at a position corresponding to the vacuum sizing sleeve (41) in the vacuum sizing box (4).

7. The one-step molding method for a plastic reinforced pipe according to any one of claims 2 to 4, characterized in that: In step b, the air plug (5) comprises a circular elastic sealing sheet (51), and the outer peripheral edge of the elastic sealing sheet (51) elastically acts on the inner wall of the fiber reinforced layer (1).

8. The one-step molding method for a plastic reinforced pipe according to any one of claims 2 to 4, characterized in that: The fiber-reinforced layer (1) in step A is obtained by the following method: An axial fiber layer is formed by wrapping a plurality of continuous fibers distributed along the axial direction of the core tube on the circumferential surface of the core tube of the forming device, and a winding fiber layer is formed by continuously winding the outer surface of the axial fiber layer along the circumferential direction of the outer tube. The axial fiber layer and the winding fiber layer together form the fiber reinforcement layer (1).

9. The one-step molding method for a plastic reinforced pipe according to any one of claims 2 to 4, characterized in that: The injection of the molten plastic material melt in step D specifically includes the simultaneous injection of a molten inner layer plastic material and a molten outer layer plastic material, so that the inner layer plastic material and the outer layer plastic material are simultaneously injected into the mold cavity of the molding mold (3) and compositely molded with the passed fiber reinforcement layer (1) in one go to form a tube blank.

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