A method for producing high-strength HDPE drain pipe

Abstract

The application discloses a kind of high-strength HDPE drainage pipe production methods, belong to HDPE water pipe production technical field, mainly including raw material preparation, raw material pretreatment, extrusion molding, cooling and shaping and stretching and cutting etc. Step, just extruded waste and traction pipe sealing adhesion, new material is affected by traction mechanism and enters into the shaping device from extruder, mainly through the way of vacuum suction and air pressure expansion to ensure that the size and shape of pipe material meet the design requirements, the traction speed of traction device is 1%-10% higher than the speed of extruder, to overcome the die swell of pipe material, secondly, the traction speed of traction device is adjustable slow speed affected by the stretching of pipe material in shaping device, effectively reduce the problem that pipe wall is thinned due to pipe material is pulled up too fast in shaping device, to improve the mechanical properties and longitudinal dimension stability of product.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of HDPE water pipe production equipment, and particularly relates to a high-strength HDPE drainage pipe production method. BACKGROUND

[0002] High-density polyethylene (HDPE) pipe material is a kind of plastic pipe material commonly used in water supply, drainage, natural gas transportation and other fields, which has excellent corrosion resistance, high strength, wear resistance, low temperature resistance and other characteristics, and is widely used in modern buildings and infrastructure construction.

[0003] The production process of the HDPE pipe material includes raw material preparation, extrusion molding, cooling and shaping, cutting and inspection and other links.

[0004] The adjustment of the traction speed is very important in the extrusion molding operation, and the traction speed directly affects the product wall thickness, size tolerance and performance appearance. If the traction speed is too fast, the pipe wall is too thin, the burst strength of the pipe wall is obviously decreased, at the same time, the product residual internal stress is large, the pipe material is bent and deformed, and even the pipe material is pulled off. SUMMARY

[0005] The purpose of the present application is to solve the problems of the prior art, such as the traction speed being too fast, the pipe wall being too thin, the burst strength of the pipe wall being obviously decreased, the product residual internal stress being large, the pipe material being bent and deformed, and even the pipe material being pulled off, and a high-strength HDPE drainage pipe production method is proposed.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0007] A high-strength HDPE drainage pipe production method mainly includes the following steps:

[0008] S1: raw material preparation, the high-density polyethylene particles and the auxiliary materials are proportionally prepared into raw material particles;

[0009] S2: raw material pretreatment, the raw material particles are put into the pretreatment equipment for drying and melting treatment into hot melt;

[0010] S3: extrusion molding, the hot melt is sent into the extruder, the hot melt is formed into a certain pressure by the rotation of the screw rod and the heating of the heater, and is extruded from the head to form a tubular shape;

[0011] S4: cooling and shaping, the extruded pipe material is quickly cooled and shaped by the shaping device to solidify the shape and size of the pipe material;

[0012] S5: Stretching and cutting, the pipe material after cooling is stretched to the required length by a traction device and cut by a cutting device to form pipe segments of different lengths, which need to be inspected to ensure that they meet the quality requirements.

[0013] In order to extrude the drain pipe, preferably, the head in S3 comprises a die sleeve assembly and a die core assembly, the die core assembly is coaxially installed in the die sleeve assembly, and the die sleeve assembly and the die core assembly are spaced apart to form an extrusion channel.

[0014] In order to pull the drain pipe, preferably, the traction device in S5 comprises support rods arranged in the circumferential direction, one end of the support rod is fixedly connected with the shaping device, the other end of the support rod is fixedly installed with a support ring, two tensioning rollers are rotatably installed on the side of the support rod close to the pipe material, and the two tensioning rollers are tensioned with a traction belt, a gear disc is rotatably installed on the support ring, the gear disc is drivingly connected with one of the tensioning rollers through a gear assembly, the other side of the gear disc is meshingly connected with a drive gear, a drive motor is fixedly installed on the die sleeve assembly, and the transmission shaft of the drive gear is drivingly connected with the drive motor through a speed regulating mechanism.

[0015] Further, the speed regulating mechanism comprises a gear box fixedly installed on the die sleeve assembly, a transmission rod rotatably installed in the gear box, a first gear and a second gear coaxially installed on the transmission rod, the upper end of the transmission rod penetrates out of the gear box and is drivingly connected with the transmission shaft of the drive gear through a belt, a sliding rod slidingly installed in the gear box, a third gear rotatably installed on the sliding rod, the third gear is meshingly connected with the first gear, a fifth gear fixedly installed on the output end of the drive motor, the fifth gear is meshingly connected with the third gear, a shaft sleeve rotatably installed in the gear box, the shaft sleeve is coaxially arranged with the sliding rod, a fourth gear fixedly installed on the shaft sleeve, the fourth gear is meshingly connected with the second gear.

[0016] In order to cool the drain pipe, further, the shaping device in S4 comprises a shaping box, the shaping box abuts against the head, a heat insulation pad is fixedly installed on the abutting surface of the shaping box and the head, a cooling jacket is opened in the wall of the shaping box, the cooling jacket is filled with cooling liquid, a water tank and a heat exchanger are arranged below the shaping box, a water pump is installed in the water tank, a conveying pipe is connected between the water tank and the heat exchanger, first heat exchange pipes are fixedly connected between the water tank, the heat exchanger and the shaping box, and the first heat exchange pipes extend into the cooling jacket.

[0017] For the shaping of the drain pipe, further comprising: air jacket is set in the box wall of the shaping box, the air jacket is filled with air, the air jacket is fixedly connected with the second heat exchange pipe between the heat exchanger; air pipe is fixedly installed in the mold core assembly, one end of the air pipe extends to the mold jacket assembly and is fixedly connected with the connecting pipe between the air jacket, the air pump is installed on the connecting pipe, the other end of the air pipe extends to the shaping box and is fixedly installed with the die disc, the air pipe wall is equidistantly provided with the air outlet hole.

[0018] For further shaping of the drain pipe, further, the air jacket is provided with an evacuation channel near the pipe material side, the one-way valve is fixedly installed in the evacuation channel.

[0019] In order to make the pipe inside form a more sealed state, further, the air pipe in the mold jacket assembly is slidably installed with a plug, a circle of abutment is fixedly installed on the air pipe inner wall, which can abut with the plug, one end of the plug and the inside of the air pipe are fixedly connected with the first spring; the air supplement chamber is set in the mold jacket assembly, the air supplement pipe is fixedly connected between the air supplement chamber and the air pipe.

[0020] In order to prewarn the traction, further, the diaphragm is fixedly installed in the air supplement chamber, the abutment rod which can contact each other is fixedly installed between the diaphragm and the bottom surface of the air supplement chamber, the electrode sheet is fixedly installed on the opposite surface of the abutment rod; the alarm lamp is fixedly installed on the mold jacket assembly, the alarm lamp and the electrode sheet are electrically connected through the wire.

[0021] In order to adjust the traction to slow down, further, the lower end of the slide rod is fixedly connected with the diaphragm, the second spring is movably installed on the slide rod, the two ends of the second spring are fixedly connected with the diaphragm and the inner top wall of the air supplement chamber respectively; the plug is fixedly installed on the wheel surface of the fourth gear, the plug is matched with the gear groove of the third gear.

[0022] Compared with the prior art, the present application provides a high-strength HDPE drain pipe production method, which has the following beneficial effects:

[0023] 1. The high-strength HDPE drain pipe production method, through the setting of the adjusting assembly, the air in the air jacket absorbs heat from the pipe and heats up, is pumped by the air pump into the connecting pipe and is delivered into the air delivery pipe, when the air pump pumps hot air, the high-speed flowing air pressure is greater than the pre-tightening force of the first spring, and then pushes the blocking block and the blocking table apart into the air delivery pipe for pressurization, if the pulling speed is too fast, the pipe wall in the sizing box is thinned by pulling, the high-pressure gas in the pipe interior decreases in pressure to generate a vacuum adsorption force, and the vacuum adsorption force is smaller than the pre-tightening force of the first spring, so that the air in the air supplement chamber below the diaphragm can only be sucked in through the air supplement pipe, the diaphragm is deformed under stress to make the two electrode sheets contact each other to connect the current of the alarm lamp, reminding the staff to adjust; at the same time, the diaphragm is deformed under stress to make the sliding rod move downward, the third gear wheel installed on the sliding rod is embedded into the wheel surface of the fourth gear wheel to drive the second gear wheel to rotate, and then the function of adjusting the pulling speed to slow down is achieved;

[0024] 2. The high-strength HDPE drain pipe production method, through the setting of the air jacket, the air in the air jacket absorbs heat from the pipe and heats up, is pumped by the air pump into the connecting pipe and is delivered into the air delivery pipe, is sprayed out through the air outlet hole on the air delivery pipe to form high pressure in the pipe interior, the setting of the die disc is used for preventing internal high pressure from leaking, and the gap between the die disc and the sizing box is consistent with the pipe wall thickness, the pipe is tightly attached to the inner diameter of the sizing box under high-pressure extrusion to form a regular circle and can ensure the uniformity and strength of the pipe during the extrusion process; secondly, the high-pressure air after being heated will not cause the temperature of the core mold to suddenly drop to cause defects in the inner wall of the pipe; at the same time, the air in the air jacket is pumped to reduce the internal pressure to generate negative pressure, so as to generate a great vacuum adsorption force to tightly attach the outer wall of the pipe to the sizing box, further improving the production quality and specifications of the pipe;

[0025] 3. The high-strength HDPE drain pipe production method, through the setting of the cooling jacket, the pipe enters the sizing box to be cooled and formed by the cooling liquid in the cooling jacket, the cooling liquid absorbs heat from the pipe to rise in temperature to form a high-temperature liquid, the high-temperature liquid is pumped into the water tank by the water pump and enters the heat exchanger for heat exchange, so as to reduce the temperature and be pumped into the cooling jacket again through the first heat exchange pipe, so as to form a cooling cycle;

[0026] 4. The high-strength HDPE drain pipe production method, through the setting of the heat exchanger, the air in the air jacket is connected with the heat exchanger through the second heat exchange pipe, the external cold air enters the heat exchanger to exchange heat with the high-temperature liquid discharged from the cooling jacket, to increase the heat of the gas while reducing the temperature of the liquid, so as to realize preheating treatment of the air entering the air jacket. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1A front view overall structure schematic diagram of a high-strength HDPE drainage pipe material production method is provided in the present application;

[0028] Figure 2 A sizing box structure schematic diagram of a high-strength HDPE drainage pipe material production method is provided in the present application;

[0029] Figure 3 A die head structure schematic diagram of a high-strength HDPE drainage pipe material production method is provided in the present application;

[0030] Figure 4 A water tank and heat exchanger connection structure schematic diagram of a high-strength HDPE drainage pipe material production method is provided in the present application;

[0031] Figure 5 A driving gear installation structure schematic diagram of a high-strength HDPE drainage pipe material production method is provided in the present application;

[0032] Figure 6 A high-strength HDPE drainage pipe material production method is provided in the present application, Figure 1 A structure enlarged schematic diagram in A of the present application;

[0033] Figure 7 A structure enlarged schematic diagram in B of the present application. Figure 3

[0034] In the figure: 1, die set assembly; 101, air supplement chamber; 2, die core assembly; 201, core rod; 202, flow guide disc; 203, flow guide block; 3, extrusion channel; 4, sizing box; 401, cooling jacket; 402, air jacket; 4021, air extraction channel; 5, heat insulation pad; 6, water tank; 601, supply pipe; 7, heat exchanger; 8, conveying pipe; 9, first heat exchange pipe; 10, second heat exchange pipe; 11, air supply pipe; 1101, air outlet hole; 1102, air supplement pipe; 1103, stop table; 12, die disc; 13, connecting pipe; 14, block; 15, first spring; 16, diaphragm; 17, support rod; 18, support ring; 19, traction belt; 20, toothed disc; 21, driving gear; 22, driving motor; 23, abutting rod; 24, electrode sheet; 25, alarm lamp; 26, sliding rod; 2601, second spring; 27, third gear; 28, gear box; 29, transmission rod; 30, first gear; 31, second gear; 32, shaft sleeve; 33, fourth gear; 3301, bolt; 34, fifth gear; 35, tensioning roller; 36, support seat; 37, connecting shaft; 38, first bevel gear; 39, sixth gear; 40, second bevel gear. DETAILED DESCRIPTION

[0035] ​The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application.

[0036] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. Embodiments:

[0037] With reference to Figure 1 - Figure 7 A high-strength HDPE drainage pipe production method mainly includes the following steps:

[0038] S1: raw material preparation, high-density polyethylene particles and auxiliary materials are prepared into raw material particles in proportion, wherein the auxiliary materials include but are not limited to antioxidants, ultraviolet stabilizers, color masterbatch, etc., to maintain the stability of the production process and the quality of polyethylene, and the proportion of color masterbatch in the production of drainage pipes is usually between 2% and 4%, to enhance the durability and anti-aging property of the HDPE drainage pipe;

[0039] S2: raw material pretreatment, the raw material particles are put into a pretreatment device for drying and melting treatment into hot melt, wherein the pretreatment device includes a drying box or a dehydrator, preferably, the pretreatment device is a drying box, and the drying method can be air flow drying, vacuum drying and hot air drying, etc., in which the polyethylene particles are exposed to hot air or a vacuum environment to remove moisture or other volatile components on the surface and inside, reducing the surface defects of the pipe in the subsequent extrusion process;

[0040] S3: extrusion molding, the hot melt is sent into an extruder, and the hot melt is formed into a certain pressure and extruded from a die head to form a tubular shape through the rotation of the screw and the heating of the heater;

[0041] S4: cooling and sizing, the extruded pipe is quickly cooled and sized by a sizing device to solidify the shape and size of the pipe;

[0042] S5: stretching and cutting, the cooled pipe is stretched to the required length by a traction device and cut by a cutting device to form pipe segments of different lengths, and the cut pipe segments need to be quality inspected to ensure that they meet the quality requirements.

[0043] In the above method steps, the just-extruded waste material is sealed and adhered to the traction pipe, and the new material is drawn into the shaping device from the extruder by the traction mechanism, and the size and shape of the pipe material are ensured to meet the design requirements mainly through vacuum suction and air pressure expansion, the traction speed of the traction device is 1%-10% higher than the speed of the extruder to overcome the die expansion of the pipe material, secondly, the traction speed of the traction device can be adjusted slowly under the influence of the stretching of the pipe material in the shaping device, effectively reducing the problem of thinning of the pipe wall caused by too fast pulling in the shaping device, thereby improving the mechanical properties and longitudinal size stability of the product.

[0044] Referring to Figure 1 and Figure 3 , the head in S3 includes a die sleeve assembly 1 and a die core assembly 2, the die core assembly 2 is coaxially installed in the die sleeve assembly 1, and the die sleeve assembly 1 and the die core assembly 2 are spaced apart to form an extrusion channel 3.

[0045] Among them, the die sleeve assembly 1 is fixedly installed at the discharge end of the extruder, the die core assembly 2 includes a core rod 201 and a flow guide disc 202 in sequence along the extrusion direction of the die sleeve assembly 1, the core rod 201 and the die sleeve assembly 1 are spaced apart to form an extrusion channel 3, and the flow guide disc 202 is fixedly installed with a flow guide block 203 on the side away from the core rod 201, the hot melt material enters the die sleeve assembly 1 through the extruder, uniformly passes through the flow guide disc 202 to fill the extrusion channel 3, and then is extruded, thereby forming a drainage pipe.

[0046] Referring to Figure 1 and Figures 5-7 , the traction device in S5 includes: support rods 17 arranged in the circumferential direction, one end of the support rod 17 is fixedly connected with the shaping device, and the other end of the support rod 17 is fixedly installed with a support ring 18; two tensioning rollers 35 symmetrically arranged are rotatably installed on the side of the support rod 17 close to the pipe material, and the traction belt 19 is tensioned between the two tensioning rollers 35; the gear plate 20 is rotatably installed on the support ring 18, the gear plate 20 is drivingly connected with one of the tensioning rollers 35 through a gear assembly on one side of the gear plate 20, the other side of the gear plate 20 is meshingly connected with a driving gear 21, a driving motor 22 is fixedly installed on the die sleeve assembly 1, and the transmission shaft of the driving gear 21 is drivingly connected with the driving motor 22 through a speed regulation mechanism.

[0047] The speed regulating mechanism comprises a gear box 28 fixedly installed on the die sleeve assembly 1, a transmission rod 29 rotatably installed in the gear box 28, a first gear 30 and a second gear 31 coaxially installed on the transmission rod 29, and the upper end of the transmission rod 29 penetrating out of the gear box 28 and connected with the transmission shaft of the driving gear 21 through a belt transmission; a slide rod 26 slidably installed in the gear box 28, a third gear 27 rotatably installed on the slide rod 26, the third gear 27 being in meshing connection with the first gear 30, a fifth gear 34 fixedly installed on the output end of the driving motor 22, the fifth gear 34 being in meshing connection with the third gear 27; and a shaft sleeve 32 rotatably installed in the gear box 28, the shaft sleeve 32 being coaxially arranged with the slide rod 26, a fourth gear 33 fixedly installed on the shaft sleeve 32, the fourth gear 33 being in meshing connection with the second gear 31.

[0048] The gear assembly comprises a support seat 36 fixedly installed on the support rod 17, a connecting shaft 37 rotatably installed in the support seat 36, a first bevel gear 38 and a sixth gear 39 fixedly installed at the two ends of the connecting shaft 37 respectively, and the sixth gear 39 being in meshing connection with the toothed disc 20, and a second bevel gear 40 coaxially installed on the tension roller 35 and in meshing connection with the first bevel gear 38, so as to realize force transmission.

[0049] The output end of the driving motor 22 drives the fifth gear 34 to rotate and transmit the rotating force to the third gear 27, the third gear 27 drives the meshing connected first gear 30 to rotate and transmit the rotating force to the transmission rod 29, the transmission rod 29 transmits the rotating force to the driving gear 21 through a belt, the driving gear 21 drives the meshing connected toothed disc 20 to rotate on the support ring 18, the rotating toothed disc 20 drives the sixth gear 39 to rotate, the sixth gear 39 drives the coaxial first bevel gear 38 to rotate, the first bevel gear 38 drives the meshing connected second bevel gear 40 to rotate and transmit the rotating force to the tension roller 35, so as to realize transmission of the traction belt 19. In the embodiment, rubber pads are arranged on the side of the traction belt 19 close to the pipe, so as to increase the contact and friction with the pipe and realize continuous traction of the pipe.

[0050] It should be noted that the diameter of the first gear 30 is smaller than that of the second gear 31 and the same as that of the third gear 27, and the diameter of the fourth gear 33 is the same as that of the first gear 30.

[0051] Referring to Figure 2 and Figure 4, the shaping device in S4 comprises: a shaping box 4 abutting against the machine head, a heat insulation pad 5 being fixedly installed on the abutting surface of the shaping box 4 and the machine head; a cooling jacket 401 being opened in the box wall of the shaping box 4, the cooling jacket 401 being filled with cooling liquid; a water tank 6 and a heat exchanger 7 being arranged below the shaping box 4, a water pump being installed in the water tank 6, a conveying pipe 8 being connected between the water tank 6 and the heat exchanger 7, and the water tank 6 and the heat exchanger 7 being fixedly connected with the shaping box 4 through first heat exchange pipes 9 respectively, the first heat exchange pipes 9 extending into the cooling jacket 401.

[0052] Wherein, the pipe material enters the shaping box 4 and is cooled and formed by the cooling liquid in the cooling jacket 401, the cooling liquid absorbs heat from the pipe material and rises in temperature to form high-temperature liquid, the high-temperature liquid is pumped into the water tank 6 under the action of the water pump and enters the heat exchanger 7 to exchange heat, so as to reduce the temperature and be pumped into the cooling jacket 401 through the first heat exchange pipes 9 again, so as to form a cooling cycle.

[0053] It should be noted that the water tank 6 is fixedly installed with a supply pipe 601, the supply pipe 601 is connected with a water source, and the cooling liquid evaporated in the cooling jacket 401 can be supplemented.

[0054] Referring to Figure 2 and Figure 3 , the shaping device further comprises: an air jacket 402 being opened in the box wall of the shaping box 4, the air jacket 402 being filled with air, the air jacket 402 being fixedly connected with the heat exchanger 7 through second heat exchange pipes 10; a gas feeding pipe 11 being fixedly installed in the mold core assembly 2, one end of the gas feeding pipe 11 extending into the mold sleeve assembly 1 and being fixedly connected with the air jacket 402 through a connecting pipe 13, the connecting pipe 13 being installed with a gas pump, the other end of the gas feeding pipe 11 extending into the shaping box 4 and being fixedly installed with a die disc 12, and air outlet holes 1101 being equidistantly opened in the pipe wall of the gas feeding pipe 11.

[0055] The air jacket 402 is opened with an air exhaust channel 4021 on the side close to the pipe material, and a one-way valve is fixedly installed in the air exhaust channel 4021.

[0056] Through the arrangement of the above structure, the air in the air jacket 402 absorbs heat from the pipe material and is heated, is pumped into the connecting pipe 13 and is delivered into the air delivery pipe 11, is sprayed out through the air outlet hole 1101 on the air delivery pipe 11, high pressure is formed in the pipe material, the die disc 12 is arranged to prevent air leakage under the high pressure, the gap between the die disc 12 and the shaping box 4 is consistent with the wall thickness of the pipe material, the pipe material is tightly attached to the inner diameter of the shaping box 4 under the extrusion of the high pressure and is formed into a regular circle and the uniformity and strength of the pipe material can be ensured during the extrusion process; secondly, the high pressure air after being heated does not cause the temperature of the core die to suddenly drop and causes defects on the inner wall of the pipe material; at the same time, the air in the air jacket 402 is pumped and the internal pressure is reduced to generate a negative pressure, so that a great vacuum adsorption force is generated to tightly attach the outer wall of the pipe material to the shaping box 4, and the production quality and specifications of the pipe material are further improved.

[0057] Further, the air in the air jacket 402 is connected with the heat exchanger 7 through the second heat exchange pipe 10, the external cold air enters the heat exchanger 7 and can exchange heat with the high-temperature liquid discharged from the cooling jacket 401, the temperature of the liquid is reduced and the heat of the gas is increased, and the air entering the air jacket 402 is preheated.

[0058] Referring to Figure 7 , the plug 14 is slidingly installed in the air delivery pipe 11 in the die sleeve assembly 1, a circle of stop tables 1103 capable of abutting against the plug 14 is fixedly installed on the inner wall of the air delivery pipe 11, and the first spring 15 is fixedly connected between one end of the plug 14 and the inside of the air delivery pipe 11; the air supplementing chamber 101 is formed in the die sleeve assembly 1, and the air supplementing pipe 1102 is fixedly connected between the air supplementing chamber 101 and the air delivery pipe 11.

[0059] The diaphragm 16 is fixedly installed in the air supplementing chamber 101, the abutting rods 23 capable of contacting each other are fixedly installed between the diaphragm 16 and the inner bottom surface of the air supplementing chamber 101, and the electrode sheets 24 are fixedly installed on the opposite surfaces of the upper and lower abutting rods 23; the alarm lamp 25 is fixedly installed on the die sleeve assembly 1, and the alarm lamp 25 and the electrode sheets 24 are electrically connected through wires.

[0060] The lower end of the sliding rod 26 is fixedly connected with the diaphragm 16, the second spring 2601 is movably installed on the sliding rod 26, and the two ends of the second spring 2601 are fixedly connected with the diaphragm 16 and the inner top wall of the air supplementing chamber 101 respectively; the latch 3301 is fixedly installed on the wheel surface of the fourth gear 33, and the latch 3301 is matched with the gear slot of the third gear 27.

[0061] Through the setting of the above structure, when the air pump pumps hot air, the high-speed flowing air pressure is greater than the pre-tightening force of the first spring 15 itself, and then pushes the block 14 to separate from the blocking table 1103 and enters the air conveying pipe 11 to increase the pressure, if the traction speed is too fast, the pipe wall in the shaping box 4 is thinned by pulling, the high-pressure gas pressure inside the pipe material decreases to produce a vacuum adsorption force, and the vacuum adsorption force is less than the pre-tightening force of the first spring 15 itself, so that the air in the air supplementing pipe 1102 is sucked into the air supplementing chamber 101 below the diaphragm 16, the diaphragm 16 is deformed under stress to make the two electrode sheets 24 contact each other to connect the current of the alarm lamp 25, reminding the staff to adjust; at the same time, the diaphragm 16 is deformed under stress to make the slide rod 26 move downward, the third gear 27 installed on the slide rod 26 is embedded in the wheel surface of the fourth gear 33, the second gear 31 is driven to rotate, and then the function of adjusting the traction speed to slow down is realized.

[0062] In summary, the working process of the present scheme is further summarized as follows:

[0063] During production, the polyethylene particles and auxiliary materials are dehydrated in the drying box and then enter the extruder for extrusion, the waste materials in the early stage are adhered to the traction pipe and are pulled into the shaping box 4, the air in the air jacket 402 absorbs heat from the pipe material and is heated, is pumped into the connecting pipe 13 by the air pump, is conveyed into the air conveying pipe 11, is sprayed out through the air outlet hole 1101 on the air conveying pipe 11, so that high pressure is formed in the pipe material, and the pipe material is tightly attached to the inner diameter of the shaping box 4 under the extrusion of high pressure to form a regular circle; at the same time, the air in the air jacket 402 is pumped and the internal pressure is reduced to produce a negative pressure, so that a great vacuum adsorption force is generated to tightly attach the outer wall of the pipe material to the shaping box 4, and the production quality and specifications of the pipe material are further improved; the pipe material enters the shaping box 4 and is cooled and formed by the cooling liquid in the cooling jacket 401, the cooling liquid absorbs heat from the pipe material and is heated to form a high-temperature liquid, the high-temperature liquid is pumped into the water tank 6 by the water pump and enters the heat exchanger 7 for heat exchange, so as to reduce the temperature and be pumped into the cooling jacket 401 again through the first heat exchange pipe 9, so as to form a cooling cycle;

[0064] In production, when the air pump pumps hot air, the high-speed flow air pressure is greater than the pre-tightening force of the first spring 15 itself, and then pushes the block 14 to separate from the blocking table 1103 and enters the air supply pipe 11 to increase the pressure. If the pulling speed is too fast, the pipe wall in the shaping box 4 is thinned by pulling, the high-pressure gas pressure inside the pipe material decreases to generate a vacuum adsorption force, and the vacuum adsorption force is less than the pre-tightening force of the first spring 15 itself. Therefore, only the gas in the air supply pipe 1102 can be sucked into the air supply chamber 101 below the diaphragm 16, the diaphragm 16 is deformed under stress to make the two electrode sheets 24 contact each other to connect the current of the alarm lamp 25, and to remind the workers to adjust. At the same time, the diaphragm 16 is deformed under stress to make the slide rod 26 move downward, the third gear 27 installed on the slide rod 26 is embedded in the wheel surface of the fourth gear 33, the second gear 31 is driven to rotate, and then the function of adjusting the pulling speed to slow down is realized, which is convenient for workers to remedy.

[0065] The above is only the preferred specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A method for producing high-strength HDPE drainage pipes, characterized in that, The main steps include: S1: Raw material preparation, high-density polyethylene granules and auxiliary materials are mixed in proportion to form raw material granules; S2: Raw material pretreatment, where raw material particles are placed into pretreatment equipment for drying and melting into a hot melt; S3: Extrusion molding. Hot melt material is fed into an extruder. Through screw rotation and heater heating, pressure is applied to the melt, causing it to be extruded from the die head to form a tubular shape. The die head includes a die sleeve assembly (1) and a die core assembly (2). The die core assembly (2) is coaxially installed inside the die sleeve assembly (1). The die sleeve assembly (1) and the die core assembly (2) are spaced apart to form an extrusion channel (3). S4: Cooling and shaping. The extruded tubing is rapidly cooled and shaped by a shaping device to solidify the shape and size of the tubing. S5: Stretching and Cutting. After cooling, the pipe is stretched to the required length using a traction device and then cut into pipe segments of different lengths using a cutting device. The cut pipe segments need to undergo quality inspection to ensure they meet quality requirements. The traction device includes: Support rods (17) are arranged in a circumferential direction. One end of the support rod (17) is fixedly connected to the shaping device, and the other end of the support rod (17) is fixedly installed with a support ring (18). The support rod (17) is rotatably mounted with two symmetrically arranged tension rollers (35) on the side near the pipe, and a traction belt (19) is tensioned between the two tension rollers (35). A gear disc (20) is rotatably mounted on the support ring (18). One side of the gear disc (20) is connected to one of the tension rollers (35) via a gear assembly. A drive gear (21) is meshed with the other side of the gear disc (20). A drive motor (22) is fixedly mounted on the mold assembly (1). The drive shaft of the drive gear (21) is connected to the drive motor (22) via a speed regulating mechanism. The speed regulating mechanism includes: A gearbox (28) is fixedly installed on the mold assembly (1). A transmission rod (29) is rotatably installed inside the gearbox (28). A first gear (30) and a second gear (31) are coaxially installed on the transmission rod (29). The upper end of the transmission rod (29) passes through the gearbox (28) and is connected to the transmission shaft of the drive gear (21) via a belt drive. A slide rod (26) is slidably installed inside the gearbox (28). A third gear (27) is rotatably installed on the slide rod (26). The third gear (27) meshes with the first gear (30). A fifth gear (34) is fixedly installed on the output end of the drive motor (22). The fifth gear (34) meshes with the third gear (27). A bushing (32) is rotatably installed inside the gearbox (28). The bushing (32) is coaxially arranged with the slide rod (26). A fourth gear (33) is fixedly installed on the bushing (32). The fourth gear (33) meshes with the second gear (31).

2. The method for producing high-strength HDPE drainage pipes according to claim 1, characterized in that, The shaping device described in S4 includes: A shaping box (4) is in contact with the machine head, and a heat insulation pad (5) is fixedly installed on the contact surface between the shaping box (4) and the machine head. A cooling jacket (401) is formed inside the wall of the shaping box (4), and the cooling jacket (401) is filled with coolant; A water tank (6) and a heat exchanger (7) are arranged below the shaping box (4). A water pump is installed in the water tank (6). A delivery pipe (8) is connected between the water tank (6) and the heat exchanger (7). A first heat exchange pipe (9) is fixedly connected between the water tank (6) and the heat exchanger (7) and the shaping box (4). The first heat exchange pipe (9) extends into the cooling jacket (401).

3. The method for producing high-strength HDPE drainage pipes according to claim 2, characterized in that, Also includes: An air jacket (402) is formed inside the wall of the shaping box (4), the air jacket (402) is filled with air, and a second heat exchange tube (10) is fixedly connected between the air jacket (402) and the heat exchanger (7). An air supply pipe (11) is fixedly installed inside the mold core assembly (2). One end of the air supply pipe (11) extends into the mold sleeve assembly (1) and is fixedly connected to the air jacket (402) by a connecting pipe (13). An air pump is installed on the connecting pipe (13). The other end of the air supply pipe (11) extends into the shaping box (4) and is fixedly installed with a mold plate (12). Air outlet holes (1101) are equidistantly opened on the pipe wall of the air supply pipe (11).

4. The method for producing high-strength HDPE drainage pipes according to claim 3, characterized in that, The air jacket (402) has an evacuation channel (4021) on the side near the pipe, and a one-way valve is fixedly installed in the evacuation channel (4021).

5. A method for producing high-strength HDPE drainage pipes according to claim 4, characterized in that, A block (14) is slidably installed inside the air supply pipe (11) in the mold assembly (1). A ring of baffles (1103) that can abut against the block (14) is fixedly installed on the inner wall of the air supply pipe (11). A first spring (15) is fixedly connected between one end of the block (14) and the inside of the air supply pipe (11). The mold assembly (1) has an air supply chamber (101) inside, and an air supply pipe (1102) is fixedly connected between the air supply chamber (101) and the air supply pipe (11).

6. A method for producing high-strength HDPE drainage pipes according to claim 5, characterized in that, A diaphragm (16) is fixedly installed inside the gas replenishment chamber (101). An abutment rod (23) that can contact each other is fixedly installed between the diaphragm (16) and the bottom surface of the gas replenishment chamber (101). Electrode plates (24) are fixedly installed on the opposite surfaces of the upper and lower abutment rods (23). An alarm light (25) is fixedly installed on the mold assembly (1), and the alarm light (25) is electrically connected to the electrode plate (24) through a wire.

7. A method for producing high-strength HDPE drainage pipes according to claim 6, characterized in that, The lower end of the slide rod (26) is fixedly connected to the diaphragm (16), and a second spring (2601) is movably installed on the slide rod (26). The two ends of the second spring (2601) are fixedly connected to the diaphragm (16) and the inner top wall of the air supply chamber (101), respectively. A pin (3301) is fixedly installed on the surface of the fourth gear (33), and the pin (3301) is adapted to the tooth groove of the third gear (27).

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