TWI812474B - Extrusion molding equipment, extrusion molding system and mold for coating polyvinyl chloride dipping liquid on metal pipes - Google Patents

Abstract

An extrusion molding equipment, an extrusion molding system and a mold for coating metal pipes with polyvinyl chloride dipping liquid. The extrusion molding equipment includes a primer device and an extrusion molding system. The primer device is used to coat a primer layer on the metal pipe. The extrusion molding system includes a feeding device, a preheating device, a mold and a sol supply device. The mold is used to extrude the polyvinyl chloride dipping liquid onto the primer layer to form a plastic layer. The mold has a pipe channel, two fluid channels and a glue channel. The glue channel is used to squeeze the polyvinyl chloride dipping liquid onto the primer layer of the metal pipe. The sol supply device has at least one glue storage cylinder for loading the polyvinyl chloride dipping solution and a driving unit. The driving unit is used to inject the polyvinyl chloride dipping liquid into the glue channel of the mold.

Description

Extrusion molding equipment, extrusion molding system and mold for coating metal pipes with polyvinyl chloride dipping liquid

The invention relates to a plastic extrusion molding equipment, in particular to an extrusion molding equipment, an extrusion molding system and a mold for coating a metal pipe with polyvinyl chloride dipping liquid.

Polyvinyl chloride (PVC) coated pipe has excellent insulation and corrosion and chemical resistance, which can extend the service life of electrical pipeline systems in harsh environments. It is often used in wire transmission pipes, petrochemical industry piping and power communication protection pipes.

The common manufacturing method of polyvinyl chloride coated pipes is dipping. First, the preheated metal pipe is completely immersed in a large dipping tank containing polyvinyl chloride solution for dipping and adhesion. After coming out of the tank, it is shaped and dried. A layer of polyvinyl chloride protective layer is formed on the outer surface of the metal pipe, but the metal pipe often suffers from vertical flow problems after coming out of the tank, which affects the quality. In addition, the film thickness and true roundness of the polyvinyl chloride protective layer produced by this method The temperature is uneven, the quality is inconsistent, and during the operation process, a large amount of operating waste gas will be generated due to the large area contact of the preheated metal pipe with the polyvinyl chloride solution, which is not environmentally friendly, so it needs to be improved.

Therefore, the first object of the present invention is to provide an extrusion molding equipment for coating metal pipes with polyvinyl chloride dipping liquid, which has stable film thickness and quality and an environmentally friendly manufacturing process.

Therefore, the extrusion molding equipment of the present invention for coating metal pipes with polyvinyl chloride dipping liquid includes a primer device and an extrusion molding system.

The primer device includes a painting unit, which is used to coat a primer layer on the outer peripheral surface of the metal pipe.

The extrusion molding system is used to extrude the polyvinyl chloride dipping liquid onto the primer layer of the metal pipe to form a plastic layer. The extrusion molding system is arranged along a feeding path and includes a feeding device, a pre-coat Thermal device, a mold and a sol supply device. The feeding device is used to drive the metal pipe to move and generate a driving force for the metal pipe to move on the feeding path, so that the metal pipe with the primer layer can advance along the feeding path. The preheating device is located on the feeding path and used to heat the metal pipe with the primer layer.

The mold is located on the feeding path and adjacent to the preheating device. The mold is used to extrude the polyvinyl chloride dipping solution onto the primer layer of the metal pipe to form the plastic layer. The mold has a mold body. and a heating module provided on the mold body. The mold body defines a pipe channel around an axis for the metal pipe to pass through. The mold body has a feeding end adjacent to the preheating device, a feeding end in the feeding path, and a feeding end adjacent to the preheating device. A discharge end that is diametrically opposite to the feed end, two fluid channels surrounding the axis and between the feed end and the discharge end, and a glue surrounding the axis and between the fluid channels. Channels, these fluid channels are used to pass in the fluid that blocks the heat source. The glue channel is connected to the pipe channel space and is used to squeeze the polyvinyl chloride dipping liquid onto the primer layer of the metal pipe. The heating module is disposed at the discharge end and used to heat the plastic layer and solidify the plastic layer. The sol supply device has at least one glue storage cylinder for loading the polyvinyl chloride dipping liquid, and a driving unit connected to the at least one glue storage cylinder. The driving unit is used to inject the polyvinyl chloride dipping liquid into the glue channel of the mold.

The second object of the present invention is to provide a mold for polyvinyl chloride dipping liquid extrusion molding equipment with stable film thickness and quality and an environmentally friendly manufacturing process.

Therefore, the mold of the polyvinyl chloride dipping liquid extrusion molding equipment of the present invention is suitable for extruding and coating the polyvinyl chloride dipping liquid into a metal pipe. The mold of the polyvinyl chloride dipping liquid extrusion molding equipment includes a The mold body and a heating module.

The mold body defines a pipe channel surrounding an axis for the metal pipe to advance along a feeding path. The mold body has an input end, a discharge end opposite to the input end, two fluid channels surrounding the axis and between the input end and the discharge end, and a fluid channel surrounding the axis and between The glue channel between the fluid channels. The fluid channels are used to pass in the fluid that blocks the heat source. The glue channel is spatially connected with the pipe channel and is used to squeeze the polyvinyl chloride dipping solution onto the metal pipe to form a plastic layer. The heating module is arranged at the discharge end of the mold body and is used to heat the plastic layer and The plastic layer is allowed to solidify.

The third object of the present invention is to provide a polyvinyl chloride dipping liquid extrusion molding system with stable film thickness and quality and an environmentally friendly manufacturing process.

Therefore, the polyvinyl chloride dipping liquid extrusion molding system of the present invention is suitable for extruding and coating the polyvinyl chloride dipping liquid into a metal pipe. The polyvinyl chloride molding liquid extrusion molding system includes a feeding device, a Preheating device, a mold and a sol supply device.

The feeding device is used to drive the metal pipe to move and generate a driving force for the metal pipe to move along a feeding path, so that the metal pipe can advance along the feeding path. The preheating device is located on the feeding path and used to heat the metal pipe. The mold is located on the feeding path and adjacent to the preheating device. The mold is used to extrude the polyvinyl chloride dipping solution onto the metal pipe to form a plastic layer. The mold has a mold body and a The heating module of the mold body defines a pipe channel surrounding an axis for the metal pipe to pass through. The mold body has a feeding end adjacent to the preheating device and a feeding end on the feeding path. Opposite to the discharge end of the feed end, two fluid channels surrounding the axis and between the feed end and the discharge end, and a glue channel surrounding the axis and between the fluid channels, The fluid channels are used to pass in the fluid that blocks the heat source. The glue channel is spatially connected with the pipe channel and is used to squeeze the polyvinyl chloride dipping liquid to cover the metal pipe. The heating module is arranged at the discharging The end is used to heat and solidify the plastic layer. The sol supply device has at least one glue storage cylinder for loading the polyvinyl chloride dipping liquid, and a drive connected to the at least one glue storage cylinder. The driving unit is used to inject the polyvinyl chloride dipping liquid into the glue channel of the mold.

The effect of the present invention is to utilize the design of the fluid channels of the mold and cooperate with the sol supply device to stably supply glue, and as the feeding device pushes the metal pipe forward, the polyvinyl chloride dipping liquid can pass through the The glue track is gradually coated on the primer layer of the metal pipe and extruded into the plastic layer. Since the present invention is covered at a single point in the mold, it can prevent sagging and save the amount of polyvinyl chloride dipping liquid. , and the plastic layer has a uniform film thickness and good roundness, and does not produce operating waste gas. It has the effects of stable film thickness and quality and an environmentally friendly process.

11: Pre-treatment device

111: Coarse unit

112: Blower unit

113:Wind cutting room

114:Vacuum cleaner

12: Primer device

120: Primer liquid

121:Painting unit

122: Air drying unit

123: Brush wheel

124: Primer barrel

125:Pneumatic vacuum valve

126:Hot air channel

127:Blower

128:Electric heater

13: Takeover device

14: Baking device

15: Cooling device

16: Unloading device

17: Pipe fitting traversing machine

200:Extrusion molding system

3: Feeding device

31: Conveyor belt

32: Positioning rotating component group

321: Rotating parts

4: Preheating device

41:Heater

5: Mold

51:Mold body

511:Tube channel

512: Feed end

513: Discharge end

514: Fluid channel

515: Glue channel

516:Exhaust channel

517:Glue injection port

518: Fluid channel

5181:Oil inlet

5182:Oil outlet

519: Air cooling barrier area

52:Heating module

53: Thermocouple

6: Sol supply device

61:Glue storage cylinder

611: Barrel body

612:Piston

613:Sealing ring parts

614:Exhaust valve

615: Discharge valve

62: Drive unit

621:Putter set

622: Motor group

623:Screw

624: Nut

625: Motor

626:Reducer

627: Positioning guide pillar

628: Pulley

63: Diverter valve

64:Supply unit

641:Cylinder

8: Pipe joint

81:Pipeline

9:Metal tube

90:PVC coated pipe

901: Inner surface

902: Outer peripheral surface

91: Primer layer

92:Plastic layer

L:Length direction

P:Feeding path

I: normal temperature zone

II: Preheating area

III:High temperature zone

S: Polyvinyl chloride dipping liquid

X: axis

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: Figure 1 is the first embodiment of the extrusion molding equipment for coating polyvinyl chloride dipping liquid on metal pipes according to the present invention. a schematic diagram; Figure 2 is a cross-sectional view illustrating a mold of an extrusion molding system of the first embodiment; Figure 3 is a partial enlarged view of Figure 1 illustrating a pre-treatment device and a Primer device; Figure 4 is a partial enlarged view of Figure 1, illustrating the extrusion molding system, a baking device and a cooling device; Figure 5 is an operational schematic diagram of a sol supply device of the first embodiment; Figure 6 is a top view of the sol supply device; Figure 7 is a flow chart illustrating the operation process of the first embodiment; Figure 8 is a cross-sectional view of the mold according to the second embodiment of the present invention; Figure 9 is a sectional view of the mold according to the second embodiment of the present invention. A cross-sectional view of the mold of a second embodiment of the invention; Figure 10 is a cross-sectional view similar to Figure 9, illustrating a variation of the mold of the third embodiment; and Figure 11 is a cross-sectional view illustrating the sol supply A variation of the device.

Referring to Figures 1 to 3, the first embodiment of the extrusion equipment for coating polyvinyl chloride dipping liquid S on metal pipes according to the present invention is suitable for extruding the polyvinyl chloride dipping liquid S through the in-mold molding method in many applications. The metal pipes 9 are each extruded to cover with a plastic layer 92 to produce a PVC covered pipe 90 . Each metal tube 9 extends along a length direction L and has an inner circumferential surface 901 and an outer circumferential surface 902 opposite to the inner circumferential surface 901. The metal tube 9 in the first embodiment is a round tube, but not This is the limit. The material of the metal pipe 9 is selected from iron, steel, copper, aluminum or alloy, and can be divided into thick conduit, thin conduit, EMT (Electric Metallic Tubing) and flexible metal pipe according to the type and pipe wall thickness. Four kinds. The polyvinyl chloride dipping liquid S is a commercial product. It is a liquid made from polyvinyl chloride (PVC) mixed with various additives and processed through multiple processes. It will undergo a cross-linking reaction and then solidify at temperatures above 160 to 170°C.

The extrusion equipment includes a pre-treatment device 11, a primer device 12, a connecting device 13, an extrusion molding system 200, a baking device 14, a cooling device 15, an unloading device 16 and multiple pipe fittings. Move machine 17.

The pretreatment device 11 is used for surface roughening the outer peripheral surface 902 of the metal pipe 9 . The pretreatment device 11 includes a roughening unit 111 for surface roughening and a blower unit 112 . The roughening unit 111 of the first embodiment is a sandblasting machine. In other embodiments, a wire wheel, a sandpaper pulley or other equivalent devices can also be used, as long as the outer peripheral surface 902 of the metal pipe 9 can be surface roughened. . The purpose of surface roughening is to increase the bonding ability between the metal pipe 9 and subsequent coating materials. The blower unit 112 forms an air-cutting chamber 113 through which airflow flows, and a vacuum cleaner 114 is used to suck the airflow to take away the dust generated during the operation of the roughening unit 111 .

The primer device 12 is located behind the pre-treatment device 11 and includes a painting unit 121 and an air-drying unit 122. The painting unit 121 is used to apply primer on the roughened outer peripheral surface 902 of the metal pipe 9 To form a primer layer 91, the primer of the first embodiment is a commercially available liquid paint, the reaction temperature is 200°C, and the reaction time is at least 10 minutes. The setting of the primer layer 91 can increase the metal content. The combination of pipe 9 and the polyvinyl chloride dipping liquid S.

The painting unit 121 of the first embodiment has at least one brush wheel 123 containing primer, a primer tube 124 containing primer liquid 120 and used to replenish primer to the brush wheel 123, and a primer tube 124 disposed on the brush wheel 123. There is a pneumatic vacuum valve 125 on the bottom side of the brush wheel 123 . It’s time to brush The wheel 123 first absorbs the primer and then rolls the primer on the outer peripheral surface 902 of the metal pipe 9 to form the primer layer 91. Specifically, the brush wheel 123 is composed of an annular paint injection seat and is coated on the outer circumferential surface 902 of the metal pipe 9. The outer circumferential surface of the annular paint injection seat is composed of annular multi-layer cloth, and the brush wheel 123 has high wear resistance. The primer barrel 124 of the first embodiment intermittently injects paint into the brush wheel 123 so that the brush wheel 123 can continuously apply primer, and the excess primer can be discharged through the pneumatic vacuum valve 125 , this coating method can save the amount of primer. In other variations, the painting unit 121 can also use a spray painting device, a painting device or other equivalent devices, as long as the primer layer 91 can be formed on the outer peripheral surface 902 of the metal pipe 9 .

The air-drying unit 122 is used to blow the air flow to the primer layer 91 of the metal tube 9 and air-dry the primer layer 91 to facilitate the subsequent production process. The air-drying unit 122 of the first embodiment has an air dryer for the metal tube 9 The hot air channel 126 passing through and containing circulating hot air, a blower 127 used to form the hot air channel 126, and an electric heating sheet 128 located on the path of the hot air channel 126 and used for heating, can be generated by the air drying unit 122 Hot air at 50° C. is circulated to dry the primer layer 91 of the metal pipe 9 . In other variations, the air-drying unit 122 can also be other air-drying devices such as a vortex fan, but is not limited thereto.

Referring to FIGS. 1 and 4 , the takeover device 13 and the primer device 12 are spatially arranged in parallel and are located behind the primer device 12 in terms of production schedule. The connecting device 13 is used to plug a pipe joint 8 between two metal pipes 9 along the length direction L so that the two metal pipes 9 are connected in series along the length direction L, thereby achieving the purpose of continuous production operations. . In other variations, the takeover device 13 and the primer device 12 can also be spatially arranged. In a straight line, as long as the production operation can be continuous.

The extrusion molding system 200 is located behind the connecting device 13 and is used to extrude the polyvinyl chloride dipping liquid S onto the primer layer 91 of the metal pipe 9 to form the plastic layer 92. The extrusion molding system 200 It is arranged along a feeding path P and includes a feeding device 3 , a preheating device 4 , a mold 5 and a sol supply device 6 . The feeding path P is parallel to the length direction L of the metal pipe 9 .

Referring to Figure 1, Figure 2 and Figure 4, the feeding device 3 is used to drive the metal pipes 9 to move and generate a driving force for the metal pipes 9 to move in the feeding path P, so that the primer layer 91 has the Each metal pipe 9 can advance along the feeding path P. The feeding device 3 of the first embodiment has two conveyor belts 31 symmetrically arranged on both top and bottom sides of the feeding path P, and multiple sets of positioning rotating component groups 32 arranged at intervals along the feeding path P. The belt 31 is a belt conveyor belt. The conveyor belts 31 are respectively sandwiched between the top and bottom sides of the metal pipe 9 to generate the driving force for the metal pipe 9 and thereby push the metal pipe 9 forward. Due to the strength of the metal pipe 9 The primer layer 91 has been dried by the air-drying unit 122, so the conveyor belts 31 can frictionally contact the metal pipe 9. The number of the conveyor belts 31 can be determined according to the diameter of the metal pipe 9. The metal pipe 9 with a smaller diameter only needs two conveyor belts 31 to have sufficient driving force, while the metal pipe 9 with a larger diameter needs four. The conveyor belts 31 are symmetrically arranged at the top, bottom, left and right positions of the feeding path P to ensure that sufficient driving force is generated. In order to allow the metal pipes 9 to accurately advance along the feeding path P, the first embodiment sets the positioning positions at appropriate intervals on the feeding path P. The rotating member assembly 32 allows the metal pipes 9 to slide through. Each positioning rotating component group 32 has two rotating components 321 for the metal tubes 9 to slide through. In this embodiment, each rotating component 321 is a ball bearing, but it can also be a roller, a pulley or a roller. and other rotatable components, and the number of the rotating members 321 can also be a group of four, so as to be suitable for the metal pipe 9 with a larger diameter.

The preheating device 4 is located on the feeding path P and used to heat the metal pipe 9 with the primer layer 91 . The preheating device 4 has a plurality of heaters 41. In the first embodiment, the heaters 41 are ovens and are numbered #1 to #4 respectively. The heating temperatures of the heaters 41 change with the change of the feeding path P. Advance and decrease, through multi-stage heating, the metal pipe 9 can reach 200°C (the reaction temperature of the primer layer 91) and completely pass through the preheating device within the time (10 minutes) that the primer layer 91 needs to react. 4. In other variations, the preheating device 4 can also be replaced by a high-frequency heater and an oven, as long as the metal pipe 9 can be heated to 200°C and the metal pipe 9 can be completely passed through the preheating device. The time of device 4 (the time from entering the oven numbered #1 to leaving the oven numbered #4) is exactly the reaction time required for the primer layer 91, so that the extrusion molding system 200 can maintain the same feeding speed.

The mold 5 is located on the feeding path P and adjacent to the heater 41 numbered #4 of the preheating device 4. The mold 5 is used to squeeze the polyvinyl chloride dipping liquid S to coat the metal pipe 9 Primer layer 91 to form the plastic layer 92. The mold 5 has a mold body 51 and a heating module 52 arranged on the mold body 51. The mold body 51 surrounds The circumference defines a tube channel 511 surrounding an axis X for the metal tube 9 to pass through. The mold body 51 of the first embodiment adopts a modular quick mold change design, and multiple modules are combined to create the required internal channels. Therefore, the metal pipe 9 of different diameters can be replaced with a suitable mold 5 for use. .

The mold body 51 has an inlet end 512 adjacent to the preheating device 4, a discharge end 513 opposite to the inlet end 512 on the feeding path P, and two internal and surrounding axis X. Fluid channels 514 and 518 between the inlet end 512 and the outlet end 513, a glue channel 515 located inside and surrounding the axis X and between the fluid channels 514 and 518, and an air-cooling barrier District 519. The fluid channels 514 and 518 are open to the outside and communicate with the surrounding environment space. The fluid channels 514 and 518 are used to introduce fluid that blocks the heat source. The fluid channel 514 of the first embodiment is adjacent to the feed end 512 and is used to pass the first fluid. Specifically, the first fluid is cooling water, and the cooling water is injected from one end and flows out from the other end. A circulating water path is formed to keep this area at normal temperature. The fluid channel 518 is further away from the feed end 512 than the fluid channel 514 and is used to pass in a second fluid with a temperature higher than that of the first fluid. Specifically, the second fluid is liquid oil at 80° C., and is used A mold temperature controller (not shown) controls the liquid oil temperature at 80°C and forms a circulating oil circuit, thereby maintaining a preheating temperature of 80°C in this area. However, in other embodiments, the fluid channels 514 and 518 can also be injected with other liquids or gases, as long as they can be maintained in a predetermined temperature range lower than the heating temperature of the heating module 52 .

The glue channel 515 is spatially connected with the pipe channel 511 and is used to allow the polyvinyl chloride dipping liquid S to pass through, so that the polyvinyl chloride dipping liquid S is extruded and coated on the primer layer 91 of the metal pipe 9 to form a The plastic layer 92. The glue channel 515 of the first embodiment has two glue injection ports 517 open to the surrounding environment (only one is shown in the figure), so it is suitable for the metal pipe 9 with a smaller diameter. If the metal pipe 9 If the diameter is smaller or larger, a mold with one or four glue injection ports 517 can be selected. The mold 5 can be designed with different numbers of the glue injection ports 517 according to the diameter of the metal tube 9 .

The air-cooling blocking area 519 is formed on the outer peripheral surface and is located between the glue channel 515 and the fluid channel 518 . The air-cooling blocking area 519 is used to block heat transfer from the fluid channel 518 to the glue channel 515 . Specifically, the air-cooling blocking area 519 is a heat dissipation fin.

The heating module 52 is disposed at the discharge end 513 and is used to heat the plastic layer 92 and pre-curing the plastic layer 92 . The heating module 52 of the first embodiment is an electric heating sheet covering the discharge end 513 and adjacent to the fluid channel 518 . In order to control the temperature of the heating module 52 to maintain at 160~170°C, a thermocouple 53 for controlling the temperature is provided inside the heating module 52 .

It should be noted that since the polyvinyl chloride dipping liquid S will begin to undergo a cross-linking reaction and gradually solidify when the temperature is higher than a certain temperature range (for example, 160~170°C), in order to allow the polyvinyl chloride dipping liquid S to The metal tube 9 can maintain its fluidity before being coated, so the glue channel 515 is designed between the fluid channels 514 and 518. Through the design of the fluid channel 514 and the air-cooling barrier area 519, the fluidity is maintained. The gathering in Glue Road 515 Vinyl chloride dipping liquid S can be in a liquid state and flow smoothly. By preheating the fluid channel 518, the polyvinyl chloride dipping liquid S near the outlet of the glue channel 515 can gradually transform into a semi-solidified but still flowable state. Finally, the polyvinyl chloride dipping liquid S begins to solidify through high-temperature heating by the heating module 52 .

Referring to FIGS. 4 to 6 , the sol supply device 6 is fluidly connected to the mold 5 through a pipeline 81 and is used to inject the polyvinyl chloride dipping liquid S into the mold 5 . The sol supply device 6 has a glue storage cylinder 61 , a driving unit 62 , a diverter valve 63 and a supply unit 64 .

The glue storage cylinder 61 is used to fill the polyvinyl chloride dipping liquid S and has a cylinder body 611 fluidly connected with the glue channel 515 of the mold 5, and a piston 612 movably disposed in the cylinder body 611. . Specifically, the barrel body 611 is made of a honed seamless steel pipe. The piston 612 has a sealing ring 613 for fluid sealing, and is also formed with an exhaust valve 614 and a discharge valve 615. The sealing ring 613 is an inner tube in a flat shape and is sealed to the inner surface of the barrel body 611 by tension, which can reduce pushing resistance and withstand high pressure.

The driving unit 62 is connected to the piston 612 of the glue storage barrel 61 and is used to drive the piston 612 to move up and down to squeeze the polyvinyl chloride dipping liquid S and inject it into the glue channel 515 of the mold 5 (see Figure 2 ). The driving unit 62 has a push rod group 621 connected to the piston 612, and a motor group 622 used to drive the push rod group 621 to move. The push rod group 621 has a screw rod 623 connected to the piston 612, and two screw rods 623 parallel to the screw rod 623. A positioning guide post 627 is provided and connected to the piston 612, and a nut 624 is provided on the screw rod 623 and connected to the motor group 622. The screw rod 623 is a trapezoidal lead screw that can rotate forward and reverse. The nut 624 It is a trapezoidal thread guide nut. The motor assembly 622 is connected to the nut 624 through a pulley 628 to drive the screw rod 623 to rotate forward and backward to move up and down, thereby driving the piston 612 to move. Specifically, the motor group 622 has a motor 625 and a reducer 626 connected to the motor 625. The motor 625 is a stepper motor. Through the speed change of the reducer 626, the transmission torque can be increased to make the polyvinyl chloride The dipping liquid S can flow out of the glue storage cylinder 61 at a constant speed and in equal amounts, so the glue supply is stable.

The diverter valve 63 is provided in the pipeline 81 and is used to divert the polyvinyl chloride dipping liquid S, and then inject it into the glue channel 515 of the mold 5 through the glue injection ports 517. If the mold 5 has only one glue injection port 517, the diverter valve 63 can be omitted.

The replenishing unit 64 is used to automatically replenish the polyvinyl chloride dipping liquid S into the glue storage cylinder 61 , for example, using a pneumatic cylinder to automatically replenish the glue storage cylinder 61 . In other embodiments, the supply unit 64 can also be omitted, and the glue storage cylinder 61 can be directly replenished manually.

The following describes the glue supply method of the sol supply device 6: first open the exhaust valve 614, the drive unit 62 pushes the piston 612 downward to exhaust the air in the barrel body 611, and stops the piston 612 after the exhaust is complete. And close the exhaust valve 614. When the discharging valve 615 is opened, the driving unit 62 starts to push the piston 612 downward to cause the barrel body 611 to discharge glue. When the polyvinyl chloride dipping liquid S in the barrel body 611 is used up, the piston When 612 is pressed down to the bottom of the barrel body 611, it will touch the micro switch and automatically stop. Then, the piston 612 is quickly raised to a predetermined position, and the polyvinyl chloride dipping liquid S is supplied to the glue storage cylinder 61 through the supply unit 64, so that the glue supply can be continued.

Through the transmission ratio design of the motor group 622, the first embodiment outputs a large torque without generating pulses, and is very suitable for squeezing the thick fluid-like polyvinyl chloride dipping liquid S, so the sol is supplied The glue supply of device 6 is more stable and smooth. It should be noted that in other variations, two glue storage barrels 61 can also be provided at the same time to increase the capacity and extend the replenishing time, and the motor 625 can also be a servo motor.

Referring to Figures 1 and 4, the baking device 14 is located after the extrusion molding system 200 and is used to heat the metal pipe 9 that has passed through the extrusion molding system 200 to completely solidify the plastic layer 92. The baking device 14 of the first embodiment is a hot air circulation oven set at 160°C.

The cooling device 15 is located after the baking device 14 and is used to cool down the metal pipe 9 with the plastic layer 92 that has passed through the baking device 14. The cooling device 15 in the first embodiment is an annular water spray. The water curtain can shorten the length and has the effect of cooling the entire pipe, thereby shortening the cooling time and reducing the production cycle. However, in other variations, the cooling device 15 can also be a water tank.

The unloading device 16 is located behind the cooling device 15 and is used to separate the two connected metal pipes 9. The unloading device 16 in the first embodiment uses a Y-shaped cutter to cut half a circle of the pipe joint 8. Separate the two metal tubes 9. But the unloading method is not based on this Limit, as long as the connected metal pipes 9 can be separated.

The pipe traversing machines 17 are used to move the metal pipes 9 in a direction perpendicular to the feeding path P. Specifically, there is a pipe traversing machine numbered #1 in front of the pre-processing device 11 17. There is a pipe traversing machine 17 numbered #2 between the takeover device 13 and the primer device 12, and a pipe traversing machine 17 numbered #3 is provided behind the unloading device 16. , using the configuration of the pipe traversing machine 17, the metal pipes 9 can be transported with the smallest floor space, reducing the overall length of the equipment on the feeding path P.

Referring to Figure 1, Figure 2 and Figure 7, the operation process of the first embodiment is further described below:

Surface roughening step 801 uses the pipe fitting traversing machine 17 numbered #1 and a set of pulleys to transfer the metal pipes 9 to the pre-treatment device 11 one by one, and perform surface roughening sandblasting on the metal pipes 9 Homework.

In the priming step 802 , the painting unit 121 is used to roll primer onto the outer peripheral surface 902 of the metal pipe 9 to form the primer layer 91 .

In the primer air-drying step 803, the air-drying unit 122 quickly air-dries the primer layer 91 with a hot air flow of 50°C.

In the taking over step 804, the metal pipes 9 are transferred to the taking over device 13 through the pipe fitting traversing machine 17 numbered #2, and each pipe joint 8 is plugged into every two metal pipes using the taking over device 13. 9. Connect the metal pipes 9 in series.

In the preheating step 805, the conveyor belts 31 of the feeding device 3 are used to entrain each of the metal pipes 9 and each metal pipe 9 passes through the heaters 41, and the heaters numbered #1 to #4 are heated. The device 41 is set to 300°C, 275°C, 250°C, and 200°C respectively. The time between each metal tube 9 entering the heater 41 numbered #1 and leaving the heater 41 numbered #4 is exactly the reaction time required for the primer layer 91 of 10 minutes. Therefore, the time required for each metal tube 9 The primer layer 91 has reacted completely after leaving the heater 41 numbered #4, and has reached the absolute activation coating temperature before arriving at the extrusion molding system 200 . During the movement, the center of each metal tube 9 is aligned with the axis X of the tube channel 511 of the mold body 51 through the positioning and rotating component groups 32, so that it can be continuously transported linearly.

In extrusion die molding step 806, as shown in Figure 5, the conveyor belts 31 continue to drive the metal pipes 9 toward the mold 5, and the design of the positioning rotating component groups 32 arranged at intervals along the feeding path P is used to make the The metal tube 9 is positioned at the center of the mold 5, which can reduce the pushing resistance of the conveyor belts 31 and make the coating thickness of the plastic layer 92 uniform. The mold 5 forms normal temperature zone I, preheating zone II and high temperature zone III in different temperature ranges based on the design of the fluid channels 514 and 518, the air-cooling isolation zone 519 and the heating module 52. The driving unit 62 drives the piston 612 in the glue storage cylinder 61 to move, and causes the polyvinyl chloride dipping liquid S to continuously and slowly discharge glue from the glue storage cylinder 61 and inject it into the glue channel through the glue injection ports 517 515. When each metal pipe 9 advances to contact the glue channel 515 , the polyvinyl chloride dipping liquid S will gradually cover the primer layer 91 of each metal pipe 9 and form its own plastic layer 92 . The present invention is a single-point in-mold molding, and the glue The amount of glue output from the channel 515 is exactly the total amount of the plastic layer 92, so the amount of the polyvinyl chloride dipping liquid S can be saved. In the normal temperature zone I, the polyvinyl chloride dipping liquid S is at normal temperature and is in a liquid and flowable state. In the preheating zone II, the polyvinyl chloride dipping liquid S is heated to 80°C and is semi-solidified. state and gradually covers the primer layer 91 of the metal tube 9 to form the plastic layer 92. In the high temperature zone III, each metal tube 9 is heated to 160~170°C by the heating module 52, so that the The plastic layer 92 and the thermally reacted primer layer 91 are bridged and joined to undergo a cross-linking reaction and start to solidify. The discharge end 513 uses the heating module 52 to be an electrothermal forming ring, so that the extrusion molding has good roundness and no sagging phenomenon. When each metal tube 9 leaves the mold 5, the pre-curing degree of the plastic layer 92 has reached at least 70% to 80%.

In the baking step 807, each metal tube 9 leaves the mold 5 and moves to the baking device 14. The baking device 14 is set to 160°C. The plastic layer 92 is completely solidified through the baking of the baking device 14. .

In cooling step 808, each metal tube 9 after baking and solidification passes through the cooling device 15 to cool down each metal tube 9 with the plastic layer 92. The surface of the plastic layer 92 becomes bright and smooth.

In the pipe cutting and separation step 809, the unloading device 16 is used to cut off the pipe joints 8 between each two metal pipes 9, thereby producing a single PVC coated pipe 90.

The above-mentioned baking device 14, the cooling device 15 and the unloading device 16 are arranged on the feeding path P, and each two metal pipes 9 are connected in series through each pipe joint 8, and The feeding device 3 can continuously push the metal tubes 9 without interruption. It can be understood that the baking device 14 , the cooling device 15 and the unloading device 16 can also be independent of the feeding path P, and use other pushing devices or moving devices to move the metal pipes 9 .

The present invention injects the liquid polyvinyl chloride dipping solution S into a closed mold for PVC coating, and produces the cured plastic layer 92. At the same time, it combines the advantages of injection molding and extrusion molding. The present invention is a single-point The coated in-mold molding can prevent sagging and save the amount of polyvinyl chloride dipping liquid S. The plastic layer 92 has a uniform film thickness, good roundness, and does not generate operating waste gas, so it has stable quality and The manufacturing process has the advantage of being more environmentally friendly, so the purpose of the present invention can indeed be achieved. In addition, when the present invention is in operation, each metal pipe 9 will only move linearly and will not rotate. Therefore, in addition to being suitable for round pipes, the present invention can also be applied to square pipes or other pipe fittings, as long as they have a uniform cross-section. A pipe fitting with a small area is sufficient, and the shape of the metal pipe 9 is not limited, so the applicability of the present invention is good.

Referring to FIG. 8 , the second embodiment of the present invention is similar to the first embodiment. The difference lies in that the mold body 51 of the mold 5 also has an air extraction channel located between the glue channel 515 and the fluid channel 514 . 516, the air extraction channel 516 is used to connect an external vacuum pump and form a negative pressure environment in the pipe channel 511, so as to increase the coating of the polyvinyl chloride dipping liquid S and the metal pipe 9. The air extraction channel 516 has two air extraction ports open to the surrounding environment, but is not limited thereto.

The mold body 51 omits the air-cooling barrier area 519 (see Figure 2) and the fluid channel 518 is passed into cooling water. The fluid channels 514 and 518 block the heat source from transmitting heat energy to the glue channel 515, which can also make the glue The polyvinyl chloride dipping liquid S in the channel 515 is kept in a flowable state, and the mold 5 forms the normal temperature zone I, the preheating zone II and the high temperature zone III.

Referring to FIG. 9 , the third embodiment of the present invention is similar to the second embodiment, except that the mold body 51 has only one air extraction port in the air extraction channel 516 .

The fluid channel 518 has two oil inlets 5181 and two oil outlets 5182. Through the two-inlet and two-outlet design, the 80°C liquid oil is diverted to achieve better temperature distribution. The polyvinyl chloride dipping liquid S in the glue channel 515 can also be kept in a flowable state, and the mold 5 can form the normal temperature zone I, the preheating zone II and the high temperature zone III.

Referring to Figure 10, in a variation, the air extraction channel 516 (see Figure 9) can be omitted, which can also keep the polyvinyl chloride dipping liquid S in the glue channel 515 in a flowable state, and make the mold 5 forms the normal temperature zone I, the preheating zone II and the high temperature zone III.

In addition, referring to FIG. 11 , which is a variation of the sol supply device 6 , the piston 612 of the glue storage cylinder 61 has two sealing rings 613 , and each of the sealing rings 613 is an O-ring. Adding a back support ring can also achieve fluid sealing.

However, the above are only examples of the present invention and should not be used to limit the scope of the present invention. Any application for patent scope and patent specification based on the present invention Simple equivalent changes and modifications to the content are still within the scope of the patent of the present invention.

11: Pre-treatment device

12: Primer device

121:Painting unit

122: Air drying unit

13: Takeover device

14: Baking device

15: Cooling device

16: Unloading device

17: Pipe fitting traversing machine

200:Extrusion molding system

3: Feeding device

31: Conveyor belt

32: Positioning rotating component group

4: Preheating device

41:Heater

5: Mold

6: Sol supply device

8: Pipe joint

9:Metal tube

90:PVC coated pipe

P:Feeding path

Claims (10)

An extrusion molding equipment for coating metal pipes with polyvinyl chloride dipping liquid, including: a primer device, including a painting unit, the painting unit is used to coat a primer layer on the outer peripheral surface of the metal pipe ; and an extrusion molding system for extruding the polyvinyl chloride dipping solution onto the primer layer of the metal pipe to form a plastic layer. The extrusion molding system is arranged along a feeding path and includes: a feeding A device used to drive the metal pipe to move and generate a driving force for the metal pipe to move on the feeding path, so that the metal pipe with the primer layer can advance along the feeding path. A preheating device is located on the feeding path. On the path and used to heat the metal pipe with the primer layer, a mold is located on the feeding path and adjacent to the preheating device, the mold is used to extrusion coat the polyvinyl chloride dipping liquid on the metal The primer layer of the pipe is used to form the plastic layer. The mold has a mold body and a heating module arranged on the mold body. The mold body defines a pipe channel surrounding an axis for the metal pipe to pass. The mold body has an inlet end adjacent to the preheating device, a discharge end opposite to the inlet end on the feeding path, and two surrounding the axis and between the inlet end and the discharge end. The fluid channels and a glue channel surrounding the axis and between the fluid channels are used to pass in the fluid that blocks the heat source. The glue channel is connected to the pipe channel space and is used to make the polychloride Vinyl dipping liquid is extruded and coated on the metal pipe On the primer layer, the heating module is arranged at the discharge end and is used to heat the plastic layer and initially solidify the plastic layer, and a sol supply device has at least one for loading the polyvinyl chloride dip A glue storage cylinder for plastic liquid, and a driving unit connected to the at least one glue storage cylinder. The driving unit is used to inject the polyvinyl chloride dipping liquid into the glue channel of the mold. The extrusion molding equipment for coating metal pipes with polyvinyl chloride dipping liquid as described in claim 1 also includes a pre-treatment device for surface roughening the outer peripheral surface of the metal pipe, and the painting unit is The primer layer is coated on the outer peripheral surface of the roughened metal pipe. The extrusion molding equipment for coating metal pipes with polyvinyl chloride dipping liquid as described in claim 1, wherein the feeding device has at least two conveyor belts symmetrically arranged on two opposite sides of the feeding path, and a plurality of groups Positioning rotating component groups are arranged at intervals along the feeding path. The conveyor belts are used to carry the metal pipe and generate the driving force for the metal pipe. Each positioning rotating component group has two positions for the metal pipe to slide. passing rotating parts. The extrusion molding equipment for coating metal pipes with polyvinyl chloride dipping liquid as described in claim 1, wherein the preheating device has a plurality of heaters, and the heating temperatures of the heaters increase along with the advancement of the feeding path. And decreasing. The extrusion molding equipment for coating polyvinyl chloride dipping liquid on metal pipes as described in claim 1 also includes a baking device, a cooling device and an unloading device arranged after the extrusion molding system. The baking device is used to heat the metal tube that has passed through the extrusion molding system to solidify the plastic layer, and the cooling device is used to heat the plastic layer that has passed through the baking device. The metal pipe is cooled down, and the unloading device is used to separate the two connected metal pipes. A mold for polyvinyl chloride dipping liquid extrusion molding equipment, suitable for extruding and coating the polyvinyl chloride dipping liquid into a metal pipe. The mold for the polyvinyl chloride dipping liquid extrusion molding equipment includes: a mold body , defining a pipe channel that surrounds an axis and allows the metal pipe to advance along a feeding path. The mold body has an inlet end, an outlet end opposite to the inlet end, and two outlets around the axis and between A fluid channel between the inlet end and the discharge end, a glue channel surrounding the axis and between the fluid channels, these fluid channels are used to pass in the fluid that blocks the heat source, the glue channel and The pipe channel is spatially connected and is used to squeeze the polyvinyl chloride dipping liquid onto the metal pipe to form a plastic layer; and a heating module is provided at the discharge end of the mold body and is used to heat the plastic The layer is heated and initially solidifies the plastic layer. The mold of polyvinyl chloride dipping liquid extrusion molding equipment as claimed in claim 6, wherein one of the fluid channels of the mold body is adjacent to the feed end and is used to pass in the first fluid, and the other fluid channel The channel is adjacent to the heating module and used to introduce a second fluid with a temperature higher than the first fluid and lower than the temperature of the heating module. A polyvinyl chloride plastic dipping liquid extrusion molding system is suitable for extruding and coating the polyvinyl chloride plastic dipping liquid into a metal pipe. The polyvinyl chloride plastic dipping liquid extrusion molding system includes: a feeding device for driving The metal tube moves and generates a driving force for the metal tube to move along a feeding path, so that the metal tube can move along the feeding path. The material path advances; a preheating device is located on the feeding path and used to heat the metal pipe; a mold is located on the feeding path and adjacent to the preheating device, and the mold is used to soak the polyvinyl chloride in plastic liquid The metal pipe is extruded to form a plastic layer. The mold has a mold body and a heating module set on the mold body. The mold body defines a pipe channel surrounding an axis for the metal pipe to pass through. , the mold body has an inlet end adjacent to the preheating device, a discharge end opposite to the inlet end on the feeding path, and two surrounding the axis and between the inlet end and the discharge end. and a glue channel surrounding the axis and between the fluid channels. The fluid channels are used to pass in the fluid that blocks the heat source. The glue channel is connected to the pipe channel space and is used to make the The polyvinyl chloride dipping liquid is extruded and coated on the metal pipe, the heating module is arranged at the discharge end and is used to heat the plastic layer and initially solidify the plastic layer; and a sol supply device has at least one A glue storage cylinder for filling the polyvinyl chloride dipping liquid, and a driving unit connected to the at least one glue storage cylinder. The driving unit is used to inject the polyvinyl chloride dipping liquid into the glue channel of the mold. The polyvinyl chloride dipping liquid extrusion molding system according to claim 8, wherein the at least one glue storage barrel has a barrel body in fluid communication with the glue channel of the mold, and a barrel movably disposed on the barrel body. There is a piston in the body, and the driving unit is used to drive the piston to move so that the polyvinyl chloride dipping liquid is injected into the glue channel of the mold. The piston has at least one sealing ring for fluid sealing. The polyvinyl chloride dipping liquid extrusion molding system as described in claim 9, wherein, The driving unit has a push rod group corresponding to the at least one glue storage barrel and connected to the piston, and a motor group used to drive the push rod group. The motor group drives the push rod group to move to drive the piston linearly. Move.

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