Krah pipe pipeline structure capable of preventing inner layer from cracking and machining method of Krah pipe pipeline structure

Abstract

The invention discloses a Krah pipe pipeline structure capable of preventing an inner layer from cracking and a processing method thereof, and relates to the technical field of plastic pipelines. The processing method comprises the steps that an HDPE raw material is plasticized and then extruded into a PE flat belt in a molten state, two supporting protrusions are symmetrically arranged in the middle of the PE flat belt, and the two supporting protrusions are in arc connection to form an arc-shaped groove; pE flat belts are synchronously wound on the surface of the preheated steel film, and every two adjacent PE flat belts are in complementary lap joint to form a lap joint position; the lap joint position is rolled after the PE flat belt is wound; the reinforcing ribs are spirally wound on the surface of the PE flat belt at intervals, the reinforcing ribs are embedded into the arc-shaped grooves during winding, and the lap joint position is located between any two adjacent reinforcing ribs; and after the composite molding is finished, cooling, curing and demolding the intermediate product. According to the prepared Krah pipe, the problem of temperature difference shrinkage is effectively solved, the risk of inner side cracking is completely eradicated, the overall structural performance is good, the production stability is good, and the application range is wide.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plastic pipe, in particular to a clara pipe structure for preventing inner layer cracking and a processing method thereof. BACKGROUND

[0002] The cross-sectional structure of the traditional clara pipe is designed by a layered winding process, and the structural composition and forming logic are as follows: the inner layer of the pipe material is made of polyethylene (PE) flat strips, which are formed by adjacent overlapping winding to form the basic inner wall of the pipe material; the outer layer is a shaped reinforcing rib, which is a single-wall corrugated pipe made of polypropylene (PP) coated with PE. The shaped reinforcing rib needs to be precisely aligned and cover the overlapping part of the inner layer PE flat strip to ensure the overall structural strength of the pipe material. In the hot-state winding forming process, the inner layer PE flat strip in the molten state will fuse with the molten coating layer on the surface of the outer layer reinforcing rib, and finally form the cross-sectional structure of the clara pipe under the hot-state winding process.

[0003] To realize the formation of a continuous and firm fusion joint of the PE flat strip in the molten state on the surface of the steel mold, two key temperature parameters need to be precisely controlled: first, the plasticizing temperature of the PE material needs to be stably maintained at 190-210℃ to ensure that the material has good fluidity and fusion; second, the steel mold temperature needs to be controlled at 150-170℃ to provide a suitable thermal environment for the formation of the fusion joint and ensure the fusion quality. After completing the fusion process, in order to meet the production needs of rapid solidification and demolding of the pipe material, the pipe material needs to be cooled to a target range of ≤50℃ to realize the shaping of the pipe material.

[0004] However, during the whole process of pipe material from hot forming (maximum temperature of 210℃) to cooling and shaping (≤50℃), there is a huge temperature difference of more than 160℃, which will cause significant material shrinkage problems: the outer layer shaped reinforcing rib will shrink significantly due to the temperature difference, and because of the physical connection between the reinforcing rib and the overlapping part of the inner layer PE flat strip, the reinforcing rib will directly embed into the overlapping gap of the inner layer PE flat strip during the shrinkage process, resulting in the effective bearing thickness of the inner layer PE flat strip being squeezed and thinned, and finally the actual thickness of the inner layer of the pipe material being lower than the minimum requirement specified in the national standard. At the same time, in the early stage of the cooling stage, the inner layer PE flat strip is still in a semi-molten state that has not been completely cooled and shaped, and under the action of the continuous shrinkage force of the outer layer shaped reinforcing rib, the flat strip overlapping position will be further "tightened", intensifying the thickness loss in this area, forming a double thickness weakening effect of "shrinkage embedding-tightening thinning".

[0005] At present, the core technical scheme of directly attacking the "excessive temperature difference causing the contraction of the reinforcing ribs" has not been found by the production enterprises in the clara pipe industry. In the existing related technologies, usually only the contact length and connection mode of the rib pipe and the pipe body are optimized to solve the problems of rib pipe cooling oval deformation and ring stiffness deficiency, without involving the core pain points of PE flat belt structure design and lap joint contraction embedding; or some related technologies focus on improving the multi-layer composite structure of the rib pipe to improve the fusion compatibility, also without considering the damage of the reinforcing rib contraction caused by the temperature difference to the inner layer of the pipe. This industry pain point not only directly leads to the non-standard thickness of the inner layer of the pipe, affecting the basic performance of the product, but also further aggravates the inner layer cracking risk of the pipe in the subsequent use process due to the uneven thickness of the inner layer and the damage of the structural integrity - especially when the conveying pressure fluctuates or the external environment changes, the weak thickness area is easy to become a stress concentration point, which finally seriously affects the structural stability and service life of the pipe.

[0006] In view of this, the present application is proposed. SUMMARY

[0007] The purpose of the present application is to provide a clara pipe pipeline structure and a processing method for preventing the inner layer from cracking.

[0008] The present application is implemented as follows: In a first aspect, the present application provides a processing method for a clara pipe pipeline structure for preventing the inner layer from cracking, which comprises: extruding a PE flat belt in a molten state after plasticizing an HDPE raw material, the PE flat belt comprising a limiting flat belt part, a first lap joint part and a second lap joint part, two support protrusions being symmetrically arranged in the middle part of the limiting flat belt part, an arc-shaped groove being formed by arc connection between the two support protrusions, and the first lap joint part and the second lap joint part being located at both ends of the limiting flat belt part and used for complementary lap joint of adjacent PE flat belts; synchronously winding the PE flat belt on the surface of a preheated steel film as the inner layer of the clara pipe pipeline structure, and complementary lap joint of two adjacent PE flat belts through the first lap joint part and the second lap joint part to form a lap joint position; 1-2 minutes after winding the PE flat belt, rolling and pressing the lap joint position by using a pressurized roller; spiral interval reinforcing ribs are wound on the surface of the PE flat belt for composite forming as the outer layer of the clara pipe pipeline structure, the reinforcing ribs are embedded in the arc-shaped groove during winding, and the lap joint position is located between any two adjacent reinforcing ribs; after the composite forming is completed, the intermediate product is cooled, solidified and demolded.

[0009] In an optional embodiment, the height of the support protrusion is 4-6 mm, the interval between two support protrusions is 35-37 mm, the circular-arc-shaped groove is recessed from the upper surface of the limiting flat band, the thickness between the bottom of the circular-arc-shaped groove and the lower surface of the limiting flat band is 2.09-2.11 mm, and the circular-arc angle of the circular-arc-shaped groove is 130-140°.

[0010] In an optional embodiment, the upper surface of the first lap joint is horizontal with the upper surface of the limiting flat band, and the lower surface of the first lap joint is located at the middle of the thickness direction of the limiting flat band and is connected to the lower surface of the limiting flat band in an arc transition; the upper surface of the second lap joint is connected to the upper surface of the limiting flat band in an arc transition at the middle of the thickness direction of the limiting flat band; and the lower surface of the second lap joint is horizontal with the lower surface of the limiting flat band.

[0011] In an optional embodiment, the length of the limiting flat band is 90-110 mm, and the length of each of the first lap joint and the second lap joint is 18-22 mm; and / or, the thickness of the limiting flat band is 2.19-2.21 mm, and the maximum thickness of each of the first lap joint and the second lap joint is half of the thickness of the limiting flat band; and / or, the thickness deviation of the first lap joint and the second lap joint after lapping is ≤±0.05 mm.

[0012] In an optional embodiment, the temperature of plasticization is 190-210℃; and / or, the preheating temperature of the steel film is 150-170℃.

[0013] In an optional embodiment, the pressure of the pressure roller on the lapping position is 0.3-0.5 MPa; Preferably, the structure of the pressure roller comprises a horizontal roller and an arc-shaped roller, the arc-shaped roller is two and located at both ends of the horizontal roller, the horizontal roller is used for rolling the lapping position of the first lap joint and the second lap joint, and the curvature of the arc-shaped roller is consistent with the curvature of one side of the support protrusion. Preferably, the fusion strength of the lapping position is ≥22 MPa.

[0014] In an optional embodiment, the structure of the PE coating layer covering the outer surface of the PP single-wall corrugated pipe formed by synchronous extrusion of PP material and modified PE material is used as the reinforcing rib, and the coating thickness of the reinforcing rib is 3.7-6.3 mm. Preferably, the outer wall of the PP single-wall corrugated pipe is provided with annular convex points for enhancing the mechanical bite force between the PP single-wall corrugated pipe and the PE cladding layer; the annular convex points have a height of 0.1-0.2 mm and a wave peak width of 2.0-3.2 mm; and the center distance is 5-10 mm. In an optional embodiment, the material of the modified PE cladding layer comprises PE base material, anti-shrinkage agent and toughening agent in a mass ratio of 100:0.5-1:0.3-0.5. Preferably, the anti-shrinkage agent is nano calcium carbonate. Preferably, the toughening agent is POE.

[0015] In an optional embodiment, the cooling comprises air cooling of the intermediate product by using an annular air duct to reduce the temperature of the intermediate product to 80-90℃, and then water cooling and shaping by using spiral spraying to reduce the temperature of the intermediate product to 50℃. Preferably, the temperature of the cooling air is 23-25℃ (when the ambient temperature is 28-30℃), the air speed of the cooling air is 5-10 m / s, and the cooling time is 10-15 min. Preferably, the temperature of the cooling water is 20-30℃, and the cooling time is 5-8 min.

[0016] In a second aspect, the application provides a clara pipe structure for preventing inner layer cracking, which is prepared by using the processing method for preventing inner layer cracking of the clara pipe structure according to any one of the above embodiments.

[0017] The application has the following beneficial effects: the processing method of the crack-proof clara pipe pipe structure provided by the application, by designing the structure of the PE flat belt 110, especially by using the circular-arc-shaped groove 115 formed by the arc-shaped connection between the two supporting protrusions 114 to accommodate the reinforcing rib 120, limiting and radially supporting the reinforcing rib 120 when the reinforcing rib 120 is wound, and avoiding the oval deformation or contraction of the reinforcing rib 120 caused by the rapid temperature drop during the cooling process. In the embodiment, the connecting position of the reinforcing rib 120 and the PE flat belt 110 is changed, and the overlapping position of the adjacent two PE flat belts 110 is transferred to between the two reinforcing ribs 120, so as to avoid the embedding of the reinforcing rib 120 into the overlapping position of the PE flat belt 110, which causes the insufficient thickness of the inner wall or the cracking of the pipe inner wall caused by the extrusion of external stress. The thickness deviation of the PE flat belt 110 is less than or equal to ±0.05 mm due to the setting of the first overlapping part 112 and the second overlapping part 113, which meets the national standard requirement of GB / T 19472.2-2017; the design of the overlapping position transfer simultaneously rolls and fuses the first overlapping part 112 and the second overlapping part 113, so as to significantly reduce the inner layer cracking rate and significantly improve the structural integrity. The embodiment realizes the integration of "limiting-anti-contracting-anti-embedding", so that the embedding depth of the rib pipe into the overlapping joint is less than or equal to 0.05 mm, and the double effects of "contraction embedding-tightening thinning" are completely avoided. The PE flat belt designed based on the deformation data of the reinforcing rib and the intuitive overlapping control significantly reduce the production waste rate and reduce the pipe forming time of each pipe; through the structural optimization and material modification, the low-temperature resistance of the pipe is improved to no brittle cracking at-30 DEG C, the chemical corrosion resistance covers the pH2-12 interval, and the pipe can be widely applied to municipal drainage, comprehensive pipe gallery, chemical park sewage and other scenes; the application innovates from the three dimensions of structure, material and process, directly attacks the core pain point of the inner layer cracking caused by the temperature difference contraction, and effectively improves the problem of the temperature difference contraction of the crack-proof clara pipe pipe structure, and eliminates the risk of the inner layer cracking, so that the overall structural performance is better, the production stability is better, and the application range is wider. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0019] Figure 1 The structural schematic diagram of the clara pipe pipe structure provided by the application is provided. Figure 2 The structural schematic diagram of the PE flat belt in the clara pipe pipe structure provided by the application is provided. Figure 3The structure schematic diagram of the metal die for forming the PE flat belt provided in the present application is shown in the figure. Figure 4 The structure schematic diagram of rolling the lap joint position of the PE flat belt provided in the present application is shown in the figure. Figure 5 The structure schematic diagram of the cooperation of the PE flat belt and the reinforcing rib in the clara pipe structure provided in the present application is shown in the figure. Figure 6 The structure schematic diagram of the reinforcing rib in the clara pipe structure provided in the present application is shown in the figure. Figure 7 The structure schematic diagram of the reinforcing rib in the clara pipe structure provided in the present application is shown in the figure. Figure 6 The cross-sectional view at A-A in the figure.

[0020] Figure legend: 100-clara pipe structure; 110-PE flat belt; 111-limited flat belt part; 112-first lap joint part; 113-second lap joint part; 114-supporting protrusion; 115-circular-arc-shaped groove; 116-arc-shaped transition; 117-lap joint position; 120-reinforcing rib; 121-PP single-wall corrugated pipe; 122-modified PE cladding layer; 123-annular convex point; 124-wave peak width; 125-central distance; 200-metal die; 300-pressing roller; 310-horizontal roller; 320-arc-shaped roller. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be clearly and completely described below. The specific conditions not mentioned in the embodiments are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments not mentioned by the manufacturer are all conventional products that can be purchased in the market.

[0022] Please refer to Figure 1 The present application provides a processing method of the clara pipe structure 100 for preventing the inner layer from cracking, which comprises: S1, extruding the PE flat belt 110 in a molten state after plasticizing the HDPE raw material.

[0023] The temperature for plasticizing is 190-210℃, and the HDPE raw material after plasticizing is extruded by the metal die 200 with special structure. The structure of the forming interval of the metal die 200 (please refer to Figure 3 ) is the same as the structure of the finally formed PE flat belt 110 (please refer to Figure 2) Keep consistent, based on a large number of special-shaped reinforcing ribs 120 heated deformation size data, using slow wire cutting process processing high-precision metal mouth mold 200 (processing precision up to ± 0.01 mm), the HDPE raw material is heated to 190-210 DEG C plasticizing temperature, through the metal mouth mold 200 melt extrusion molding, ensure the precise realization of PE flat belt 110.

[0024] Specifically, in the present application, please refer to Figure 2 , PE flat belt 110 includes limit flat belt part 111, first lap part 112 and second lap part 113, the middle part of limit flat belt part 111 is symmetrically provided with two supporting protrusions 114, the two supporting protrusions 114 are arc-shapedly connected to form a circular arc-shaped groove 115, the first lap part 112 and the second lap part 113 are located at both ends of the limit flat belt part 111 and are used for complementary lap of adjacent PE flat belts 110.

[0025] In the prior art, the conventional flat belt is flat and equal-thickness, and two adjacent flat belts are connected by lap joint, and the reinforcing rib 120 is arranged at the lap joint. In the embodiment, the structure of the PE flat belt 110 is improved, so that the PE flat belt 110 has two supporting protrusions 114, the circular arc-shaped groove 115 formed by arc-shaped connection between the two supporting protrusions 114 accommodates the reinforcing rib 120, so that the reinforcing rib 120 is limited and radially supported during winding, and the oval deformation or contraction of the reinforcing rib 120 caused by rapid temperature drop during cooling is avoided.

[0026] In the present application, the height of the supporting protrusion 114 is 4-6 mm, the distance between the two supporting protrusions 114 is 35-37 mm, the circular arc-shaped groove 115 is recessed towards the upper surface of the limit flat belt part 111, the thickness between the bottom of the circular arc-shaped groove 115 and the lower surface of the limit flat belt part 111 is 2.09-2.11 mm, and the circular arc angle of the circular arc-shaped groove 115 is 130-140°.

[0027] In the present application, the height of the supporting protrusion 114 is limited, which is designed based on the actual shrinkage of the reinforcing rib 120 at 160 DEG C temperature difference of 0.08~0.2 mm, so that the two supporting protrusions 114 can rigidly engage the rib pipe during cooling. The distance between the two supporting protrusions 114 and the design of the circular arc-shaped groove 115 make the matching degree of the reinforcing rib 120 high, so that the reinforcing rib 120 can be embedded in the circular arc-shaped groove 115 and can effectively limit and engage the reinforcing rib 120. By recessing the circular arc-shaped groove 115 downward, the lowest point is lower than the upper surface of the limit flat belt part 111, so that the reinforcing rib 120 is more matched with the structure of the circular arc-shaped groove 115 when it is arc-shapedly contracted, so that the connection between the limit flat belt part 111 and the reinforcing rib 120 is more closely.

[0028] The upper surface of the first lap joint portion 112 is horizontal with the upper surface of the limiting flat belt portion 111, and the lower surface of the first lap joint portion 112 is located at the middle of the thickness direction of the limiting flat belt portion 111 and connected with the lower surface of the limiting flat belt portion 111 through the arc-shaped transition 116; the upper surface of the second lap joint portion 113 is connected with the upper surface of the limiting flat belt portion 111 through the arc-shaped transition 116 at the middle of the thickness direction of the limiting flat belt portion 111; and the lower surface of the second lap joint portion 113 is horizontal with the lower surface of the limiting flat belt portion 111.

[0029] The thickness of the limiting flat belt portion 111 is 2.19-2.21mm, and the maximum thickness of the first lap joint portion 112 and the second lap joint portion 113 is half of the thickness of the limiting flat belt portion 111; wherein the upper surface and the lower surface of the first lap joint portion 112 are also connected through the arc-shaped transition 116, and the upper surface and the lower surface of the second lap joint portion 113 are also connected through the arc-shaped transition 116. The angle of the arc-shaped transition 116 in the embodiment is about 30°-45°, which can facilitate the matching and alignment of the first lap joint portion 112 and the second lap joint portion 113 of the adjacent two PE flat belts 110 during the lap joint process, thereby improving the lap joint effect, and since the thickness of the first lap joint portion 112 and the second lap joint portion 113 is about half of the thickness of the limiting flat belt portion 111, a complete and conformable surface is formed after the roll pressure fusion lap joint, and the thickness deviation is ≤±0.05mm. In the embodiment, the first lap joint portion 112 and the second lap joint portion 113 with the wedge-shaped complementary on both sides can intuitively judge the lap joint position 117, which can prevent excessive lap joint from causing local thickness exceeding the standard and can avoid insufficient lap joint from causing the thickness not meeting the standard, thereby facilitating real-time adjustment of the lap joint precision during production. In the embodiment, the lap joint position 117 is roll-pressed, which can improve the lap joint effect and reduce the cracking rate of the PE flat belt 110.

[0030] The length of the limiting flat belt portion 111 is 90-110mm, and the length of the first lap joint portion 112 and the second lap joint portion 113 is 18-22mm; by limiting the size of the PE flat belt 110, the pitch of the reinforcing ribs 120 is matched, the adjacent flat belts are accurately lap jointed according to the preset pitch, and the lap joint position 117 is located between the corresponding areas of the two reinforcing ribs 120.

[0031] S2, the PE flat belt 110 is synchronously wound on the surface of the preheated steel film as the inner layer of the Kevlar tube pipeline structure 100, and the adjacent two PE flat belts 110 are complementarily lap jointed through the first lap joint portion 112 and the second lap joint portion 113 to form the lap joint position 117.

[0032] The preheating temperature of the steel film is 150-170℃, the PE flat belt 110 is continuously extruded through the metal mouth die 200 and is synchronously wound on the surface of the steel film, and the adjacent PE flat belts 110 are complementarily overlapped through the first overlapping part 112 and the second overlapping part 113 at a preset pitch, and the overlapping position 117 is located between the corresponding regions of the two reinforcing ribs 120.

[0033] S3, 1-2 minutes after the PE flat belt 110 is wound, the overlapping position 117 is rolled by the pressure roller 300 as shown. Figure 4

[0034] 1-2 minutes after the PE flat belt 110 is wound, the PE flat belt 110 is in a semi-melted state, the melt index is 1.5-2.0 g / 10 min, the overlapping position 117 is rolled by the pressure roller 300, the pressure of the pressure roller 300 on the overlapping position 117 is 0.3-0.5 MPa, the PE at the overlapping position is fully melted and combined, the inner wall surface overlapping joint is eliminated, the smoothness Ra of the inner wall is ensured to be ≤0.8 μm, the fusion strength is ≥22 MPa, and the thickness deviation of the continuously extruded adjacent first overlapping part 112 and second overlapping part 113 after overlapping is ≤±0.05 mm.

[0035] The structure of the pressure roller 300 includes a horizontal roller 310 and an arc-shaped roller 320, the arc-shaped roller 320 is two and located at both ends of the horizontal roller 310, the horizontal roller 310 is used for rolling the overlapping position 117 of the adjacent two first overlapping parts 112 and second overlapping parts 113, and the arc of the arc-shaped roller 320 is consistent with the arc of one side of the supporting protrusion 114. Through the arrangement of the horizontal roller 310 and the arc-shaped roller 320, the overlapping position 117 between any two adjacent PE flat belts 110 can be fully rolled, and the supporting protrusion 114 is supported by the arc-shaped roller 320 and will not be deformed when the overlapping position 117 is rolled, so that the precision of the supporting protrusion 114 is well ensured.

[0036] S4, please refer to Figure 5 The reinforcing rib 120 is spirally and interval-wound on the surface of the PE flat belt 110 to be compounded and formed as an outer layer of the Kevlar tube pipeline structure 100, the reinforcing rib 120 is embedded in the circular-arc-shaped groove 115 during winding, and the overlapping position 117 is located between any two adjacent reinforcing ribs 120.

[0037] Please refer to Figure 6 and Figure 7 ​The reinforcing rib 120 in the application is formed by synchronous extrusion of PP material and modified PE material to form a structure of a PP single-wall corrugated pipe 121 coated with a modified PE coating layer 122 as the reinforcing rib 120, and the coating thickness of the reinforcing rib 120 is 3.7-6.3 mm; the coating thickness is matched with the spacing between the two supporting protrusions 114, the height of each supporting protrusion 114, and the arc of the circular-arc-shaped groove 115, and precise matching can realize sufficient fixing and limiting of the reinforcing rib 120.

[0038] The PP single-wall corrugated pipe 121 provides basic rigidity, and the modified PE coating layer 122 can improve the fusion effect of the reinforcing rib 120 and the PE flat belt 110 by coating the PP single-wall corrugated pipe 121 with PE. Figure 7 The height of the annular protrusion 123 is 0.1-0.2 mm, the wave peak width 124 is 2.0-3.2 mm, and the center spacing 125 is 5-10 mm, and at this time, the interfacial bonding strength of the PP single-wall corrugated pipe 121 and the modified PE coating layer 122 is ≥25 MPa.

[0039] Further, the modified PE coating layer 122 in the application is obtained by modifying PE, wherein the material of the modified PE coating layer 122 includes PE base material, anti-shrinkage agent and toughening agent in a mass ratio of 100:0.5-1:0.3-0.5; preferably, the anti-shrinkage agent is nano calcium carbonate, and the toughening agent is POE.

[0040] In the application, PE is modified, nano calcium carbonate is used as a rigid inorganic filler and filled in the gap of the PE molecular chain to limit the crystallization orientation and relaxation shrinkage of the molecular chain; the interface bonding energy between the nano particles and the PE matrix is high, which can anchor the molecular chain and reduce the volume shrinkage after molding. At the same time, POE (polyolefin elastomer) is a non-crystalline elastomer, which can relieve the shrinkage stress of the crystalline phase and further assist in reducing the overall shrinkage rate, and can further reduce the overall shrinkage rate of the rib pipe from the traditional 2.5% to below 1.0%.

[0041] Meanwhile, PE and PP belong to the same polyolefin and have certain compatibility, but the interface bonding force of pure PE and PP is weak; the molecular structure (ethylene-octene copolymer) of POE is compatible with the non-polar segments of PE and PP, and can be used as an interface compatibilizer to enhance the interface bonding strength of the modified PE coating layer 122 and the modified PE coating layer 122, and can also improve the fusion stability of the reinforcing rib 120 and the PE flat belt 110.

[0042] In addition, unlike the conventional lap position 117 (the reinforcing rib 120 is arranged at the lap joint), the connection position of the reinforcing rib 120 and the PE flat belt 110 is changed in the embodiment, and the conventional reinforcing rib 120 is connected above the lap joint of the PE flat belt 110, while in the embodiment, the lap position of the adjacent two PE flat belts 110 is shifted to between the two reinforcing ribs 120, so that the reinforcing rib 120 is prevented from being embedded in the lap position of the PE flat belt 110 to cause insufficient inner wall thickness or cracking of the inner wall of the pipe due to extrusion under external stress.

[0043] S5, after the completion of the composite molding, the intermediate product is cooled, solidified and demolded.

[0044] After the completion of the composite molding, the intermediate product is transported as a whole to a cooling section for cooling, wherein the cooling includes first air cooling the intermediate product by using an annular air duct to reduce the temperature of the intermediate product to 80-90℃, and then water cooling and shaping by using a spiral spray to reduce the temperature of the intermediate product to 50℃.

[0045] In the present application, the temperature of the intermediate product is slowly reduced by first air cooling and then water cooling, wherein preferably, the temperature of the cooling air is 23-25℃ (when the ambient temperature is 28-30℃), the speed of the cooling air is 5-10m / s, and the cooling time is 10-15min; the speed of the cooling air refers to the exhaust speed, and in actual cooling, due to the PE flat belt 110 and the protruding reinforcing rib 120 of the intermediate product, the local speed is inconsistent, wherein the protruding reinforcing rib 120 first contacts the cooling air, and the cooling speed is higher than that of other areas. Subsequently, water cooling is used for further cooling, and the temperature of the cooling water is 20-30℃, and the cooling time is 5-8min. The temperature of the cooling water is controlled by water temperature closed loop control, and the temperature of the intermediate product is reduced to below 50℃ by water cooling, and the product is demolded after solidification to obtain the anti-cracking clara pipe structure 100.

[0046] The anti-cracking clara pipe structure 100 effectively improves the problem of temperature difference shrinkage, eliminates the risk of internal cracking, has better overall structural performance, and has better production stability. Through structural optimization and material modification, the low-temperature resistance of the pipe is improved to no brittle cracking at -30℃, the chemical corrosion resistance covers the pH2-12 interval, and the pipe can be widely used in municipal drainage, comprehensive pipe gallery, chemical park sewage, etc.

[0047] The features and properties of the present application are further described in detail below in conjunction with the embodiments.

[0048] Embodiment 1 The embodiment provides a processing method of a clara pipe pipe structure 100 for preventing inner layer cracking, which comprises the following steps: S1, after the HDPE raw material is plasticized at 200 DEG C, the plasticized HDPE raw material is extruded into a PE flat strip 110 in a molten state by a metal die 200, and the structure of the metal die 200 is consistent with the structure of the finally formed PE flat strip 110.

[0049] The thickness of the limiting flat strip part 111 of the extruded PE flat strip 110 is 2.2mm, and the maximum thickness of the first lap part 112 and the second lap part 113 is half of the thickness of the limiting flat strip part 111; wherein the upper surface and the lower surface of the first lap part 112 are also connected by arc-shaped transitions 116, and the upper surface and the lower surface of the second lap part 113 are also connected by arc-shaped transitions 116. The angle of the arc-shaped transitions 116 in the embodiment is about 45°; the length of the limiting flat strip part 111 is 100mm; and the length of the first lap part 112 and the second lap part 113 is 20mm.

[0050] The height of the supporting protrusion 114 on the limiting flat strip part 111 is 5mm, the distance between the two supporting protrusions 114 is 36mm, the circular-arc-shaped groove 115 is recessed to the upper surface of the limiting flat strip part 111, the thickness between the bottom of the circular-arc-shaped groove 115 and the lower surface of the limiting flat strip part 111 is 2.1mm, and the circular-arc angle of the circular-arc-shaped groove 115 is 135°.

[0051] S2, the PE flat strip 110 continuously extruded by the metal die 200 is synchronously wound on the surface of the steel film preheated to 160 DEG C as the inner layer of the clara pipe pipe structure 100 according to a preset pitch, and the adjacent two PE flat strips 110 are complementarily lapped by the first lap part 112 and the second lap part 113 to form a lap position 117, and the lap position 117 is located between the corresponding regions of the two reinforcing ribs 120.

[0052] S3, 2min after the PE flat strip 110 is wound, the lap position 117 is rolled by the pressurized roller 300, the pressure during rolling is 0.4MPa, so that the PE at the lap position is fully fused and combined, and the thickness deviation of the continuously extruded adjacent first lap part 112 and second lap part 113 after lapping is ≤±0.05mm.

[0053] S4, forming a structure of a PP single-wall corrugated pipe 121 coated with a PE coating layer as a reinforcing rib 120 by synchronous extrusion of the PP material and the modified PE material, the coating thickness of the reinforcing rib 120 being 4 mm; and winding the reinforcing rib 120 on the surface of the PE flat belt 110 in a spiral interval to form a composite as an outer layer of the Krah pipe structure 100, and embedding the reinforcing rib 120 in the circular-arc-shaped groove 115 during winding, and locating the lap joint position 117 between any two adjacent reinforcing ribs 120.

[0054] The outer wall of the PP single-wall corrugated pipe 121 is provided with annular protrusions 123 for enhancing the mechanical interlocking force between the PP single-wall corrugated pipe 121 and the modified PE coating layer 122, the height of the annular protrusions 123 being 0.15 mm, the peak width 124 being 2.8 mm, and the center distance 125 being 8 mm, so that the interfacial bonding strength of the PP single-wall corrugated pipe 121 and the modified PE coating layer 122 is ≥ 25 MPa.

[0055] The material of the modified PE coating layer 122 comprises PE base material, anti-shrinkage agent and toughening agent in a mass ratio of 100:0.8:0.4; the anti-shrinkage agent is nano calcium carbonate; and the toughening agent is POE.

[0056] S5, after the composite molding is completed, the intermediate product is transported as a whole to a cooling section to be cooled by air and water in sequence, wherein the temperature of the cooling air is 23℃ (when the ambient temperature is 28℃), the air speed of the cooling air is 8 m / s, the cooling time is 12 min, the temperature of the intermediate product is reduced to 85℃, and then the intermediate product is further cooled by water cooling, the temperature of the cooling water is 25℃, the cooling time is 7 min, the temperature of the intermediate product is reduced to below 50℃ by water cooling, and the product Krah pipe structure 100 is demolded after solidification.

[0057] Example 2 The embodiment provides a processing method of a Krah pipe structure 100 capable of preventing the inner layer from cracking, which comprises the following steps: S1, extruding the PE flat belt 110 in a molten state from the HDPE raw material after plasticizing at 190℃ by using a metal die 200, the structure of the metal die 200 being consistent with the structure of the finally formed PE flat belt 110.

[0058] The thickness of the limiting flat belt part 111 of the extruded PE flat belt 110 is 2.19 mm, and the maximum thickness of the first lap part 112 and the second lap part 113 is half of the thickness of the limiting flat belt part 111; wherein the upper surface and the lower surface of the first lap part 112 are also connected by arc-shaped transitions 116, and the upper surface and the lower surface of the second lap part 113 are also connected by arc-shaped transitions 116. The angle of the arc-shaped transitions 116 in this embodiment is about 30°-45°; the length of the limiting flat belt part 111 is 90 mm; and the length of the first lap part 112 and the second lap part 113 is 18 mm.

[0059] The height of the support protrusion 114 on the limiting flat belt part 111 is 4 mm, the distance between the two support protrusions 114 is 35 mm, the circular-arc-shaped groove 115 is recessed towards the upper surface of the limiting flat belt part 111, the thickness between the bottom of the circular-arc-shaped groove 115 and the lower surface of the limiting flat belt part 111 is 2.09 mm, and the circular-arc angle of the circular-arc-shaped groove 115 is 130°.

[0060] S2, the continuously extruded PE flat belt 110 of the metal die 200 is synchronously wound on the steel film surface preheated to 150°C as the inner layer of the Krah pipe structure 100, and the first lap part 112 and the second lap part 113 of the two adjacent PE flat belts 110 are complementarily lapped to form a lap position 117, and the lap position 117 is located between the corresponding regions of the two reinforcing ribs 120.

[0061] S3, 1 min after the PE flat belt 110 is wound, the lap position 117 is rolled and pressed by the pressurized roller 300, and the pressure during rolling and pressing is 0.3 MPa, so that the PE at the lap position is fully fused and combined, and the thickness deviation of the continuously extruded first lap part 112 and the second lap part 113 after lapping is ≤±0.05 mm.

[0062] S4, the PP material and the modified PE material are synchronously extruded to form a structure of a PP single-wall corrugated pipe 121 with a PE coating layer as a reinforcing rib 120, and the coating thickness of the reinforcing rib 120 is 3.7 mm; the reinforcing rib 120 is spirally and intervaliy wound on the surface of the PE flat belt 110 for composite molding as the outer layer of the Krah pipe structure 100, and the reinforcing rib 120 is embedded in the circular-arc-shaped groove 115 during winding, and the lap position 117 is located between any two adjacent reinforcing ribs 120.

[0063] The outer wall of the PP single-wall corrugated pipe 121 is provided with annular convex points 123 for enhancing the mechanical bite force of the PP single-wall corrugated pipe 121 and the modified PE cladding layer 122, the height of the annular convex points 123 is 0.1 mm, the peak width 124 is 2.0 mm, and the center distance 125 is 5 mm, at this time, the interfacial bonding strength of the PP single-wall corrugated pipe 121 and the modified PE cladding layer 122 is greater than or equal to 25 MPa.

[0064] The material of the modified PE cladding layer 122 includes PE base material, anti-shrinkage agent and toughening agent in a mass ratio of 100:0.5:0.3; the anti-shrinkage agent is nano calcium carbonate; and the toughening agent is POE.

[0065] S5, after the composite molding is completed, the intermediate product is transported as a whole to a cooling section to sequentially perform air cooling and water cooling, wherein the temperature of the cooling air is 25 DEG C (when the ambient temperature is 30 DEG C), the air speed of the cooling air is 5 m / s, the cooling time is 15 min, the temperature of the intermediate product is reduced to 90 DEG C, and then water cooling is further performed to cool the intermediate product, the temperature of the cooling water is 20 DEG C, the cooling time is 5 min, the temperature of the intermediate product is reduced to below 50 DEG C through water cooling, and after solidification, the intermediate product is demolded to obtain the finished product, i.e., the clara pipe pipeline structure 100 capable of preventing the inner layer from cracking.

[0066] Embodiment 3 The embodiment provides a processing method of a clara pipe pipeline structure 100 capable of preventing the inner layer from cracking, which comprises the following steps: S1, after the HDPE raw material is plasticized at 210 DEG C, the plasticized HDPE raw material is extruded into a PE flat strip 110 in a molten state through a metal die 200, and the structure of the metal die 200 is consistent with the structure of the finally formed PE flat strip 110.

[0067] The thickness of the limiting flat strip part 111 of the extruded PE flat strip 110 is 2.21 mm, and the maximum thickness of the first lap part 112 and the second lap part 113 is half of the thickness of the limiting flat strip part 111; wherein the upper surface and the lower surface of the first lap part 112 are also connected through arc-shaped transitions 116, and the upper surface and the lower surface of the second lap part 113 are also connected through arc-shaped transitions 116. The angle of the arc-shaped transitions 116 in the embodiment is about 45 DEG ; the length of the limiting flat strip part 111 is 110 mm; and the length of the first lap part 112 and the second lap part 113 is 22 mm.

[0068] The height of the support protrusions 114 on the limiting flat strip part 111 is 6 mm, the distance between the two support protrusions 114 is 37 mm, the circular-arc-shaped grooves 115 are recessed towards the upper surface of the limiting flat strip part 111, the thickness between the bottom of the circular-arc-shaped grooves 115 and the lower surface of the limiting flat strip part 111 is 2.11 mm, and the circular-arc angle of the circular-arc-shaped grooves 115 is 140 DEG.

[0069] S2, the continuously extruded PE flat tape 110 of the metal die 200 is synchronously wound on the steel film surface preheated to 170 DEG C as the inner layer of the corrugated pipe structure 100, and the adjacent two PE flat tapes 110 are complementarily overlapped by the first and second overlapping portions 112 and 113 to form overlapping positions 117, and the overlapping positions 117 are located between the corresponding regions of the two reinforcing ribs 120.

[0070] S3, 2 minutes after the PE flat tape 110 is wound, the overlapping position 117 is rolled by the pressure roller 300, and the pressure during rolling is 0.5 MPa, so that the PE at the overlapping position is fully fused and combined, and the thickness deviation of the continuously extruded first and second overlapping portions 112 and 113 after overlapping is ≤ ± 0.05 mm.

[0071] S4, the PP single-wall corrugated pipe 121 is formed by synchronously extruding the PP material and the modified PE material to form a structure of the PE coating layer as the reinforcing rib 120, and the coating thickness of the reinforcing rib 120 is 6.3 mm; the reinforcing rib 120 is spirally and intervaliy wound on the surface of the PE flat tape 110 to be compounded as the outer layer of the corrugated pipe structure 100, and the reinforcing rib 120 is embedded in the circular-arc-shaped groove 115 during winding, and the overlapping position 117 is located between any two adjacent reinforcing ribs 120.

[0072] The outer wall of the PP single-wall corrugated pipe 121 is provided with annular protrusions 123 for enhancing the mechanical engagement force of the PP single-wall corrugated pipe 121 and the modified PE coating layer 122, the height of the annular protrusions 123 is 0.2 mm, the peak width 124 is 3.2 mm, and the center distance 125 is 10 mm, and at this time, the interface bonding strength of the PP single-wall corrugated pipe 121 and the modified PE coating layer 122 is ≥ 25 MPa.

[0073] The material of the modified PE coating layer 122 includes PE base material, anti-shrinkage agent and toughening agent in a mass ratio of 100:1:0.5; the anti-shrinkage agent is nano calcium carbonate; and the toughening agent is POE.

[0074] S5, after the compounding is completed, the intermediate product is transported as a whole to a cooling section to be air-cooled and water-cooled in sequence, wherein the cooling air has a temperature of 23 DEG C (when the ambient temperature is 28 DEG C), the cooling air has a wind speed of 10 m / s, and the cooling time is 10 min, so that the temperature of the intermediate product is reduced to 80 DEG C; then the water cooling is further carried out, and the cooling water has a temperature of 30 DEG C, and the cooling time is 8 min, so that the temperature of the intermediate product is reduced to below 50 DEG C through water cooling, and the demolding is completed after solidification, and the finished product is obtained.

[0075] Comparative Example 1 The comparative example provides a clara tube which is basically the same as example 1, and the difference is only that the structure of the PE flat belt 110 is different, the rolling step is omitted, the PE coating layer is directly prepared by using conventional PE material, and the connection position of the flat belt and the reinforcing rib 120 is different, which specifically includes the following steps: S1, the HDPE raw material is plasticized at 200 DEG C, and the PE flat belt 110 in the extruded melt state is obtained by extruding the above plasticized HDPE raw material through the metal die 200. The PE flat belt 110 is a flat belt with a horizontal surface, which does not contain the supporting protrusion 114 and the circular arc groove 115 in example 1, and only has the first lap joint part 112 and the second lap joint part 113.

[0076] S2, the PE flat belt 110 continuously extruded by the metal die 200 is synchronously wound on the surface of the steel film preheated to 160 DEG C as the inner layer of the clara tube pipeline structure 100, and the adjacent two PE flat belts 110 are complementarily jointed by the first lap joint part 112 and the second lap joint part 113 to form the joint position 117.

[0077] S3, the PP material and the PE material are synchronously extruded to form the structure of the PP single-wall corrugated pipe 121 with a PE coating layer as the reinforcing rib 120, and the coating thickness of the reinforcing rib 120 is 4mm; the reinforcing rib 120 is spirally and interval wound on the surface of the PE flat belt 110 for composite forming as the outer layer of the clara tube pipeline structure 100, and the reinforcing rib 120 is located directly above the joint position 117 during winding.

[0078] S4, after the composite forming is completed, the intermediate product is transported to the cooling section in whole to be air cooled and water cooled in turn, wherein the cooling air temperature is 23 DEG C (when the ambient temperature is 28 DEG C), the cooling air speed is 8m / s, the cooling time is 12min, the temperature of the intermediate product is reduced to 85 DEG C, and then the water cooling is further carried out, the cooling water temperature is 25 DEG C, the cooling time is 7min, the temperature of the intermediate product is reduced to below 50 DEG C through the water cooling, the solidification is completed, the mold is demolded, and the finished clara tube is obtained.

[0079] Comparative example 2 The comparative example is basically the same as example 1, and the difference is only that the height of the supporting protrusion 114 in the comparative example is 3mm, the distance between the two supporting protrusions 114 is 32mm, and the circular arc angle of the circular arc groove 115 is 120 DEG.

[0080] Comparative example 3 The comparative example is basically the same as example 1, and the difference is only that the height of the supporting protrusion 114 in the comparative example is 7mm, the distance between the two supporting protrusions 114 is 40mm, and the circular arc angle of the circular arc groove 115 is 150 DEG.

[0081] Comparative example 4 This comparative example is basically the same as Example 1, the only difference is that the step S3 is omitted in this comparative example.

[0082] Comparative Example 5 This comparative example is basically the same as Example 1, the only difference is that the pressure during rolling is 0.8 MPa in this comparative example.

[0083] Comparative Example 6 This comparative example is basically the same as Example 1, the only difference is that the material of the PE coating layer only contains PE base material in this comparative example.

[0084] Experimental Example This experimental example detects the performance of the clara pipe provided in the above examples and comparative examples, and the detection items include: ring stiffness, tensile force at the welding position, pitch (center distance between adjacent reinforcing ribs), distance between the lowermost reinforcing rib and the inner wall of the pipe material (i.e. the distance between the bottom of the PP single-wall corrugated pipe and the bottom of the flat band measured by cross section).

[0085]

[0086] From the above table, it can be seen that: (1) The cracking rate of the PE flat band 110 is related to the pressure of the overlapping position 117, the reinforcing rib 120 and the pressure roller 300 during rolling. The overlapping position 117 is below the reinforcing rib 120, which is easy to cause the PE flat band 110 to crack; in addition, the overlapping position is outside the reinforcing rib 120, and when rolling through the pressure roller 300, if the pressure exceeds the pressure range, the overlapping position 117 is also easy to crack and the interfacial bonding force is reduced; (2) The bonding force of the overlapping part of the PE flat band 110 (i.e. the tensile force at the welding position) is related to whether the overlapping position 117 is below the reinforcing rib 120 and whether the pressure roller 300 is added for rolling, and the pressure of the rolling also has a very close effect. If the rolling air pressure exceeds the range, the overlapping part is not tight or the overall thickness of the overlapping part is thinned, which is not tight, and the bonding force of the overlapping part is low; if the thickness is thinned, the tensile force will also be reduced; (3) The winding deviation rate and the shrinkage embedding rate of the reinforcing rib 120 are related to the structure of the flat band. The PE flat band 110 has support protrusions 114 and arc-shaped grooves 115 structure, but if the support protrusions 114, the support spacing and the arc angle exceed the range, it is easy to cause the winding deviation rate of the reinforcing rib to increase, the shrinkage embedding rate of the reinforcing rib to increase, and also has a certain influence on the stiffness; (4) The ring stiffness of the clara pipe is related to whether the reinforcing rib 120 and the PE flat band 110 have support protrusions 114 and arc-shaped grooves 115 structure, and the modified PE coating layer 122. The most important thing is to have a PP single-wall corrugated pipe as an inner support for the reinforcing rib 120, otherwise, it cannot be formed and the ring stiffness is very low.

[0087] In summary, the processing method of the anti-inner-layer-cracking clara pipe pipe structure 100 provided by the present application, by designing the structure of the PE flat belt 110, especially using the circular-arc-shaped groove 115 formed by the arc-shaped connection between the two supporting protrusions 114 to accommodate the reinforcing rib 120, limiting and radially supporting the reinforcing rib 120 when it is wound, avoiding the oval deformation or contraction of the reinforcing rib 120 caused by the rapid temperature drop during the cooling process. In this embodiment, the connection position of the reinforcing rib 120 and the PE flat belt 110 is changed, and the lap joint position of the adjacent two PE flat belts 110 is shifted to between the two reinforcing ribs 120, avoiding the embedding of the reinforcing rib 120 into the lap joint position of the PE flat belt 110, which causes the inner wall thickness to be insufficient or extruded by external stress, resulting in cracking of the pipe inner wall. The thickness deviation of the PE flat belt 110 is ≤±0.05mm due to the setting of the first lap joint part 112 and the second lap joint part 113, which meets the national standard requirement of GB / T 19472.2-2017, and the precision is improved by 75% compared with the traditional process; the lap joint position is shifted, and the first lap joint part 112 and the second lap joint part 113 are simultaneously rolled and fused, which reduces the inner layer cracking rate from 15~20% to 0% in the traditional process, and the structural integrity is significantly improved. The embodiment realizes the integration of "limiting-anti-shrinking-anti-embedding", and the depth of the rib pipe embedded in the lap joint is ≤0.05mm, completely avoiding the double effects of "shrinkage embedding-tightening thinning". In addition, the coating of the reinforcing rib 120 is modified in the present application, so that it can realize molecular-level fusion with the PE flat belt 110, so that the pipe ring stiffness can reach SN16-SN24 (improved by 100% compared with the traditional one), the interface bonding strength is ≥25MPa, the hydraulic friction coefficient is ≤0.009, the conveying efficiency is improved and the impurity accumulation is reduced; the PE flat belt 110 and the direct lap joint control designed based on the deformation data of the reinforcing rib 120 in the present application reduce the production waste rate by more than 75% (from 8~10% to ≤2%) compared with the traditional process, and the forming time of each pipe is reduced by 10-15min; through structural optimization and material modification, the low-temperature resistance of the pipe is improved to no brittle cracking at-30℃, and the chemical corrosion resistance covers the pH2-12 interval, which can be widely used in municipal drainage, comprehensive pipe gallery, chemical park sewage and other scenes; the present application innovates from the three dimensions of structure, material and process, directly attacks the core pain point of inner layer cracking caused by temperature difference shrinkage, and effectively improves the problem of temperature difference shrinkage of the anti-inner-layer-cracking clara pipe pipe structure 100 prepared, and eliminates the risk of inner layer cracking, the overall structural performance is better, the production stability is better, and the application range is wider.

[0088] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method of processing a clara pipe pipe structure for preventing cracking of an inner layer, characterized by, It comprises: The PE flat belt in the extruded melt state is obtained after the HDPE raw material is plasticized, the PE flat belt comprises a limiting flat belt part, a first lap joint part and a second lap joint part, two support protrusions are symmetrically arranged in the middle part of the limiting flat belt part, the two support protrusions are connected in an arc shape to form a circular-arc-shaped groove, and the first lap joint part and the second lap joint part are located at two ends of the limiting flat belt part and are used for complementary lap joint of adjacent PE flat belts; The PE flat belt is synchronously wound on the surface of the preheated steel film as the inner layer of the Krah pipe structure, and adjacent two PE flat belts are complementary lap jointed through the first lap joint part and the second lap joint part to form a lap joint position; The lap joint position is rolled by a pressure roller 1-2 minutes after the PE flat belt is wound; The reinforcing rib is embedded in the circular-arc-shaped groove during winding, and the lap joint position is located between any two adjacent reinforcing ribs; After the composite molding is completed, the intermediate product is cooled, solidified and demolded.

2. The method of processing a Corzan® pipe pipe structure to prevent cracking of the inner layer according to claim 1, wherein, The height of the support protrusion is 4-6 mm, the spacing between the two support protrusions is 35-37 mm, the circular-arc-shaped groove is recessed towards the upper surface of the limiting flat belt part, the thickness between the bottom of the circular-arc-shaped groove and the lower surface of the limiting flat belt part is 2.09-2.11 mm, and the circular-arc angle of the circular-arc-shaped groove is 130-140°.

3. The method of processing a Corzan® pipe pipe structure to prevent cracking of the inner layer of claim 1, wherein, The upper surface of the first lap joint part is horizontal with the upper surface of the limiting flat belt part, and the lower surface of the first lap joint part is located in the middle of the thickness direction of the limiting flat belt part and is arc-shaped transitionally connected with the lower surface of the limiting flat belt part. The upper surface of the second lap joint part is arc-shaped transitionally connected with the upper surface of the limiting flat belt part in the middle of the thickness direction of the limiting flat belt part, and the lower surface of the second lap joint part is horizontal with the lower surface of the limiting flat belt part.

4. The method of processing a Corzan® pipe pipe structure to prevent cracking of the inner layer of claim 3, wherein, The length of the limiting flat belt part is 90-110 mm, and the length of the first lap joint part and the second lap joint part is 18-22 mm. And / or, the thickness of the limiting flat belt part is 2.19-2.21 mm, and the maximum thickness of the first lap joint part and the second lap joint part is half of the thickness of the limiting flat belt part. And / or, the thickness deviation of the adjacent first lap joint part and second lap joint part after lap joint is ≤±0.05 mm.

5. The method of processing a Corzan® pipe pipe structure to prevent cracking of the inner layer of claim 1, wherein, The plasticizing temperature is 190-210℃; And / or, the preheating temperature of the steel film is 150-170℃.

6. The method of processing a Corzan® pipe pipe structure to prevent cracking of the inner layer of claim 1, wherein, The pressure of the pressure roller on the lap joint position is 0.3-0.5 MPa. Preferably, the structure of the pressure roller comprises a horizontal roller and an arc-shaped roller, the arc-shaped roller is two and located at two ends of the horizontal roller, the horizontal roller is used for rolling the lap joint position of adjacent two first lap joint parts and second lap joint parts, and the curvature of the arc-shaped roller is consistent with the curvature of one side of the support protrusion. Preferably, the fusion strength of the lap joint position is ≥22 MPa.

7. The method of processing a Corzan® pipe pipe structure to prevent cracking of the inner layer of claim 1, wherein, The outer surface of the PP single-wall corrugated pipe is coated with a modified PE coating layer by synchronous extrusion of PP material and modified PE material, the coating thickness of the reinforcing rib is 3.7-6.3mm; Preferably, the outer wall of the PP single-wall corrugated pipe is provided with annular convex points for enhancing the mechanical bite force between the PP single-wall corrugated pipe and the PE coating layer; the height of the annular convex points is 0.1-0.2mm, the peak width is 2.0-3.2mm, and the center distance is 5-10mm.

8. The method of processing a Corzan® pipe pipe structure to prevent cracking of the inner layer of claim 7, wherein, The material of the modified PE coating layer comprises PE base material, anti-shrinkage agent and toughening agent in a mass ratio of 100:0.5-1:0.3-0.5; Preferably, the anti-shrinkage agent is nano calcium carbonate; Preferably, the toughening agent is POE.

9. The method of processing a clara pipe pipe structure to prevent cracking of the inner layer according to any one of claims 1 to 8, characterized in that, The cooling comprises air cooling of the intermediate product by using an annular air duct to reduce the temperature of the intermediate product to 80-90℃, and then water cooling and shaping by using spiral spraying to reduce the temperature of the intermediate product to 50℃; Preferably, the temperature of the cooling air is 23-25℃, the air speed is 5-10m / s, and the cooling time is 10-15min; Preferably, the temperature of the cooling water is 20-30℃, and the cooling time is 5-8min.

10. A clara pipe conduit structure for preventing cracking of an inner layer, characterized by, The pipe is prepared by the processing method of the pipe structure for preventing the inner layer from cracking according to any one of claims 1-9.

Images