Manufacturing method of high thermal conductive perforated steel belt composite plastic pipe

Abstract

The application provides a manufacturing method of a high-thermal-conductivity hole net steel belt composite plastic pipe and relates to the technical field of composite plastic pipe manufacturing. The application comprises the following steps: step one, configuring raw materials of modified resin; step two, blending and pretreating the modified resin raw materials to form blended modified materials; and step three, adding the blended modified materials into an extruder to be combined with a metal framework to form a composite plastic pipe. The application can prepare a high-thermal-conductivity composite plastic pipe with high pressure resistance and heat resistance. The pipe material is made of pipeline-grade heat-resistant plastic resin which is modified to be a new composite plastic pipe material with a wider application range, and the use temperature, service life, heat transfer efficiency and energy-saving effect are obviously improved.

Description

Technical Field

[0001] This invention relates to the field of composite plastic pipe manufacturing technology, and in particular to a method for manufacturing high thermal conductivity perforated steel strip composite plastic pipes. Background Technology

[0002] Perforated steel-reinforced composite pipe is a new type of steel-plastic composite pipe with polyethylene plastic as the matrix and welded perforated steel strip as the reinforcement. This composite pipe effectively combines steel and plastic materials, thus possessing excellent comprehensive properties such as pressure resistance and corrosion resistance. However, in some pipelines or heat exchangers used in petrochemical processes involving high strength and corrosive endothermic or exothermic substances, although perforated steel-reinforced plastic composite pipe has excellent pressure resistance and corrosion resistance, its thermal conductivity is below 0.46 W / (m·K), resulting in poor heat transfer capacity (1 / 100 to 1 / 300 of the thermal conductivity of common metals), limiting its direct application in heat exchange fields. Especially in recent years, the demand for dehumidification of some corrosive liquids, heat pumps, and low-temperature heat source utilization has been significant, requiring design lifespans of several decades. Most metal pipes are prone to corrosion and cannot meet these requirements.

[0003] Therefore, there is an urgent need for a manufacturing method for high thermal conductivity perforated steel strip composite plastic pipes that can effectively improve the operating temperature, service life, heat transfer efficiency, energy saving effect, and corrosion resistance of composite plastic pipes. Summary of the Invention

[0004] The purpose of this invention is to provide a method for manufacturing high thermal conductivity perforated steel strip composite plastic pipes, which can effectively improve the operating temperature, service life, heat transfer efficiency, energy saving effect, and corrosion resistance of composite plastic pipes. The preferred technical solutions among the various technical solutions provided by this invention and their numerous technical effects are detailed below.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The manufacturing method of the high thermal conductivity perforated steel strip composite plastic pipe provided by the present invention includes the following steps:

[0007] Step 1: Prepare the raw materials for the modified resin;

[0008] Step 2: Perform a blending pretreatment on the modified resin raw materials to form a blended modified material;

[0009] Step 3: Add the blended modified material into an extruder and combine it with the metal skeleton to form a composite plastic pipe.

[0010] Preferably, the raw materials for the modified resin in step one include heat-resistant polyethylene plastic as the matrix, carbon-based fillers, and additives.

[0011] Preferably, the matrix accounts for 70 to 85 parts of the modified resin.

[0012] Preferably, the carbon-based filler accounts for 10 to 30 parts of the modified resin.

[0013] Preferably, the additive accounts for 0.1 to 10 parts of the modified resin.

[0014] Preferably, the carbon-based packing is divided into a primary packing and an auxiliary packing, and the ratio of the primary packing to the auxiliary packing is 3 to 10:1.

[0015] Preferably, the blending pretreatment in step two includes the following operations:

[0016] a. The carbon-based filler is added to a high-speed mixer for drying, heated to 100℃~110℃, and held for 10min-15min;

[0017] b. Continue adding the additives to the high-speed mixer to form a first mixture, and heat for 2 min-3 min;

[0018] c. After the first mixture has cooled to room temperature, the first mixture and the matrix are uniformly mixed in the high-speed mixer to obtain the blended modified material.

[0019] Preferably, in step three, the blended modified material is granulated and then fed into the single-screw extruder.

[0020] Preferably, in step three, the blended modified material is directly added into the twin-screw extruder.

[0021] Preferred options also include:

[0022] Step 4: Perform performance testing on the composite plastic pipe.

[0023] The technical solution provided by this invention can produce a heat-conducting composite plastic pipe with high pressure resistance and heat resistance. By modifying pipe-grade heat-resistant plastic resin, a new type of composite plastic pipe with a wider range of applications can be made, thus significantly improving the operating temperature, service life, heat transfer efficiency, and energy-saving effect. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a cross-sectional schematic diagram of the composite plastic pipe of the present invention;

[0026] Figure 2 This is a process flow diagram of the composite plastic pipe of the present invention.

[0027] In the diagram, 1-composite plastic pipe; 2-metal skeleton; 3-anti-corrosion layer. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0029] refer to Figure 1-2 The present invention provides a method for manufacturing a high thermal conductivity perforated steel strip composite plastic pipe, comprising the following steps:

[0030] Step 1: Prepare the raw materials for the modified resin;

[0031] Step 2: Perform a blending pretreatment on the modified resin raw materials to form a blended modified material;

[0032] Step 3: Add the blended modified material into the extruder and combine it with the metal skeleton 2 to form a composite plastic pipe 1.

[0033] The composite plastic pipe 1 includes a metal skeleton 2 and an anti-corrosion layer 3. The pressure-bearing layer is the metal skeleton 2, and the inner and outer anti-corrosion layers form the anti-corrosion layer 3.

[0034] This invention can produce heat-conducting composite plastic pipes with high pressure resistance and heat resistance. By modifying pipe-grade heat-resistant plastic resin, a new type of composite plastic pipe with a wider range of applications is made, which significantly improves the operating temperature, service life, heat transfer efficiency and energy saving effect.

[0035] Further optimization of the scheme: the raw materials for the modified resin in step one include heat-resistant polyethylene plastic (PE-RT) as the matrix, carbon-based filler, and additives; the matrix can be divided according to the pipe temperature of 70℃. When the pipe operating temperature is below 70℃, PE80 grade or higher pipe resin is selected as the matrix. When the pipe operating temperature is above 70℃, heat-resistant polyethylene grade pipe resin (PE-RTⅠ or PE-RTⅡ type) is selected as the matrix.

[0036] Due to the high surface energy of carbon-based fillers, they are prone to agglomeration and difficult to disperse completely in the polymer matrix, thus hindering the improvement of the material's thermal conductivity. To enhance the performance of polyethylene (PE) / carbon-based thermally conductive composite materials, improve the dispersibility of carbon-based fillers in the composite material, and improve the interfacial compatibility between carbon-based fillers and PE, a silane coupling agent (such as aminopropyltriethoxysilane) is selected to treat the dispersibility of the carbon-based material. Maleic anhydride grafting (such as POE-g-MAH) is added as an interfacial compatibilizer to improve the interfacial bonding between PE and carbon-based fillers, thereby improving the overall performance of the composite material and obtaining a polymer thermally conductive composite pipe with excellent mechanical properties.

[0037] Further optimization of the scheme: the matrix accounts for 70 to 85 parts of the modified resin.

[0038] Further optimization of the scheme: the carbon-based filler includes monomeric carbon-based filler and composite carbon-based filler, with the monomeric carbon-based filler or composite carbon-based filler accounting for 10 to 30 parts of the modified resin.

[0039] Further optimization of the scheme involves using additives in a proportion of 0.1 to 10 parts of the modified resin; these additives include coupling agents, adhesive resins, surface treatment agents, dispersants, lubricants, and solubilizers.

[0040] Further optimization of the scheme: the composite carbon-based filler is divided into a main filler and an auxiliary filler. The single carbon-based filler includes the main filler, and the ratio of the main filler to the auxiliary filler is 3 to 10:1. The main filler includes expanded graphite or graphite. The auxiliary filler includes carbon fiber, graphene, and carbon nanotubes.

[0041] To further optimize the scheme, the blending pretreatment in step two includes the following operations:

[0042] a. Add the carbon-based filler to a high-speed mixer for drying, dehumidification and refining, and heat to 100℃~110℃, maintaining for 10min-15min;

[0043] b. Continue to add the coupling agent of aminopropyltriethoxysilane to the high-speed mixer and mix for 2 min-3 min; then add the maleic anhydride surface treatment agent POE-g-MAH and mix evenly to form the first mixture.

[0044] c. After the first mixture has cooled to room temperature, the first mixture and the matrix are uniformly mixed in a high-speed mixer to obtain a blended modified material.

[0045] To further optimize the scheme, in step three, the blended modified material is granulated and then added to a single-screw extruder.

[0046] To further optimize the solution, in step three, the blended modified material is directly added into a twin-screw extruder.

[0047] Further optimizations to the plan include:

[0048] Step 4: Perform performance testing on composite plastic pipe 1.

[0049] Based on the weight percentage of raw materials for different modified resins, the following formulations were established, and conclusions were drawn:

[0050] In the formulation 1, the selected matrix is ​​PE-RTⅠ type with a ratio of 85 parts, the monomer carbon-based filler has a ratio of 10 parts, and the silane coupling agent and maleic anhydride surface treatment agent POE-g-MAH in the additives have a ratio of 2.5wt% and 3.5wt% respectively of monomer carbon-based filler. After performance testing, the thermal conductivity of this tube type is 0.71, and the operating temperature is ≤90℃.

[0051] 2. When using PE-RTⅡ type matrix with a ratio of 85 parts and monomeric carbon-based filler with a ratio of 10 parts, the proportion of silane coupling agent and maleic anhydride surface treatment agent POE-g-MAH in the additives is 2.5wt% and 3.5wt% of monomeric carbon-based filler, respectively. After performance testing, the thermal conductivity of this tube type is 0.75 and the operating temperature is ≤95℃.

[0052] In formula 3, 70 parts of PE-RTⅠ type matrix are selected, 30 parts of monomeric carbon-based filler are selected, and the proportions of silane coupling agent and maleic anhydride surface treatment agent POE-g-MAH in the additives are 2.5wt% and 3.5wt% of monomeric carbon-based filler, respectively. After performance testing, the thermal conductivity of this tube type is 1.45 and the operating temperature is ≤90℃.

[0053] 4. When using PE-RTⅡ type matrix with a ratio of 70 parts and monomeric carbon-based filler with a ratio of 30 parts, the proportion of silane coupling agent and maleic anhydride surface treatment agent POE-g-MAH in the additives is 2.5wt% and 3.5wt% of monomeric carbon-based filler, respectively. After performance testing, the thermal conductivity of this tube type is 1.52 and the operating temperature is ≤100℃.

[0054] 5. When using PE-RTⅡ type matrix with a ratio of 70 parts, carbon-based main and auxiliary fillers account for 30 parts. The proportion of silane coupling agent and maleic anhydride surface treatment agent POE-g-MAH in the additives is 2.5wt% and 3.5wt% of the monomeric carbon-based filler, respectively. After performance testing, the thermal conductivity of this tube type is 1.85 and the operating temperature is ≤100℃.

[0055] 6. When using PE-RTⅡ type matrix with a ratio of 100 parts, after performance testing, the thermal conductivity of PE-RTⅡ pipe is 0.48 and the operating temperature is ≤90℃.

[0056] 7. When using HDPE material matrix with a ratio of 100 parts, after performance testing, the thermal conductivity of HDPE pipe is 0.46 and the operating temperature is ≤70℃.

[0057] From the perspective of formulation design, selecting thermally conductive fillers and resin matrices with good compatibility, increasing the amount of thermally conductive fillers added, improving their dispersant stacking mode in the matrix, and improving the interfacial strength of the two phases are all beneficial for preparing polymers with higher thermal conductivity.

[0058] Traditional HDPE composite pipes have a thermal conductivity of 0.46, limiting their application in high-temperature, high-pressure heat exchange applications to temperatures not exceeding 70°C and pressures not exceeding 1 MPa. PE-RT possesses excellent long-term high-temperature hydrostatic strength, and the carbon-based material particles filling the polymer effectively increase the heat distortion temperature of the matrix. Therefore, using heat-resistant polyethylene as a raw material with various additives (carbon-based materials, auxiliaries) to produce composite pipes allows for the addition of high-temperature resistance to the already advantageous operating conditions of 1 MPa and 100°C. For example, formulas 5 and 4 both use PE-RT II type and 30 parts of carbon-based material, improving the pipe's operating temperature range to ≤100°C.

[0059] When carbon-based materials are uniformly dispersed in the HDPE matrix, and the amount of carbon-based materials is above 10 wt%, the HDPE / carbon-based thermally conductive composite material forms a thermally conductive network, and the thermal conductivity of the composite material is rapidly improved. According to the data in the above proportion table, when the carbon-based material content in the matrix increases by 10 wt%, the thermal conductivity of the matrix without added carbon-based materials increases from 0.46 to 0.71. The thermal conductivity of composite materials in proportions 1, 2, 6, and 7 is increased by more than 35%.

[0060] The thermal conductivity of composite materials can be synergistically enhanced by simultaneously incorporating certain proportions of different types of thermally conductive fillers. Therefore, at the same filler content, carbon-based fillers exhibit higher thermal conductivity enhancement efficiency, and the resulting thermal interface material has better stability and is lighter in weight. Looking at the data from proportions 3, 4, and 5 in the above proportion table, the thermal conductivity of the matrix filled with a combination of carbon-based main and auxiliary fillers is significantly higher than that of the same carbon-based material content at a filler content of 30 parts, with the thermal conductivity of the composite material increasing by more than 22%.

[0061] The above proportions are shown in the table:

[0062]

[0063] In summary, it can be seen that the high thermal conductivity perforated steel strip composite plastic pipe of the present invention uses carbon-based thermally conductive functional particles filled with heat-resistant polyethylene resin as the modified material, which gives the composite pipe excellent thermal conductivity, increasing its thermal conductivity coefficient from 0.46 to 1.85 W / m·K and raising the operating temperature from 70℃ to 100℃, thereby enhancing its thermal conductivity effect and improving the heat dissipation efficiency of the pipe. Therefore, the new heat-resistant thermally conductive composite plastic pipe has the characteristics of high operating temperature, long service life, high heat transfer efficiency, and significant energy-saving effect.

[0064] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for manufacturing a high thermal conductivity perforated steel strip composite plastic pipe, characterized in that, Includes the following steps: Step 1: Prepare the raw materials for the modified resin; Step 2: Perform a blending pretreatment on the modified resin raw materials to form a blended modified material; Step 3: Add the blended modified material into an extruder and combine it with the metal skeleton (2) to form a composite plastic pipe (1); The raw materials for the modified resin in step one include heat-resistant polyethylene plastic as the matrix, carbon-based filler, and additives; the additives include silane coupling agent and maleic anhydride graft as an interface compatibilizer. The carbon-based packing is divided into a main packing and an auxiliary packing, and the ratio of the main packing to the auxiliary packing is 3~10:

1. The blending pretreatment in step two includes the following operations: a. The carbon-based filler is added to a high-speed mixer for drying, heated to 100℃~110℃, and held for 10min-15min; b. Continue to add silane coupling agent to the high-speed mixer, and then add maleic anhydride graft as an interface compatibilizer and mix evenly to form the first mixture. The heating time is 2 min-3 min. c. After the first mixture has cooled to room temperature, the first mixture and the matrix are uniformly mixed in the high-speed mixer to obtain the blended modified material.

2. The manufacturing method of the high thermal conductivity perforated steel strip composite plastic pipe according to claim 1, characterized in that: The matrix comprises 70 to 85 parts of the modified resin.

3. The manufacturing method of the high thermal conductivity perforated steel strip composite plastic pipe according to claim 1, characterized in that: The carbon-based filler accounts for 10 to 30 parts of the modified resin.

4. The manufacturing method of the high thermal conductivity perforated steel strip composite plastic pipe according to claim 1, characterized in that: The additives account for 0.1 to 10 parts of the modified resin.

5. The manufacturing method of the high thermal conductivity perforated steel strip composite plastic pipe according to claim 1, characterized in that: In step three, the blended modified material is granulated and then fed into the single-screw extruder.

6. The manufacturing method of the high thermal conductivity perforated steel strip composite plastic pipe according to claim 1, characterized in that: In step three, the blended modified material is directly added into the twin-screw extruder.

7. The method for manufacturing the high thermal conductivity perforated steel strip composite plastic pipe according to claim 5 or 6, characterized in that, Also includes: Step 4: Perform performance testing on the composite plastic pipe (1).

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