Composite construction hose and method of making same

Abstract

The application relates to the field of composite materials, and particularly discloses a composite structure rubber tube and a manufacturing method thereof. The composite structure rubber tube comprises a surface layer, an intermediate layer and an inner layer, the raw material of the surface layer is chloroprene rubber, the raw material of the intermediate layer is nitrile rubber, and the raw material of the inner layer comprises ultrahigh molecular weight polyethylene, silicon carbide, nano zirconium oxide and a toughening agent; the surface layer, the intermediate layer and the inner layer are pre-mixed respectively, and then are one-time composite extruded to obtain the composite structure rubber tube after vulcanization treatment; and the manufacturing method comprises the following steps: mixing the raw materials of the inner layer and high-temperature mixing to obtain inner layer pre-mixed material; putting the obtained inner layer pre-mixed material, the raw material of the surface layer and the raw material of the intermediate layer into a machine for co-extrusion to obtain a blank, and forming the composite structure rubber tube after vulcanization treatment. The composition disclosed by the application can be used for pneumatic transportation and has the advantages of high wear resistance and good impact resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of composite materials, more particularly, it relates to a composite structure rubber pipe and a manufacturing method thereof. BACKGROUND

[0002] Pneumatic conveying is a highly efficient and continuous conveying method, which is widely used in industrial production and accounts for a large proportion in the whole material transportation. In particular, in the chemical, metallurgical, coal, petroleum and other industries, a large amount of manpower and energy is required for the transportation of raw materials and products. In order to improve the quality and production efficiency of products, pneumatic conveying technology is widely used in the conveying of powder and granular materials.

[0003] The composite structure rubber pipe is a pipe structure composed of multiple materials, which has excellent wear resistance, pressure resistance, high temperature resistance, corrosion resistance and other properties, and is widely used in pneumatic conveying systems. However, when conveying solid particles, the inner wall of the composite structure rubber pipe is often severely worn due to the hardness, size and transportation speed of the solid particles. This wear can cause the diameter of the pipe to decrease, affecting the transportation efficiency of the material. At the same time, wear can also cause the pipe to break, seriously affecting the safety of material transportation. In addition, wear can also increase the frequency of pipe replacement and increase the use cost. Therefore, how to improve the wear resistance of the composite structure rubber pipe and prolong its service life has become a problem to be solved. SUMMARY

[0004] In order to improve the wear resistance of the composite structure rubber pipe, the present application provides a composite structure rubber pipe and a manufacturing method thereof.

[0005] In the first aspect, the present application provides a composite structure rubber pipe and a manufacturing method thereof, which adopts the following technical scheme: a composite structure rubber pipe, the composite structure rubber pipe includes a surface layer, an intermediate layer and an inner layer, the surface layer raw material adopts chloroprene rubber; the intermediate layer raw material adopts nitrile rubber; the inner layer raw material includes ultra-high molecular weight polyethylene, silicon carbide, nano zirconium oxide and toughening agent; the surface layer, the intermediate layer and the inner layer are respectively pre-mixed, then one-time composite extrusion, after vulcanization treatment, the composite structure rubber pipe is obtained.

[0006] By adopting the technical scheme, the surface layer adopts chloroprene rubber to provide good weather resistance and corrosion resistance, prevent the rubber tube from being affected by external environment during use, and improve the service life; the middle layer adopts nitrile rubber to play a reinforcing role and further enhance the air tightness; the inner layer of the rubber tube adopts ultra-high molecular weight polyethylene with a molecular weight of 1.5 million to 10 million as a base material, which has the advantages of high wear resistance and high impact resistance, and has a small internal friction coefficient, surface non-adhesion, which is beneficial to pipeline transportation and improves the conveying efficiency. The further addition of silicon carbide and nano zirconium oxide further provides better wear resistance for the inner layer. By optimizing the rubber materials of each layer, the layers have good compatibility, and the wear resistance of the inner layer rubber tube is enhanced through vulcanization.

[0007] The carbonized silicon and nano zirconium oxide in the inner layer raw material are high-strength and wear-resistant materials, and the addition of carbonized silicon and nano zirconium oxide can significantly improve the wear resistance and resist friction and impact during pneumatic transportation. The addition of a toughening agent reacts with polyethylene to have better toughness while maintaining high strength, preventing the rubber tube from breaking due to vibration and impact during pneumatic transportation, and further improving the wear resistance and impact resistance of the rubber tube.

[0008] Optionally, the inner layer raw material includes: 2-4 parts of silicon carbide, 0.2-0.6 parts of a toughening agent, 3-5 parts of nano zirconium oxide, and 18-20 parts of ultra-high molecular weight polyethylene.

[0009] By adopting the technical scheme, the inner layer raw material is prepared by using the above raw material ratio, which can further improve the wear resistance of the inner layer rubber tube while improving the stability of the rubber tube.

[0010] Optionally, the inner layer raw material further includes 2-3 parts of maleic rosin glycol acrylate and 0.02-0.05 parts of butadiene-based tin oxide.

[0011] By adopting the technical scheme, maleic rosin glycol acrylate contains various unsaturated bonds and hydroxyl groups, and the use of maleic rosin glycol acrylate for polyethylene modification occurs grafting reaction under the catalysis of butadiene-based tin oxide, which introduces new functional groups to the polyethylene chain, on the one hand, improves the compatibility between polyethylene and other materials, and on the other hand, enhances the adhesion between polyethylene and fillers, prevents the filler particles from falling off during long-term use and wear, and further improves the wear resistance of the inner layer rubber tube.

[0012] Optionally, the particle size of the silicon carbide is 40-65 μm.

[0013] By adopting the technical scheme, the silicon carbide filler has a smaller particle size in this period, can be more uniformly dispersed in the paint, has a large contact area with the paint, the interaction between the silicon carbide and the polyethylene molecular chain is enhanced, the interface compatibility is improved, stress concentration is reduced when stressed, and the wear resistance of the inner layer of the rubber tube is improved.

[0014] Optionally, the nano zirconium oxide is tetragonal zirconium oxide, and the particle size of the nano zirconium oxide is 20-50 nm.

[0015] By adopting the technical scheme, the tetragonal zirconium oxide is used, the mechanical properties are high and stable, the bending strength and fracture toughness of the tetragonal zirconium oxide with a particle size of 20-50 nm are good, and the tetragonal zirconium oxide used as a reinforcing material is added to the inner layer raw material, so that the wear resistance of the inner layer rubber tube is improved.

[0016] Optionally, the toughening agent is epoxy resin.

[0017] By adopting the technical scheme, the epoxy resin has high chemical activity, the hydroxyl groups in the inner layer rubber tube raw material component can make the epoxy resin ring-opening, cross-linking with polyethylene in the raw material to form a network structure, and the wear resistance and impact strength of the composite structure rubber tube are improved.

[0018] In a second aspect, the application provides a preparation method of a composite structure rubber tube, which adopts the following technical scheme:

[0019] A preparation method of a composite structure rubber tube, which comprises the following steps:

[0020] Preparation of inner layer premix: mixing and high-temperature mixing of silicon carbide, nano zirconium oxide, ultra-high molecular weight polyethylene and a toughening agent to obtain an inner layer premix;

[0021] Co-extrusion: the inner layer premix prepared above, the surface layer raw material and the intermediate layer raw material are respectively put into a machine for co-extrusion to obtain an inner layer, an intermediate layer and a surface layer composite composite structure rubber tube blank, and the composite structure rubber tube is formed after vulcanization treatment.

[0022] By adopting the technical scheme, the inner layer raw material is pre-melted and blended, and then each layer raw material is put into an extruder for one-time co-extrusion, so that the complex production process is omitted, the production process is simplified, and the production efficiency is improved.

[0023] Preferably, steam vulcanization is adopted in the vulcanization process, the vulcanization pressure is 4-6 kg, the vulcanization temperature is 160-180 DEG C, and the time is 60-70 min.

[0024] By adopting the technical scheme, steam vulcanization can provide uniform temperature distribution, so that the rubber materials of the inner and outer layers of the rubber tube can be fully vulcanized, and vulcanization effect is improved, and meanwhile, by controlling the pressure and temperature of steam vulcanization, residual stress generated in the vulcanization process can be reduced, and mechanical properties of the rubber tube are improved.

[0025] In summary, the present application has the following beneficial effects:

[0026] 1. Since the present application uses chloroprene rubber as the surface layer of the rubber tube, it has good wear resistance and weather resistance, can resist the influence of the external environment, and ensures the stability and durability of the performance of the rubber tube; the intermediate layer uses nitrile rubber, which can improve the wear resistance and temperature resistance of the rubber tube, and is suitable for high-pressure and high-speed pneumatic transportation occasions; the inner layer is the contact surface of the transportation material wear and impact, and uses ultra-high molecular weight polyethylene as the base material, adds high-strength and high-hardness fillers such as silicon carbide and nano zirconium oxide, greatly improves the friction resistance of the inner layer of the rubber tube, adds a toughening agent to ensure that the rubber tube can withstand impact without breaking, and has high impact resistance.

[0027] 2. In the present application, ultra-high molecular weight polyethylene is preferably used as the raw material of the inner layer of the rubber tube, which has good wear resistance and impact resistance, and the surface of the inner tube prepared is smooth and has a small friction coefficient, which is beneficial to pneumatic transportation and improves transportation efficiency. High-hardness and high-wear-resistant materials such as silicon carbide and nano zirconium oxide are added to polyethylene for blending, further improving the friction resistance of the inner layer of the rubber tube, and maleic rosin glycol acrylate and butadiene-based tin oxide are further added to modify the polyethylene, so that unsaturated bonds and hydroxyl groups and other functional groups are introduced on the molecular chain of the polyethylene, improving the compatibility and adhesion between the polyethylene and other powder fillers, and further improving the wear resistance of the rubber tube.

[0028] 3. The method of the present application co-extrudes the inner layer premix with the surface layer raw material and the intermediate layer raw material, which saves the complex production process, simplifies the production process, and improves the production efficiency. DETAILED DESCRIPTION

[0029] The present application will be further described in detail below in conjunction with examples.

[0030] Unless otherwise specified, the specific conditions in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not specified by the manufacturer, and are all conventional products that can be purchased on the market.

[0031] The ultra-high molecular weight polyethylene has a molecular weight of 800w and a model number of GUR4150, which is purchased from Dongguan Xingshengli Plastic New Material Technology Co., Ltd. The epoxy resin has a model number of 901 and is purchased from Hebei Yanjie Anticorrosion Material Co., Ltd.

[0032] EXAMPLE

[0033] Example 1

[0034] A composite structure rubber pipe, the composite structure rubber pipe comprising a surface layer, a middle layer and an inner layer, the surface layer raw material using 12kg of neoprene, model SN12; the middle layer raw material using 14kg of nitrile rubber, model NBR26; the inner layer raw material comprising ultra-high molecular weight polyethylene, silicon carbide, nano zirconium oxide and toughening agent, the preparation comprising the following steps: preparing an inner layer premix: taking 2kg of silicon carbide, 5kg of nano zirconium oxide, 18kg of ultra-high molecular weight polyethylene and 0.2kg of epoxy resin (toughening agent) and mixing them into a mixer for high-temperature mixing at 150°C, to obtain an inner layer premix;

[0035] Co-extrusion: the above prepared inner layer premix, surface layer raw material and middle layer raw material are respectively put into a machine for co-extrusion at 210°C, to obtain a composite structure rubber pipe blank with a pipe diameter of 150mm, the inner layer, the middle layer and the surface layer being combined, the composite structure rubber pipe blank is subjected to steam vulcanization, the vulcanization pressure is 4kg, the vulcanization temperature is 160°C, and the time is 60min, to form the composite structure rubber pipe. The particle size of the silicon carbide is 40μm, the nano zirconium oxide is tetragonal zirconium oxide, and the particle size is 20nm.

[0036] Example 2

[0037] A composite structure rubber pipe, the composite structure rubber pipe comprising a surface layer, a middle layer and an inner layer, the surface layer raw material using 12kg of neoprene, model SN12; the middle layer raw material using 14kg of nitrile rubber, model NBR26; the inner layer raw material comprising ultra-high molecular weight polyethylene, silicon carbide, nano zirconium oxide and toughening agent, the preparation comprising the following steps: preparing an inner layer premix: taking 3kg of silicon carbide, 4kg of nano zirconium oxide, 30kg of ultra-high molecular weight polyethylene and 0.4kg of epoxy resin (toughening agent) and mixing them into a mixer for high-temperature mixing at 150°C, to obtain an inner layer premix;

[0038] Co-extrusion: the above prepared inner layer premix, surface layer raw material and middle layer raw material are respectively put into a machine for co-extrusion at 180°C, to obtain a composite structure rubber pipe blank with a pipe diameter of 150mm, the inner layer, the middle layer and the surface layer being combined, the composite structure rubber pipe blank is subjected to steam vulcanization, the vulcanization pressure is 5kg, the vulcanization temperature is 170°C, and the time is 65min, to form the composite structure rubber pipe. The particle size of the silicon carbide is 50μm, the nano zirconium oxide is tetragonal zirconium oxide, and the particle size is 40nm.

[0039] Example 3

[0040] A composite structure rubber pipe, the composite structure rubber pipe comprises a surface layer, an intermediate layer and an inner layer, the surface layer raw material adopts 12 kg neoprene, model number is SN12; the intermediate layer raw material adopts 14 kg nitrile rubber, model number is NBR26; the inner layer raw material includes ultra-high molecular weight polyethylene, silicon carbide, nano zirconium oxide and toughening agent, and preparation includes the following steps: preparing inner layer premix: 4 kg silicon carbide, 3 kg nano zirconium oxide, 19 kg ultra-high molecular weight polyethylene and 0.6 kg epoxy resin (toughening agent) are mixed and put into a mixer for high-temperature mixing at 150 DEG C, to obtain the inner layer premix;

[0041] Co-extrusion: the inner layer premix prepared above, the surface layer raw material and the intermediate layer raw material are respectively put into a machine for co-extrusion at 235 DEG C, to obtain a composite structure rubber pipe blank with an inner layer, an intermediate layer and a surface layer with a diameter of 150 mm, and the composite structure rubber pipe blank is subjected to steam vulcanization, with a vulcanization pressure of 6 kg, a vulcanization temperature of 180 DEG C and a time of 70 min, to form the composite structure rubber pipe. The silicon carbide particle size is 65 μm, and the nano zirconium oxide is tetragonal zirconium oxide with a particle size of 50 nm.

[0042] Example 4

[0043] A composite structure rubber pipe, which is different from example 1 in that the inner layer raw material further includes 2 kg of maleic rosin glycol acrylate and 0.02 kg of butadiene tin oxide, and the preparation method is as follows:

[0044] Preparation of inner layer premix: 18 kg of ultra-high molecular weight polyethylene and 2 kg of maleic rosin glycol acrylate are premixed in a mixer at 180 DEG C for 5 h, 0.02 kg of butadiene tin oxide is added, 2 kg of silicon carbide, 5 kg of nano zirconium oxide and 0.2 kg of epoxy resin (toughening agent) are mixed and put into a mixer for high-temperature mixing at 150 DEG C, to obtain the inner layer premix.

[0045] Co-extrusion: the inner layer premix prepared above, the surface layer raw material and the intermediate layer raw material are respectively put into a machine for co-extrusion at 180 DEG C, to obtain a composite structure rubber pipe blank with an inner layer, an intermediate layer and a surface layer, and the composite structure rubber pipe blank is subjected to steam vulcanization, with a vulcanization pressure of 4 kg, a vulcanization temperature of 160 DEG C and a time of 60 min, to form the composite structure rubber pipe.

[0046] Example 5

[0047] A composite structure rubber pipe, which is different from example 1 in that the maleic rosin glycol acrylate added in the inner layer raw material is 3 kg, and the butadiene tin oxide is 0.05 kg.

[0048] Example 6

[0049] A composite structure rubber tube, which is different from that of Example 1 in that the particle size of silicon carbide in the inner layer raw material is 30 μm in this example.

[0050] Example 7

[0051] A composite structure rubber tube, which is different from that of Example 1 in that the particle size of silicon carbide in the inner layer raw material is 100 μm in this example.

[0052] Example 8

[0053] A composite structure rubber tube, which is different from that of Example 4 in that the toughening agent added in this example is a poly (methyl methacrylate) organosiloxane methacrylate core-shell copolymer, Mitsubishi Rayon, model: S-2030.

[0054] Comparative Example

[0055] Comparative Example 1

[0056] A composite structure rubber tube, which is different from that of Example 1 in that the inner layer raw material in this comparative example is 25.2 kg of ultra-high molecular weight polyethylene.

[0057] Comparative Example 2

[0058] A composite structure rubber tube, which is different from that of Example 1 in that the composite structure rubber tube blank prepared is not subjected to vulcanization treatment in this comparative example, and the composite structure rubber tube is obtained after co-extrusion and normal temperature curing.

[0059] Performance detection test

[0060] Detection method / test method

[0061] Impact strength: GB / T 1681-1991 "Determination of resilience of vulcanized rubber";

[0062] Abrasion resistance detection: silicon carbide (density 3.1 g / mm 3 ) is used as the abrasive, and the abrasion resistance of the composite structure rubber tube is tested by sand blasting erosion abrasion test, the sand blasting pressure is 60 kg / cm 2 , the mass of the rubber tube before and after the abrasion test is tested at 5 min and 10 min of erosion respectively, the abrasion amount is calculated, and the greater the mass loss of erosion abrasion, the poorer the abrasion resistance.

[0063] Table 1 Test detection results

[0064]

[0065] It can be seen from the combination of examples 1-3 and comparative example 1 and table 1 that the test data of examples 1-3 are all better than that of comparative example 1, which shows that only using high molecular weight polyethylene as the inner layer of the tube cannot achieve good wear resistance, and the inner layer tube prepared by using the inner layer material of the application has the advantages of high wear resistance and good impact resistance, and adding fillers with high hardness and high wear resistance as aggregates can greatly improve the wear resistance of the polyethylene surface and interact with the polyethylene to improve the crystallinity and molecular chain structure of the polyethylene, thereby greatly enhancing the wear resistance of the composite structure tube.

[0066] It can be seen from the combination of examples 1-5 and table 1 that the test data of examples 4-5 are all better than that of examples 1-3, which shows that adding maleic rosin glycol acrylate and butadiene tin oxide can introduce new functional groups to the polyethylene chain, improve the compatibility between polyethylene and other fillers, and further improve the wear resistance of the composite structure tube. It can also be seen that adding maleic rosin glycol acrylate and butadiene tin oxide can greatly improve the adhesion between polyethylene and fillers, the amount of particle wear increases less over a long period of time, maintains constant, and has good wear resistance.

[0067] It can be seen from the combination of examples 1, examples 6-7 and table 1 that the test data of example 1 are all better than that of examples 6-7, which shows that the particle size of silicon carbide can affect the performance of the tube, and selecting silicon carbide with a suitable particle size range can be uniformly dispersed in the polyethylene base material, enhance the interaction with the polyethylene chain, and improve the wear resistance of the tube.

[0068] It can be seen from the combination of example 4 and example 8 and table 1 that when the toughening agent uses epoxy resin, it can react with the hydroxyl groups on the modified polyethylene molecular chain, and cross-link with the ultra-high molecular polyethylene in the raw material to form a network structure, thereby further improving the wear resistance and impact strength of the composite structure tube.

[0069] The specific embodiments are only an explanation of the application, and are not a limitation of the application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, but as long as the modifications are within the scope of the claims of the application, they are protected by the patent law.

Claims

1. A composite construction hose, characterized in that, The composite structure rubber tube comprises a surface layer, an intermediate layer and an inner layer, the surface layer raw material adopts chloroprene rubber; the intermediate layer raw material adopts nitrile rubber; the inner layer raw material comprises ultrahigh molecular weight polyethylene, silicon carbide, nano zirconium oxide and toughening agent; the inner layer raw material further comprises 2-3 parts of maleic rosin glycol acrylate and 0.02-0.05 parts of butadiene-based tin oxide; the surface layer, the intermediate layer and the inner layer are premixed respectively, then are extruded once, and after vulcanization treatment, the composite structure rubber tube is obtained.

2. A composite construction hose according to claim 1, characterised in that: The inner layer raw material comprises 2-4 parts of silicon carbide, 0.2-0.6 parts of toughening agent, 3-5 parts of nano zirconium oxide and 18-20 parts of ultrahigh molecular weight polyethylene.

3. The composite structural hose of claim 1, wherein: The silicon carbide particle size is 40-65 μm.

4. The composite structural hose of claim 1, wherein: The nano zirconium oxide is tetragonal zirconium oxide, and the nano zirconium oxide particle size is 20-50 nm.

5. The composite structural hose of claim 2, wherein: The toughening agent is epoxy resin.

6. A method of manufacturing the composite structure hose according to any one of claims 1 to 5, characterized by, The preparation comprises the following steps: Preparation of inner layer premix: mixing silicon carbide, nano zirconium oxide, ultrahigh molecular weight polyethylene and toughening agent at high temperature to obtain the inner layer premix; Co-extrusion: putting the prepared inner layer premix, the surface layer raw material and the intermediate layer raw material into machines respectively for co-extrusion to obtain the inner layer, the intermediate layer and the surface layer composite composite structure rubber tube blank, and after vulcanization treatment, the composite structure rubber tube is formed.

7. A method of manufacturing a composite construction hose according to claim 6, characterized in that In the vulcanization process, steam vulcanization is adopted, the vulcanization pressure is 4-6 kg, the vulcanization temperature is 160-180 ℃, and the time is 60-70 min.

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