Composite rubber tube and preparation method thereof

Abstract

The invention relates to the technical field of hoses, in particular to a composite rubber hose and a preparation method thereof. The composite rubber pipe sequentially comprises a nylon layer, a rubber layer and a rubber layer from inside to outside in the pipe diameter direction, the inner rubber layer is formed on the nylon layer, and the inner rubber layer is made of nitrile rubber; the inner rubber layer is obtained by pressing nitrile rubber into an inner rubber sheet through an open mill and coating the nylon layer with the inner rubber sheet; the steel wire woven skeleton layer is formed on the nitrile rubber layer; the outer rubber layer is formed on the steel wire woven framework layer, and the outer rubber layer is made of nitrile rubber. Aiming at the problem that the bonding performance of nylon and rubber is poor, the nylon layer is treated, the production process of the inner rubber layer is changed, and other steps are matched for combined action, so that the bonding performance of the finally obtained composite rubber tube is relatively excellent.

Description

Technical Field

[0001] This invention relates to the field of hose technology, and in particular to a composite hose and its preparation method. Background Technology

[0002] The existing bonding properties between nylon and rubber are very poor. According to customer requirements, pipes carrying compressed natural gas (CNG) are needed, which necessitates process improvements to address the adhesion problem between nylon and rubber.

[0003] In the original ordinary rubber hose production process, an inner rubber layer needs to be extruded on a nylon layer. Due to the poor adhesion between nylon and rubber materials, the resulting hose has low bonding performance and the product performance does not meet the standards. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a composite hose and a method for preparing the same, wherein the composite hose provided by the present invention has superior adhesive properties.

[0005] This invention provides a composite hose, comprising, from the inside to the outside along the hose diameter direction:

[0006] Nylon layer;

[0007] An inner rubber layer is formed on the nylon layer, the material of which includes nitrile rubber; the inner rubber layer is obtained by pressing nitrile rubber into an inner rubber sheet through a two-mill and covering it onto the nylon layer.

[0008] A steel wire braided skeleton layer formed on the nitrile rubber layer;

[0009] An outer adhesive layer is formed on the steel wire braided skeleton layer, and the material of the outer adhesive layer includes nitrile rubber.

[0010] Preferably, the nylon layer is made of nylon P-12;

[0011] The thickness of the nylon layer is 0.5~1.5 mm.

[0012] Preferably, the inner rubber layer is made of nitrile rubber SO21-2;

[0013] The thickness of the inner adhesive layer is 1.5~2.5 mm.

[0014] Preferably, the steel wires in the steel wire braided skeleton layer are 3 to 5 strands, the diameter of the steel wires is 0.2 to 0.4 mm, the strength of the steel wires is 2700 to 2800 MPa, and the braiding density is 45% to 55%.

[0015] The thickness of the steel wire braided skeleton layer is 0.5~1.5 mm.

[0016] Preferably, the outer adhesive layer is made of nitrile rubber 674-2;

[0017] The thickness of the outer adhesive layer is 1~2 mm.

[0018] The present invention also provides a method for preparing the composite hose, comprising the following steps:

[0019] A) After mixing the granulated nylon resin and the raw nylon resin, the mixture is heated and extruded, and then shaped using a vacuum sizing method to obtain a hollow nylon layer.

[0020] B) After polishing the outer surface of the hollow nylon layer, treat it with sodium naphthalene treatment solution, and then treat it with chemiluminescent solution.

[0021] C) Press the nitrile rubber into an inner sheet using an open mill, and wrap it over the outer surface of the nylon layer treated in step B) to obtain the inner rubber layer;

[0022] D) Weave a steel wire skeleton on the inner adhesive layer to obtain a steel wire braided skeleton layer;

[0023] E) The granulated nitrile rubber is extruded and formed on the steel wire braided skeleton layer to obtain the outer rubber layer; thereby obtaining the composite rubber tube.

[0024] Preferably, in step A), the mass ratio of the nylon resin granules to the nylon resin raw materials is 3~5:24~26;

[0025] Before the heating and extrusion, the process further includes drying; the drying temperature is 85~105℃, and the time is 2~4 hours.

[0026] The temperature of the heating zone in the heated extrusion is 200~220℃.

[0027] Preferably, in step A), the pressure used in the vacuum sizing method is -0.02 to -0.04 MPa.

[0028] Preferably, in step D), before weaving, the process further includes freezing; the freezing temperature is -60 to -30 ℃.

[0029] The weaving rate is 25~35 r / min.

[0030] Preferably, in step E), the extrusion screw temperature is 40~60°C, the plasticizing section temperature is 50~70°C, the extruder temperature is 60~80°C, and the die head temperature is 70~90°C; the extrusion screw speed is 15~25 r / min, and the screw length-to-diameter ratio is 20~22:1.

[0031] The forming method is vacuum forming; the vacuum forming pressure is -0.07~-0.04 MPa.

[0032] To address the problem of poor adhesion between nylon and rubber, this invention treats the nylon layer, alters the production process of the inner rubber layer, and works in conjunction with other steps to ultimately obtain a composite hose with superior adhesion performance. Detailed Implementation

[0033] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] This invention provides a composite hose, comprising, from the inside to the outside along the hose diameter direction:

[0035] Nylon layer;

[0036] An inner rubber layer is formed on the nylon layer, the material of which includes nitrile rubber; the inner rubber layer is obtained by pressing nitrile rubber into an inner rubber sheet through a two-mill and covering it onto the nylon layer.

[0037] A steel wire braided skeleton layer formed on the nitrile rubber layer;

[0038] An outer adhesive layer is formed on the steel wire braided skeleton layer, and the material of the outer adhesive layer includes nitrile rubber.

[0039] In some embodiments of the present invention, the nylon layer is made of nylon P-12. The thickness of the nylon layer is 0.5~1.5 mm, for example, 1 mm. The outer diameter of the nylon layer is 14~15 mm, for example, 14.5 mm.

[0040] In some embodiments of the present invention, the inner rubber layer is made of nitrile rubber SO21-2. The thickness of the inner rubber layer is 1.5~2.5 mm, for example, 2 mm.

[0041] In some embodiments of the present invention, the steel wire braided skeleton layer has 3 to 5 strands of steel wire, the diameter of the steel wire is 0.2 to 0.4 mm, the strength of the steel wire is 2700 to 2800 MPa, and the braiding density is 45% to 55%. Specifically, the steel wire braided skeleton layer is a single layer; the steel wire has 4 strands of steel wire, the diameter of the steel wire is 0.3 mm, the strength of the steel wire is 2750 MPa, and the braiding density is 49.5%.

[0042] The steel wire braided skeleton layer is braided using a braiding machine, specifically a 24-spindle braiding machine.

[0043] The thickness of the steel wire braided skeleton layer is 0.5~1.5 mm, for example, 1 mm.

[0044] In some embodiments of the present invention, the outer adhesive layer is made of nitrile rubber 674-2. The thickness of the outer adhesive layer is 1~2 mm, for example 1.7 mm.

[0045] This invention provides a method for preparing the composite hose described above, comprising the following steps:

[0046] A) After mixing the granulated nylon resin and the raw nylon resin, the mixture is heated and extruded, and then shaped using a vacuum sizing method to obtain a hollow nylon layer.

[0047] B) After polishing the outer surface of the hollow nylon layer, treat it with sodium naphthalene treatment solution, and then treat it with chemiluminescent solution.

[0048] C) Press the nitrile rubber into an inner sheet using an open mill, and wrap it over the outer surface of the nylon layer treated in step B) to obtain the inner rubber layer;

[0049] D) Weave a steel wire skeleton on the inner adhesive layer to obtain a steel wire braided skeleton layer;

[0050] E) The granulated nitrile rubber is extruded and formed on the steel wire braided skeleton layer to obtain the outer rubber layer; thereby obtaining the composite rubber tube.

[0051] Regarding step A):

[0052] After mixing the granulated nylon resin and the raw nylon resin, the mixture is heated and extruded, and then shaped using a vacuum sizing method to obtain a hollow nylon layer.

[0053] In some embodiments of the present invention, the mass ratio of the nylon resin granules to the nylon resin raw materials is 3~5:24~26, for example 4:25.

[0054] In some embodiments of the present invention, before the heated extrusion, the process further includes drying; the drying temperature is 85~105℃, for example 95℃; and the drying time is 2~4 h, for example 3 h.

[0055] In some embodiments of the present invention, the heated extrusion is performed using a nylon extruder, such as a φ120 mm nylon extruder. The temperature of the heating zone in the heated extrusion is 200~220°C.

[0056] In some embodiments of the present invention, the vacuum sizing method uses a pressure of -0.02 to -0.04 MPa, for example -0.03 MPa. The mandrel material used in the vacuum sizing method is a TPX soft mandrel.

[0057] In some embodiments of the present invention, after shaping, the process further includes cooling. The cooling method is water cooling. Specifically, a cooling water tank can be used.

[0058] Regarding step B):

[0059] After polishing the outer surface of the hollow nylon layer, it is treated with sodium naphthalene solution and then with chemiluminescent solution.

[0060] In some embodiments of the present invention, the polishing process further includes cleaning debris from the tube body.

[0061] In some embodiments of the present invention, the treatment with sodium naphthalene treatment solution includes: scrubbing the surface of the polished hollow nylon layer with the sodium naphthalene treatment solution. The sodium naphthalene treatment solution mainly consists of naphthalene and sodium in a mass ratio of 1:4; it also contains a small amount of tetrahydrofuran (negligible). The sodium naphthalene treatment solution can be commercially available.

[0062] In some embodiments of the present invention, treatment with Chemlock solution includes: scrubbing the surface of the hollow nylon layer with Chemlock solution. Chemlock solution can disrupt the structure of the outer surface of the nylon layer, improving its adhesion to the rubber layer. Since Chemlock solution is a volatile liquid, after treatment with Chemlock solution, it can be air-dried at room temperature. Direct sunlight should be avoided.

[0063] Regarding step C):

[0064] Nitrile rubber is pressed into an inner sheet using an open mill and then wrapped around the outer surface of the nylon layer treated in step B) to obtain the inner rubber layer.

[0065] In some embodiments of the present invention, the width of the inner film is 45-55 mm, for example 50 mm; and the thickness is 1-3 mm, for example 2 mm.

[0066] Regarding step D):

[0067] A steel wire skeleton is woven on the inner rubber layer to obtain a steel wire woven skeleton layer.

[0068] In some embodiments of the present invention, prior to weaving, the process further includes freezing (i.e., freezing the multilayer structure obtained in step C). The freezing temperature is -60 to -30 °C. Specifically, it is controlled at -60 to -40 °C in summer and -50 to -30 °C in winter, for example, -45 °C.

[0069] The weaving speed is 25~35 r / min, for example 30 r / min.

[0070] In some embodiments of the present invention, the steel wire braided skeleton layer is a single layer, and changing the wire is strictly prohibited during the weaving process. The spindle tension is 6.3~6.7 kg, for example, 6.5 kg. The present invention further limits the spindle tension to prevent the steel wire from being too tense and digging into the rubber layer.

[0071] In some embodiments of the present invention, the process after weaving further includes drying to remove residual moisture from the weaving process.

[0072] Regarding step E):

[0073] Nitrile rubber granules are extruded and formed on the steel wire braided skeleton layer to obtain the outer rubber layer; thus, a composite rubber tube is obtained.

[0074] In some embodiments of the present invention, the extrusion screw temperature is 40~60°C, for example 50°C; the plasticizing section temperature is 50~70°C, for example 60°C; the extruder temperature is 60~80°C, for example 70°C; and the die head temperature is 70~90°C, for example 80°C.

[0075] The extrusion screw rotates at a speed of 15-25 r / min, for example, 25 r / min; the length-to-diameter ratio of the screw is 20-22:1, for example, 21:1. The extrusion is carried out in a φ120 mm extruder.

[0076] In some embodiments of the present invention, after extrusion, the process further includes cooling. The cooling method is water cooling.

[0077] The present invention does not impose any special restrictions on the source of the raw materials used above, and they can be commercially available.

[0078] To further illustrate the present invention, the following detailed description of a composite hose and its preparation method provided by the present invention is provided in conjunction with embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0079] Example 1

[0080] Preparation of composite hoses:

[0081] The granulated material of nylon resin P-12 and the raw material of nylon resin P-12 are mixed evenly at a mass ratio of 4:25, poured into a barrel, and dried in a dryer at a temperature of 95℃ for 3 hours. Then, the mixture is heated and extruded through a φ120 mm nylon extruder at a heating zone temperature of 200~220℃. After shaping using a vacuum sizing method (the pressure used in the vacuum sizing method is -0.03 MPa; the mandrel material used in the vacuum sizing method is TPX soft mandrel), the mixture is passed through a cooling water tank to obtain a hollow nylon layer.

[0082] The nylon layer has a thickness of 1 mm and an outer diameter of 14.5 mm.

[0083] 2. After polishing the outer surface of the hollow nylon layer, clean the debris from the tube body, and then scrub the polished hollow nylon layer surface with a sodium naphthalene treatment solution. The sodium naphthalene treatment solution mainly consists of naphthalene and sodium in a mass ratio of 1:4; it also contains a small amount of tetrahydrofuran (which can be ignored). Then, treat and scrub the hollow nylon layer surface with a Chemlock solution, and then air dry it at room temperature.

[0084] 3. The nitrile rubber S021-2 is pressed into an inner rubber sheet using an open mill. The inner rubber sheet has a width of 50 mm and a thickness of 2 mm. It is then wrapped around the outer surface of the nylon layer treated in step 2) to obtain the inner rubber layer.

[0085] The thickness of the inner adhesive layer is 2 mm.

[0086] 4. Freeze the multi-layer structure obtained in step 3 at a temperature of -45 ℃; weave a steel wire skeleton on the inner rubber layer, and after drying, obtain a steel wire woven skeleton layer;

[0087] The steel wire braided skeleton layer consists of 4 strands of steel wire, with a diameter of 0.3 mm, a strength of 2750 MPa, and a braiding density of 49.5%.

[0088] The weaving speed is 30 r / min, and the weaving is carried out using a 24-spindle weaving machine;

[0089] The tension of the first layer of spindles is 6.5 kg; the tension of the second layer of spindles is 7 kg.

[0090] The thickness of the steel wire braided skeleton layer is 1.0 mm.

[0091] 5. The nitrile rubber 674-2 is extruded in a φ120 mm extruder; the screw temperature during extrusion is 50℃, the plasticizing section temperature is 60℃, the extruder temperature is 70℃, and the die head temperature is 80℃; the screw speed during extrusion is 25 r / min, and the length-to-diameter ratio of the screw is 21:1.

[0092] After water cooling, a composite hose is obtained; the thickness of the outer rubber layer is 1.7 mm.

[0093] Referring to GB / T 3683-2011 Rubber hoses and hose assemblies for oil-based or water-based fluids, the adhesive properties of the composite hose were tested using an electronic tensile testing machine JDL-2500N. The experimental results showed that the adhesive properties of the composite hose were 1.8 N / mm.

[0094] Comparative Example 1

[0095] The difference from Example 1 is as follows:

[0096] Replace the nylon resin P-12 in step 1 with nylon 11 P40 (brand: Arkema).

[0097] The remaining steps and parameters are the same as in Example 1, resulting in a composite hose.

[0098] Referring to GB / T 3683-2011 Rubber hoses and hose assemblies for oil-based or water-based fluids, the adhesive properties of the composite hose were tested using an electronic tensile testing machine JDL-2500N. The experimental results showed that the adhesive properties of the composite hose were 1.09 N / mm.

[0099] Comparative Example 2

[0100] The difference from Example 1 is that the inner adhesive layer is extruded using a conventional method;

[0101] Specifically, step 3 is as follows:

[0102] Nitrile rubber S021-2 is extruded in a φ120 mm extruder; the screw temperature during extrusion is 45℃, the plasticizing section temperature is 55℃, the extruder temperature is 65℃, and the die head temperature is 70℃; the screw speed during extrusion is 21 r / min, and the length-to-diameter ratio of the screw is 21:1.

[0103] The remaining steps and parameters are the same as in Example 1, resulting in a composite hose.

[0104] Referring to GB / T 3683-2011 Rubber hoses and hose assemblies for oil-based or water-based fluids, the adhesive properties of the composite hose were tested using an electronic tensile testing machine JDL-2500N. The experimental results showed that the adhesive properties of the composite hose were 0.37 N / mm.

[0105] The descriptions of the above embodiments are merely illustrative of the methods and core ideas of the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A composite hose, comprising, from the inside to the outside along the pipe diameter direction: Nylon layer; An inner rubber layer is formed on the nylon layer, the material of which includes nitrile rubber; the inner rubber layer is obtained by pressing nitrile rubber into an inner rubber sheet through a two-mill and covering it onto the nylon layer. A steel wire braided skeleton layer formed on the nitrile rubber layer; An outer adhesive layer is formed on the steel wire braided skeleton layer, and the material of the outer adhesive layer includes nitrile rubber.

2. The composite hose according to claim 1, characterized in that, The nylon layer is made of nylon P-12; The thickness of the nylon layer is 0.5~1.5 mm.

3. The composite hose according to claim 1, characterized in that, The inner rubber layer is made of nitrile rubber S021-2; The thickness of the inner adhesive layer is 1.5~2.5 mm.

4. The composite hose according to claim 1, characterized in that, The steel wire in the braided skeleton layer consists of 3 to 5 strands, with a diameter of 0.2 to 0.4 mm, a strength of 2700 to 2800 MPa, and a braiding density of 45% to 55%. The thickness of the steel wire braided skeleton layer is 0.5~1.5 mm.

5. The composite hose according to claim 1, characterized in that, The outer rubber layer is made of nitrile rubber 674-2; The thickness of the outer adhesive layer is 1~2 mm.

6. A method for preparing the composite hose, comprising the following steps: A) After mixing the granulated nylon resin and the raw nylon resin, the mixture is heated and extruded, and then shaped using a vacuum sizing method to obtain a hollow nylon layer. B) After polishing the outer surface of the hollow nylon layer, treat it with sodium naphthalene treatment solution, and then treat it with chemiluminescent solution. C) Press the nitrile rubber into an inner sheet using an open mill, and wrap it over the outer surface of the nylon layer treated in step B) to obtain the inner rubber layer; D) Weave a steel wire skeleton on the inner adhesive layer to obtain a steel wire braided skeleton layer; E) The granulated nitrile rubber is extruded and formed on the steel wire braided skeleton layer to obtain the outer rubber layer; thereby obtaining the composite rubber tube.

7. The preparation method according to claim 6, characterized in that, In step A), the mass ratio of the nylon resin granules to the nylon resin raw materials is 3~5:24~26; Before the heating and extrusion, the process further includes drying; the drying temperature is 85~105℃, and the time is 2~4 hours. The temperature of the heating zone in the heated extrusion is 200~220℃.

8. The preparation method according to claim 6, characterized in that, In step A), the pressure used in the vacuum sizing method is -0.02 to -0.04 MPa.

9. The preparation method according to claim 6, characterized in that, In step D), before weaving, the process further includes freezing; the freezing temperature is -60 to -30 ℃. The weaving rate is 25~35 r / min.

10. The preparation method according to claim 6, characterized in that, In step E), the extrusion screw temperature is 40~60°C, the plasticizing section temperature is 50~70°C, the extruder temperature is 60~80°C, and the die head temperature is 70~90°C; the extrusion screw speed is 15~25 r / min, and the screw length-to-diameter ratio is 20~22:

1. The forming method is vacuum forming; the vacuum forming pressure is -0.07~-0.04 MPa.