Preparation method and process of UHMWPE (Ultra High Molecular Weight Polyethylene) high-strength polyethylene pipe

Abstract

The invention discloses a preparation method and process of a UHMWPE (Ultra High Molecular Weight Polyethylene) high-strength polyethylene pipe, and relates to the technical field of optimized production of pipes, and the preparation method and process of the UHMWPE high-strength polyethylene pipe have the advantages that on the premise that the material cost and the manufacturing cost of the pipe are not greatly increased and a material formula with higher strength is used, the production efficiency is greatly improved; a single-layer pipe is designed to be of a double-layer structure with the inner sleeve and the outer sleeve connected in a sleeved mode, the outer sleeve is rolled to abut against the supporting and conducting lines on the outer wall of the inner sleeve, a gap is reserved between the inner sleeve and the outer sleeve, and when the outer sleeve is subjected to acting force, deformation buffering acting force is generated through the thin pipe wall; meanwhile, the residual acting force can be conducted to the house type side wall of the inner sleeve to be buffered, the resistance to the acting force is better, in addition, the gap between the inner sleeve and the outer sleeve can be filled with different materials, and therefore the novel pipe is endowed with the strength in the aspects of abrasion resistance, impact resistance, chemical corrosion resistance and the like.

Description

Technical Field

[0001] The invention relates to a method for preparing a polyethylene pipe, and in particular to a method and process for preparing a UHMWPE high-strength polyethylene pipe. Background Art

[0002] High molecular weight polyethylene material has excellent properties such as high strength, impact resistance, wear resistance, self-lubrication, chemical corrosion resistance, and low temperature resistance. It is widely used in many fields. With the widespread use of high-strength polyethylene in various pipes, the corresponding requirements for the strength of polyethylene pipes are also getting higher and higher.

[0003] The existing technology usually has the following ways to ensure the strength of pipes: increasing the wall thickness of the pipe, selecting materials with better performance and optimizing the structural design of the pipe. However, the thickness of the pipe is almost directly proportional to the cost. The research and development of new and stronger material formulas is also difficult. The research and development of higher strength polyethylene pipe formulas has not yet produced any results. Therefore, it is more practical to optimize the structure of the pipe itself to improve the strength of the pipe. However, while optimizing the pipe structure, it is also necessary to pay attention to the increased material cost and the production difficulty cost.

[0004] To this end, technicians in this field have proposed a method and process for preparing UHMWPE high-strength polyethylene pipes. According to the strength differences of different structures and material costs, combined with the production difficulty, the pipe structure is optimized accordingly, which can appropriately increase the strength of the pipe and make it safer and more reliable in use. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a method and process for preparing a UHMWPE high-strength polyethylene pipe, in which the existing single-layer structure, which relies on material strength and pipe wall thickness to ensure strength, is configured into a double-layer structure of an inner and outer sleeve, and a support structure is processed between the inner and outer sleeves by rolling. When the outer sleeve is subjected to a force, the force is transmitted to the outer wall of the inner sleeve through the support structure, and the arc-shaped outer wall of the outer sleeve offsets part of the extrusion effect and continues to consume the force through the arc-shaped outer wall of the inner sleeve. In addition, the filler between the inner and outer sleeves can enable the new pipe to buffer impact, increase heat resistance and further buffer the force.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a UHMWPE high-strength polyethylene pipe preparation process, which sets the existing integrated structure pipe as a double-layer pipe fitting with inner and outer sleeves, and buffers the forces twice through the double-layer arc-shaped side wall. At the same time, the thinner side wall can absorb part of the force through deformation.

[0007] The space between the inner and outer pipes is filled with fillers, which can give the new pipes better heat resistance, impact resistance and other properties.

[0008] The inner and outer tubes are supported by heating and pressing, and the intermediate filler is positioned. The support structure is rolled between the inner and outer tubes, which can enhance the structural strength between the inner and outer tubes, serve as a contact conduction path for the force, and can position the filler between the inner and outer tubes to prevent large amounts of leakage.

[0009] Preferably, the preparation process of the above-mentioned pipe comprises the following steps:

[0010] S1. Coaxially sleeve and install two sets of inner and outer tubes with different diameters;

[0011] S2, heating and softening the outer casing, and pressing the outer tube by rollers to prepare a support structure between the inner and outer tubes;

[0012] S3. Fill the hollow parts of the inner and outer tubes with fillers, heat and soften them again, and press them to shape the fillers.

[0013] Preferably, the wall thickness of the inner and outer tubes in the S1 step is half of the original tube, so that the material used in the new composite tube is only slightly more than the consumables of the original tube, avoiding a large increase in raw material costs. In addition, the material formula and the production steps of the tube are the same as those of the prior art tube, and the production cost will not be increased too much, which is more in line with the need to improve the strength of the tube under existing conditions.

[0014] Preferably, there is a 6-20mm difference in diameter between the inner and outer tubes prepared in the S1 step, ensuring that there is a 3-10mm gap between the inner and outer tubes after they are coaxially sleeved for supporting structure pressing and filling of fillers. The double-layer sleeve structure can utilize a thinner wall thickness to perform deformation buffering on the applied force, utilize the gap between the inner and outer sleeves to buffer the applied force, and then conduct the force through the rolled support structure between the inner and outer sleeves. The inner and outer sleeves respectively utilize arc surfaces to buffer the applied force twice, thereby achieving a better buffering effect.

[0015] Preferably, in step S1, the inner and outer tubes are installed with an inclination to the horizontal plane. The inclined structure is conducive to filling the gap between the inner and outer tubes, and gravity is used to help the filler slide in the smooth gap.

[0016] The inner and outer tubes are respectively pressed and limited at both ends of the inner and outer tubes, and the inner and outer tubes are respectively positioned at both ends to ensure the coaxial sleeve installation relationship of the inner and outer tubes without affecting the filling of the tube wall gap from one end.

[0017] Preferably, in step S2, the metal tube is heated by passing an electromagnetic field, the outer layer of the combined tube is heated and softened in a manner that it is coaxial with the metal tube and passes through at a uniform speed, the energized coil quickly heats the inner metal tube, and the combined tube passing coaxially is then heated and softened by the heated metal tube. The softened tube wall is convenient for surface rolling, and a supporting conduction structure is formed between the inner and outer tube walls by local concave deformation, which positions the inner and outer tube walls and serves as an intermediate structure for force conduction, while ensuring the buffering of the curved surface of the outer sleeve.

[0018] Preferably, in step S2, a pressing structure parallel to the advancing direction of the combined pipe is provided at the rear end of the metal pipe, and vertical lines are pressed by pressing against the combined pipe and rolling to form a support structure between the inner and outer pipes. As the heated combined pipe advances, the rolling roller in contact with it presses against its side surface, exerting a force on the softened part of the outer sleeve to deform it and press against the side wall of the inner sleeve. After cooling and solidification, the positioning between the inner and outer sleeves is completed, and the conduction path of the force between the inner and outer sleeves is improved. A gap is used between the inner and outer sleeves to serve as a deformation buffer zone for the force, and fillers are added through a fixed gap. The performance of the new pipe is correspondingly enhanced by different fillers.

[0019] Preferably, after the completion of step S2, the combined pipe is cooled and filled with any one or more of the combined components of sand, wood, stone and metal fillers according to the needs of use. Fillers of different materials can enhance the heat resistance, pressure resistance, corrosion resistance and other properties of the new pipe to different degrees.

[0020] Preferably, after completing the filler in the middle of the combined pipe in step S3, the heating and softening of the sleeve is repeated. The heating time is related to the thermal conductivity of the filler. Because the materials of the intermediate filler are different, their thermal conductivity and specific heat capacity are different. The time required to complete the heating and softening of the outer sleeve is different, and the requirements for ensuring that the inner pipe does not deform due to temperature increase are also different. Therefore, the time for the secondary softening heating needs to be controlled accordingly.

[0021] Preferably, after the casing of the combined pipe is heated and softened again in step S3, transverse lines are rolled between the inner and outer casings by rolling, and the internal filler is positioned by rolling the transverse lines on the side of the new pipe in cooperation with the vertical lines to prevent the problem of large-scale leakage of filler due to local damage of the outer casing. In addition, the force conduction between the inner and outer casings can be strengthened to ensure that when the outer casing is subjected to a large force that cannot be fully absorbed, it can be evenly transmitted to the side wall of the inner casing.

[0022] The present invention discloses a method and process for preparing a UHMWPE high-strength polyethylene pipe, which has the following beneficial effects:

[0023] The UHMWPE high-strength polyethylene pipe preparation method and process, without greatly increasing the material cost and production cost of the pipe and using a higher strength material formula, designs the single-layer pipe into a double-layer structure with inner and outer sleeves, the outer sleeve is rolled to press against the support and conduction lines of the outer wall of the inner sleeve, and a gap is left between the inner and outer sleeves. When the outer sleeve is subjected to a force, the thinner pipe wall deforms to buffer the force, and the remaining force can be transmitted to the arc-shaped side wall of the inner sleeve for buffering, so that the resistance to the force is better. In addition, the gap between the inner and outer sleeves can be filled with different materials to give the new pipe strength in terms of wear resistance, impact resistance, chemical corrosion resistance, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the distribution relationship of the inner and outer tube diameters and the installation structure of the present invention;

[0027] Figure 3 It is a schematic diagram of the overall cross-section of the inner and outer sleeves of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The embodiment of the present invention discloses a method and process for preparing a UHMWPE high-strength polyethylene pipe;

[0030] The existing integrated structure pipe is set as a double-layer sleeve pipe fitting with inner and outer sleeves. The double-layer curved side wall can buffer the force twice. At the same time, the thinner side wall can deform through the gap between the inner and outer sleeves to absorb part of the force, thereby obtaining more flexible and better impact resistance than a single-layer pipe wall.

[0031] The gap between the inner and outer pipes can also be filled with fillers of all materials. Fillers of different materials can also improve the new pipe's better heat resistance, impact resistance and corrosion resistance.

[0032] The support structure between the inner and outer tubes is processed by heating and pressing. After the outer casing is heated and softened, it is partially concave inward by rolling, pressed against the outer wall of the inner casing and bonded to it for positioning. In addition, the concave structure can serve as a transmission structure for the force exerted by the outer casing on the inner casing, and the force exerted on the outer casing is evenly transmitted to the side wall of the inner casing, so as to realize the effect of the double-layer arc tube wall in buffering the impact force.

[0033] In addition, the recessed structure can also position the middle filler in the gap between the pipe walls to prevent the outer casing from being partially damaged and causing a large amount of filler to leak out.

[0034] Preferably, the preparation process of the above-mentioned pipe comprises the following steps:

[0035] S1. Coaxially sleeve and install two sets of inner and outer tubes with different diameters;

[0036] S2, heat and soften the outer casing, and press the outer casing with a roller to form a parallel supporting conductive structure between the inner and outer casings;

[0037] S3. Fill the gap between the inner and outer tubes with fillers, heat and soften the outer casing again, and press the outer casing transversely with rollers to position the fillers in the gap.

[0038] Fillers of different materials have different strengthening effects on the performance of new pipes. In order to verify the strength difference between the new pipe and the original integrated pipe, and to study the strengthening of the performance of the new pipe by fillers of different materials, a certain experimental base is set up below to facilitate the strength comparison between the existing pipe and the new casing, as well as the same casing, different material fillers to strengthen the performance of the pipe.

[0039] The diameter, length and thickness of the sample polyethylene pipe are limited to facilitate the study of the strength difference between the double-layer sleeve of the present invention and the existing integrated pipe on the basis of the same material and materials, as well as the strengthening effect of the same double-layer sleeve on the pipe strength when the filling material is different. The existing UHMWPE high-strength polyethylene material pipe with a diameter of 100mm, a length of 100mm and a wall thickness of 10mm is taken as the sample.

[0040] Comparative Example 1

[0041] Based on the preparation of the above new pipe, an existing UHMWPE high-strength polyethylene pipe with a diameter of 100 mm, a length of 100 mm, and a wall thickness of 10 mm was selected as Comparative Example 1.

[0042] Example 1

[0043] According to the UHMWPE high-strength polyethylene material pipe selected in Example 1, inner and outer sleeves with inner ring diameters of 100 mm and 110.68 mm, a length of 100 mm, and a wall thickness of 2.34 mm were prepared with the same material of similar volume. The inner and outer sleeves were coaxially sleeved and installed with a gap of 6 mm to form a combined pipe. This pipe was not filled with fillers and served as a sample of Example 1.

[0044] Example 2

[0045] Take the sample in Example 1, select fine sand as the intermediate filler, and obtain the sample in Example 2.

[0046] Example 3

[0047] Take the sample in Example 1, select wood strips as the intermediate filler, and obtain the sample of Example 3.

[0048] Example 4

[0049] Take the sample in Example 1, select crushed stone as the intermediate filler, and obtain the sample of Example 4.

[0050] Example 5

[0051] Take the sample in Example 1, select metal strips as the intermediate filler, and obtain the sample in Example 5.

[0052] The stress of the materials of the above 6 groups of pipes was studied by experimental equipment, and the corresponding research data was recorded to obtain the following table.

[0053]

[0054] According to the data analysis recorded in the above table, the various data of the inner and outer sleeve structure compared with the integrated pipe have shown a significant increase. In addition, through the experimental data analysis of five groups of embodiment samples, the double-layer sleeves with different material fillers have a significant effect on different strengths.

[0055] According to the experimental data comparison of the five groups of embodiments and comparative example 1, the double-layer pipe has greatly enhanced performance in all aspects compared with the single-layer structure pipe in the prior art. The double-layer pipe with sand filler has greatly improved compression and impact resistance, but it will affect the tensile strength of the pipe to a certain extent. The double-layer pipe with wood filler has a certain improvement in bending strength, and a great improvement in compressive strength and impact strength. The double-layer pipe with stone filler has obvious improvements in tensile strength, bending strength, compressive strength and impact strength. Finally, the double-layer pipe with metal filler has the most significant improvement in strength in all aspects, but the corresponding cost increase is also the largest. Different material fillers need to be selected according to the use of the pipe.

[0056] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A process for preparing a UHMWPE high-strength polyethylene pipe, characterized in that: The existing integrated structure pipe is set as a double-layer pipe fitting with inner and outer sleeves, the inner and outer pipes are filled with fillers, and then the inner and outer pipes are supported by heating and pressing, and the middle filler is positioned.

2. A method for preparing a UHMWPE high-strength polyethylene pipe, characterized in that: The preparation process of the pipe according to claim 1 comprises the following steps: S1. Coaxially sleeve and install two sets of inner and outer tubes with different diameters; S2, heating and softening the outer casing, and pressing the outer tube by rollers to prepare a support structure between the inner and outer tubes; S3. Fill the hollow parts of the inner and outer tubes with fillers, heat and soften them again, and press them to shape the fillers.

3. The method for preparing a UHMWPE high-strength polyethylene pipe according to claim 2, characterized in that: In the step S1, the wall thickness of the inner and outer tubes is half of the original tube, so that the new composite tube uses slightly more material than the original tube. The production formula and production steps are the same as those of the prior art tube.

4. The method for preparing a UHMWPE high-strength polyethylene pipe according to claim 2, characterized in that: The inner and outer tubes prepared in step S1 have a diameter difference of 6-20 mm, ensuring that after the inner and outer tubes are coaxially sleeved, there is a spacing of 3-10 mm between the two for supporting structure pressing and filling of fillers.

5. The method for preparing a UHMWPE high-strength polyethylene pipe according to claim 2, characterized in that: In step S1, the inner and outer tubes are installed in a sleeve manner and are tilted relative to the horizontal plane, and the inner and outer tubes are respectively pressed and limited at both ends.

6. The method for preparing a UHMWPE high-strength polyethylene pipe according to claim 2, characterized in that: In the step S2, the metal tube is heated by passing an electromagnetic field, and the outer layer of the combined tube is heated and softened in a manner that the combined tube passes through the metal tube coaxially and at a uniform speed.

7. The method for preparing a UHMWPE high-strength polyethylene pipe according to claim 6, characterized in that: In step S2, a pressing structure parallel to the advancing direction of the combined pipe is arranged at the rear end of the metal pipe, and the vertical lines are pressed by pressing against and rolling the combined pipe to form a supporting structure between the inner and outer pipes.

8. The method for preparing a UHMWPE high-strength polyethylene pipe according to claim 2, characterized in that: After the step S2 is completed, the combined pipe is cooled and then filled with any one or more of the combined components of sand, wood, stone and metal fillers according to the use requirements.

9. The method for preparing a UHMWPE high-strength polyethylene pipe according to claim 2, characterized in that: After the intermediate filling of the combined pipe is completed in step S3, the heating and softening of the sleeve is repeated, and the heating time is related to the thermal conductivity of the filling.

10. The method for preparing a UHMWPE high-strength polyethylene pipe according to claim 2, characterized in that: In step S3, after the sleeve of the combined pipe is heated and softened again, transverse lines are rolled between the inner and outer sleeves by rolling.

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