CN112500630A

CN112500630A - Composite material fusion welding pipe

Info

Publication number: CN112500630A
Application number: CN202011233229.1A
Authority: CN
Inventors: 马修
Original assignee: Vivani International Ltd
Current assignee: Vivani International Ltd
Priority date: 2020-11-06
Filing date: 2020-11-06
Publication date: 2021-03-16
Also published as: WO2022095309A1

Abstract

The invention discloses a fusion welding pipe made of composite materials, which is formed by compounding and co-extruding II type PE-RT and LLDPE materials, and comprises the following components in percentage by mass: 56-98% of II type PE-RT and 2-44% of LLDPE, the composite material fusion welding pipe has good flexibility, is convenient and economical to lay, can reduce the using amount of pipe fittings by coiling, bending and other methods during construction, reduces the construction cost, and has excellent low temperature resistance, so that the pipe can be constructed under the low temperature condition in winter, and does not need to be preheated during bending.

Description

Composite material fusion welding pipe

Technical Field

The invention belongs to the technical field of fusion welding pipe modification, and particularly relates to a composite fusion welding pipe.

Background

The pipe has wide application in the fields of daily life, engineering construction, industrial conveying and the like, wherein common pipes comprise a PE pipe (polyethylene pipe) and a PPR pipe (polypropylene pipe), and in actual use, the PE pipe has the defects of poor heat resistance, low compressive strength and the like, so that the PE pipe can only be used for the pipe with low pressure and small diameter, and the PE plastic is sensitive to environmental stress (chemical and mechanical effects) and is easy to stress crack; the PPR pipe has the defects of insufficient high-temperature rigidity, low-temperature brittleness, low environment resistance, low continuous use temperature, large creep property, no long-term load resistance and the like, and is specifically embodied as follows:

1. the pressure resistance is poor, when the same pressure is met, the metal pipe shows higher toughness, and the PPR pipe can be damaged, so that the PPR pipe cannot be normally used;

2. the heat resistance is weak, and the long-term working temperature of the PPR pipe cannot exceed 70 ℃ generally, otherwise, the service life of the PPR pipe is reduced;

3. the thermal expansion coefficient is larger at high temperature, and the pipe deforms and bends;

4. the low-temperature impact property is poor, and the actual use requirement cannot be met;

5. the fittings are high in price, the length of each section of the PPR pipe is limited to a certain extent, a large number of joints are needed to connect the PPR pipes under the condition of longer construction distance, and compared with the PPR pipes, the PPR pipes are low in price, and the joints frequently used in the PPR pipe construction are high-price products;

6. the PPR pipe is not anti-freezing, the PPR pipe is installed, the anti-freezing is probably not needed in the south of China, but in the north area with the temperature below-10 ℃ which is still kept in winter, the anti-freezing protection measure needs to be done on the PPR pipe, and the outside of the water pipe is wrapped with heat-insulating cotton;

7. the PPR pipe is not sun-proof, and especially in summer with strong sunlight, the white PPR pipe can be yellow after being exposed in summer, even the inner wall of the pipe is scaled, and the water quality is polluted. The remedy measure is that a layer of sun-proof layer is wrapped on the tube body of the white PPR tube to resist strong ultraviolet rays.

It is therefore desirable to develop a composite fusion welded pipe to address the above problems simultaneously.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides the composite material fusion welding pipe which is low in cost, high in environmental resistance and high in compressive and compressive strength.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a fusion welding pipe made of composite materials is formed by compounding and co-extruding II type PE-RT and LLDPE materials, and the weight percentage is as follows: 56-98% of II type PE-RT and 2-44% of LLDPE.

In the invention, the II type PE-RT material has a bimodal molecular weight distribution structure with low sag property.

In the present invention, the type II PE-RT is copolymerized from polyethylene, ethylene and butene.

In the present invention, LLDPE is prepared by copolymerizing ethylene and an a-olefin under low temperature and pressure conditions.

In the present invention, the a-olefin is one of butene, hexene or octene.

In the invention, the maximum caliber of the pipe is 500 mm.

The invention has the beneficial effects that:

1. the composite material fusion welding pipe has good flexibility, is convenient and economic to lay, can reduce the using amount of pipe fittings by coiling, bending and other methods during construction, and reduces the construction cost.

2. The composite material fusion welding pipe has excellent low temperature resistance, so that the composite material fusion welding pipe can be constructed even under the condition of low temperature in winter, and the pipe does not need to be preheated when being bent.

3. The composite material fusion welding pipe has good chemical corrosion resistance and long service life.

4. The composite material fusion welding pipe has good environmental adaptability, light weight and good flexibility, and can be supplied by a coil pipe.

5. The composite material fusion welding pipe can be safely used for more than 50 years under the conditions that the working temperature is 70 ℃ and the pressure is 0.4 MPa.

6. The pipe is not added with any toxic auxiliary agent in the production process. The inner wall is smooth, no scale is formed, no bacteria are bred, and the method can be safely applied to the fields of drinking water delivery and the like.

Detailed Description

In order to make the objects, 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 below.

Example (b):

the embodiment discloses a fusion welding pipe made of composite materials, which is formed by compounding and co-extruding II type PE-RT and LLDPE materials, and the mass percentages are as follows: 56-98% of II type PE-RT and 2-44% of LLDPE, wherein the compounding method of the II type PE-RT and the LLDPE material can be any type of mixing machine or manual compounding method, and the technical effect of the invention can be achieved. The II type PE-RT material is a double-peak molecular weight distribution structure with low sag property, and is the only raw material for extruding and producing large-caliber plastic pipelines for hot water transportation at present. The raw material has the processing characteristic of low sagging, the maximum caliber of the pipe can be produced to 500mm, and the requirement of large flow in thermal transmission is completely met. The type II PE-RT is copolymerized by polyethylene, ethylene and butylene. LLDPE is copolymerized by ethylene and a-olefin under the conditions of low temperature and pressure, wherein the a-olefin is one of butene, hexene or octene. According to the invention, the II type PE-RT and LLDPE materials are subjected to blending modification, so that the prepared blending modified material has the specific properties of the two materials, the flexibility and the environment resistance of the pipe are greatly improved, the compressive and compressive strength is increased, the application range is expanded, the market competition with other fusion welding pipes such as PE pipes, PPR pipes, PE-RT pipes and the like is enhanced, and the production and installation cost of the product is reduced. The detection proves that the pipe material has the same wall thickness and diameter; the pipe material has higher pressure resistance and higher impact resistance, can solve the problem of pipeline cracks caused by impact under the same pressure and temperature conditions (in cold weather of minus 20 ℃), has higher flexibility, can be coiled for supply, can reduce the reason of using joint accessories due to long coiling, does not need to use the joint accessories to connect the pipe material in the middle during installation, is quicker to install, and also reduces the leakage risk. The pipe material of the invention can replace PPR pipe, PE pipe and PE-RT pipe, and improve the weakness of the pipes.

The pipe of this example was produced in the following manner: adding the II type PE-RT and LLDPE materials into an internal mixer according to mass percent, uniformly mixing, then extruding and molding through an extruder, and then shaping through a shaping machine, wherein the extrusion process temperature of the extruder is 170-190 ℃, and the shaping machine is water-cooled and shaped.

After the pipe is modified, all performances are optimized and improved, so that the pipe with smaller pipe diameter and wall thickness can be used under the condition of the same use requirement, the effects of saving materials and cost are achieved, meanwhile, the weight of the pipe is lightened, and the pipe is easy to transport and install by combining a coiling delivery mode; meanwhile, the pipe has excellent flexibility, so that the pipe can be coiled and bent, the use of connecting accessories is reduced, and the installation cost is reduced. Since the pipe of the invention is flexible andthe tubing of the present invention is easier to install, because it is easier to shape, has memory to maintain straight line, unlike PE tubing, PPR tubing or PE-RT tubing, which is easier to crimp. In addition, the pipe has very high stress resistance and cracking resistance, the coefficient of thermal expansion of the pipe is 0.2mm/mK, and the elastic modulus is 550mm²The stress of the bent part can be released quickly when the pipeline is bent, and the pipe can be quickly laid on a large area with the performance, and the pipe is simple to install even at the temperature lower than the subzero temperature.

The pipe has low brittle fracture temperature, so the pipe has wider working temperature range and can normally work within the range of-40 ℃ to 95 ℃. When the PPR pipe becomes brittle at about 0 ℃, the pipe of the invention is still flexible at the temperature of less than-40 ℃. The pipe has good chemical corrosion resistance and long service life, and can be safely used for 50 years under normal conditions; the pipe is not easy to break, and the notch impact strength of the pipe reaches 13KJ/m at-30 ℃ through testing²The normal working state can be kept without impact at the low temperature of minus 40 ℃, and the PPR pipeline can be damaged at the low temperature of less than minus 20 ℃.

The pipe can be welded with a socket as PPR, the performance is as reliable as PPR, the welding performance of the socket of PE-RT is not reliable, in addition, the pipe can be flexibly bent by using a coil supply mode, the corner does not need to use an elbow, a plurality of joints do not need to be used, and the installation cost is effectively reduced. Because of the use of much fewer elbows, most pipes can use smaller pipe diameters, such as the original 25mm pipe, and the present invention can use 20mm instead. Because the bend creates flow resistance, reducing flow, while reducing the use of the bend means an increase in flow.

Compared with the installation of a PPR pipe, the material cost is reduced, and in the installation of the pipe, the material cost can be reduced by 15 percent because the pipe needs fewer accessories.

Compared with the installation of the PPR pipe, the labor cost is reduced, the installation of a plurality of joint accessories is saved in the installation process, the installation process is simplified, and the efficiency of pipeline installation is greatly improved, so that the labor cost of the installation can be reduced by 35%.

The product of the invention has better flexibility, can be connected in a plurality of connection modes, and is more convenient and time-saving in construction.

PPR pipe is typically shipped in units of 4 meters. The pipe provided by the invention is supplied in coils, and is usually delivered in the form of a coil with the diameter of 20mm and the length of 100 meters, a coil with the diameter of 25mm and a coil with the diameter of 60 meters, so that the pipe is more convenient to transport and load and saves space. When the pipeline leakage protector is installed, the probability of pipeline leakage is low due to the reduction of joints.

The composite fusion welded tubing of the present invention can be used in the following applications:

1. a cold and hot water system of a building, including a central heating system;

2. the heating system in the building comprises a floor, a wall plate and a radiant heating system;

3. a purified water supply system capable of directly drinking;

4. central (central) air conditioning systems, ventilation equipment and solar water heating systems;

5. industrial pipe systems for conveying or discharging chemical media have relatively high temperature and high corrosion resistance, and the conveying pipe systems are required to have high temperature resistance and corrosion resistance.

The above description is only a preferred embodiment of the present invention, and the technical solutions that achieve the objects of the present invention by substantially the same means are within the protection scope of the present invention.

Claims

1. A composite material fusion welding pipe is characterized in that: the composite material is prepared by compounding and co-extruding II type PE-RT and LLDPE materials, and the mass percentage is as follows: 56-98% of II type PE-RT and 2-44% of LLDPE.

2. A composite material fusion welded tubing according to claim 1, characterized in that: the II type PE-RT material is a bimodal molecular weight distribution structure with low sag property.

3. A composite material fusion welded tubing according to claim 1, characterized in that: the type II PE-RT is copolymerized by polyethylene, ethylene and butylene.

4. A composite material fusion welded tubing according to claim 1, characterized in that: LLDPE is made from the copolymerization of ethylene and a-olefins under low temperature and pressure conditions.

5. A composite material fusion welded tubing according to claim 4, characterized in that: the alpha-olefin is one of butene, hexene or octene.

6. A composite material fusion welded tubing according to claim 1, characterized in that: the maximum caliber of the pipe is 500 mm.