Flame-retardant PVC (polyvinyl chloride) pipe

Abstract

The utility model relates to the technical field of PVC (polyvinyl chloride) pipes, and discloses a flame-retardant PVC pipe which comprises a PVC main pipe, a filling layer and a protective outer pipe which are sequentially arranged from inside to outside, flame-retardant coatings are coated on the inner wall and the outer wall of the PVC main pipe, a metal net is embedded on the outer pipe wall of the protective outer pipe, and the protective outer pipe is a CPE (chlorinated polyethylene) modified PVC pipe. The problems that in the prior art, when an existing PVC pipe encounters part of extreme use environments, a coating on the surface of the PVC pipe is scraped and leaks out of a bottom pipe, and the service life of the bottom pipe is shortened are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of PVC pipes, in particular to a flame-retardant PVC pipe. Background Art

[0002] PVC pipes are inexpensive and of good quality, with good tensile and compressive strength and strong corrosion resistance, etc., and are one of the most widely recognized pipes currently.

[0003] Since conventional PVC pipes will melt or burn when encountering a high-temperature environment during use, in the prior art, a flame-retardant layer or heat-insulating layer is usually coated on the surface of the PVC pipe for protecting the PVC pipe, thereby improving the flame-retardant performance of the PVC pipe. However, due to the wide range of use scenarios of PVC pipes, when encountering some extreme use environments, such as during installation, maintenance or transportation, if the PVC pipe is scratched, impacted or extruded by a sharp object, the coating on the surface of the PVC pipe will be scraped off to expose the bottom pipe, and the bottom pipe will have a shortened service life in an extreme use environment without protection. Summary of the Utility Model

[0004] In view of this, the purpose of the utility model is to provide a flame-retardant PVC pipe to solve the problem that when the existing PVC pipe in the prior art encounters some extreme use environments, the coating on the surface of the PVC pipe will be scraped off to expose the bottom pipe, and the service life of the bottom pipe is shortened.

[0005] The utility model solves the above technical problems through the following technical means: a flame-retardant PVC pipe, comprising a PVC main pipe, a filling layer and a protective outer pipe which are arranged in sequence from the inside to the outside, the inner wall and the outer wall of the PVC main pipe are both coated with a flame-retardant coating, a metal mesh is embedded in the outer wall of the protective outer pipe, and the protective outer pipe is a CPE-modified PVC pipe.

[0006] Optionally, the PVC main pipe and the protective outer pipe are bonded and welded. The PVC main pipe and the protective outer pipe are fixed by a welding method to ensure the fitting property.

[0007] Optionally, a plurality of radial grooves are circumferentially and uniformly distributed on the inner wall of the protective outer pipe, and a plurality of filling cavities are formed between the radial grooves and the outer wall of the PVC main pipe, and a flame-retardant material is filled in the filling cavities to form a filling layer. The spaced filling cavities reduce the amount of the flame-retardant material, and at the same time ensure the welding between the PVC main pipe and the protective outer pipe.

[0008] Optionally, the flame-retardant material is a flame-retardant polyurethane foam material. The flame-retardant polyurethane foam material has a certain buffering effect while having excellent flame-retardant performance, and is used to protect the PVC main pipe.

[0009] Optionally, the flame-retardant coating on the inner wall of the PVC main pipe is a perlite paint coating, and the flame-retardant coating on the outer wall of the PVC main pipe is a vinyl perchloride resin flame-retardant coating. The perlite paint has both heat insulation and anti-corrosion properties and is relatively environmentally friendly. The vinyl perchloride resin flame-retardant coating has good flame-retardant performance and does not affect the welding with the protective outer pipe.

[0010] Optionally, the metal mesh is a stainless steel wire mesh. This improves the protection ability of the protective outer pipe and prevents the PVC main pipe from being cut by sharp objects.

[0011] Optionally, the flame-retardant rating of the CPE-modified PVC pipe is not lower than the V-1 rating of the UL94 standard. This enables the protective outer pipe to have excellent flame-retardant performance while being resistant to being cut by sharp objects.

[0012] Advantages of the present utility model:

[0013] In the present utility model, by providing a protective outer pipe embedded with a metal mesh outside the PVC main pipe, the protection ability of the protective outer pipe is improved, thereby preventing the PVC main pipe from being cut by sharp objects. Using a CPE-modified PVC pipe as the protective outer pipe enables the protective outer pipe to have better flame-retardant performance than the PVC main pipe. At the same time, embedding a stainless steel wire mesh and providing a flame-retardant polyurethane foam material filling layer with both flame-retardant and buffering functions, in cooperation with the PVC main pipe, makes the force structure of the entire PVC pipe more reasonable, and the impact resistance and compressive capacity are significantly enhanced. Description of the Drawings

[0014] Figure 1 is a schematic structural diagram of the present utility model;

[0015] Figure 2 is a cross-sectional view of the pipe of the present utility model.

[0016] Wherein, 1 - PVC main pipe, 11 - flame-retardant coating, 2 - filling layer, 21 - radial groove, 3 - protective outer pipe, 31 - metal mesh. Specific Embodiments

[0017] The following specific embodiments are used to illustrate the implementation manners of the present utility model. Those skilled in the art can understand the advantages and effects of the present utility model from the content disclosed in this specification. It should be noted that the drawings provided in the following embodiments are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to the present utility model. To better illustrate the embodiments of the present utility model, some components in the drawings will be omitted, enlarged or reduced, which do not represent the actual sizes of the products; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0018] In the figures of the embodiments of the present utility model, the same or similar reference numerals correspond to the same or similar components. In the description of the present utility model, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the figure. This is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the figure are only for exemplary illustration and cannot be understood as a limitation to the present utility model. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0019] As Figure 1 - Figure 2 shown, a flame-retardant PVC pipe of the present utility model includes a PVC main pipe 1, a filling layer 2, and a protective outer pipe 3 arranged in sequence from the inside to the outside. The inner wall and outer wall of the PVC main pipe 1 are both coated with a flame-retardant coating 11. A metal mesh 31 is embedded in the outer wall of the protective outer pipe 3, and the protective outer pipe 3 is a CPE-modified PVC pipe.

[0020] In this embodiment, the PVC main pipe 1 and the protective outer pipe 3 are bonded and welded. At least part of the inner wall of the outer wall of the PVC main pipe 1 and the protective outer pipe 3 are bonded and welded, so that the main pipe and the outer pipe will not slide relative to each other, and the connection is firm.

[0021] In this embodiment, a plurality of radial grooves 21 are evenly distributed in the circumferential direction of the inner wall of the protective outer pipe 3. A plurality of filling cavities are formed between the radial grooves 21 and the outer wall of the PVC main pipe 1, and a flame-retardant material is filled in the filling cavities to form a filling layer 2.

[0022] In this embodiment, a filling layer 2 is provided between the PVC main pipe 1 and the protective outer pipe 3. Flame-retardant polyurethane foam material is selected as the filling material. The flame-retardant polyurethane foam material is formed by adding a flame retardant to rigid polyurethane foam. The flame retardant includes halogen-based flame retardants, nitrogen-based flame retardants, phosphorus-based flame retardants, and inorganic flame retardants, etc. The existing flame-retardant polyurethane foam material can reach the flame-retardant standard of UL-94 V0; at the same time, while having excellent flame-retardant performance, using the flame-retardant polyurethane foam material as the filling material of the filling layer 2 can also provide a certain buffering effect to protect the PVC main pipe, thereby improving the impact resistance of the entire pipe.

[0023] In this embodiment, the flame-retardant coating 11 on the inner wall of the PVC main pipe 1 is perlite paint, and the flame-retardant coating 11 on the outer wall of the PVC main pipe 1 is a perchloroethylene resin flame-retardant coating 11. Perlite paint has both heat insulation and anti-corrosion properties and is relatively environmentally friendly. The perchloroethylene resin flame-retardant coating has good flame-retardant performance and certain hot melt properties, and does not affect the welding with the protective outer pipe 3.

[0024] In this embodiment, the metal mesh 31 is a stainless steel wire mesh. A stainless steel wire mesh is embedded in the wall of the protective outer pipe 3 to improve the strength and protection ability of the protective outer pipe 3 and prevent the PVC main pipe from being cut by sharp objects.

[0025] In this embodiment, the flame retardant grade of the CPE-modified PVC pipe is not lower than the V-1 grade of the UL94 standard. Specifically, the content of the V-1 grade of the UL94 standard: After two 10-second combustion tests on the sample, the afterflame or afterglow extinguishes within 60 seconds, and the dripping particles cannot ignite cotton.

[0026] For example, the CPE-modified PVC pipe uses a base material with a ratio of 40-55 parts of PVC and 7-20 parts of CPE, and adds 4-20 parts of phosphate plasticizer, 3-7 parts of magnesium hydroxide filler, 3-6 parts of zinc borate, 3-6 parts of antimony trioxide and some necessary and existing processing aids, so that the CPE-modified PVC pipe made of the above ratio has good flame retardancy and smoke suppression properties, and at the same time it has excellent steam permeability, making the usage scenarios of the PVC main pipe 1 protected by the protective outer pipe 3 more diverse.

[0027] The working principle of the present utility model is as follows:

[0028] When in use, since the protective outer pipe 3 is made of a CPE-modified PVC pipe with functions such as flame retardancy and anti-seepage, and a stainless steel metal mesh is embedded inside, the protective outer pipe can protect the PVC main pipe 1 from being cut by sharp objects; a filling layer 2 with both flame retardant and buffering functions is provided between the protective outer pipe 3 and the PVC main pipe 1, and different flame retardant coatings are applied on the inner and outer surfaces of the PVC main pipe 1. The CPE-modified PVC pipe, the filling layer 2, and the flame retardant coatings can effectively prevent or block the spread of fire in extreme cases such as open fire combustion.

[0029] The flame retardant PVC pipe of the present utility model has a multi-level and multi-angle flame retardant system, excellent flame retardant performance, reasonable force structure, and at the same time takes into account the impact resistance and anti-cutting performance. In addition, using a relatively small amount of the protective outer pipe 3 to protect the PVC main pipe 1 has a certain cost advantage compared to modifying the entire PVC main pipe 1 or other methods to improve the flame retardant and protection performance.

[0030] The above embodiments are only used to illustrate the technical solutions of the present utility model and not to limit them. Although the present utility model has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present utility model can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present utility model, and they should all be covered within the scope of the claims of the present utility model. The technologies, shapes, and structures not described in detail in the present utility model are all well-known technologies.

Claims

1. A flame-retardant PVC pipe, characterized in that: It includes a PVC main pipe (1), a filling layer (2) and a protective outer pipe (3) which are arranged in sequence from the inside to the outside. The inner wall and the outer wall of the PVC main pipe (1) are both coated with a flame retardant coating (11). A metal mesh (31) is embedded in the outer pipe wall of the protective outer pipe (3), and the protective outer pipe (3) is a CPE modified PVC pipe.

2. The flame-retardant PVC pipe according to claim 1, wherein: The PVC main pipe (1) and the protective outer pipe (3) are bonded and welded together.

3. The flame-retardant PVC pipe according to claim 1, characterized in that: A plurality of radial grooves (21) are circumferentially and evenly distributed on the inner wall of the protective outer pipe (3). A plurality of filling cavities are formed between the radial grooves (21) and the outer wall of the PVC main pipe (1). The filling cavities are filled with a flame retardant material to form a filling layer (2).

4. The flame-retardant PVC pipe according to claim 3, characterized in that: The flame retardant material is a flame retardant polyurethane foam material.

5. The flame-retardant PVC pipe according to claim 1, characterized in that: The flame retardant coating (11) on the inner wall of the PVC main pipe (1) is a perlite coating, and the flame retardant coating (11) on the outer wall of the PVC main pipe (1) is a perchloroethylene resin flame retardant coating.

6. The flame-retardant PVC pipe according to claim 1, wherein: The metal mesh (31) is a stainless steel wire mesh.

7. The flame-retardant PVC pipe according to claim 1, wherein: The flame retardant grade of the CPE modified PVC pipe is not lower than the V-1 grade of the UL94 standard.

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