Environment-friendly flame-retardant PVC (polyvinyl chloride) hose

Abstract

The utility model relates to the technical field of PVC (polyvinyl chloride) hoses, in particular to an environment-friendly flame-retardant PVC hose, which sequentially comprises a lining layer, a flame-retardant layer, an aramid fiber reinforced layer, a nano layer and an outer protective layer from inside to outside, the lining layer 1 is made of PVC resin, the inner surface of the lining layer is polished, the nano layer is made of nano fibers and layered double hydroxides and covers the aramid fiber reinforced layer, and the outer protective layer is made of nano fibers and layered double hydroxides. The outer protection layer is a waterborne polyurethane layer, multiple protection coatings are further coated on the outer protection layer and used for achieving ultraviolet resistance, corrosion resistance and abrasion resistance, and the PVC hose has the advantages of being environmentally friendly, flame retardant, longer in service life and anti-fatigue capacity, provided with the surface which is not prone to dust sticking and easy to clean, good in anti-corrosion performance, good in anti-corrosion performance and good in anti-corrosion performance. The excellent weather resistance is realized.

Description

Technical Field

[0001] This utility model belongs to the field of PVC hose technology, specifically an environmentally friendly flame-retardant PVC hose. Background Technology

[0002] In existing technologies, the flame-retardant properties of common PVC hoses generally rely on the addition of halogenated flame retardants. However, when these flame retardants burn, they release large amounts of halogenated toxic gases and corrosive fumes, which not only seriously pollute the environment but also produce dense smoke and toxic substances at the fire scene, greatly hindering personnel escape and fire rescue, posing significant safety hazards.

[0003] Furthermore, existing PVC hoses have deficiencies in mechanical properties, particularly in resistance to repeated bending fatigue and the ability to maintain flexibility over long-term use. During use, the hoses are prone to localized hardening and embrittlement due to repeated bending or stress, leading to cracking or even rupture. This mechanical deficiency not only shortens the hose's service life but also potentially increases the risk of pipeline system failure, causing further safety issues.

[0004] Therefore, there is an urgent need in this field to develop a new type of hose material or structure that can meet environmentally friendly requirements, have high flame retardancy, and improve resistance to bending fatigue. Utility Model Content

[0005] Based on this, this solution provides an environmentally friendly flame-retardant PVC hose, which has environmentally friendly flame-retardant properties, strong bending resistance, is not easy to attract dust, has better weather resistance, and a longer service life.

[0006] The technical solution of this utility model to solve the above-mentioned technical problems is as follows:

[0007] An environmentally friendly flame-retardant PVC hose comprises, from the inside out, an inner lining layer, a flame-retardant layer, an aramid fiber reinforcement layer, a nano-layer, and an outer protective layer. The inner lining layer is made of PVC resin and its inner surface is polished. The nano-layer consists of nanofibers and layered double hydroxides and covers the aramid fiber reinforcement layer to improve its strength. The outer protective layer is a water-based polyurethane layer and is further coated with multiple protective coatings to achieve UV protection, corrosion resistance, and wear resistance.

[0008] Optionally, in one embodiment of the present invention, the thickness of the inner lining layer is 0.5mm ± 0.03mm.

[0009] Optionally, in one embodiment of the present invention, the thickness of the flame-retardant layer is 0.3mm-0.5mm.

[0010] Optionally, in one embodiment of the present invention, both sides of the aramid fiber reinforcing layer are coated with an adhesive layer to ensure a stable connection between the aramid fiber reinforcing layer and the upper and lower layers.

[0011] Optionally, in one embodiment of the present invention, the nanolayer is formed by spraying a 5-8 μm coating on the surface of the aramid fiber reinforcing layer.

[0012] Optionally, in one embodiment of the present invention, an intumescent flame-retardant layer is further provided between the nanolayer and the outer protective layer.

[0013] Optionally, in one embodiment of the present invention, the outer surface of the flame-retardant layer is provided with a diamond-shaped mesh pattern to provide mechanical anchor points for the aramid fibers.

[0014] Compared with the prior art, the environmentally friendly flame-retardant PVC hose provided by this utility model has the following characteristics:

[0015] Employing a multi-layered composite structure, this product utilizes halogen-free flame retardants, a water-based phosphorus-nitrogen intumescent coating, natural nanofibers, layered double hydroxides, aramid braiding reinforcement, and a diamond-patterned texture. While ensuring excellent mechanical properties and environmental friendliness, it also achieves highly efficient flame retardancy when exposed to fire. When burning, it rapidly forms an expanding, heat-insulating char layer and a dense physical barrier, preventing flame spread, material dripping, and heat-oxygen transfer. This reduces smoke and toxic gas release during combustion, thereby improving the fire resistance and environmental performance of the PVC hose. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a three-dimensional schematic diagram of the layered PVC hose of Embodiment 1 of this utility model;

[0018] Figure 2 This is a schematic cross-sectional view of the PVC hose in Embodiment 1 of this utility model;

[0019] Figure reference numerals: Inner lining layer 1, Flame retardant layer 2, Aramid fiber reinforcement layer 3, Nano layer 4, Intumescent flame retardant layer 5, Outer protective layer 6. Detailed Implementation

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments of the present invention can be combined with each other. The technical solutions of the present invention will be further described below with reference to the accompanying drawings of the embodiments. The present invention is not limited to the specific embodiments described below.

[0021] It should be understood that the same or similar reference numerals in the accompanying drawings of the embodiments correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "front," "rear," "left," "right," "top," and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms describing positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0022] Example 1

[0023] Because existing PVC hoses mostly use halogenated flame retardants for flame retardancy, which are not environmentally friendly and produce harmful gases when burned, affecting escape, and their mechanical properties also need improvement, a hose with environmentally friendly flame retardancy and good mechanical properties was designed. The specific solution is as follows:

[0024] like Figure 1-2 As shown, an environmentally friendly flame-retardant PVC hose comprises, from the inside out, an inner lining layer 1, a flame-retardant layer 2, an aramid fiber reinforcement layer 3, a nano layer 4, and an outer protective layer 6. The inner lining layer 1 is made of PVC resin, and its inner surface is polished. The nano layer 4 consists of nanofibers and layered double hydroxides, and it covers the aramid fiber reinforcement layer 3 to improve strength. The outer protective layer 6 is a water-based polyurethane layer, and multiple protective coatings are also applied to the outer protective layer 6 to achieve UV protection, corrosion resistance, and wear resistance.

[0025] The outer protective layer 6 is preferably made of aliphatic waterborne polyurethane, which has good resistance to yellowing, weathering and mechanical properties, and meets environmental protection requirements.

[0026] The multi-layer protective coating is processed by multi-layer spraying. Each layer of coating needs to be fully dried and cured. The multi-layer protective coating includes an anti-UV coating, an anti-corrosion layer, a wear-resistant layer, and a top layer. The top layer is the outermost topcoat and uses fluorine-modified water-based resin to achieve better weather resistance and reduce dust adhesion.

[0027] The thickness of the inner liner 1 is 0.5mm ± 0.03mm. Specifically, the PVC resin of the inner liner 1 is preferably SG-5 or SG-7 for the processing and manufacturing of the inner liner 1, which provides better mechanical strength, heat resistance and processing stability. The inner surface of the inner liner 1 is smooth, which reduces fluid retention, reduces the frequency of cleaning and the use of chemical cleaning agents, and indirectly improves environmental protection.

[0028] The thickness of flame retardant layer 2 is 0.3mm-0.5mm. Specifically, flame retardant layer 2 is still mainly made of PVC resin and uses halogen-free, low-smoke, and low-toxicity composite flame retardants, such as aluminum hydroxide and magnesium hydroxide. During the processing of flame retardant layer 2, zinc borate can be added as a synergist, which can promote charring at lower temperatures and help reduce the release of smoke and toxic gases.

[0029] Both sides of the aramid fiber reinforcing layer 3 are coated with an adhesive layer to ensure a stable connection between the aramid fiber reinforcing layer 3 and the upper and lower layers. Specifically, the thickness of the aramid fiber reinforcing layer 3 is 0.15mm ± 0.02mm, the aramid fiber is twill woven, and the adhesive layers on both sides are epoxy PU base adhesive, preferably water-based epoxy modified polyurethane base adhesive.

[0030] The nanolayer 4 is formed by spraying a 5-8 μm coating on the surface of the aramid fiber reinforcing layer 3. Specifically, the nanofiber is preferably made of natural materials, such as cellulose or nanofiber. When the nanolayer 4 is burned, it forms a dense carbon layer, which effectively isolates heat and oxygen and can adsorb acidic gases and smoke particles produced by combustion.

[0031] An intumescent flame-retardant layer 5 is also provided between the nanolayer 4 and the outer protective layer 6. Specifically, the intumescent flame-retardant layer 5 is a water-based phosphorus-nitrogen intumescent coating that rapidly expands and foams when exposed to fire, forming a thick, porous char layer with a coating thickness of 30μm-50μm.

[0032] The outer surface of the flame-retardant layer 2 is provided with a diamond-shaped mesh pattern to provide mechanical anchors for the aramid fibers. The groove structure of the diamond-shaped mesh pattern can effectively retain the epoxy PU base coat that is subsequently applied, greatly increasing the effective bonding area and mechanical interlocking strength with the aramid fiber layer. During processing, it can be formed by pressing with an embossing roller in a semi-molten state. The mesh pattern depth is ≤0.1mm. The diamond-shaped mesh pattern is used to enhance interlayer bonding and prevent interlayer peeling.

[0033] Flame retardant description:

[0034] In the outer protective layer 6, polyurethane and fluororesin themselves have certain flame retardancy. When exposed to open flame, they will burn and decompose first. However, the intumescent flame retardant layer 5 reacts rapidly below it to form a heat-insulating char layer. The fluorine modification of the topcoat helps to reduce the initial flame adhesion and spread rate.

[0035] When the intumescent flame-retardant layer 5 is exposed to fire, it undergoes a rapid chemical reaction, producing non-combustible gas. This causes the coating to expand violently, forming a porous foam carbon layer. The foam carbon layer isolates the heat from the flame from being transferred to the internal materials and covers the aramid fiber reinforced layer 3 and the nano layer 4, protecting their structural integrity.

[0036] Nanofibers themselves have good carbonization properties, which helps to form a stronger and more continuous carbon layer. Layered double hydroxides decompose and dehydrate at high temperatures, absorbing heat. Their layered structure can effectively block the diffusion path of heat and oxygen. Layered double hydroxides and the carbon layer formed have a large specific surface area and adsorption capacity, which can adsorb acidic gases and smoke particles produced by combustion, reducing smoke and toxicity.

[0037] Aramid fibers have extremely high thermal decomposition temperatures. When exposed to fire, they do not melt and drip, maintaining their basic structural shape and preventing the hose from collapsing. They also provide good mechanical strength in flames, maintaining the shape of the hose and preventing internal fluid leakage that could fuel combustion.

[0038] Aluminum hydroxide and magnesium hydroxide absorb heat and release water vapor when they decompose under heat, effectively reducing the temperature of the surface and surrounding area. The released water vapor dilutes the oxygen and flammable gas concentrations. Zinc borate promotes the formation of a stable char layer in PVC at lower temperatures, preventing heat from being transferred and diffused into the interior. PVC itself is prone to melting and dripping, and the char layer can effectively control the dripping of PVC, reducing the amount of smoke and toxic gas released during combustion. The flame retardant itself is halogen-free, low-smoke, and low-toxic.

[0039] The PVC hose in this solution adopts a multi-layer composite structure, using halogen-free flame retardants, water-based phosphorus and nitrogen expanding coatings, natural nanofibers, layered double hydroxides, aramid braiding reinforcement, and diamond mesh. Through multi-layer flame retardancy, while ensuring the PVC hose has excellent mechanical properties and environmental friendliness, it achieves highly efficient flame retardancy when exposed to fire. When exposed to fire, it quickly forms an expanding heat-insulating char layer and a dense physical barrier, preventing the spread of flames, the dripping of molten material, and the transfer of heat and oxygen, reducing the release of smoke and toxic gases produced during combustion, and improving the fire resistance and environmental performance of the PVC hose.

[0040] Example 2

[0041] In this embodiment, the structure of the PVC hose is basically the same as that in Embodiment 1. The difference is that recycled wood cellulose nanofibers are used instead of natural nanocellulose to reduce costs, and the intumescent flame retardant layer 5 and the outer protective layer 6 are processed into a single-layer structure to simplify the hose processing technology.

[0042] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An environmentally friendly flame-retardant PVC flexible hose, characterized in that, From the inside out, the structure consists of an inner lining layer, a flame-retardant layer, an aramid fiber reinforcement layer, a nano layer, and an outer protective layer. The inner lining layer is made of PVC resin and its inner surface is polished. The nano layer is composed of nanofibers and layered double hydroxides and is applied over the aramid fiber reinforcement layer to improve its strength. The outer protective layer is made of water-based polyurethane and is coated with multiple protective coatings to provide UV protection, corrosion resistance, and wear resistance.

2. The environmentally friendly flame-retardant PVC flexible hose according to claim 1, characterized in that: The thickness of the inner lining layer is 0.5mm ± 0.03mm.

3. The environmentally friendly flame-retardant PVC flexible hose according to claim 1, characterized in that: The thickness of the flame-retardant layer is 0.3mm-0.5mm.

4. The environmentally friendly flame-retardant PVC flexible hose according to claim 1, characterized in that: Both sides of the aramid fiber reinforcement layer are coated with an adhesive layer to ensure a stable connection between the aramid fiber reinforcement layer and the upper and lower layers.

5. The environmentally friendly flame-retardant PVC flexible hose according to claim 1, characterized in that: The nanolayer is formed by spraying a 5-8 μm coating on the surface of the aramid fiber reinforcement layer.

6. The environmentally friendly flame-retardant PVC flexible hose according to claim 1, characterized in that: An expansion flame-retardant layer is also provided between the nanolayer and the outer protective layer.

7. The environmentally friendly flame-retardant PVC flexible hose according to claim 1, characterized in that: The outer surface of the flame-retardant layer is provided with a diamond-shaped mesh pattern to provide mechanical anchor points for the aramid fibers.

Images