Winding mould pressing and technology for large-diameter composite pipe fitting

Abstract

The large-diameter composite pipe fitting winding mould pressing technology comprises a pipe fitting body, the pipe fitting body sequentially comprises an inner surface layer, an impermeable layer, a structural layer and an outer protective layer from inside to outside, sealing structures are arranged at the two ends of the pipe fitting body, and each sealing structure comprises a general R-opening groove meeting the international standard size. A sanitary anti-overturning sealing ring is installed in the R-opening groove, through the arrangement of the universal R-opening groove, flexible connection of various plastic pipelines can be directly adapted, and the pipe fitting body has extremely high universality and engineering adaptability. The invention relates to the technical field of pipeline connecting pieces, provides a high-strength corrosion-resistant plastic resin composite flexible connection large-diameter pipe fitting and a winding and mold pressing process thereof, and aims to solve the technical problems of insufficient strength, poor corrosion resistance, complex process, limited specification and the like of large-diameter pipe fittings in the prior art.

Description

Technical Field

[0001] This invention relates to the field of pipe fittings technology, specifically to a large-diameter composite pipe fitting winding molding and its process. Background Technology

[0002] Flexible pipe fittings for medium and low pressure (below 1.25MPa) that are compatible with plastic pipes are mainly made of PVC and PE materials, manufactured using injection molding, with specifications ranging from 20mm to 400mm. However, due to the limitations of the injection molding process, the maximum size of PVC fittings can only reach 315mm; PE fittings, due to their lower strength, would have significantly higher production costs to meet high-pressure requirements.

[0003] With the continued rapid growth of the plastic pipe application market, the market demand for high-pressure resistant plastic pipes is expanding. Currently, the main materials for high-pressure resistant pipe fittings on the market are welded steel plates and ductile iron, with specifications ranging from 50mm to 2000mm. However, the maximum size of ductile iron fittings is limited to 400mm due to complex casting processes and high material costs. While welded steel plate fittings offer good machinability, the strength of the weld joints and the quality of the internal and external anti-corrosion layers are difficult to control effectively, leading to problems such as leakage and anti-corrosion layer peeling during actual use. Specifically, the existing technology has the following main defects and shortcomings: 1. Currently, the mainstream PVC and PE injection molded pipe fittings have obvious limitations in pressure resistance: PVC material is restricted by the technical bottleneck of injection molding process and cannot produce pipe fittings with a diameter of more than 400mm; while if the pressure resistance of PE material is to be improved to 1.25MPa or above, its material cost will increase significantly, and it lacks market competitiveness in terms of economy, making it difficult to meet the application needs of medium and high pressure scenarios.

[0004] 2. Existing high-pressure resistant flexible large-diameter pipe fittings mainly rely on two technical routes: ductile iron and welded steel plates. However, both have significant shortcomings. Ductile iron pipe fittings are limited by complex casting processes and high raw material costs, with a maximum size of only 400mm, which cannot meet the connection requirements of large-diameter pipeline systems. Although welded steel plate pipe fittings have better machinability, the strength and stability of the welded joints are difficult to guarantee, and the internal and external anti-corrosion layers of the pipe fittings are easily damaged during the welding process, leading to frequent problems such as leakage and anti-corrosion layer peeling in actual use.

[0005] Therefore, improvements are needed to address the shortcomings of existing flexible connection large-diameter pipe fittings in terms of material properties and manufacturing processes. Summary of the Invention

[0006] In view of the above situation and to overcome the existing defects, the present invention provides a high-strength corrosion-resistant plastic resin composite flexible connection large-diameter pipe fitting and its winding molding process, aiming to solve the technical problems of insufficient strength, poor corrosion resistance, complex process and limited specifications of large-diameter pipe fittings in the prior art.

[0007] The present invention provides the following technical solution: This solution provides a large-diameter composite pipe fitting, including a pipe fitting body, which includes an inner surface layer, a seepage-proof layer, a structural layer and an outer protective layer from the inside to the outside. The two ends of the pipe fitting body are provided with sealing structures, which include universal R-grooves conforming to international standard dimensions. Sanitary anti-overturning sealing rings are installed in the R-grooves. Through the universal R-grooves, it can be directly adapted to the flexible connection of various plastic pipes, so that the pipe fitting body has strong versatility and engineering adaptability.

[0008] The inner surface layer is made of carbon fiber and food-grade resin. This inner surface layer provides the pipe body with excellent corrosion resistance and basic strength, while the food-grade resin ensures safety when in contact with drinking water.

[0009] The impermeable layer is made of glass fiber and food-grade resin. The impermeable layer can effectively prevent the medium from penetrating and improve the sealing performance of the pipe body.

[0010] The structural layer is composed of glass fiber and food-grade resin. This structural layer provides the main mechanical support for the pipe body, ensuring its ability to withstand high pressure.

[0011] The outer protective layer is a gel coat layer coated on the outer surface of the structural layer. The outer protective layer enhances the weather resistance and anti-aging ability of the pipe body.

[0012] Furthermore, food-grade colorant is added to the inner surface layer, the impermeable layer, and the structural layer to meet the appearance marking requirements of the pipe body in different application scenarios.

[0013] This invention also provides a spiral winding molding process for high-strength, corrosion-resistant plastic resin composite flexible connection large-diameter pipe fittings, specifically including the following steps: Step 1: Install the customized molding mold on the rotating hydraulic equipment and spray the release agent and color paste.

[0014] Step 2: Using a winding molding process, the inner surface layer, the waterproof layer, and the structural layer are formed by winding and extruding the material from the inside out on the mold. Specifically, carbon fiber is first wound and impregnated with food-grade resin to form an inner surface layer; then glass fiber is wound and impregnated with food-grade resin to form a waterproof layer; finally, glass fiber is wound and impregnated with food-grade resin to form a structural layer. The winding and molding process is controlled by automatic machinery, which extrudes the material while winding, resulting in better material adhesion, higher density, and effective removal of material flow marks and material stress.

[0015] Step 3: Apply an outer protective gel coat to the outer surface of the structural layer.

[0016] Step 4: Machining universal R-grooves conforming to international standard dimensions at both ends of the pipe fitting.

[0017] Step 5: Install the sanitary anti-tipping sealing ring in the R-groove.

[0018] The beneficial effects achieved by the present invention using the above structure are as follows: The advantages of the present invention, which relates to a large-diameter composite pipe winding molding process, are as follows: 1. This invention uses food-grade high-strength modified plastic resin as the matrix and carbon fiber and glass fiber as the reinforcing phase, and is formed into pipe fittings through composite winding and extrusion processes. Through the composite design of sanitary resin and fiber reinforcement layers, and the innovative winding molding process, the material adhesion is better, the density is higher, and flow marks and stress are effectively removed, thereby extending the product's service life. The production process of this invention is precise and controllable, with high processing flexibility. It retains the convenient installation method of traditional flexible connection pipe fittings and overcomes the problems of insufficient strength of traditional large-diameter plastic pipe fittings, easy corrosion of steel pipe fittings, and complex processing of ductile iron pipe fittings. This invention has excellent high and low temperature resistance and weather resistance, and can adapt to complex and harsh working environments. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a three-dimensional structural schematic diagram of the pipe fitting body of the present invention; Figure 2 This is an enlarged cross-sectional view of the pipe fitting body of the present invention.

[0020] The components are: 1. Pipe body; 2. Inner surface layer; 3. Anti-seepage layer; 4. Structural layer; 5. Outer protective layer; 6. R-groove. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that the terms “front,” “back,” “left,” “right,” “up,” and “down” used in the following description refer to the directions shown in the attached diagram, while the terms “inside” and “outside” refer to the directions toward or away from the geometric center of a specific component, respectively.

[0023] This solution provides a large-diameter composite pipe fitting, including a pipe fitting body 1. The pipe fitting body 1 includes, from the inside out, an inner surface layer 2, a seepage-proof layer 3, a structural layer 4, and an outer protective layer 5. Both ends of the pipe fitting body 1 are provided with sealing structures. The sealing structures include universal R-grooves 6 that conform to international standard dimensions. Sanitary anti-overturning sealing rings are installed in the R-grooves 6. Through the universal R-grooves 6, it can be directly adapted to the flexible connection of various plastic pipes, giving the pipe fitting body 1 strong versatility and engineering adaptability.

[0024] Example 1: This embodiment provides a spiral molding process for a DN400 high-strength, corrosion-resistant plastic resin composite flexible connection straight pipe fitting. The specific steps are as follows: 1. Based on the dimensions of the DN400 pipe fitting, install the customized forming mold on a specially designed rotating hydraulic device and ensure that the device operates smoothly.

[0025] 2. Spray a release agent evenly on the surface of the mold, and then spray a layer of food-grade color paste as the base color of the inner surface layer 2.

[0026] 3. Start the winding molding program, and the automated robotic arm will begin working: 1. First, carbon fiber is wound and simultaneously impregnated with food-grade resin to form an inner surface layer 2 on the mold. During the winding process, the molding device applies pressure simultaneously to fully impregnate the fiber with resin and remove air bubbles, ensuring that the inner surface layer 2 is dense.

[0027] 2. Before the inner surface layer 2 is cured, immediately begin to wrap glass fiber and impregnate it with food-grade resin to form a waterproof layer 3. Similarly, while wrapping, mold it to enhance the interlayer bonding force and improve the waterproof performance.

[0028] 3. Continue to wind multiple layers of glass fiber on the impermeable layer 3 and impregnate it with food-grade resin to form the structural layer 4. This step controls the winding angle and thickness of the fiber, as well as the molding pressure, to meet the pressure resistance rating of 1.25MPa to 2.5MPa required for DN400 pipe fittings.

[0029] 4. After the structural layer 4 is wound and molded, a layer of outer protective layer 5 gel coat is uniformly coated on its outer surface to enhance the weather resistance and anti-aging ability of the pipe fitting.

[0030] 4. Send the mold with each layer structure into the curing oven for curing treatment.

[0031] 6. After curing and demolding, the pipe fittings are machined at both ends to produce universal R-grooves 6 that conform to ISO international standards.

[0032] 7. Install the matching sanitary anti-tipping sealing ring in the R-groove 6 to complete the preparation of the pipe fitting.

[0033] Example 2: This embodiment provides a spiral winding molding process for a high-strength, corrosion-resistant plastic resin composite flexible connection elbow with a DN1000 specification. The steps are basically the same as in Embodiment 1, with the difference being: 1. The custom-made mold used is in the shape of an elbow.

[0034] 2. In the fourth stage of structural layer winding, the winding path and angle of the fiber were optimized according to the stress characteristics of the elbow to ensure that the stress distribution of each part of the elbow is uniform when it is subjected to internal pressure, and to avoid stress concentration.

[0035] 3. The R-groove 6 produced also conforms to ISO international standards, ensuring versatility and sealing with straight pipes or other pipe fittings.

[0036] Example 3: This embodiment provides a spiral molding process for a high-strength, corrosion-resistant plastic resin composite flexible connection tee with a DN2000 specification. The steps are basically the same as in Embodiment 1, with the difference being: 1. The custom-made mold used is in the shape of a T-junction.

[0037] 2. During the fourth stage of structural layer winding, the branch connection of the tee was locally reinforced. By increasing the number of fiber winding layers or adjusting the winding angle, the strength of this key part was ensured to meet the high pressure resistance requirements.

[0038] 3. All three ports are machined with universal R-grooves 6 conforming to ISO international standards and are equipped with sealing rings to achieve reliable connection with other pipe fittings.

[0039] Example 4: Based on Examples 1, 2 and 3, food-grade colorant is added to the inner surface layer 2, the impermeable layer 3 and the structural layer 4 to meet the appearance marking requirements of different application scenarios, such as blue marking for drinking water transportation and green marking for sewage discharge.

[0040] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, material, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, material, or apparatus.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A large-diameter composite pipe fitting, characterized in that, The pipe body (1) includes an inner surface layer (2), a seepage-proof layer (3), a structural layer (4), and an outer protective layer (5) from the inside out. The inner surface layer (2) is made of carbon fiber and food-grade resin. The seepage-proof layer (3) is made of glass fiber and food-grade resin. The structural layer (4) is made of glass fiber and food-grade resin. The outer protective layer (5) is a gel coat layer coated on the outer surface of the structural layer (4). The two ends of the pipe body (1) are provided with sealing structures. The sealing structures include a universal R-groove (6) conforming to international standard dimensions and a sanitary anti-tipping sealing ring installed in the R-groove (6).

2. The large-diameter composite pipe fitting according to claim 1, characterized in that, Food-grade pigments are also added to the inner surface layer (2), the impermeable layer (3), and the structural layer (4).

3. A spiral winding molding process for a large-diameter composite pipe fitting according to any one of claims 1 to 2, characterized in that, Specifically, the following steps are included: Step 1: Install the customized molding mold on the rotating hydraulic equipment and spray the mold release agent and color paste; Step 2: Using a winding molding process, the inner surface layer (2), the impermeable layer (3), and the structural layer (4) are formed by winding and extruding the material from the inside to the outside of the mold. Step 3: Apply an outer protective layer (5) gel coat to the outer surface of the structural layer (4); Step 4: Machining universal R-grooves conforming to international standard dimensions at both ends of the pipe fitting (6); Step 5: Install a sanitary anti-tipping sealing ring in the R-groove (6).

4. The spiral winding molding process for a large-diameter composite pipe fitting according to claim 3, characterized in that, Step two specifically includes: Forming the inner surface layer (2): winding carbon fibers and impregnating them with food-grade resin; Forming a waterproof layer (3): Winding glass fiber and impregnating it with food-grade resin; Forming a structural layer (4): Winding glass fiber and impregnating it with food-grade resin.

5. The spiral winding molding process for a large-diameter composite pipe fitting according to claim 3, characterized in that, The winding and molding processes in step two are controlled by automated machinery.

6. The spiral winding molding process for a large-diameter composite pipe fitting according to claim 3, characterized in that, The specifications of the pipe fitting body (1) range from DN400 to DN2000.

7. The spiral winding molding process for a large-diameter composite pipe fitting according to claim 3, characterized in that, The pipe fitting body (1) is any one of a straight head, elbow, tee, oblique tee or flange.

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