Shaft epoxy resin forging and shaft forging epoxy coating method

Abstract

The present invention relates to a shaft epoxy resin forging and a shaft forging epoxy coating method, comprising a shaft forging, wherein the surface of the shaft forging is coated with a bottom adhesive resin layer, a bottom spiral glass fiber reinforced plastic reinforcement tape is provided on the bottom adhesive resin layer, the bottom spiral glass fiber reinforced plastic reinforcement tape surface is impregnated with adhesive resin to form a second adhesive resin layer, the second spiral glass fiber reinforced plastic reinforcement tape is wrapped around the second adhesive resin layer, the second spiral glass fiber reinforced plastic reinforcement tape surface is impregnated with adhesive resin to form a third adhesive resin layer, the third spiral glass fiber reinforced plastic reinforcement tape is wrapped around the third adhesive resin layer, the third spiral glass fiber reinforced plastic reinforcement tape surface is impregnated with adhesive resin to form a fourth adhesive resin layer, the fourth spiral glass fiber reinforced plastic reinforcement tape is wrapped around the fourth adhesive resin layer, and a fifth adhesive resin layer (10) is coated on the fourth spiral glass fiber reinforced plastic reinforcement tape (9). Advantages: The coating layer produced by this method is uniform and dense, with no defects such as bubbles and protrusions on the surface. It can completely isolate the shaft from contact with seawater or seawater vapor, achieving the purpose of corrosion and rust prevention.

Description

Technical Field

[0001] The present invention relates to a shaft epoxy resin forging and a shaft forging epoxy coating method, which has a uniform and dense coating layer, is free of defects such as bubbles and protrusions on the surface, and can completely isolate the shaft from contact with seawater or seawater vapor to achieve corrosion and rust prevention. Background Art

[0002] During ship operation, the cabin is inevitably subject to long-term corrosion from seawater. Propeller shafts are made of steel and are susceptible to rust in seawater, leading to continuous corrosion and reduced strength. Therefore, completely sealing the shaft surface to block air and seawater is crucial, as this can even affect the ship's service life. Conventional epoxy resin mixtures, besides being unsuitable for marine propeller shaft coating, generally lack long-term seawater corrosion resistance, and lack precise control over the dosage of additives, hindering their effectiveness. Summary of the Invention

[0003] Design purpose: To avoid the shortcomings of the background technology, design a shaft epoxy resin forging and shaft forging epoxy coating method with a uniform and dense coating layer, no bubbles, protrusions and other defects on the surface, and the ability to completely isolate the shaft itself from contact with seawater or seawater vapor to achieve corrosion and rust prevention.

[0004] Design: Propeller shafts are shaft forgings with a conventional weight of 5-50 tons and a length of 5-25 meters. The diameter of the coated area ranges from 100-700 mm. Therefore, the coating process needs to be carried out on a machine tool and a specific roller frame, and the rotation speed during coating is controlled at 3-5 rpm. In terms of structural design, the present invention combines an adhesive resin layer with a fiberglass reinforced plastic tape on the basis of existing shafting forgings, forming an anti-corrosion layer on the shafting forging composed of an adhesive resin layer and a spiral fiberglass reinforced plastic tape winding layer. The anti-corrosion layer is uniform and dense, with no defects such as bubbles and protrusions on the surface, and can completely isolate the shaft itself from contact with seawater or seawater vapor, thereby achieving long-term anti-corrosion and anti-rust effects. In terms of the coating method, the coating material includes glass ribbons and an adhesive composed of resin, hardener, plasticizer and diluent. After the various components are mixed in a certain proportion, the coating material adhesive resin and fiberglass reinforced plastics reinforcement tape are evenly coated on the surface of the shaft forging, and the grid of the glass ribbon should ensure that the tape can be soaked by the adhesive resin. The main purpose is to prevent corrosion from seawater and prevent the fatigue resistance of the shaft from being reduced due to rust, or even breakage, which may cause accidents.

[0005] The epoxy resin mixing and proportioning method of the present invention is applicable to the coating of propeller shafts. Propeller shafts are shaft forgings with a typical weight of 5-50 tons, a length of 5-25 meters, and a diameter at the coating site of 100-700 mm. Therefore, propeller shaft coating can only be performed on a machine tool or a rolling stand. Therefore, the coating process must be coordinated with the propeller shaft speed. The epoxy resin mixing and proportioning method of the present invention is based on a propeller shaft speed of 3-5 rpm. The epoxy resin mixing and proportioning ratio is closely related to temperature.

[0006] The epoxy resin mixture consists of the following organic compounds:

[0007]

[0008] The relationship between the epoxy resin mixture ratio and the ambient temperature. The epoxy resin mixing ratio is carried out at a temperature of 0 to 30°C:

[0009]

[0010] This epoxy resin mixing and proportioning method, based on the precise proportions at different temperatures, especially the precise addition of the two hardeners, can solve the problem of uneven thickness caused by unstable fluidity during the coating process. The proportioned epoxy resin mixture can also achieve axial continuous coating without interruption, avoiding the occurrence of pores, seams, and other problems that affect the overall corrosion resistance during coating.

[0011] Technical Solution 1: A shaft epoxy resin forging includes a shaft forging, the surface of the shaft forging is coated with a bottom adhesive resin layer, a bottom spiral fiberglass reinforced plastic reinforcement tape is provided on the bottom adhesive resin layer, the bottom spiral fiberglass reinforced plastic reinforcement tape surface is impregnated with adhesive resin to form a second adhesive resin layer, the second spiral fiberglass reinforced plastic reinforcement tape is wrapped around the second adhesive resin layer, the second spiral fiberglass reinforced plastic reinforcement tape surface is impregnated with adhesive resin to form a third adhesive resin layer, the third spiral fiberglass reinforced plastic reinforcement tape is wrapped around the third adhesive resin layer, the third spiral fiberglass reinforced plastic reinforcement tape surface is impregnated with adhesive resin to form a fourth adhesive resin layer, the fourth spiral fiberglass reinforced plastic reinforcement tape is wrapped around the fourth adhesive resin layer, and a fifth adhesive resin layer is coated on the fourth spiral fiberglass reinforced plastic reinforcement tape.

[0012] Technical Solution 2: A method for epoxy coating of shaft forgings, comprising a shaft forging and a coating material, wherein the coating material is composed of glass ribbon and an adhesive. 1. Preparation of the adhesive: 1. Ensure that the container and agitator are clean. 8-10 parts by weight of plasticizer and 0-15 parts by weight of diluent are uniformly stirred with an electric or pneumatic agitator with 100 parts by weight of epoxy resin. 2. Pour 15-30 parts by weight of 593 curing agent and 8-10 parts by weight of triethylenetetramine into the container and immediately stir evenly. The agitator speed should not exceed 175 rpm. 3. Stir thoroughly and fully to ensure that the resin and hardener on the container wall are completely mixed. If the mixture is milky, it means that the mixing speed is too fast. The resin and hardener should be mixed very quickly (within 5 minutes) before coating. 2. Selection of glass ribbon: For thin shafts <150mm, use 60-80 Use tape 100-150mm wide for shafts 150mm or larger. III. Coating Process: 1. Leveling: Keep the epoxy coating section level. 2. Surface Cleaning: Remove rust using sandblasting or sandpaper. Pour a sufficient amount of solvent onto the shaft to clean it. Rinse twice. Do not wipe dry with cloth, paper, or similar. Inspect the shaft surface to ensure it is free of oil, rust, or water. 3. Pour Resin: Pour the epoxy resin mixture evenly onto the propeller shaft. As the shaft rotates, use a portable plastic scraper to spread the mixture roughly evenly. Then, use a plastic scraper approximately 300mm wide and attached to a spirit level to completely spread the resin evenly. The coating thickness is approximately 1mm. 4. Use a glass ribbon with a width of 100-150mm. At the beginning, wrap it around the propeller shaft once and press the head of the ribbon. After one circle, continue to wrap the glass ribbon in a spiral shape to ensure that there is a 3 / 4 overlap between the layers; continue to wrap in a spiral shape until it approaches the other end of the shaft, gradually reduce the spiral angle until the last complete circle is wrapped, cut the ribbon, and do not stop the shaft; 5. Continue to pour the epoxy resin mixture in the same way as the first mixture wrapping; continue to wrap with glass ribbon in the same way as the first glass ribbon wrapping until the fourth layer of glass ribbon is completely wrapped; 6. After the fourth layer of glass ribbon is wrapped, continue to pour the resin mixture as the fifth layer of resin wrapping; 7. The entire wrapping process requires five layers of resin mixture and four layers of glass ribbon; 8. After the wrapping is completed, the wrapping thickness must be greater than 4mm, the propeller shaft continues to rotate, and the rotation time must be greater than 24h, and the resin mixture is completely cured.

[0013] Compared with the background technology, the present invention has the following advantages: first, the thickness of the coating is uniform. The propeller shaft rotates at high speed during actual use, and the uniformity of the coating can effectively prevent the shaft from being eccentric under the action of centrifugal force; second, the bonding strength of the epoxy resin mixture covering layer is stable, and it will not fall off under long-term movement, thereby improving the service life; third, the epoxy resin mixture covering layer has a dense structure, which effectively isolates the corrosion of air or seawater atmosphere and has excellent corrosion resistance; fourth, the epoxy resin mixture covering layer is wrapped with layers of glass ribbons, which has excellent stability and will not fall off after the resin hardens. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the cross-sectional structure of the shaft epoxy resin forging. DETAILED DESCRIPTION

[0015] Example 1: Refer to the attached Figure 1 A shaft epoxy resin forging comprises a shaft forging 1, wherein the surface of the shaft forging 1 is coated with a bottom adhesive resin layer 2, a bottom spiral glass fiber reinforced plastic reinforcement tape 3 is provided on the bottom adhesive resin layer 2, the bottom spiral glass fiber reinforced plastic reinforcement tape 3 is impregnated with adhesive resin to form a second adhesive resin layer 4, a second spiral glass fiber reinforced plastic reinforcement tape 5 is wrapped around the second adhesive resin layer 4, the second spiral glass fiber reinforced plastic reinforcement tape 5 is impregnated with adhesive resin to form a third adhesive resin layer 6, a third spiral glass fiber reinforced plastic reinforcement tape 7 is wrapped around the third adhesive resin layer 6, the third spiral glass fiber reinforced plastic reinforcement tape 7 is impregnated with adhesive resin to form a fourth adhesive resin layer 8, a fourth spiral glass fiber reinforced plastic reinforcement tape 9 is wrapped around the fourth adhesive resin layer 8, and a fifth adhesive resin layer (10) is coated on the fourth spiral glass fiber reinforced plastic reinforcement tape (9).

[0016] The helical direction of the second layer of spiral FRP reinforcement tape 5 is opposite to that of the bottom layer of spiral FRP reinforcement tape 3. The helical direction of the third layer of spiral FRP reinforcement tape 7 is opposite to that of the second layer of spiral FRP reinforcement tape 5. The helical direction of the fourth layer of spiral FRP reinforcement tape 9 is opposite to that of the third layer of spiral FRP reinforcement tape 7.

[0017] Example 2: A method for epoxy coating of a shaft forging, comprising a shaft forging and a coating material, wherein the coating material is composed of a glass ribbon and an adhesive.

[0018] Formula of main materials and adhesive: The main materials include glass ribbon and adhesive composed of resin, hardener, plasticizer and diluent. The formula of main materials and adhesive is as follows:

[0019]

[0020] Note: The mesh of the glass ribbon should ensure that the ribbon can be soaked.

[0021] 2. Mixing of adhesives:

[0022] 2.1 Ensure the container and stirrer are clean, weigh the plasticizer and diluent in proportion, and stir them evenly with the epoxy resin using an electric or pneumatic stirrer.

[0023] 2.2 Weigh the hardener in proportion, pour it into the container, and stir it evenly immediately. The speed of the stirrer should not exceed 175 rpm.

[0024] 2.3 Stir thoroughly to ensure that the resin and hardener on the container wall are completely mixed. If the mixture is milky, it means that the mixing speed is too fast. The resin and hardener should be mixed within a short time before coating.

[0025] 2. Coating process:

[0026] 1. Environmental requirements: The relative humidity of the air should not be higher than 80%. If the humidity is higher than 80%, the shaft needs to be preheated to 40-50°C with a lamp (usually infrared or 500W lamps are used).

[0027] 2. Preparation: Fix the shaft on the lathe or powered roller, and cover the bed or the ground with polyethylene film or thick paper to prevent dripping and spilling.

[0028] 3. Surface cleaning: Use sandblasting or sandpaper to remove rust, pour enough solvent on the shaft (acetone, gasoline, banana oil or carbon tetrachloride) to clean it, wash it twice, do not use any cloth, paper or similar things to wipe it dry, check the surface of the shaft to make sure there is no oil, rust or water marks, generally do not use acid cleaning.

[0029] 4. Wrapping (dumping and wrapping):

[0030] 4.1 Pour the resin evenly onto the rotating shaft. Use gloved hands or a roller to spread the resin evenly over the entire surface of the shaft (use disposable plastic gloves, clean reusable rubber gloves, or a bristle-free roller). There should be no dry areas on the shaft surface, and there should be no resin drips on the shaft.

[0031] 4.2 Wrapping fiberglass reinforced belt:

[0032] (1) When you start wrapping the tape, wrap it around once, pressing the tape head. After one circle, continue wrapping the tape in a spiral shape, ensuring that there is a 3 / 4 overlap between the layers.

[0033] (2) Continue wrapping the tape in a spiral until you reach the other end of the shaft, gradually reducing the spiral angle until you have completed a complete circle, then cut the tape without stopping the shaft.

[0034] (3) Allow the resin to completely soak into the tape, then apply another layer of resin using the same method as the first layer. Allow it to soak in and repeat the above steps until the fourth layer of tape is wrapped.

[0035] (4) After the fourth layer of tape is completely soaked, apply a large amount of resin again, and keep the shaft rotating slowly until the resin solidifies. If the speed is too fast at this stage, ridges may appear on the resin coating;

[0036] (5) Do not use the remaining short sections, as this will increase the number of joints. If the tape runs out halfway, the new tape should be pressed completely around the broken end of the previous roll before continuing to wrap in a spiral. Wrinkles should be smoothed out as much as possible. Large wrinkles need to be cut open and flattened with scissors. If the wrinkles are too large, the folded triangular part needs to be trimmed.

[0037] (6) For the tapered part of the shaft: always wrap from large to small. When wrapping the tapered part, do not interrupt it in the middle. Before starting to wrap the tapered part, wrap a full circle around the cylindrical part close to the tapered part.

[0038] (7) Be careful not to create wrinkles and avoid unnecessary overlapping of wrapping.

[0039] 4.3 Curing time: below 25℃, let it stand for more than 24 hours.

[0040] 3. Product quality inspection:

[0041] 1. Appearance inspection: First, an inspection is carried out after wrapping, which must meet the following requirements: uniform color, smooth surface, no sagging, no impurities, no cracks, no white areas, no bulges, no bubbles, no glass ribbon protruding outside the outermost layer of resin, and no other defects; second, holes and / or pits on the coating can be repaired as follows: grind the hole / pit and the surrounding area deeper, then fill it with resin; polish it with sandpaper; apply a layer of mixed resin and hardener to the repaired area; if the repair area is large, it needs to be repaired with resin and glass ribbon.

[0042] It should be understood that although the above embodiments provide a relatively detailed textual description of the design ideas of the present invention, these textual descriptions are only simple textual descriptions of the design ideas of the present invention, rather than limitations on the design ideas of the present invention. Any combination, addition or modification that does not exceed the design ideas of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for coating a shaft forging with epoxy resin, comprising a shaft forging and a coating material, characterized in that: The coating material is composed of glass ribbon and adhesive; the characteristics are: the shaft forging is a propeller shaft, the conventional weight is 5-50 tons, the length is 5-25 meters, the diameter range of the coating part is 100-700 mm, the surface of the shaft forging (1) is coated with a bottom adhesive resin layer (2), the bottom adhesive resin layer (2) is provided with a bottom spiral glass fiber reinforced plastic reinforcement tape (3), the bottom spiral glass fiber reinforced plastic reinforcement tape (3) is impregnated with adhesive resin to form a second adhesive resin layer (4), the second spiral glass fiber reinforced plastic reinforcement tape (5) is wrapped around the second adhesive resin layer ( 4), the second layer of spiral glass fiber reinforced plastic reinforcement tape (5) is impregnated with adhesive resin to form a third layer of adhesive resin layer (6), the third layer of spiral glass fiber reinforced plastic reinforcement tape (7) is wrapped around the third layer of adhesive resin layer (6), the third layer of spiral glass fiber reinforced plastic reinforcement tape (7) is impregnated with adhesive resin to form a fourth layer of adhesive resin layer (8), the fourth layer of spiral glass fiber reinforced plastic reinforcement tape (9) is wrapped around the fourth layer of adhesive resin layer (8), and the fifth layer of adhesive resin layer (10) is coated on the fourth layer of spiral glass fiber reinforced plastic reinforcement tape (9); Epoxy coating method for shaft forgings, 1. Production of adhesive:

1. Ensure the container and stirrer are clean. Use an electric or pneumatic stirrer to evenly mix 8-10 parts by weight of plasticizer and <15 parts by weight of diluent with 100 parts by weight of epoxy resin.

2. Pour 15-30 parts by weight of 593 curing agent and 8-10 parts by weight of triethylenetetramine into a container and stir immediately. The stirrer speed should not exceed 175 rpm.

3. Stir thoroughly to ensure that the epoxy resin and hardener on the container wall are completely mixed. If the mixture is milky, it means that the mixing speed is too fast. The epoxy resin and hardener should be mixed within 5 minutes before coating.

2. Glass ribbon selection: For thin shafts with a diameter of less than 150 mm, use a 60-80 mm wide belt; for shafts with a diameter of ≥150 mm, use a 100-150 mm wide belt.

3. Coating process:

1. Adjust the level. The epoxy coating section needs to be kept level.

2. Surface cleaning: Use sandblasting or sandpaper to remove rust. Pour enough solvent on the shaft to clean it. Wash it twice. Do not wipe it with any cloth or paper. Inspect the surface of the shaft to ensure there is no oil, rust or water marks.

3. Pour the resin: Pour the epoxy resin mixture evenly on the surface of the propeller shaft. As the shaft rotates, use a portable plastic scraper to spread the mixture roughly evenly. Then use a 300mm wide plastic scraper fixed with a level to scrape the resin evenly. The coverage thickness is 1mm.

4. Use a glass ribbon with a width of 100-150mm. Initially wrap it around the propeller shaft once, pressing the ribbon head. After one circle, continue wrapping the glass ribbon in a spiral shape, ensuring that there is a 3 / 4 overlap between layers. Continue wrapping the ribbon in a spiral shape until it reaches the other end of the shaft, gradually reducing the spiral angle until a complete circle is completed. Cut the ribbon without stopping the shaft.

5. Continue pouring the epoxy resin mixture in the same way as the first layer of mixture; then continue wrapping with glass ribbon in the same way as the first layer of glass ribbon, until the fourth layer of glass ribbon is completely wrapped; 6. After the fourth layer of glass ribbon is wrapped, continue pouring the resin mixture as the fifth layer of resin wrap; 7. The entire coating process requires five layers of resin mixture and four layers of glass ribbon; 8. After coating is completed, the coating thickness must be greater than 4mm, and the propeller shaft continues to rotate for more than 24 hours to allow the resin mixture to completely cure.

2. The method for coating a shaft with epoxy resin forging according to claim 1, wherein: The spiral direction of the second layer of spiral FRP reinforcement strip 5 is opposite to the spiral direction of the bottom layer of spiral FRP reinforcement strip 3 .

3. The method for coating a shaft with epoxy resin forging according to claim 1, wherein: The spiral direction of the third layer of spiral FRP reinforcement tape 7 is opposite to the spiral direction of the second layer of spiral FRP reinforcement tape 5 .

4. The method for coating a shaft with epoxy resin forging according to claim 1, wherein: The spiral direction of the fourth layer of spiral FRP reinforcement tape 9 is opposite to the spiral direction of the third layer of spiral FRP reinforcement tape 7 .

5. The method for coating a shaft with epoxy resin forging according to claim 1, wherein: If the air humidity during coating is higher than 80%, use infrared or 500W lamp to preheat the shaft to 40-50℃.

6. The method for coating a shaft with epoxy resin forging according to claim 1, wherein: The solvent refers to acetone, gasoline, banana oil or carbon tetrachloride solvent.

7. The method for coating a shaft with epoxy resin forging according to claim 1, wherein: The relative humidity of the air during wrapping should not be higher than 80%.

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