A lubricant for a condom comprising hyaluronic acid and a method for preparing and applying the same

Abstract

The application belongs to the technical field of condom production and manufacturing, and particularly relates to a hyaluronic acid lubricant with high adaptability for condoms, and a preparation and coating method thereof. The hyaluronic acid lubricant comprises 70%-99% of polyol, 0.1%-1% of sodium hyaluronate, 0.1%-1% of thickening agent, and 0.8%-28% of deionized water, and the total mass satisfies 100%. The viscosity of the lubricant is 100-500 mPa.s at room temperature, and the lubricant is suitable for various quantitative coating mechanisms. The specific oil brushing mechanism is not limited, and any quantitative oiling mode such as, but not limited to, peristaltic pump dripping, compressed air spraying, roller coating, micro-jet, capillary flow, quantitative valve coating, and dipping can be adopted. The core is to accurately control the oil brushing amount of a single condom to be 20-200 mg, and the lubricant is only coated on the middle region of the condom which is away from the opening end and the storage sac end by more than 3 cm. The application solves the problems of poor adaptability, uncontrollable oil brushing amount, curling and oil overflow, equipment pollution, and raw material waste of the traditional lubricant.

Description

Technical Field

[0001] This invention belongs to the field of condom manufacturing technology, specifically relating to a highly adaptable hyaluronic acid lubricant for condoms and its preparation and application methods. Background Technology

[0002] In the condom manufacturing process, the quality of the surface lubricant coating directly determines the product's comfort, safety, and storage stability. The main technical challenges currently facing the industry are as follows:

[0003] Unreasonable lubricant formulations: Traditional condom lubricants mostly use silicone oil as the main component, which has problems such as poor lubrication durability, difficulty in washing, and risk of skin irritation; existing water-based lubricants are mostly ordinary moisturizing formulas with low polyol content (usually below 50%), resulting in insufficient lubrication effect, and the rheological properties are not optimized for different application methods, which can easily lead to problems such as delivery blockage and uneven coating; some lubricants containing hyaluronic acid have defects such as strong stickiness and easy runoff due to improper selection of sodium hyaluronate molecular weight or imbalance in ratio.

[0004] In existing technologies, the water content in normal hyaluronic acid lubricants is 40-80%, which gives the lubricant a relatively large spreadability. In previous tests on the lubrication process on condoms, lubricants with a water ratio exceeding 40% could only be applied to the condom with about 20mg of lubricant. If it exceeds 20mg, two possibilities arise: first, the lubricant is easily squeezed out of the condom and cannot complete the production in the automatic vibrating chamber; second, the lubricant spreads rapidly on the condom, but the curling brush cannot curl it, resulting in curling failure.

[0005] However, simply controlling the water content to below 40% in the lubricant won't guarantee successful application. In actual testing, for example, when the hyaluronic acid content exceeds 1% or the molecular weight of the hyaluronic acid is very large, the lubricant, when sprayed from the nozzle, will form a tangled, thread-like consistency, continuously pulling on the first or a few condoms it contacts. This, combined with the movement of the condom's die and the condom's curling, eventually leads to accumulation on a small section of the condom, being squeezed out to the reservoir tip, or failing to curl properly, resulting in curling failure. Subsequent condoms may also fail to receive sufficient lubricant, causing application failure. Furthermore, an inappropriate ratio of cellulose to water can prevent the cellulose in the application area from swelling sufficiently, thus compromising condom lubrication and proper condom use.

[0006] The limitations of brushing methods are significant: existing brushing technologies are mostly limited to protecting a specific equipment structure or a single brushing method, such as only protecting peristaltic pump drip coating devices or a single high-pressure spraying mechanism. Competitors can circumvent patent protection by simply changing the brushing method (such as changing the peristaltic pump to roller coating), resulting in a narrow scope of protection and great difficulty in enforcing rights.

[0007] Poor precision control: Existing technology lacks strict limits on both the amount of oil applied and the application location. The amount of oil applied often depends on manual experience for adjustment, which can easily lead to insufficient oil causing lubrication failure, or excessive oil causing oil spillage during curling, contaminating equipment and products. At the same time, there are no clear standards for the application location of the lubricant, which can easily cover the curled edge of the condom opening or the end of the reservoir tip, affecting the structural stability and safety of the product.

[0008] Low resource utilization: The raw material cost of high-end hyaluronic acid lubricants is relatively high. The existing production process lacks an efficient recycling system, and excess lubricant is directly wasted, which not only increases production costs but also causes environmental burden.

[0009] Currently, there is no suitable formulation that uses a high proportion of polyols as the main component and combines them with sodium hyaluronate of a specific molecular weight. At the same time, there is no universal oiling method that does not limit the specific oiling mechanism and only limits the formulation, oiling amount, coating position and recycling process to achieve broad protection. Summary of the Invention

[0010] The purpose of this invention is to provide a hyaluronic acid lubricant for condoms with strong adaptability and excellent lubrication effect, and a method for preparing the same.

[0011] The hyaluronic acid lubricant for condoms provided by this invention comprises polyol, sodium hyaluronate, thickener, and deionized water.

[0012] The polyol comprises 70%–99% by mass and is selected from one or more of glycerol, propylene glycol, and polyethylene glycol (molecular weight 200–600);

[0013] The sodium hyaluronate has a mass percentage of 0.1%–1% and a molecular weight of 200,000–3,000,000 Da; this avoids the lubricant becoming sticky due to excessive content, or failing to exert its moisturizing and lubricating effect due to insufficient content.

[0014] The thickener, comprising 0.1%–1% by mass, is selected from one or more of hydroxyethyl cellulose, carbomer, and sodium polyacrylate.

[0015] The deionized water, comprising 0.8%–28% by mass, serves as both a solvent and a dispersion medium.

[0016] The total mass meets 100%.

[0017] In this invention, the polyol is a mixture of glycerol and propylene glycol in a mass ratio of (3–5):1; the synergistic effect of the two can balance lubrication durability and rapid spreading, and improve coating uniformity.

[0018] In this invention, the sodium hyaluronate preferably has a molecular weight of 500,000 to 1,500,000; the thickener preferably has a mass ratio of 0.2% to 0.5% to achieve optimal viscosity stability.

[0019] In this invention, the thickener is selected from carbomer 940 or hydroxyethyl cellulose.

[0020] The preparation method of the hyaluronic acid lubricant for condoms of the present invention comprises the following steps:

[0021] Weigh each component according to the formula ratio, add the polyol and deionized water into the mixing tank, and stir evenly at 30–40℃.

[0022] Slowly add sodium hyaluronate and thickener, and continue stirring for 1–2 hours until all components are completely dissolved, ensuring there are no particulate impurities.

[0023] Then let it stand for 20–40 minutes to remove air bubbles and obtain a uniform and stable hyaluronic acid lubricant.

[0024] The preparation process is simple and easy to carry out, requires no special equipment, and is suitable for industrial production.

[0025] In this invention, the application method of the hyaluronic acid lubricant for condoms includes the following specific steps:

[0026] (1) Apply oil

[0027] Method 1: When the deionized water content is less than 10%, peristaltic pump drip coating, compressed air spraying, roller coating, micro-spraying, capillary dipping, metering valve coating, and dip coating are used.

[0028] Method 2: When the deionized water content is above 10%, use compressed air spraying, micro-spraying, capillary diversion, or metering valve coating.

[0029] Both of the above methods follow the following control conditions:

[0030] Quantitative control: The amount of oil applied in a single application is strictly controlled within 20–200 mg, with a deviation of ≤±10%;

[0031] Position control: Lubricant is only applied to the middle area of ​​the condom body, which is 3-5cm away from the opening end and 3-5cm away from the reservoir end;

[0032] In this way, quantitative control can prevent the brushing oil from being less than 20mg, which would not form an effective lubricating layer and affect the user experience, and also prevent the lubricant from overflowing due to compression during the curling process when the amount of oil is more than 200mg, which would contaminate the curling brush and equipment; position control can prevent the covering of the curled edge of the opening (affecting the sealing performance of the product) and the end of the reservoir (affecting the structural stability).

[0033] (2) Curling and shaping

[0034] After the oil is applied, the curled brush moves toward the condom under the drive of the cylinder, rotates and moves axially along the axis of the electric inspection mold, and rolls the condom off the mold and shapes it.

[0035] Because the lubricant is only distributed in the central area and the amount used is precise, there will be no lubricant overflow during the curling process, effectively avoiding contamination of the brush and equipment.

[0036] (3) Lubricant recovery

[0037] An oil collection tank is installed below the oiling station and in the gap of the electrical inspection mold to collect the excess lubricant. The lubricant is then transported to a filter (filtration accuracy 5–20μm) through a recycling pipeline to remove impurities and small particles, and then returned to the lubricant storage container for recycling.

[0038] This recycling system can achieve a comprehensive lubricant recovery rate of ≥90%, significantly reducing production costs while also reducing environmental burden.

[0039] Furthermore, in Method 1, a peristaltic pump is used for drip coating: a peristaltic pump with a flow rate of 150ml / min–4000ml / min is selected, paired with a food-grade silicone tube with an inner diameter of 1mm–8mm. The brushing time is controlled by adjusting the pump speed to achieve quantitative drip coating, which is suitable for medium and low speed production lines.

[0040] Furthermore, in Method 2, compressed air spraying is used: a sealed stainless steel container is used to store the lubricant, and a high-pressure nozzle is driven by compressed air at 0.2–0.5MPa to atomize the lubricant into tiny droplets of 50–150μm, which are sprayed onto the surface of the condom at a distance of 8–15cm. The spraying time is controlled by a solenoid valve to achieve quantitative spraying, which is suitable for high-speed production lines.

[0041] This invention does not limit the specific oiling mechanism; any method that can achieve quantitative coating can be selected according to the production line requirements. For example, roller coating, capillary diversion, etc., can all be applied to the method of this invention as long as the quantitative and positional requirements are met.

[0042] In this invention, when the peristaltic pump, roller coating, or dip coating has a high water content (typically above 50%), the lubricant may over-wet the condom body, causing the condom to not curl properly or to fail to curl. When the water content is below 10%, the system itself has weak lubrication. It relies on the water-soluble lubricant dripping from the reservoir tip to conduct water to the oiling area, allowing the hyaluronic acid and thickener to absorb water and swell, thus achieving full wetting of the condom body and improved lubrication.

[0043] In this invention, the polyol not only has excellent lubricity and moisturizing properties, but also reduces the overall viscosity of the lubricant, ensuring that it can adapt to the delivery needs of different brushing mechanisms and avoid problems such as pipeline blockage and poor nozzle atomization.

[0044] The sodium hyaluronate has excellent biocompatibility, moisturizing properties and lubricating extensibility within the corresponding molecular weight range. It can form a uniform lubricating film on the surface of the condom to avoid dryness during use. At the same time, it works synergistically with polyols to significantly improve lubrication durability.

[0045] The core function of the thickener is to adjust the viscosity of the lubricant to 100–500 mPa·s (at room temperature, such as 25℃). This viscosity range ensures that the lubricant has good fluidity during transportation and prevents it from flowing away quickly after coating, ensuring that a uniform lubricating layer is formed on the surface of the condom. It is suitable for various oiling methods such as drip coating, spray coating, and roller coating.

[0046] The deionized water is used to adjust the overall fluidity of the formulation. Its water content is low (far lower than the conventional 50%), resulting in low fluidity. This ensures that the polyol, sodium hyaluronate, and thickener can be fully dissolved and evenly dispersed. At the same time, the viscosity and spreading speed of the lubricant can be finely adjusted according to the needs of different brushing methods, further preventing rapid loss after coating.

[0047] This invention does not limit the specific oiling mechanism and can employ any quantitative oiling method, including but not limited to peristaltic pump dripping, compressed air spraying, roller coating, micro-spraying, capillary dipping, metering valve coating, and dip coating. The applicable method is limited according to the water content of the lubricant: all oiling methods are applicable for water content below 10%, while compressed air spraying, micro-spraying, capillary dipping, and metering valve coating are only applicable for water content above 10%, to avoid excessive wetting in high-water systems that could lead to curling failure. Formulas with water content below 10% rely on the water-soluble lubricant in the reservoir tip to conduct moisture, allowing hyaluronic acid and thickeners to absorb water and activate, improving the overall lubricity of the condom. The core is to precisely control the amount of oil applied to a single condom between 20–200 mg, and to apply the lubricant only to the central area ≥3 cm from both the condom opening and the reservoir tip. Excess lubricant is collected, filtered, and recycled, achieving a utilization rate of ≥90%.

[0048] This invention solves the problems of poor compatibility of traditional lubricants, uncontrolled oil application, oil spillage due to curling, equipment pollution, and waste of raw materials. It addresses the technical issues of insufficient precision control and resource waste. Furthermore, it has a low water content and low fluidity, while still maintaining certain lubrication performance, rheological properties, and compatibility, thus achieving efficient, precise, and environmentally friendly production of condom oiling processes. Attached Figure Description

[0049] Figure 1 is a schematic diagram of the composition and proportion of hyaluronic acid lubricant formulation.

[0050] Figure 2 is a schematic diagram showing the area where oil is applied to the condom. Detailed Implementation

[0051] Example 1: Formulation and application method of basic lubricating hyaluronic acid lubricant

[0052] 1. Formulation composition (by weight): Glycerin 82%, Propylene Glycol 10%, Sodium Hyaluronate (molecular weight 800,000) 0.5%, Carbomer 940 0.3%, Deionized Water 7.2% (below 10%).

[0053] 2. Preparation process: Glycerin, propylene glycol and deionized water are added to a mixing tank and stirred at 35°C for 10 minutes to mix evenly. Sodium hyaluronate and carbomer 940 are slowly added and stirred for 1.5 hours until completely dissolved. After standing for 30 minutes to remove bubbles, a hyaluronic acid lubricant with a viscosity of 280 mPa·s at 25°C and a pH of 6.8 is obtained.

[0054] 3. Application method: Peristaltic pump drip application is used, with a flow rate of 800ml / min and a silicone tube with an inner diameter of 3mm. The application time is 0.006 minutes (0.36 seconds), and the amount of oil applied to a single condom is 60mg.

[0055] 4. Application location: The central area 3.5cm from the opening of the condom and 3.5cm from the reservoir tip;

[0056] 5. Performance Test: The lubricant is evenly applied without accumulation or missed areas; there is no oil overflow during the curling process, and the curling brush remains clean; the product has a long-lasting lubricating effect, is easy to clean after use, and leaves no residue; the lubricant recycling rate is 92%, and it still maintains stable performance after 5 cycles of use.

[0057] Example 2: Formulation and application method of high-moisturizing hyaluronic acid lubricant

[0058] 1. Formulation composition (mass percentage): Propylene glycol 88%, Sodium hyaluronate (molecular weight 1.2 million) 0.6%, Hydroxyethyl cellulose 0.4%, Deionized water 11.0% (above 10%).

[0059] 2. Preparation process: Add propylene glycol and deionized water to a mixing tank and stir at 38°C for 15 minutes to mix evenly. Add sodium hyaluronate and hydroxyethyl cellulose and stir for 2 hours until completely dissolved. Let stand for 40 minutes to remove bubbles and obtain a hyaluronic acid lubricant with a viscosity of 380 mPa·s at 25°C and a pH of 7.0.

[0060] 3. Oil application method: Compressed air spraying is used. The lubricant level in the stainless steel bucket is maintained at 1 / 2–2 / 3 of the bucket body. The compressed air pressure is 0.35MPa, the nozzle atomization particle size is 80μm, the spraying distance is 10cm, the spraying time is 0.2 seconds, and the amount of oil applied to a single condom is 90mg.

[0061] 4. Application location: The central area 4cm from the opening of the condom and 4cm from the reservoir tip;

[0062] 5. Performance test: The lubricant atomizes evenly without dripping or splashing; the product surface is smooth after rolling and molding, with excellent moisturizing properties and no dryness during use; the lubricant recycling rate is 93%, and there is still no stratification or odor after 6 cycles of use.

[0063] Example 3: General-purpose hyaluronic acid lubricant formulation and application method

[0064] 1. Formulation composition (mass percentage): Polyethylene glycol 400 90%, Sodium hyaluronate (molecular weight 500,000) 0.2%, Sodium polyacrylate 0.2%, Deionized water 9.6% (below 10%);

[0065] 2. Preparation process: Polyethylene glycol 400 and deionized water were added to a mixing tank and stirred at 32°C for 8 minutes to mix evenly. Sodium hyaluronate and sodium polyacrylate were added and stirred for 1 hour until completely dissolved. After standing for 25 minutes to remove bubbles, a hyaluronic acid lubricant with a viscosity of 200 mPa·s at 25°C and a pH value of 6.5 was obtained.

[0066] 3. Oil application method: It can be switched between roller coating or capillary coating. When roller coating, the amount of oil is controlled by adjusting the roller speed. When capillary coating, the amount of oil is controlled by the inner diameter and flow rate of the guide tube. The amount of oil applied to a single condom is 100mg.

[0067] 4. Application location: The central area 3cm from the opening of the condom and 3cm from the reservoir tip;

[0068] 5. Performance test: Both brushing methods can achieve precise quantitative coating, the lubricant adheres firmly to the condom film, and there is no deterioration or migration after 6 months of storage; the lubricant recycling rate is 91%, which is suitable for production line requirements of different speeds.

[0069] Example 4: Extremely Low Water Content Formulation

[0070] 1. Formulation composition (by weight): Glycerin 85.0%, Propylene glycol 13.7%, Sodium hyaluronate (molecular weight 1 million) 0.3%, Carbomer 940 0.2%, Deionized water 0.8% (below 10%).

[0071] 2. Preparation process: Glycerin, propylene glycol and deionized water were added to a mixing tank and stirred at 35°C for 15 minutes. Sodium hyaluronate and carbomer 940 were slowly added and stirred for 1.5 hours until completely dissolved. The mixture was allowed to stand for 30 minutes to remove bubbles, resulting in a hyaluronic acid lubricant with a viscosity of 320 mPa·s at 25°C and a pH of 6.9.

[0072] 3. Oil application method: peristaltic pump drip application (suitable for water < 10%), flow rate 1000ml / min, 4mm inner diameter silicone tubing, single application amount 70mg;

[0073] 4. Application location: The central area 3.2cm from the opening and 3.2cm from the reservoir tip;

[0074] 5. Performance test: The lubricant has a high viscosity and moderate fluidity, with concentrated coating and a small wetting range; after the water-soluble lubricant at the reservoir tip conducts moisture, the sleeve gradually becomes wet and the lubrication improves; it curls smoothly without oil spillage, has a recovery rate of 92%, and remains stable after 5 cycles.

[0075] Example 5: Extremely High Water Content Formulation

[0076] 1. Formula composition (by weight): Glycerin 50.0%, Propylene glycol 20.0%, Sodium hyaluronate (molecular weight 800,000) 0.6%, Hydroxyethyl cellulose 0.4%, Deionized water 28.0% (above 10%).

[0077] 2. Preparation process: Glycerin, propylene glycol, and deionized water were stirred at 38°C for 15 minutes. Sodium hyaluronate and hydroxyethyl cellulose were added and stirred for 2 hours to dissolve. The mixture was allowed to stand for 40 minutes to remove bubbles, resulting in a lubricant with a viscosity of 180 mPa·s at 25°C and a pH of 7.2.

[0078] 3. Oiling method: Compressed air spraying (water > 10%, only applicable to spraying / micro-spraying / capillary flow / metering valve), pressure 0.3MPa, atomized particle size 100μm, spraying distance 12cm, single brushing amount 80mg;

[0079] 4. Application location: 3.5cm from the opening end and 3.5cm from the reservoir end, in the middle area;

[0080] 5. Performance test: The lubricant has strong fluidity, uniform atomization, and controllable wetting; no large-area wetting occurred, and it formed good curling; it has good moisturizing properties, is smooth to use, has a recovery rate of 91%, and is stable after 5 cycles.

[0081] Water content and oil application method matching rules:

[0082] Water content below 10%: The system is predominantly oil-phase with moderate viscosity and controllable wetting range, suitable for peristaltic pump drip coating, compressed air spraying, roller coating, micro-spraying, capillary dipping, metering valve coating, and dip coating. In this water content range, the lubricant itself has relatively weak lubricity. During production, the water-soluble lubricant dripping from the reservoir transfers water to the brushing area, causing the hyaluronic acid and thickener in the brushing lubricant to gradually absorb water and swell, ultimately achieving full wetting of the casing and improved lubricity, ensuring effective lubrication during use.

[0083] Water content above 10%: The system has a high proportion of water phase, strong fluidity and strong penetration ability. If peristaltic pump, roller coating or dip coating is used, it is easy to cause large-area diffusion and excessive wetting of lubricant, resulting in the condom not forming properly or being unable to complete the curling. Therefore, it is only suitable for compressed air spraying, micro-spraying, capillary diversion and metering valve coating.

[0084] In this invention:

[0085] 1. Formula Innovation: For the first time, a high proportion of polyols of 70%–99% is used as the main component, combined with sodium hyaluronate with a molecular weight of 200,000–3,000,000 and a specific thickener, to form a hyaluronic acid lubricant formula that is suitable for a variety of brushing methods. This solves the problems of poor lubrication durability and insufficient compatibility of traditional formulas. No existing patent has the same formula ratio and component combination.

[0086] 2. Methodological Innovation: Breaking away from the reliance of existing technologies on a single brushing mechanism, this method adopts a core limiting approach of "formula + brushing amount + coating position + recycling process". The scope of protection covers all mechanisms that can achieve quantitative oiling, greatly reducing the risk of infringement avoidance. No such general brushing method exists in the existing technology that does not limit the execution mechanism but only limits the core process parameters.

[0087] 3. Precise control innovation: The amount of lubricant applied to a single condom is clearly limited (20–200 mg) and the application position (≥3 cm from each end). At the same time, the lubricant recovery rate is required to be ≥90%, forming a complete closed-loop process. This solves the problems of uncontrolled lubricant volume, disordered application position, and serious waste in traditional processes. This combination of core parameters has not been disclosed in existing patents.

[0088] 4. Innovative water content adaptation: For the first time, the applicable scope of the oiling method is divided according to a water content of 10%, and the technical reasons for prohibiting peristaltic pumps, roller coating, and dip coating in high water systems are explained; for low water systems, a reservoir water replenishment and activation mechanism is proposed, improving the logic of lubrication effect guarantee and filling the technical gap in the industry;

[0089] 5. Conflict Avoidance: The technical solution of this invention is completely independent of any existing equipment or formula patents, does not rely on the technical features of any external patents, and forms an independent technical barrier through unique formula ratios, general process design and core parameter limitations. After searching, it does not conflict with any existing effective and published patents, and has novelty, inventiveness and utility.

Claims

1. A highly adaptable hyaluronic acid lubricant for condoms, characterized in that, The components include polyols, sodium hyaluronate, thickeners, and deionized water; The polyol comprises 70%–99% by mass and is selected from one or more of glycerol, propylene glycol, and polyethylene glycol (molecular weight 200–600); The sodium hyaluronate has a mass percentage of 0.1%–1% and a molecular weight of 200,000–3,000,000 Da; The thickener, comprising 0.1%–1% by mass, is selected from one or more of hydroxyethyl cellulose, carbomer, and sodium polyacrylate. The deionized water, comprising 0.8%–28% by mass, serves as both a solvent and a dispersion medium. The total mass meets 100%.

2. The hyaluronic acid lubricant for condoms as described in claim 1, characterized in that, The polyol is a mixture of glycerol and propylene glycol in a mass ratio of (3–5):

1.

3. The hyaluronic acid lubricant for condoms as described in claim 1, characterized in that, The sodium hyaluronate is preferably composed of a molecular weight of 500,000 to 1,500,000; the thickener is preferably present in a mass ratio of 0.2% to 0.5% to achieve optimal viscosity stability.

4. The hyaluronic acid lubricant for condoms as described in claim 1, characterized in that, The thickener is selected from carbomer 940 or hydroxyethyl cellulose.

5. A method for preparing a hyaluronic acid lubricant for condoms as described in any one of claims 1 to 4, characterized in that, The specific steps are as follows: Weigh each component according to the formula ratio, add the polyol and deionized water into the mixing tank, and stir evenly at 30–40℃. Slowly add sodium hyaluronate and thickener, and continue stirring for 1–2 hours until all components are completely dissolved, ensuring there are no particulate impurities. Then let it stand for 20–40 minutes to remove air bubbles and obtain a uniform and stable hyaluronic acid lubricant.

6. A method for applying a hyaluronic acid lubricant for condoms as described in any one of claims 1 to 4, characterized in that, The specific steps are as follows: (1) Apply oil Method 1: When the deionized water content is less than 10%, peristaltic pump drip coating, compressed air spraying, roller coating, micro-spraying, capillary dipping, metering valve coating, and dip coating are used. Method 2: When the deionized water content is above 10%, use compressed air spraying, micro-spraying, capillary diversion, or metering valve coating. Both of the above methods follow the following control conditions: Quantitative control: The amount of oil applied in a single application is strictly controlled within 20–200 mg, with a deviation of ≤±10%; Position control: Lubricant is applied only to the middle area of ​​the condom, which is 3-5 cm from the opening and 3-5 cm from the reservoir tip. (2) Curling and shaping After the oil is applied, the curled brush moves toward the condom under the drive of the cylinder, rotates and moves axially along the axis of the electric inspection mold, and rolls the condom off the mold and shapes it. (3) Lubricant recovery An oil collection tank is installed below the oiling station and in the gap of the electrical inspection mold to collect the excess lubricant. The lubricant is then transported to a filter through a recycling pipeline. The filter has a filtration accuracy of 5–20 μm to remove impurities and small particles. After that, the lubricant is returned to the lubricant storage container for recycling.

7. The application method as described in claim 6, characterized in that, In Method 1, peristaltic pump drip coating is used: a peristaltic pump with a flow rate of 150ml / min–4000ml / min is selected, and a food-grade silicone tube with an inner diameter of 1mm–8mm is used. The brushing time is controlled by adjusting the pump speed to achieve quantitative drip coating, which is suitable for medium and low speed production lines.

8. The application method as described in claim 6, characterized in that, Method 2 uses compressed air spraying: a sealed stainless steel container is used to store the lubricant. High-pressure nozzles are driven by compressed air at 0.2–0.5MPa to atomize the lubricant into tiny droplets of 50–150μm, which are then sprayed onto the surface of the condom at a distance of 8–15cm. The spraying time is controlled by a solenoid valve to achieve quantitative spraying, making it suitable for high-speed production lines.

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