PVA (Polyvinyl Alcohol) film toilet seat cushion as well as production method and equipment

Abstract

The invention provides a PVA (Polyvinyl Alcohol) film toilet seat cushion as well as a production method and equipment. The production method of the PVA film toilet seat cushion specifically comprises the following steps: S1, preparing a modified PVA film; s2, unwinding is carried out; s3, preheating the PVA film; s4, the PVA film is atomized; s5, covering is carried out; s6, on-line pressure detection is carried out; s7, atomization of the toilet seat cushion; and S8, rolling is conducted. And the like. After the PVA film is modified, the plasticizing and moisturizing properties of the PVA film are realized, so that the PVA film has the function of an adhesive when being coated with water and heated, good bonding strength can be obtained without additionally adding an adhesive in the process of coating paper on the PVA film, and the antibacterial and bacteriostatic effects of the product are improved; the produced PVA film toilet seat cushion product has the advantages of no chemical adhesive, excellent antibacterial and bacteriostatic performance, comfort in use (skid resistance and flexibility), capability of being quickly dissolved in water, environment friendliness and stable and reliable production quality.

Description

A PVA film toilet seat, its production method and equipment Technical Field

[0001] This invention relates to the field of PVA material technology, specifically to a PVA film toilet seat, its production method, and equipment. Background Technology

[0002] Disposable toilet seat covers are commonly used in public restrooms, such as hospitals, hotels, and airports, to help maintain hygiene standards and limit contamination and cross-infection between users. Current market trends favor disposable toilet seat covers made with water-soluble biodegradable films. After use, they can be removed from the toilet seat and flushed down the toilet. These water-soluble biodegradable films are mostly made of polyvinyl alcohol (PVA).

[0003] In existing technologies, PVA film toilet seat covers typically use adhesives to bond paper layers to the top and bottom surfaces of the PVA film. For example, CN112918050A discloses a water-soluble biodegradable toilet seat cover and its preparation method. This toilet seat cover comprises five layers: a central layer, upper and lower surface layers, and an adhesive layer between the central layer and the upper and lower surface layers. The central layer is a water-soluble film layer, and the upper and lower surface layers are both medical-grade sterile paper layers. The shape of the toilet seat cover is identical to the top view of a toilet seat ring. This toilet seat cover, formed by the water-soluble film and medical-grade sterile paper, dissolves within 60 seconds of contact with water at room temperature. The sterile paper is subsequently decomposed by microorganisms, preventing toilet clogging. It is also flexible, comfortable, antibacterial, and retains a pleasant fragrance. However, this water-soluble biodegradable toilet seat requires an adhesive layer. The presence of this layer not only increases production costs and complexity, but some adhesives may also contain irritating chemicals that could cause discomfort to those with sensitive skin. In humid and warm environments, inferior adhesives may also emit unpleasant odors, making them environmentally unfriendly. While PVA film itself is adhesive, PVA is hydrophilic and easily absorbs moisture in humid environments, causing the adhesive layer to soften, become sticky, or lose strength. Relying solely on the adhesive properties of the PVA film is insufficient to stably bond the fast-dissolving pure wood pulp paper together and maintain its adhesion for a long time. Furthermore, existing PVA toilet seat covers have poor antibacterial and bacteriostatic effects, thus requiring improvement. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a method, equipment, and product for producing PVA film toilet seat covers. This method modifies the PVA film to enhance its plasticizing and moisturizing properties, enabling it to function as an adhesive when heated with water. No additional adhesive is needed during the PVA film lamination process to achieve good bonding strength. Furthermore, the addition of various nanomaterials during PVA modification synergistically enhances the product's antibacterial and bacteriostatic effects.

[0005] To achieve the above technical solution, the present invention provides a method for producing PVA film toilet seat covers, specifically including the following steps:

[0006] S1. Preparation of modified PVA film: By weight, 100 parts PVA, 3-8 parts starch, 5-12 parts glycerol, 5-10 parts polyethylene glycol, 3-8 parts sorbitol, 3-8 parts citric acid, 2-5 parts sodium citrate, 1-6 parts nano titanium dioxide, 5-10 parts tea polyphenols, and 1-5 parts chitosan are added to 300-700 parts purified water to dissolve and mix evenly. The mixture is then coated, dried, and heat-treated to obtain a modified PVA film with bactericidal, bacteriostatic, and water-heat-adhesive functions.

[0007] S2. Place the modified PVA film on the PVA film unwinding mechanism, and place the fast-dissolving pure wood pulp paper on the upper fast-dissolving pure wood pulp paper unwinding mechanism and the lower fast-dissolving pure wood pulp paper unwinding mechanism respectively. The upper and lower fast-dissolving pure wood pulp paper are unwound simultaneously by the upper and lower fast-dissolving pure wood pulp paper unwinding mechanisms, and the modified PVA film is unwound simultaneously by the PVA film unwinding mechanism. The modified PVA film is located between the upper and lower fast-dissolving pure wood pulp paper.

[0008] S3, the modified PVA film is preheated by three heating rollers, gradually preheated to 40-50 degrees, 60-70 degrees, and 80-100 degrees;

[0009] S4. Apply water to both sides of the preheated modified PVA film using an atomizer;

[0010] S5. The modified PVA film after the atomizer is covered with water, the upper layer of fast-dissolving pure wood pulp paper, and the lower layer of fast-dissolving pure wood pulp paper are laminated at the laminating roller to obtain a PVA film toilet seat.

[0011] S6. Conduct online testing on the laminated PVA film toilet seat to prevent false lamination;

[0012] S7. The PVA film toilet seat is atomized by an automatic atomizer;

[0013] S8. Rewinding is performed using an automatic rewinding machine.

[0014] Preferably, in step S1, by weight, 100 parts PVA, 6 parts starch, 8 parts glycerin, 8 parts polyethylene glycol, 5 parts sorbitol, 5 parts citric acid, 3 parts sodium citrate, 3 parts nano titanium dioxide, 6 parts tea polyphenols, and 3 parts chitosan are dissolved and mixed evenly with 500 parts purified water. The mixture is then sequentially coated, dried, and heat-treated to obtain a modified PVA film with antibacterial, bacteriostatic, and water-heat-bonded properties. Optimizing this formulation achieves an optimal balance between antibacterial performance, film mechanical strength, adhesive activity, and cost control, ensuring stable, excellent, and economical product performance.

[0015] Preferably, in step S4, a dehumidifier is used to remove excess water vapor from the spray when the atomizer is watered. By removing excess water vapor, the ambient humidity of the water-covered area is precisely controlled. This avoids uneven lamination, loss of film strength, or production interruption caused by premature or excessive dissolution of the PVA film due to excessive humidity. It also prevents the quick-dissolving paper from losing strength due to excessive moisture absorption, and prevents water vapor from contacting the quick-dissolving pure wood pulp paper, thus avoiding defects such as breakage.

[0016] Preferably, in step S4, a hygrometer is installed at the contact point between the atomizer and the modified PVA film. The hygrometer is electrically connected to the dehumidifier and automatically adjusts the power of the dehumidifier accordingly. This achieves automated and intelligent closed-loop control of humidity. The system can automatically adjust the dehumidification power according to the real-time humidity, ensuring that the process conditions are always within the optimal and most stable range.

[0017] Preferably, in step S5, the laminating roller includes an upper laminating roller and a lower laminating roller. The upper laminating roller is an embossed chrome-plated steel roller with internal heating. During lamination, the surface temperature of the silicone roller is maintained at 90-110 degrees Celsius. The internal heating of the upper laminating roller and the lower silicone roller provide continuous and uniform heat, which, together with atomized moisture, thoroughly activates the adhesion of the PVA film, ensuring a firm lamination. The silicone material provides flexible pressure, avoiding damage to the film material.

[0018] Preferably, the embossing on the surface of the embossing roller is a gentle, wavy pattern to avoid sharp corners. This design avoids sharp corners for two reasons: first, it prevents stress concentration that could cause the film to be punctured by sharp corners during lamination or subsequent winding; second, it makes the embossed pattern softer, greatly improving comfort when in contact with the skin, without any stinging or foreign body sensation.

[0019] Preferably, in step S6, an online pressure testing roller is used to perform online testing on the laminated PVA film toilet seat. The online pressure testing roller includes an upper pressure roller and a lower pressure roller, wherein the upper pressure roller has adjustable pressure to match the testing effect. This achieves real-time quality monitoring during the production process. Testing with the adjustable pressure upper pressure roller can immediately detect "false lamination" (i.e., weak interlayer adhesion) caused by insufficient preheating, uneven water coverage, or improper pressure.

[0020] The present invention also provides a PVA film toilet seat, comprising a PVA film layer, an upper fast-dissolving pure wood pulp paper and a lower fast-dissolving pure wood pulp paper, wherein the upper fast-dissolving pure wood pulp paper and the lower fast-dissolving pure wood pulp paper are respectively laminated on the upper and lower surfaces of the PVA film layer, and are produced using the above-described PVA film toilet seat production method.

[0021] This invention also provides a PVA film toilet seat production equipment for implementing the above-mentioned PVA film toilet seat production method. Specifically, it includes: an upper fast-dissolving pure wood pulp paper unwinding mechanism, a lower fast-dissolving pure wood pulp paper unwinding mechanism, and a PVA film unwinding mechanism. A first preheating roller, a second preheating roller, and a third preheating roller are sequentially installed behind the PVA film unwinding mechanism. A first atomizer is installed behind the third preheating roller. A dehumidifier is installed behind the first atomizer. A laminating device consisting of an upper laminating roller and a lower laminating roller is installed behind the dehumidifier. An online pressure detection device consisting of an upper pressure roller and a lower pressure roller is installed behind the laminating device. A second atomizer is installed behind the online pressure detection device. A winding mechanism is installed behind the first atomizer. This PVA film toilet seat production equipment is a highly integrated and automated dedicated production line. The equipment is designed according to the core production process flow, with each mechanism (unwinding, preheating, atomization, lamination, detection, and rewinding) connected in sequence to ensure that the method can be executed efficiently, accurately, and continuously.

[0022] Preferably, an upper unwinding roller is installed between the upper fast-dissolving pure wood pulp unwinding mechanism and the laminating device, and a lower unwinding roller is installed between the lower fast-dissolving pure wood pulp unwinding mechanism and the laminating device. Adding the unwinding roller eliminates internal stress, wrinkles, and curling edges generated during the unwinding process before the fast-dissolving pure wood pulp paper enters the laminating device, ensuring the paper enters the laminating device smoothly. This is a key detail in obtaining high-quality laminated products that are bubble-free, wrinkle-free, and aesthetically pleasing, further improving the product's appearance and lamination uniformity.

[0023] The beneficial effects of the PVA film toilet seat, production method, and equipment provided by this invention are as follows:

[0024] (1) This invention completely abandons the traditional adhesive layer. Through the original process of "modified PVA film + preheating + atomized water coating + heating and bonding", the self-adhesiveness of the modified PVA film activated by water heating is utilized to achieve a stable composite with the upper and lower layers of fast-dissolving pure wood pulp paper, thus eliminating the problems of cost, complex process, chemical irritation and odor caused by glue from the root.

[0025] (2) This invention endows the product with multiple high-efficiency antibacterial functions. By adding nano titanium dioxide, it provides photocatalytic antibacterial effect, which is long-lasting and effective. By adding tea polyphenols and chitosan, both of which are natural, broad-spectrum and high-efficiency antibacterial agents, they work synergistically to enhance the immediate contact antibacterial and bacteriostatic effects. By adding citric acid and sodium citrate, in addition to acting as crosslinking agents and plasticizers, they can also regulate the slightly acidic environment and inhibit bacterial growth.

[0026] (3) This invention effectively plasticizes and enhances the flexibility, strength, and water resistance of the film by compounding starch, glycerol, polyethylene glycol, and sorbitol, overcoming the disadvantage of pure PVA film being prone to softening in humid environments. Citric acid and sodium citrate can act as crosslinking agents, undergoing esterification or hydrogen bonding with PVA, starch, etc., to improve the thermal stability and wet strength of the film, enabling it to withstand a certain amount of heat and moisture without excessive dissolution during preheating and lamination, thereby precisely controlling the bonding process and significantly improving the mechanical and adhesive properties of the PVA film.

[0027] (4) The present invention uses a three-stage preheating, atomized water coating and heating and bonding process to precisely and uniformly activate the adhesion of the PVA film, ensuring the strength, uniformity and production efficiency of the composite, which is suitable for continuous industrial mass production.

[0028] (5) The PVA film toilet seat products produced by this invention have the advantages of: no chemical adhesives, excellent antibacterial and bacteriostatic properties, comfortable to use (non-slip, flexible), quick dissolution in water, environmental protection and stable and reliable production quality. Attached Figure Description

[0029] Figure 1 is a schematic diagram of the production equipment in this invention.

[0030] Figure 2 is a schematic diagram of the PVA film toilet seat structure in this invention.

[0031] In the diagram: 1. Upper fast-dissolving pure wood pulp paper unwinding mechanism; 2. Lower fast-dissolving pure wood pulp paper unwinding mechanism; 3. PVA film unwinding mechanism; 4. First preheating roller; 5. Second preheating roller; 6. Third preheating roller; 7. First atomizer; 8. Dehumidifier; 9. Upper stretching roller; 10. Lower stretching roller; 11. PVA film stretching roller; 12. Upper laminating roller; 13. Lower laminating roller; 14. Upper embossed chrome-plated steel roller; 15. Lower pressure roller; 16. Second atomizer; 17. Rewinding mechanism; 100. Upper fast-dissolving pure wood pulp paper layer; 200. PVA film layer; 300. Lower fast-dissolving pure wood pulp paper layer. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 without creative effort are within the protection scope of the present invention.

[0033] Example 1: A method for producing PVA film toilet seat covers

[0034] A method for producing PVA film toilet seat covers specifically includes the following steps:

[0035] S1. Preparation of modified PVA film: By weight, 100 parts PVA, 6 parts starch, 8 parts glycerol, 8 parts polyethylene glycol, 5 parts sorbitol, 5 parts citric acid, 3 parts sodium citrate, 3 parts nano titanium dioxide, 6 parts tea polyphenols, and 3 parts chitosan are dissolved and mixed evenly in 500 parts purified water. The mixture is then sequentially coated, dried, and heat-treated to obtain a modified PVA film with antibacterial, bacteriostatic, and water-heat-bonded properties.

[0036] In step S1 above, the addition of nano-titanium dioxide provides a photocatalytic antibacterial effect that is long-lasting and effective. The addition of tea polyphenols and chitosan, both natural, broad-spectrum, and highly effective antibacterial agents, works synergistically to enhance both immediate contact antibacterial and bacteriostatic effects. The addition of citric acid and sodium citrate, in addition to acting as cross-linking agents and plasticizers, also regulates the slightly acidic environment, inhibiting bacterial growth. The addition of nano-titanium dioxide provides a long-lasting and effective photocatalytic antibacterial effect.

[0037] By adding tea polyphenols and chitosan, both of which are natural, broad-spectrum, and highly effective antibacterial agents, their synergistic effect enhances the immediate contact antibacterial and bacteriostatic effects. By adding citric acid and sodium citrate, in addition to acting as cross-linking agents and plasticizers, they can also regulate the slightly acidic environment and inhibit bacterial growth.

[0038] Furthermore, by optimizing this ratio, an optimal balance can be achieved between antibacterial properties, membrane mechanical strength, adhesive activity, and cost control, ensuring stable, excellent, and economical product performance.

[0039] S2. Place the modified PVA film on the PVA film unwinding mechanism. Place the fast-dissolving pure wood pulp paper on the upper and lower fast-dissolving pure wood pulp paper unwinding mechanisms, respectively. Simultaneously, the upper and lower fast-dissolving pure wood pulp paper are unwound by the upper and lower fast-dissolving pure wood pulp paper unwinding mechanisms, while the modified PVA film is unwound by the PVA film unwinding mechanism. The modified PVA film is positioned between the upper and lower fast-dissolving pure wood pulp paper. This ensures that the upper and lower fast-dissolving pure wood pulp paper are evenly laminated on both sides of the modified PVA film.

[0040] S3. The modified PVA film is preheated by three heating rollers, gradually preheating to 40-50 degrees, 60-70 degrees, and 80-100 degrees. Through the three-stage temperature gradient preheating, the adhesion of the PVA film can be gradually activated, and the adhesion of the PVA film can be prevented from being activated too quickly, which would cause the film to stick to the rollers.

[0041] S4. Atomizers are used to spray water onto both sides of the preheated modified PVA film to further and precisely activate its adhesion. During the spraying process, a dehumidifier is used to remove excess water vapor. By removing excess water vapor, the ambient humidity in the sprayed area is precisely controlled. This avoids premature and excessive dissolution of the PVA film due to excessive humidity, which could lead to uneven lamination, loss of film strength, or production interruption. It also prevents the quick-dissolving paper from losing strength due to excessive moisture absorption, and prevents water vapor from contacting the quick-dissolving pure wood pulp paper, thus avoiding defects such as breakage.

[0042] A hygrometer is installed at the contact point between the atomizer and the modified PVA film. This hygrometer is electrically connected to the dehumidifier and automatically adjusts the dehumidifier's power accordingly. This achieves automated and intelligent closed-loop control of humidity. The system can automatically adjust the dehumidification power based on real-time humidity, ensuring that process conditions are always within the optimal and most stable range.

[0043] S5. The modified PVA film after the atomizer is water-covered, the upper layer of fast-dissolving pure wood pulp paper, and the lower layer of fast-dissolving pure wood pulp paper are laminated at the laminating roller to obtain a PVA film toilet seat. This completely eliminates the need for traditional adhesive layers. By utilizing the self-adhesive properties of the modified PVA film activated by water heating, a stable composite with the upper and lower layers of fast-dissolving pure wood pulp paper is achieved, fundamentally eliminating the cost, complex process, chemical irritation, and odor problems caused by glue.

[0044] The laminating rollers consist of an upper laminating roller and a lower laminating roller. The lower laminating roller is a silicone roller, while the upper laminating roller is an embossed chrome-plated steel roller with internal heating. During lamination, the surface temperature of the silicone roller is maintained at 100 degrees Celsius. The internal heating of the upper laminating roller and the continuous, uniform heat provided by the lower silicone roller, combined with atomized moisture, thoroughly activate the adhesion of the PVA film, ensuring a strong lamination. The silicone material provides flexible pressure, preventing damage to the film material.

[0045] The embossing on the surface of the embossing roller is a gentle, wavy pattern to avoid sharp corners. This design avoids sharp corners for two reasons: first, it prevents stress concentration that could cause the film to be punctured by the sharp corners of the embossing during lamination or subsequent winding; second, it makes the embossed pattern softer, greatly improving comfort when in contact with the skin, without any stinging or foreign body sensation.

[0046] S6. Online inspection of the laminated PVA film toilet seat is performed to prevent false lamination. An online pressure testing roller, comprising an upper pressure roller and a lower pressure roller, is used to perform online inspection of the laminated PVA film toilet seat. The upper pressure roller has adjustable pressure to match the inspection effect. This achieves real-time quality monitoring during the production process. Inspection using the adjustable pressure upper pressure roller can immediately detect "false lamination" (i.e., weak interlayer adhesion) caused by insufficient preheating, uneven water coverage, or improper pressure.

[0047] S7. The PVA film toilet seat is atomized by an automatic atomizer. After the PVA film is covered with paper, it becomes hard and not soft, making it uncomfortable to use. During production, the PVA film is atomized again to restore its softness and skin-friendly feel, but the PVA film and wood pulp paper do not peel off.

[0048] S8. Rewinding is performed using an automatic rewinding machine.

[0049] This invention completely abandons the traditional adhesive layer. Through a unique "modified PVA film + preheating + atomized water coating + heated lamination" process, it utilizes the self-adhesive properties of the modified PVA film activated by water heating to achieve a stable composite with two layers of fast-dissolving pure wood pulp paper. This eliminates the cost, complex processes, chemical irritation, and odor problems associated with adhesives at the source. The three-stage preheating, atomized water coating, and heated lamination process ensures precise and uniform activation of the PVA film's adhesiveness, guaranteeing composite strength, uniformity, and production efficiency, making it suitable for continuous industrial mass production. The resulting PVA film toilet seat possesses reliable wet strength, rapid water solubility, long-lasting antibacterial and bacteriostatic functions, and excellent anti-slip comfort. Furthermore, the process is simplified, eliminating complex steps such as glue application and drying; the equipment is highly automated, and online monitoring reduces waste and lowers overall production costs. Automatic humidity control, temperature gradient preheating, and online pressure monitoring ensure stable production parameters and highly consistent product quality.

[0050] Example 2: A PVA film toilet seat production equipment

[0051] Referring to Figure 1, a PVA film toilet seat production equipment is used to implement the PVA film toilet seat production method described in Example 1. Specifically, it includes: an upper fast-dissolving pure wood pulp paper unwinding mechanism 1, a lower fast-dissolving pure wood pulp paper unwinding mechanism 2, and a PVA film unwinding mechanism 3. A first preheating roller 4, a second preheating roller 5, and a third preheating roller 6 are sequentially installed behind the PVA film unwinding mechanism 3. A first atomizer 7 is installed behind the third preheating roller 6. A dehumidifier 8 is installed behind the first atomizer 7. A laminating device consisting of an upper laminating roller 12 and a lower laminating roller 13 is installed behind the dehumidifier 8. An online pressure detection device consisting of an upper pressure roller 14 and a lower pressure roller 15 is installed behind the laminating device. A second atomizer 16 is installed behind the online pressure detection device. A winding mechanism 17 is installed behind the first atomizer 16. An upper stretching roller 9 is installed between the upper fast-dissolving pure wood pulp unwinding mechanism 1 and the laminating device. A lower stretching roller 10 is installed between the lower fast-dissolving pure wood pulp unwinding mechanism 2 and the laminating device. The addition of the stretching roller can eliminate the internal stress, wrinkles and curling edges generated during the unwinding process of the paper roll before the fast-dissolving pure wood pulp paper enters the laminating device, ensuring that the paper enters the laminating device flat.

[0052] This PVA film toilet seat production equipment is a highly integrated and automated dedicated production line. The equipment is designed according to the core production process flow, with each mechanism (unwinding, preheating, atomization, lamination, testing, and rewinding) sequentially connected to ensure that the method described in Example 1 can be executed efficiently, accurately, and continuously.

[0053] Example 3: A PVA film toilet seat

[0054] Referring to Figure 2, a PVA film toilet seat includes a PVA film layer 200, an upper fast-dissolving pure wood pulp paper layer 100, and a lower fast-dissolving pure wood pulp paper layer 300, wherein the upper fast-dissolving pure wood pulp paper layer 100 and the lower fast-dissolving pure wood pulp paper layer 300 are respectively laminated onto the upper and lower surfaces of the PVA film layer 200. It is produced using the method described in Example 1. The PVA film toilet seat product produced by this invention has the advantages of: no chemical adhesives, excellent antibacterial and bacteriostatic properties, comfortable use (non-slip, flexible), rapid dissolution in water, environmental friendliness, and stable and reliable production quality.

[0055] The above description is only a preferred embodiment of the present invention, but the present invention should not be limited to the content disclosed in the embodiments and drawings. Therefore, any equivalent or modified embodiments made without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for producing PVA film toilet seat covers, characterized in that, Specifically, the steps are as follows: S1. Preparation of modified PVA film: by mass, 100 parts PVA, 3-8 parts starch, 5-12 parts glycerol, 5-10 parts polyethylene glycol, 3-8 parts sorbitol, 3-8 parts citric acid, 2-5 parts sodium citrate, 1-6 parts nano titanium dioxide, 5-10 parts tea polyphenols, and 1-5 parts chitosan are added to 300-700 parts of purified water to dissolve and mix evenly. Then, the mixture is successively coated, dried, and heat-treated to obtain a modified PVA film with bactericidal and bacteriostatic properties as well as water-coated and heat-adhesive functions. S2. Place the modified PVA film on the PVA film unwinding mechanism, and place the fast-dissolving pure wood pulp paper on the upper and lower fast-dissolving pure wood pulp paper unwinding mechanisms respectively. The upper and lower fast-dissolving pure wood pulp paper are simultaneously unwound by the upper and lower fast-dissolving pure wood pulp paper unwinding mechanisms, while the modified PVA film is unwound by the PVA film unwinding mechanism. The modified PVA film is positioned between the upper and lower fast-dissolving pure wood pulp paper. S3. The modified PVA film passes through three stages of heated rollers. Preheating: Gradually preheat to 40-50 degrees Celsius, 60-70 degrees Celsius, and 80-100 degrees Celsius; S4: Apply water to both sides of the preheated modified PVA film using an atomizer; S5: Lay the water-laden modified PVA film, the upper layer of fast-dissolving pure wood pulp paper, and the lower layer of fast-dissolving pure wood pulp paper together at the laminating roller to obtain a PVA film toilet seat; S6: Perform online inspection on the laminated PVA film toilet seat to prevent false lamination; S7: Atomize the PVA film toilet seat using an automatic atomizer; S8: Rewind using an automatic winding machine.

2. The method for producing PVA film toilet seat covers according to claim 1, characterized in that: In step S1, by weight, 100 parts PVA, 6 parts starch, 8 parts glycerin, 8 parts polyethylene glycol, 5 parts sorbitol, 5 parts citric acid, 3 parts sodium citrate, 3 parts nano titanium dioxide, 6 parts tea polyphenols, and 3 parts chitosan are dissolved and mixed evenly with 500 parts purified water. The mixture is then sequentially coated, dried, and heat-treated to obtain a modified PVA film with bactericidal, bacteriostatic, and water-heat-adhesive functions.

3. The method for producing PVA film toilet seat covers according to claim 1, characterized in that: In step S4, when the atomizer is covered with water, a dehumidifier is used to remove and drain the excess water vapor from the spray.

4. The method for producing PVA film toilet seat covers according to claim 3, characterized in that: In step S4, a hygrometer is installed at the contact point between the atomizer and the modified PVA film. The hygrometer is electrically connected to the dehumidifier and automatically adjusts the power of the dehumidifier.

5. The method for producing PVA film toilet seat covers according to claim 1, characterized in that: In step S5, the laminating roller includes an upper laminating roller and a lower laminating roller. The lower laminating roller is a silicone roller, and the upper laminating roller is an embossed chrome-plated steel roller. It is internally heated, and the surface temperature of the silicone roller is maintained at 90-110 degrees Celsius during lamination.

6. The method for producing PVA film toilet seat covers according to claim 5, characterized in that: The embossing on the surface of the embossing roller is a gentle, wavy pattern to avoid sharp corners.

7. The method for producing PVA film toilet seat covers according to claim 1, characterized in that: In step S6, an online pressure detection roller is used to perform online testing on the laminated PVA film toilet seat. The online pressure detection roller includes an upper pressure roller and a lower pressure roller, wherein the pressure of the upper pressure roller can be adjusted to match the testing effect.

8. A PVA film toilet seat, comprising a PVA film layer, an upper fast-dissolving pure wood pulp paper layer, and a lower fast-dissolving pure wood pulp paper layer, wherein the upper and lower fast-dissolving pure wood pulp paper layers are respectively laminated onto the upper and lower surfaces of the PVA film layer, characterized in that, Produced using any one of the methods described in claims 1-7.

9. A PVA film toilet seat production equipment, characterized in that, The method for producing PVA film toilet seat covers according to any one of claims 1-7 specifically includes: an upper fast-dissolving pure wood pulp paper unwinding mechanism, a lower fast-dissolving pure wood pulp paper unwinding mechanism, and a PVA film unwinding mechanism. A first preheating roller, a second preheating roller, and a third preheating roller are sequentially installed behind the PVA film unwinding mechanism. A first atomizer is installed behind the third preheating roller. A dehumidifier is installed behind the first atomizer. A laminating device composed of an upper laminating roller and a lower laminating roller is installed behind the dehumidifier. An online pressure detection device composed of an upper pressure roller and a lower pressure roller is installed behind the laminating device. A second atomizer is installed behind the online pressure detection device. A winding mechanism is installed behind the first atomizer.

10. The PVA film toilet seat production equipment according to claim 9, characterized in that: An upper stretching roller is installed between the upper fast-dissolving pure wood pulp unwinding mechanism and the laminating device, and a lower stretching roller is installed between the lower fast-dissolving pure wood pulp unwinding mechanism and the laminating device.

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