A wet wipe liquid spraying device and method for wet wipe production

Abstract

The present invention discloses a wet wipe liquid spraying device and method for wet wipe production, which relates to the field of liquid-phase treatment of textile materials. The method includes the following steps: S1. Spray the wet wipe liquid onto the surface of the wet wipe substrate at a pressure of 0.15 - 0.25 MPa; S2. Then spray the remaining total amount of the wet wipe liquid onto the pre-wetted wet wipe substrate at a pressure of 0.6 - 0.8 MPa; S3. During the pre-wetting spraying and post-high-pressure spraying, eject gas towards the edge of the wet wipe substrate to form an edge air curtain to restrain droplets. Through the composite process of staged spraying and air curtain restraint, the low-pressure pre-spray gently wets the surface of the substrate, and the high-pressure post-spray drives the liquid molecules deep into the substrate with the guidance of the pre-wetting channel. At the same time, the air curtain restraint effectively prevents the scattering and escape of droplets, further improving the spraying efficiency and liquid utilization rate, thereby significantly reducing the foaming rate, improving the liquid utilization rate, and ensuring the uniformity of the liquid distribution on the wet wipe substrate, thus greatly enhancing the use effect of the wet wipe.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid-phase treatment of textile materials, particularly to spraying or jetting, and specifically to a wet wipe liquid spraying device and method for wet wipe production. Background Art

[0002] With the increasing global environmental awareness, degradable materials are increasingly widely used in the field of personal hygiene products, especially environmentally friendly wet wipes based on natural materials such as bamboo fiber and cotton fiber. Such degradable wet wipes can not only reduce plastic pollution but also be favored by consumers due to their natural skin-friendly characteristics. However, the performance of environmentally friendly degradable wet wipes highly depends on the uniform distribution and effective penetration of the wet wipe liquid, and the formula of the wet wipe liquid is gradually transforming towards naturalization, for example, using plant extracts such as saponins and polysaccharides as surface active components. Although such natural components are environmentally friendly and safe, their physical properties (such as large viscosity fluctuations, easy foaming, and complex interfacial activity) pose higher requirements for the spraying process.

[0003] Traditional wet wipe liquid spraying mostly relies on high-pressure jetting to achieve rapid coverage through high-speed liquid flow. However, the surface active substances in the natural-component wet wipe liquid are prone to generate foam under high shear force, and when the high-viscosity liquid penetrates into the degradable substrate with complex pores, the interfacial tension easily causes the liquid to accumulate on the fiber surface, forming local dry areas or bubble retention. The presence of bubbles not only reduces the liquid utilization rate but also affects the cleaning effect and touch of the wet wipes.

[0004] Therefore, it is necessary to improve the deficiencies in the prior art to solve the above problems. Summary of the Invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a wet wipe liquid spraying device and method for wet wipe production. Through innovative processes and equipment, uniform spraying of the wet wipe liquid is achieved, the liquid utilization rate is improved, and the production cost is reduced, thereby meeting the market demand for high-quality and environmentally friendly wet wipes.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a wet wipe liquid spraying method for wet wipe production, the spraying method is applicable to the spraying operation of degradable environmentally friendly wet wipes containing natural-component wet wipe liquid, and the spraying method includes the following steps:

[0007] S1. Spray the wet wipe liquid onto the surface of the wet wipe substrate at a pressure of 0.15 - 0.25 MPa to achieve pre-wetting spraying;

[0008] S2. After a certain interval after the low-pressure pre-spraying, spray the remaining total amount of the wet wipe liquid onto the pre-wetted wet wipe substrate at a pressure of 0.6 - 0.8 MPa to achieve post-high-pressure spraying;

[0009] S3. During pre-wetting spraying and post-high-pressure spraying, gas is ejected towards the edges of the wet wipe substrate to form an edge air curtain to confine the droplets.

[0010] In a preferred embodiment of the present invention, the natural ingredient wet wipe liquid contains saponin or polysaccharide components and has a viscosity of 50 - 200 mPa·s; the substrate of the degradable and environmentally friendly wet wipe is one of bamboo fiber, cotton fiber or non-woven fabric, and the porosity of the substrate is 30 - 70%.

[0011] In a preferred embodiment of the present invention, in the step of S1, the duration of the pre-wetting spraying is 1 - 2 s, the droplet diameter is 80 - 120 μm, and the spraying amount is 15 - 30% of the total spraying amount.

[0012] In a preferred embodiment of the present invention, the spraying distances of the pre-wetting spraying and the post-high-pressure spraying relative to the wet wipe substrate are 10 - 15 cm, and the spraying interval time between the two is 3 - 6 s.

[0013] In a preferred embodiment of the present invention, in the step of S2, the duration of the post-high-pressure spraying is 3 - 4 s, the droplet diameter is 20 - 50 μm, and the spraying amount is 70 - 85% of the total spraying amount.

[0014] In a preferred embodiment of the present invention, in the step of S3, the jetting angle of the gas from the outside to the edge direction of the wet wipe substrate is 15 - 30°, the air flow pressure is 0.05 - 0.1 MPa, the air flow velocity is 5 - 8 m / s, and the distance between the edge of the edge air curtain and the edge of the wet wipe substrate is 0 - 13 mm.

[0015] The present invention provides a spraying device for a wet wipe liquid spraying method in wet wipe production, including: an equipment frame, a plurality of conveying rollers rotatably connected to the top of the equipment frame, and two spraying boxes segmentally fixed to the top of the equipment frame;

[0016] Inside both of the two spraying boxes, a spraying mechanism and a jetting mechanism are provided. The spraying mechanism is used to respectively perform pre-wetting spraying and post-high-pressure spraying on the wet wipe substrate, and the jetting mechanism is used to confine the droplets at the edges of the wet wipe substrate during pre-wetting spraying and post-high-pressure spraying; a power mechanism for driving the plurality of conveying rollers to rotate synchronously is installed on the equipment frame.

[0017] In a preferred embodiment of the present invention, the spraying mechanism includes: a plurality of mounting plates fixed inside the spraying box, a plurality of spraying heads mounted on the mounting plates, and an infusion pipe fixed on the tops of the plurality of spraying heads; an infusion head for externally connecting an infusion device to supply the wet wipe liquid is installed on the top of the infusion pipe.

[0018] In a preferred embodiment of the present invention, the jetting mechanism includes: a plurality of mounting rods fixed inside the spraying box, a plurality of connecting rods disposed at the bottoms of the mounting rods, and a plurality of jetting heads disposed on one side of the plurality of connecting rods; a gas supply head for externally connecting a gas supply device to achieve gas supply is installed at the top end of the jetting head, and both ends of the connecting rod are respectively connected to the mounting rod and the jetting head through pipe clamps for adjusting the jetting direction of the jetting head.

[0019] In a preferred embodiment of the present invention, a limiting plate for preventing deviation during the conveyance of the wet wipe substrate is fixed to the side surface of the spraying box, and conical frames for recovering the wet wipe liquid are installed at the bottoms of both the equipment frame and the spraying box, and a recovery pipe is fixed to the bottom of the conical frame.

[0020] The present invention solves the defects existing in the background art and has the following beneficial effects:

[0021] (1) The present invention provides a wet wipe liquid spraying device and method for wet wipe production. Through the composite process of staged spraying and air curtain constraint, the spraying process of degradable wet wipes is comprehensively optimized. By using low-pressure pre-spraying, the surface of the substrate is gently wetted to form a continuous liquid film, reducing the interfacial tension between the fiber and the liquid, reducing the bubble nuclei generated when the high-viscosity liquid contacts the pore structure, and through high-pressure post-spraying, with the guidance of the pre-wetting channel, driving the liquid molecules to penetrate deep into the substrate interior, and avoiding the direct impact of high pressure on the non-wetted area resulting in gas retention. At the same time, the air curtain constraint effectively prevents the scattering and escape of droplets, further improving the spraying efficiency and liquid utilization rate, thereby significantly reducing the foaming rate, increasing the liquid utilization rate, and ensuring the uniform distribution of the liquid on the wet wipe substrate, thus greatly improving the use effect of the wet wipe.

[0022] (2) In the present invention, by adopting low-pressure pre-spraying, the kinetic energy of the droplets is low, and the surfactant molecules in the wet wipe liquid can be arranged orderly on the fiber surface to form a stable liquid film through hydrogen bonds and van der Waals forces, reducing the interfacial energy between the liquid and the fiber, promoting capillary penetration, and using the conductive effect of the polar molecules in the wetting liquid film to neutralize the surface charge of the substrate, eliminating electrostatic repulsion, and preventing the droplets from scattering due to electrostatic repulsion during subsequent spraying, thereby providing a basis for uniform liquid distribution and ensuring the uniform coverage effect of the wet wipe liquid on the substrate.

[0023] (3) In the present invention, by adopting high-pressure post-spraying on the basis of pre-wetting and using kinetic energy conversion, it is possible to drive the liquid to penetrate deep into the substrate interior along the pre-wetting channel, achieving deeper penetration, thereby improving the liquid distribution uniformity. At the same time, since the pre-wetting liquid film has occupied the pores of the substrate, the residual gas is compressed and discharged, which can avoid the formation of bubble residues due to gas compression under high pressure, thus further improving the quality and use effect of the wet wipe.

[0024] (4) In the present invention, during the spraying process, an edge air curtain formed by injecting gas is used. By utilizing the hydrodynamic effect, the droplet trajectory can be constrained. The Coanda effect generated by it makes the air flow along the curved surface of the substrate edge. The escaping droplets are affected by the shear force of the air curtain and change their movement directions, so that they are re-adsorbed into the spraying area. Furthermore, the directional guidance of the air flow to the droplets enhances the contact probability between the liquid and the fibers, improves the effective utilization rate of the intermolecular force, not only reduces liquid waste, but also ensures uniform wetting in the edge area, thereby improving the moisture retention performance and cleaning effect of the wet wipes. Brief Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 is a three-dimensional structure diagram of the spraying device according to the preferred embodiment of the present invention;

[0027] Figure 2 is a semi-sectional front view structure diagram of the spraying box according to the preferred embodiment of the present invention;

[0028] Figure 3 is a semi-sectional side view structure diagram of the spraying box according to the preferred embodiment of the present invention;

[0029] In the figure: 1, equipment frame; 2, conveying roller; 3, spraying box; 31, mounting plate; 311, spraying head; 312, infusion tube; 313, infusion head; 32, mounting rod; 321, connecting rod; 322, air jet head; 323, air delivery head; 4, limiting plate; 5, conical frame; 51, recovery pipe. Detailed Description of the Embodiments

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0031] Many specific details are set forth in the following description in order to provide a thorough understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited by the specific embodiments disclosed below.

[0032] In the description of this application, it should be understood that the orientation or positional relationship indicated by "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the protection scope of this application. In addition, in the description of this invention, unless otherwise specified, the meaning of "several" is two or more.

[0033] In the description of this application, it should be noted that unless otherwise clearly specified and limited, the terms "install", "connect", and "couple" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood through specific circumstances.

[0034] It should be noted that: the raw materials, equipment, reagents, etc. used in this invention can all be obtained through market purchase or by the preparation methods of the existing technology.

[0035] A wet wipe liquid spraying method for wet wipe production, the spraying method is applicable to the spraying operation of degradable environmental protection wet wipes containing natural ingredient wet wipe liquid, and the spraying method includes the following steps:

[0036] S1. Spray the wet wipe liquid onto the surface of the wet wipe substrate at a pressure of 0.15 - 0.25 MPa to achieve pre-wetting spraying;

[0037] S2. After a certain time interval after the low-pressure pre-spraying, spray the remaining total amount of the wet wipe liquid onto the pre-wetted wet wipe substrate at a pressure of 0.6 - 0.8 MPa to achieve post-high-pressure spraying;

[0038] S3. During the pre-wetting spraying and post-high-pressure spraying, spray gas towards the edge of the wet wipe substrate to form an edge air curtain to restrain the droplets.

[0039] In some specific embodiments, the natural ingredient wet wipe liquid contains saponin or polysaccharide components, and the viscosity is 50 - 200 mPa·s; the substrate of the degradable environmental protection wet wipe is one of bamboo fiber, cotton fiber or non-woven fabric, and the porosity of the substrate is 30 - 70%.

[0040] In some specific embodiments, in the step of S1, the duration of the pre-wetting spraying is 1 - 2 s, the droplet size is 80 - 120 μm, and the spraying amount is 15 - 30% of the total spraying amount.

[0041] In some specific embodiments, the spraying distances of pre-wetting spraying and post high-pressure spraying relative to the wet wipe substrate are 10-15 cm, and the spraying interval time between the two is 3-6 s.

[0042] In some specific embodiments, in the step of S2, the duration of post high-pressure spraying is 3-4 s, the droplet size is 20-50 μm, and the spraying amount is 70-85% of the total spraying amount.

[0043] In some specific embodiments, in the step of S3, the jet angle of the gas from the outside to the edge direction of the wet wipe substrate is 15-30°, the air flow pressure is 0.05-0.1 MPa, the air flow velocity is 5-8 m / s, and the distance between the edge of the edge air curtain and the edge of the wet wipe substrate is 0-13 mm.

[0044] To further make the purpose and effect of the present invention simple and easy to understand, the present invention will be further elaborated in combination with examples and comparative examples.

[0045] It should be noted that in the examples and comparative examples, the wet wipe substrate and the wet wipe solution are described as follows:

[0046] Wet wipe substrate: Bamboo fiber non-woven fabric, porosity 47%, gram weight 60 g / m², thickness 1.8 mm, initial humidity: 3.45 kg of water per 100 kg of substrate;

[0047] Wet wipe solution: It includes the following preparation raw materials: saponin extract (purity ≥ 95%) with a mass ratio of 5%, seaweed polysaccharide (molecular weight 10-50 kDa) with a mass ratio of 3%, glycerol with a mass ratio of 2%, water with a mass ratio of 89.8%, and phenoxyethanol with a mass ratio of 0.2%;

[0048] It includes the following preparation steps: 1. Heat water to 40 °C, stir at 200 rpm, slowly add saponin extract, and continuously stir for 30 min until completely dissolved to form a transparent solution; 2. Then add seaweed polysaccharide, raise the temperature to 50 °C, and stir for 1 h until the polysaccharide is fully swollen and dispersed evenly; 3. Cool down to below 30 °C, add glycerol and phenoxyethanol in sequence, and stir for 15 min to mix evenly; 4. Pass through a 200-mesh filter screen, let it stand to defoam, and obtain a wet wipe solution with a viscosity of 120 mPa·s.

[0049] Example 1

[0050] A method for spraying a wet wipe solution for wet wipe production includes the following steps:

[0051] S1. Spray 3 kg of the wet wipe solution onto the surface of the wet wipe substrate at a pressure of 0.2 MPa, a droplet size of 100 μm, and a duration of 1.5 s to achieve pre-wetting spraying;

[0052] S2. After a 5 - second interval following low - pressure pre - spraying, spray 7 kg of wet - wipe liquid onto the pre - wetted wet - wipe substrate surface at a pressure of 0.7 MPa, with a droplet size of 40 μm, for 3.5 s to achieve post - high - pressure spraying.

[0053] S3. During pre - wetting spraying and post - high - pressure spraying, spray gas at a jet angle of 20°, an air - flow pressure of 0.08 MPa, and an air - flow speed of 6 m / s towards the edge of the wet - wipe substrate to form an edge air curtain to confine droplets, and maintain the distance between the edge of the edge air curtain and the edge of the wet - wipe substrate at 5 mm.

[0054] Among them, the spraying distances of pre - wetting spraying and the post - high - pressure spraying relative to the wet - wipe substrate are 12 cm.

[0055] Example 2

[0056] This example is basically the same as Example 1, with the difference that the step of S2 is specifically: after a 3 - second interval following low - pressure pre - spraying, spray 7 kg of wet - wipe liquid onto the pre - wetted wet - wipe substrate surface at a pressure of 0.7 MPa, with a droplet size of 40 μm, for 3.5 s to achieve post - high - pressure spraying.

[0057] Example 3

[0058] This example is basically the same as Example 1, with the difference that the step of S2 is specifically: after a 6 - second interval following low - pressure pre - spraying, spray 7 kg of wet - wipe liquid onto the pre - wetted wet - wipe substrate surface at a pressure of 0.7 MPa, with a droplet size of 40 μm, for 3.5 s to achieve post - high - pressure spraying.

[0059] Example 4

[0060] This example is basically the same as Example 1, with the difference that the step of S3 is specifically: during pre - wetting spraying and post - high - pressure spraying, spray gas at a jet angle of 15°, an air - flow pressure of 0.08 MPa, and an air - flow speed of 6 m / s towards the edge of the wet - wipe substrate to form an edge air curtain to confine droplets, and maintain the distance between the edge of the edge air curtain and the edge of the wet - wipe substrate at 5 mm.

[0061] Example 5

[0062] This example is basically the same as Example 1, with the difference that the step of S3 is specifically: during pre - wetting spraying and post - high - pressure spraying, spray gas at a jet angle of 30°, an air - flow pressure of 0.08 MPa, and an air - flow speed of 6 m / s towards the edge of the wet - wipe substrate to form an edge air curtain to confine droplets, and maintain the distance between the edge of the edge air curtain and the edge of the wet - wipe substrate at 5 mm.

[0063] Example 6

[0064] This example is basically the same as Example 1, the difference is that: the steps of S3 are specifically: during pre-wetting spraying and post-high-pressure spraying, gas is sprayed towards the edge of the wet wipe substrate at a jet angle of 20°, a gas flow pressure of 0.08 MPa, and a gas flow velocity of 6 m / s to form an edge air curtain to restrain droplets, and the edge of the edge air curtain is kept coincident with the edge of the wet wipe substrate.

[0065] Example 7

[0066] This example is basically the same as Example 1, the difference is that: the steps of S3 are specifically: during pre-wetting spraying and post-high-pressure spraying, gas is sprayed towards the edge of the wet wipe substrate at a jet angle of 20°, a gas flow pressure of 0.08 MPa, and a gas flow velocity of 6 m / s to form an edge air curtain to restrain droplets, and the distance between the edge of the edge air curtain and the edge of the wet wipe substrate is 13 mm.

[0067] Comparative Example 1

[0068] A method for spraying wet wipe liquid in wet wipe production includes the following steps:

[0069] S1. 10 kg of wet wipe liquid is sprayed onto the surface of the pre-wetted wet wipe substrate at a pressure of 0.7 MPa, a droplet size of 40 μm, and continuously for 3.5 s to achieve high-pressure spraying;

[0070] S2. During high-pressure spraying, gas is sprayed towards the edge of the wet wipe substrate at a jet angle of 20°, a gas flow pressure of 0.08 MPa, and a gas flow velocity of 6 m / s to form an edge air curtain to restrain droplets, and the distance between the edge of the edge air curtain and the edge of the wet wipe substrate is 5 mm.

[0071] Comparative Example 2

[0072] A method for spraying wet wipe liquid in wet wipe production includes the following steps:

[0073] S1. 7 kg of wet wipe liquid is sprayed onto the surface of the wet wipe substrate at a pressure of 0.7 MPa, a droplet size of 40 μm, and continuously for 3.5 s to achieve pre-high-pressure spraying;

[0074] S2. After a 5 s interval from pre-high-pressure spraying, another 3 kg of wet wipe liquid is sprayed onto the surface of the wet wipe substrate at a pressure of 0.2 MPa, a droplet size of 100 μm, and continuously for 1.5 s to achieve post-low-pressure spraying;

[0075] S3. During pre-high-pressure spraying and post-low-pressure spraying, gas is ejected towards the edge of the wet wipe substrate at a jet angle of 20°, with an air flow pressure of 0.08 MPa and an air flow velocity of 6 m / s to form an edge air curtain to confine droplets, and the distance between the edge of the edge air curtain and the edge of the wet wipe substrate is maintained at 5 mm.

[0076] Comparative Example 3

[0077] This comparative example is basically the same as Example 1, the difference being that: the specific steps of S2 are: 1.5 s after low-pressure pre-spraying, 7 kg of wet wipe liquid is then sprayed onto the pre-wetted wet wipe substrate surface at a pressure of 0.7 MPa and a droplet size of 40 μm for 3.5 s to achieve post-high-pressure spraying.

[0078] Comparative Example 4

[0079] This comparative example is basically the same as Example 1, the difference being that: the specific steps of S2 are: 7 s after low-pressure pre-spraying, 7 kg of wet wipe liquid is then sprayed onto the pre-wetted wet wipe substrate surface at a pressure of 0.7 MPa and a droplet size of 40 μm for 3.5 s to achieve post-high-pressure spraying.

[0080] Comparative Example 5

[0081] This comparative example is basically the same as Example 1, the difference being that there is no edge air curtain confinement in step S3.

[0082] Comparative Example 6

[0083] This comparative example is basically the same as Example 1, the difference being that: the specific steps of S3 are: during pre-wetting spraying and post-high-pressure spraying, gas is ejected towards the edge of the wet wipe substrate at a vertical jet angle, with an air flow pressure of 0.08 MPa and an air flow velocity of 6 m / s to form an edge air curtain to confine droplets, and the distance between the edge of the edge air curtain and the edge of the wet wipe substrate is maintained at 5 mm.

[0084] Comparative Example 7

[0085] This comparative example is basically the same as Example 1, the difference being that: the specific steps of S3 are: during pre-wetting spraying and post-high-pressure spraying, gas is ejected towards the edge of the wet wipe substrate at a jet angle of 35°, with an air flow pressure of 0.08 MPa and an air flow velocity of 6 m / s to form an edge air curtain to confine droplets, and the distance between the edge of the edge air curtain and the edge of the wet wipe substrate is maintained at 5 mm.

[0086] Comparative Example 8

[0087] This comparative example is basically the same as Example 1, and the difference lies in that: the steps of S3 are specifically as follows: during pre-wetting spraying and post-high-pressure spraying, gas is sprayed at a jet angle of 20°, a gas flow pressure of 0.08 MPa, and a gas flow velocity of 6 m / s towards the edge of the wet wipe substrate to form an edge air curtain to restrain droplets, and the distance between the edge of the edge air curtain and the edge of the wet wipe substrate is maintained at 15 mm.

[0088] Performance detection: The wet wipes after spraying the wet wipe liquid in Examples 1-7 and Comparative Examples 1-8 were successively subjected to performance tests on the uniformity of wet wipe liquid distribution, foaming rate, and utilization rate of wet wipe liquid, and the results are shown in Table 1.

[0089] Uniformity of wet wipe liquid distribution: Referring to the test method of liquid content in Article 6.3 of the standard GB / T 27728-2011 "Wet Wipes", 5 wet wipes were taken, cut into 9 zones, and the liquid amount difference in each zone was calculated by the weighing method, and evaluated by the CV value.

[0090] Foaming rate: The sprayed wet wipe was cut into pieces of 10 10 cm in size, weighed and recorded , the wet wipe was cut into pieces and put into a 50 mL centrifuge tube, 40 mL of water was added, sealed and left standing for 5 min, centrifuged at 2000 rpm for 5 min to break and float the bubbles in the wet wipe, carefully pour out the supernatant, collect the wet wipe fragments and liquid remaining at the bottom of the tube, transfer the residue to a filter paper of known mass, dry the surface moisture and then weigh , calculate the liquid mass in the wet wipe:

[0091] ,

[0092] According to the liquid density , calculate the actual liquid volume:

[0093] ,

[0094] Total pore volume of wet wipe Pre-determined by mercury intrusion method, bubble volume:

[0095] ,

[0096] The unit is converted to mL / 100 g of wet wipe to measure the foaming rate.

[0097] Utilization rate of wet wipe liquid: .

[0098] Table 1: Performance test results of Examples 1-7 and Comparative Examples 1-8

[0099]

[0100] As shown in Table 1:

[0101] From the comparison between Example 1 and Comparative Example 1, it can be seen that: when directly impacting the unwetted substrate by single high-pressure spraying, the interfacial tension between the liquid and the fiber is not destroyed, the surfactant molecules cannot be arranged orderly, and the liquid is difficult to penetrate uniformly. Furthermore, when the high-pressure impacts the unwetted area, the residual gas is compressed to form bubble nuclei, and the electrostatic repulsion causes the droplets to scatter. Although there is an air curtain constraint, the problems of uneven liquid distribution and bubble residue cannot be solved.

[0102] From the comparison between Example 1 and Comparative Example 2, it can be seen that: when the high-pressure liquid flow directly impacts the dry substrate first, the kinetic energy of the surfactant molecules is too high to form a stable liquid film, resulting in the liquid accumulating on the surface layer and insufficient deep penetration. The subsequent low-pressure spraying cannot effectively drive the liquid deep into the pores, but instead exacerbates the droplet scattering and reduces the efficiency of the air curtain constraint. As a result, the distribution uniformity (CV value 14.3 %), the foaming rate (12.5 mL / 100g), and the utilization rate (72.1%) are all much lower than those in Example 1.

[0103] From the comparison between Examples 1-3 and Comparative Examples 3 and 4, it can be seen that: when the interval time after pre-spraying is too short and the subsequent high-pressure spraying is carried out directly, the pre-wetted liquid film is not fully stabilized, the residual gas is not completely discharged, and the bubbles are compressed and retained during the high-pressure post-spraying, resulting in an increase in the foaming rate (8.3 mL / 100g). Moreover, when the interval time is too long, the pre-wetted liquid film is partially dried, and the secondary interfacial tension is locally formed, hindering the liquid penetration, so it is difficult to maintain the performance.

[0104] From the comparison between Example 1 and Comparative Example 5, it can be seen that: when there is no air curtain constraint, the droplets scatter to non-target areas due to impacts and air flow disturbances, etc., resulting in insufficient wetting at the edges and a decrease in the liquid utilization rate. At the same time, the scattered droplets volatilize in the air, leading to unstable composition and exacerbating bubble formation.

[0105] From the comparison between Examples 1, 4, and 5 and Comparative Examples 6 and 7, it can be seen that: when there is no air curtain constraint, for the edge air curtain formed by the vertical jetting angle, the air flow conflicts with the movement direction of the droplets, easily causing the escaped droplets not to be adsorbed back to the spraying area, resulting in insufficient liquid volume at the edges. Moreover, with too large a jetting angle, the coverage range of the air flow is dispersed, the Coanda effect is weakened, and the droplet trajectory constraint efficiency is reduced.

[0106] From the comparison between Examples 1, 6, and 7 and Comparative Example 8, it can be seen that: when the distance between the outer edge of the air curtain and the outer edge of the substrate is too large, the escaped droplets exceed the air curtain constraint range and cannot be adsorbed back to the spraying area, resulting in uneven liquid volume in the edge area and exacerbating the component separation due to the volatilization of the droplets in the air.

[0107] As Figure 1As shown in the figure, the present invention provides a spraying device for a wet wipe liquid spraying method in wet wipe production, including: a device frame 1, a plurality of conveying rollers 2 rotatably connected to the top of the device frame 1, and two spraying boxes 3 fixedly segmented on the top of the device frame 1; a spraying mechanism and a jetting mechanism are arranged inside both of the two spraying boxes 3. The spraying mechanism is used to perform pre-wetting spraying and post-high-pressure spraying on the wet wipe substrate respectively, and the jetting mechanism is used to perform droplet constraint on the edge of the wet wipe substrate during pre-wetting spraying and post-high-pressure spraying; a power mechanism for driving the plurality of conveying rollers 2 to rotate synchronously is installed on the device frame 1.

[0108] It should be noted that the power mechanism is a structure for rotational power transmission, at least including a servo motor providing rotational power, and a power transmission structure located at the output end of the servo motor and one end of the plurality of conveying rollers 2. The power transmission structure is one of belt transmission, synchronous belt transmission or sprocket transmission, which belongs to the common knowledge in the art. Therefore, the control method and specific structure are not explained in detail in this application and will not be elaborated here; the device frame 1 is the support structure of the entire spraying device, and the plurality of conveying rollers 2 are rotatably connected to the top of the device frame 1 for conveying the wet wipe substrate. The power mechanism drives the synchronous rotation of the conveying rollers 2, thereby driving the wet wipe substrate to move on the device, so that pre-wetting spraying and post-high-pressure spraying can be respectively performed on the wet wipe substrate through the two spraying boxes 3, and droplet constraint operation can be performed on the edge of the wet wipe substrate during pre-wetting spraying and post-high-pressure spraying.

[0109] As Figure 2 and Figure 3 As shown in the figure, in some specific embodiments, the spraying mechanism includes: a plurality of mounting plates 31 fixed inside the spraying box 3, a plurality of spraying heads 311 mounted on the mounting plates 31, and an infusion pipe 312 fixed on the tops of the plurality of spraying heads 311; an infusion head 313 for externally connecting an infusion device to supply wet wipe liquid is installed on the top of the infusion pipe 312.

[0110] It should be noted that the plurality of mounting plates 31 are evenly distributed in a linear array along the traveling direction of the wet wipe substrate, and the plurality of spraying heads 311 are evenly distributed in a linear array along the length direction of the mounting plates 31; the plurality of mounting plates 31 are fixed inside the spraying box 3 to provide an installation basis for the spraying heads 311. The infusion pipe 312 is fixed on the tops of the plurality of spraying heads 311, and the infusion head 313 is installed on the top of the infusion pipe 312 to externally connect an infusion device to supply wet wipe liquid. The wet wipe liquid enters the infusion pipe 312 through the infusion head 313, and then is distributed to each spraying head 311. The spraying heads 311 perform pre-wetting spraying and post-high-pressure spraying on the wet wipe substrate according to predetermined spraying parameters, so that the wet wipe substrate can uniformly absorb the wet wipe liquid and achieve the required spraying effect.

[0111] In some specific embodiments, the jetting mechanism includes: a plurality of mounting rods 32 fixed inside the spraying tank 3, a plurality of connecting rods 321 disposed at the bottom of the mounting rods 32, and a plurality of jetting nozzles 322 disposed on one side of the plurality of connecting rods 321; a gas delivery head 323 for externally connecting a gas delivery device to achieve gas supply is installed at the top end of the jetting nozzle 322, and both ends of the connecting rod 321 are connected to the mounting rod 32 and the jetting nozzle 322 respectively through pipe clamps to achieve adjustment of the jetting direction of the jetting nozzle 322.

[0112] It should be noted that the number of jetting nozzles 322 is the same as that of the connecting rods 321, and the plurality of connecting rods 321 are uniformly distributed in a linear array; the plurality of mounting rods 32 are fixed inside the spraying tank 3 to provide a mounting basis for the connecting rods 321 and the jetting nozzles 322. The connecting rods 321 are disposed at the bottom of the mounting rods 32, and the jetting nozzles 322 are disposed on one side of the plurality of connecting rods 321. Both ends of the connecting rod 321 are connected to the mounting rod 32 and the jetting nozzle 322 respectively through pipe clamps. By adjusting the pipe clamps, the jetting direction of the jetting nozzle 322 can be adjusted. The gas delivery head 323 is installed at the top end of the jetting nozzle 322, and a gas delivery device is externally connected to achieve gas supply; during pre-wetting spraying and post-high-pressure spraying, the jetting nozzles 322 eject gas to form an air curtain at the edge of the wet wipe substrate, realizing droplet constraint, preventing the wet wipe liquid from overflowing at the edge of the wet wipe substrate, and ensuring the uniformity and quality of spraying.

[0113] In some specific embodiments, a limiting plate 4 for preventing deviation during the conveyance of the wet wipe substrate is fixed to the side surface of the spraying tank 3, and conical frames 5 for recovering the wet wipe liquid are installed at the bottoms of the equipment frame 1 and the spraying tank 3. A recovery pipe 51 is fixed to the bottom of the conical frame 5.

[0114] It should be noted that the limiting plate 4 is made of polytetrafluoroethylene (PTFE) and has a smooth surface to reduce friction. It is installed on the inlet and outlet sides of the spraying tank 3, 2 - 3 mm away from the edge of the substrate, to guide the substrate to be conveyed centered; the conical frames 5 at the bottoms of the equipment frame 1 and the spraying tank 3 use gravity to collect the wet wipe liquid into the recovery pipe 51, accelerating the liquid reflux collection, guiding the recovered wet wipe liquid to a designated recovery device, realizing the recycling of the wet wipe liquid, and reducing resource waste and environmental pollution.

[0115] Based on the above enlightenment of the ideal embodiments of the present invention, through the above description, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0116] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A wet wipe liquid spraying method for wet wipe production, characterized in that, The spraying method is applicable to the spraying operation of degradable and environmentally friendly wet wipes containing wet wipe liquid with natural ingredients. The spraying method includes the following steps: S1. Spray the wet wipe liquid onto the surface of the wet wipe substrate at a pressure of 0.15 - 0.25 MPa to achieve pre-wetting spraying; S2. After a certain time interval after the low-pressure pre-spraying, spray the remaining total amount of the wet wipe liquid onto the pre-wetted wet wipe substrate at a pressure of 0.6 - 0.8 MPa to achieve post-high-pressure spraying; S3. During the pre-wetting spraying and the post-high-pressure spraying, spray gas onto the edge of the wet wipe substrate to form an edge air curtain to confine the droplets; Among them, the viscosity of the wet wipe liquid with natural ingredients is 50 - 200 mPa·s; the porosity of the substrate of the degradable and environmentally friendly wet wipes is 30 - 70%; the spraying interval time between the pre-wetting spraying and the post-high-pressure spraying is 3 - 6 s; the jet angle of the gas from the outside to the edge direction of the wet wipe substrate is 15 - 30°, and the distance between the edge of the edge air curtain and the edge of the wet wipe substrate is 0 - 13 mm.

2. A wet wipe liquid spraying method for wet wipe production according to claim 1, characterized in that: The wet wipe liquid with natural ingredients contains saponin or polysaccharide components; the substrate of the degradable and environmentally friendly wet wipes is one of bamboo fiber, cotton fiber or non-woven fabric.

3. A method for spraying wet wipe liquid in the production of wet wipes according to claim 1, characterized in that: In the step of S1, the duration of the pre-wetting spraying is 1 - 2 s, the droplet size is 80 - 120 μm, and the spraying amount is 15 - 30% of the total spraying amount.

4. A wet wipe liquid spraying method for wet wipe production according to claim 1, characterized in that: The spraying distances of the pre-wetting spraying and the post-high-pressure spraying relative to the wet wipe substrate are 10 - 15 cm.

5. A wet wipe liquid spraying method for wet wipe production according to claim 1, characterized in that: In the step of S2, the duration of the post-high-pressure spraying is 3 - 4 s, the droplet size is 20 - 50 μm, and the spraying amount is 70 - 85% of the total spraying amount.

6. A wet wipe liquid spraying method for wet wipe production according to claim 1, characterized in that: In the step of S3, the air flow pressure of the gas from the outside to the edge direction of the wet wipe substrate is 0.05 - 0.1 MPa, and the air flow speed is 5 - 8 m / s.

7. A spraying device for the wet wipe liquid spraying method for producing wet wipes according to any one of claims 1-6, characterized in that, Including: An equipment frame, several conveying rollers rotatably connected to the top of the equipment frame, and two spraying boxes fixedly segmented on the top of the equipment frame; Spraying mechanisms and air jetting mechanisms are arranged inside both of the two spraying boxes. The spraying mechanisms are used to respectively achieve pre-wetting spraying and post-high-pressure spraying on the wet wipe substrate, and the air jetting mechanisms are used to confine the droplets at the edge of the wet wipe substrate during the pre-wetting spraying and the post-high-pressure spraying; a power mechanism for driving several of the conveying rollers to rotate synchronously is installed on the equipment frame.

8. The spraying device for the wet wipe liquid spraying method in wet wipe production according to claim 7, wherein: The spraying mechanism includes: several mounting plates fixed inside the spraying box, several spraying heads mounted on the mounting plates, and an infusion pipe fixed on the tops of several of the spraying heads; an infusion head for externally connecting an infusion device to supply the wet wipe liquid is installed on the top of the infusion pipe.

9. The spraying device for the wet wipe liquid spraying method in wet wipe production according to claim 7, characterized in that: The air jetting mechanism includes: several mounting rods fixed inside the spraying box, several connecting rods arranged at the bottoms of the mounting rods, and several air jetting heads arranged on one side of several of the connecting rods; an air supply head for externally connecting an air supply device to supply gas is installed at the top end of the air jetting head, and both ends of the connecting rod are respectively connected to the mounting rod and the air jetting head through pipe clamps for adjusting the jetting direction of the air jetting head.

10. The spraying device for the wet wipe liquid spraying method in the production of wet wipes according to claim 7, wherein: A limiting plate for preventing deviation during the conveyance of the wet wipe substrate is fixed to the side of the spraying box. Conical frames for recovering the wet wipe liquid are installed at the bottoms of both the equipment frame and the spraying box, and a recovery pipe is fixed to the bottom of the conical frame.

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