A dry runner and a preparation method and application thereof

Abstract

The present application relates to the technical field of kitchen appliances, in particular to a drying rotating wheel, a preparation method and application thereof. The drying rotating wheel has a wheel structure formed by rolling a flexible web. The flexible web comprises a flexible substrate and a moisture absorbing layer. The moisture absorbing layer is formed by coating a moisture absorbing slurry containing a temperature-sensitive polymer on the surface of the flexible substrate. By coating the temperature-sensitive polymer on the surface of the flexible substrate and rolling it into a wheel, the present application significantly improves the dehumidification efficiency of the drying assembly of the dishwasher, shortens the drying time, and significantly reduces the regeneration temperature of the drying assembly, thereby reducing the regeneration energy consumption.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of kitchen appliances, in particular to a drying rotating wheel, a preparation method and application thereof. BACKGROUND

[0002] After the washing program of the dishwasher ends, the cleaning inner tank needs to be dried to avoid moisture returning to the dishwasher, leading to a series of problems such as bacterial growth and odor production.

[0003] The existing drying technology of the dishwasher is mainly hot air drying technology, that is, hot air is generated by blowing through a heating module by a fan and blown into the inner tank to dry the dishes and the inner tank. This method can easily bring dust and bacteria in the air into the inner tank of the dishwasher to contaminate the dishes, and the hot air drying process takes a long time.

[0004] In order to improve the dehumidification efficiency, researchers designed an open-door drying method, that is, the dishwasher cabinet door is automatically opened by about 30° during the drying stage. This drying method can completely remove the moisture, but it needs to be manually closed again, which is not good for the user experience, and insects and dust can easily enter.

[0005] In view of the problems of low dehumidification efficiency and long drying time of the existing dishwasher, CN108968876A proposes a movable moisture absorbing wheel device. The moisture absorbing wheel is rotatably arranged at a position opposite to the communication port of the cleaning cavity of the dishwasher, and the different parts of the moisture absorbing body are opposite to the communication port through movement. Through this structural design, the water vapor can quickly contact different parts of the moisture absorbing body, avoiding the water vapor contacting the parts of the moisture absorbing body that have completed adsorption and have weak adsorption capacity for a long time, thereby improving the diffusion rate of the water vapor on the moisture absorbing body, realizing the rapid adsorption of the water vapor by the moisture absorbing body, and improving the drying effect of the dishwasher.

[0006] However, the moisture absorbing wheel is made of physical adsorption material, specifically silica gel activated alumina, activated carbon or molecular sieve material. Since the regeneration desorption temperature of such moisture absorbing material is relatively high, usually reaching 150℃, the regeneration energy consumption is large. In addition, the bonding strength of the inorganic substance and the base material is not ideal, which is easy to fall off and cause failure. SUMMARY

[0007] In a first aspect, the present application provides a drying rotating wheel which not only has high dehumidification efficiency and greatly shortens the drying time, but also can realize regeneration at a lower temperature, thereby reducing the regeneration energy consumption of the moisture absorbing material. At the same time, the drying rotating wheel also has good mechanical properties and better durability.

[0008] The drying rotating wheel provided by the present application has a wheel-shaped structure formed by rolling a flexible web. The flexible web includes a flexible base material and a moisture absorbing layer. The moisture absorbing layer is formed by coating a moisture absorbing slurry containing a temperature-sensitive polymer on the surface of the flexible base material.

[0009] The present application is found by screening the existing hygroscopic material that the temperature-sensitive polymer has the characteristics of hydrophilic-hydrophobic transition at a certain temperature, so that the effect of water absorption and drying inner container and dehydration regeneration can be achieved at a certain temperature. However, it is difficult to directly replace molecular sieve because the synthesis process of temperature-sensitive polymer is difficult and the use cost is high.

[0010] Therefore, the present application proposes to fix the temperature-sensitive polymer on the surface of the base material by coating to make a composite roll, and then roll the roll into a wheel, which reduces the use cost of the temperature-sensitive polymer, realizes the new application of the temperature-sensitive polymer as a hygroscopic material, and solves the problems of large regeneration energy consumption and poor combination of physical adsorption materials such as molecular sieve. In addition, the obtained drying runner can also realize water absorption and dehumidification under cold wind, and regeneration dehydration at a lower temperature (<60℃).

[0011] Further, the diameter of the drying runner is 50mm-400mm; and the thickness is 10mm-100mm. In specific implementation, the diameter of the drying runner is preferably 15-20cm, and the thickness is 2-5cm. By reasonably controlling the size ratio of the wheel structure, the drying runner is better applied to the internal space size of the dishwasher under the premise of ensuring the dehumidification efficiency. For example, for the gap between the side plate and the door plate of the dishwasher, the runner with a diameter of 15cm and 20cm and a thickness of 2cm is selected; for the base of the dishwasher, the runner with a diameter of 15cm and a thickness of 3-5cm can be selected.

[0012] Further, in the process of making the flexible roll, it is found that the thickness of the base material affects the number of roll-up turns, and then affects the load of the high-temperature-sensitive polymer. The thinner the base material, the more the number of roll-up turns, and under the condition of a certain diameter of the runner, the more the load of the temperature-sensitive polymer, which is beneficial to improve the dehumidification effect, but the base material is too thin, which will affect the service life and effect of the runner. Therefore, the present application proposes to control the thickness of the flexible base material to be 0.1mm-5mm, so as to optimize the size of the base material and take into account the dehumidification efficiency and the durability of the drying runner.

[0013] Further, increasing the load of the temperature-sensitive polymer will certainly help to improve the dehumidification effect, but the present application finds that based on the limitation of the coating process, the coating is too thick, which will reduce the combination performance of the hygroscopic layer and the base material, and will also increase the diameter of the runner, which is not suitable for placing in the dishwasher with small internal space. Therefore, the present application controls the thickness of the hygroscopic layer to be 0.01mm-1mm.

[0014] Preferably, the thickness ratio of the hygroscopic layer to the flexible base material is 0.7-1:1; by reasonably controlling the size relationship between the hygroscopic layer and the base material, the relationship between the hygroscopic material content and the size of the drying runner is further optimized, and the dehumidification efficiency is improved.

[0015] The flexible substrate of the present application can be selected from substrates with certain rigidity and strength index characteristics, which can be used to prepare a drying roller, such as asbestos fiber paper, glass fiber, carbon fiber paper or ceramic fiber.

[0016] The temperature-sensitive polymer is selected from one or more of poly-N-isopropyl acrylamide, polyvinyl ether, polyethylene glycol, polypropylene glycol, polymethacrylic acid, polyvinyl alcohol, polyvinyl pyrrolidone, methyl cellulose, hydroxymethyl cellulose, polyphosphazene derivatives, poly-N-vinyl caprolactam or polyethylene. The above-mentioned temperature-sensitive polymer has high water absorption, and can be dehydrated at a lower temperature (<60℃), thereby achieving the effects of cold air drying and low-temperature regeneration.

[0017] Further, in order to ensure that the temperature-sensitive polymer forms a firm moisture absorption layer on the surface of the substrate, the slurry should also contain a cross-linking agent and a curing agent. Moreover, during the coating process, the present application finds that the addition ratio of the cross-linking agent and the curing agent affects the concentration of the slurry and the coating effect. If the amount of the additive is too much, the coating layer is thick, which is not conducive to improving the dehumidification effect; if the amount of the additive is too little, the moisture absorption layer has poor adhesion to the substrate, which affects the service life of the drying roller; therefore, the present application controls the mass ratio of the cross-linking agent, the curing agent and the temperature-sensitive polymer to be (1-10):(0.05-1):(100-500). By adjusting the ratio of the cross-linking agent, the curing agent and the temperature-sensitive polymer, the thickness of the moisture absorption layer is moderate, the adhesion to the substrate is good, and the moisture absorption layer also has certain durability. Preferably, the mass ratio of the cross-linking agent and the curing agent is (3-5):(0.06-0.1), and the mass ratio of the cross-linking agent and the temperature-sensitive polymer is (3-5):(150-300).

[0018] The cross-linking agent is selected from one or more of a silane coupling agent, isocyanate, glutaraldehyde, acrylate or epoxy resin.

[0019] The curing agent is selected from one or more of benzoyl peroxide, azobisisobutyronitrile or potassium persulfate.

[0020] As a specific embodiment of the present application, the moisture absorption slurry is composed of the following components by weight percentage: 30-35wt% of the temperature-sensitive polymer polyvinyl ether, 1-2wt% of the cross-linking agent (composed of a silane coupling agent and epoxy resin in a mass ratio of 1:3), 0.4-0.6wt% of the curing agent benzoyl peroxide, and the balance is ethanol.

[0021] Further, the present application finds that, in order to shorten the preparation time and improve the solubility and dispersibility of the material, the solvent used in the slurry is also optimized. Preferably, the solvent is one or more of ethanol, methanol or acetone.

[0022] In a second aspect, the application provides a preparation method of the drying roller, comprising:

[0023] forming a moisture absorption layer on the surface of the flexible substrate by coating the moisture absorption slurry containing the temperature-sensitive polymer to obtain the flexible coiled material;

[0024] coiling the flexible coiled material into a wheel structure.

[0025] Compared with physical adsorption materials such as molecular sieves, the temperature-sensitive polymer has the temperature response characteristics of molecular chain expansion and contraction with temperature change, and thus has the hydrophilic-hydrophobic phase change characteristics, which can reduce the regeneration energy consumption. However, the synthesis process of the temperature-sensitive polymer is difficult and the cost is high, so it is difficult to directly replace the molecular sieve. Therefore, the application reduces the use cost of the temperature-sensitive polymer by the above coating method and coiling into a wheel, simplifies the use process, and realizes the application of the temperature-sensitive polymer as a moisture absorption material in the drying assembly of the dishwasher, thereby significantly reducing the regeneration energy consumption of the moisture absorption material while ensuring the dehumidification efficiency.

[0026] The coating method of the application is film scraping by a film scraper or coating by a coating machine. In order to ensure that the slurry can form a uniform, dense and firm and relatively thin coating on the surface of the substrate, the following methods can be used in the specific coating process: the moisture absorption slurry containing the temperature-sensitive polymer is placed on the surface of the substrate, and a solid metal magnet bar is used to uniformly hang the film; wherein the size of the solid metal magnet bar is 15-30 mm in diameter and 10-100 cm in length, and the weight of the magnet bar is directly related to the thickness of the film.

[0027] Preferably, in the specific film hanging process, after being scraped twice, it is dried in a 60℃ oven, and then scraped twice again. After 10 times of film scraping-drying cycles, it is dried at 80-85℃. By using the cycle method of film scraping-drying, the composite strength of the moisture absorption layer and the substrate is improved, which is more conducive to improving the moisture absorption effect.

[0028] Further, the application finds that when the loading amount of the temperature-sensitive polymer material is high, the dehumidification effect is good, but the regeneration is not complete, the moisture absorption efficiency is reduced, and the like, thereby affecting the bonding performance of the moisture absorption layer and the substrate, and the moisture absorption layer is prone to shrinkage, expansion and bubbling, which causes the deformation of the substrate and affects the moisture absorption effect of the roller. Therefore, on the basis of selecting a substrate with certain rigidity and strength index characteristics for preparing the drying roller, the application further proposes to perform acid or alkali treatment on the substrate to generate chemical active groups on the surface of the substrate and have the characteristics of chemical reactivity, so that the temperature-sensitive polymer material can be as firmly loaded as possible on the surface of the substrate, which helps to improve the dehumidification effect and the service life of the drying roller.

[0029] In a third aspect, the application provides the application of the drying roller in a household appliance with dehumidification function.

[0030] Specifically, the drying roller provided by the application can be used in various household appliances with dehumidification function requirements, such as dishwashers, dryers, storage cabinets, dehumidifiers and the like. The household appliances containing the drying roller can not only greatly improve the dehumidification effect and shorten the dehumidification time, but also significantly reduce the regeneration energy consumption of the hygroscopic material, and are more energy-saving and environment-friendly.

[0031] In a fourth aspect, the application provides a dishwasher provided with the drying roller provided by the application, so that the regeneration can be realized at a lower temperature, the energy consumption of the dishwasher is greatly reduced, the dehumidification efficiency of the dishwasher is improved, and the drying time is greatly shortened.

[0032] The application has the following beneficial effects:

[0033] The application realizes the application of the temperature-sensitive polymer as the hygroscopic material in the dishwasher by fixing the temperature-sensitive polymer on the surface of the base material in the form of coating to prepare a composite roll, and then rolling the roll into a roller. The drying roller not only has a high dehumidification efficiency and significantly shortens the dehumidification time, but also greatly reduces the regeneration energy consumption. At the same time, by optimizing the size structure, slurry formula and coating process of the drying roller, the dehumidification efficiency is improved, the mechanical properties of the drying roller are ensured, the durability of the drying roller is improved, and the drying roller is more practical. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The structure diagram of the drying roller described in Example 1.

[0035] Figure 2 The internal structure diagram of the dishwasher using the drying roller described in the application. DETAILED DESCRIPTION

[0036] The following examples are used to illustrate the application, but not to limit the scope of the application.

[0037] Example 1

[0038] The example provides a drying roller, which has a wheel structure formed by rolling a flexible roll; wherein:

[0039] The flexible roll includes a hygroscopic layer and a flexible base material; the hygroscopic layer is formed by coating a hygroscopic slurry on the surface of the flexible base material, and the hygroscopic slurry contains a temperature-sensitive polymer.

[0040] The specific structure of the drying roller is shown in Figure 1 .

[0041] The material of the flexible base material is fiber paper, the width of the fiber paper is 50 cm, and the thickness is 0.5 mm.

[0042] The temperature-sensitive polymer is polyvinyl methyl ether, and the thickness of the moisture absorption layer formed is 0.5 mm; the thickness ratio of the moisture absorption layer to the fiber paper is 1:1.

[0043] The diameter of the wheel-shaped structure is 30 cm, and the thickness is 4 cm.

[0044] The embodiment also provides a preparation method of the above-mentioned drying roller, comprising the following steps:

[0045] (1) 30wt% of temperature-sensitive polymer polyvinyl methyl ether, 1wt% of crosslinking agent (consisting of silane coupling agent and epoxy resin in a mass ratio of 1:3), and 0.5wt% of curing agent benzoyl peroxide are dissolved in solvent ethanol to obtain a moisture absorption slurry;

[0046] (2) The moisture absorption slurry is uniformly coated on a flexible substrate fiber paper sheet, and a magnetic rod with a diameter of 2 cm and a length of 10 cm is used for film scraping, and after every 2 times of scraping, it is placed in a 60°C oven for drying for 5 min, and then scraped for two more times. After 10 times of film scraping-drying, it is dried at 80°C to obtain a composite flexible roll, which is further rolled into a wheel-shaped structure.

[0047] Example 2

[0048] The embodiment provides a drying roller, which is different from the drying roller of example 1 in that the temperature-sensitive polymer is poly-N-isopropyl acrylamide.

[0049] Example 3

[0050] The embodiment provides a drying roller, which is different from the drying roller of example 1 in that the thickness of the moisture absorption layer is 0.1 mm.

[0051] Example 4

[0052] The embodiment provides a drying roller, which is different from the drying roller of example 1 in that the coating conditions are different, specifically, a magnetic rod with a diameter of 3 cm and a length of 15 cm is used for film scraping.

[0053] Example 5

[0054] The embodiment provides a dishwasher, wherein the moisture absorption module is provided with the drying roller of example 1.

[0055] The drying roller RW obtained in example 1 and the air inlet system HT are arranged on the dishwasher in a manner as shown in the figure: Figure 2 RW-drying roller, LK-roller and driving device connection belt, SP-driving device, PU-pump, HT-hot air drying system, ND-inner container, BK-bowl basket, WK-outer shell.

[0056] After the end of the washing program, the inner tank is full of water mist, at this time, the demisting program is started, and the HT starts to run to blow into the ND. The wind blown by the HT stirs the water vapor to be transported into the RW through the ND connecting port;

[0057] The RW starts to rotate at a speed of 20 r / min under the driving of the SP shaft through the LK connection to absorb water vapor. The RW is internally provided with another heating element for drying and regenerating the runner, so that the runner can continuously adsorb the moisture in the inner tank, and after 40 min, the ND is completely dried. After drying, the humidity in the inner tank is 30-40%, which meets the standard.

[0058] Comparative Example 1

[0059] The traditional hot air drying technology of the dishwasher is used, and the drying time required to reach the same drying degree (humidity of 30-40%) is 90-120 min. It can be seen that the hot air drying technology has low dehumidification efficiency and incomplete dehumidification.

[0060] Comparative Example 2

[0061] The dishwasher using the existing molecular sieve drying technology is tested, and the drying time required to reach the same drying degree (humidity of 30-40%) is 30-40 min. It can be seen that the dehumidification efficiency of the molecular sieve drying technology is higher, but the regeneration desorption thereof needs to use hot air at about 150°C, which has high energy consumption.

[0062] Comparative Example 3

[0063] This comparative example provides a drying runner, which is different from Example 1 in that the thickness ratio of the moisture absorption layer to the flexible substrate is too small; specifically, the thickness of the substrate is 1 mm. The thickness ratio of the moisture absorption layer to the flexible substrate is 0.5:1.

[0064] The same test experiment as Example 1 is used, and the results show that the dehumidification effect is not ideal in the same time, and the specific performance is that small water droplets can be seen on the inner tank wall of the dishwasher.

[0065] Comparative Example 4

[0066] This comparative example provides a preparation of a drying runner, which is different from Example 1 in that the thickness of the moisture absorption layer and the thickness ratio thereof to the substrate are too large, specifically 2:1.

[0067] The same test experiment as Example 1 is used, and the results show that the dehumidification effect is not ideal in the same time, and the specific performance is that the moisture absorption layer is excessively expanded, which causes the runner gap to become small and affects the adsorption performance.

[0068] Comparative Example 6

[0069] The comparative example 1 provides a preparation of a dry rotating wheel, which is different from the example 1 in that the slurry formula is different, specifically, 40wt% of temperature-sensitive polymer polyethylene glycol, 1.5wt% of crosslinking agent bisacrylamide, and 0.6wt% of curing agent benzoyl peroxide are dissolved in solvent methanol to obtain a hygroscopic slurry;

[0070] The same test experiment as in example 1 is adopted, and the results show that the regeneration temperature of the hygroscopic material is too high, the hygroscopic effect is not ideal, and there are still small water droplets in the inner container.

[0071] Comparative example 7

[0072] The comparative example 1 provides a preparation of a dry rotating wheel, which is different from the example 1 in that the coating process conditions are different, specifically, the slurry is spread on the surface of the substrate, a magnetic rod with a diameter of 3cm and a length of 10cm is used to scrape the film, and after 10 times of continuous scraping, it is dried at 80 degrees.

[0073] The same test experiment as in example 1 is adopted, and the results show that the hygroscopic effect is not ideal, there are still small water droplets in the inner container, and the moisture adsorption amount of the rotating wheel is reduced.

[0074] Although the present application has been described in detail with general description and specific embodiments above, some modifications or improvements can be made on the basis of the present application, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the present application, all belong to the scope of the present application.

Claims

1. A drying impeller, characterized in that, It has a wheel-shaped structure formed by rolling up a flexible roll material; the flexible roll material includes a flexible substrate and a moisture-absorbing layer. The moisture-absorbing layer is formed by coating the surface of the flexible substrate with a moisture-absorbing slurry containing a temperature-sensitive polymer; the temperature-sensitive polymer is selected from one or more of poly(N-isopropylacrylamide) and polyvinyl methyl ether; the coating process adopts a scraping-drying cycle; the thickness of the flexible substrate is 0.1 mm to 5 mm; the thickness ratio of the moisture-absorbing layer to the flexible substrate is 0.7 to 1:

1.

2. The drying impeller according to claim 1, characterized in that, The diameter of the drying wheel is 50mm-400mm, and the thickness of the drying wheel is 10mm-100mm.

3. The drying impeller according to claim 2, characterized in that, The diameter of the drying wheel is 15-20cm and the thickness is 2-5cm.

4. The drying impeller according to claim 3, characterized in that, The thickness of the moisture-absorbing layer is 0.01mm-1mm.

5. The drying impeller according to claim 4, characterized in that, The flexible substrate is asbestos fiber paper, glass fiber, carbon fiber paper, or ceramic fiber.

6. The drying impeller according to claim 5, characterized in that, The slurry also includes a crosslinking agent and a curing agent; The mass ratio of the crosslinking agent, curing agent and temperature-sensitive polymer is (1-10):(0.05-1):(100-500).

7. The method for preparing the drying rotor according to any one of claims 1-6, characterized in that, include: The flexible roll material is obtained by coating a moisture-absorbing slurry containing a temperature-sensitive polymer onto the surface of a flexible substrate to form a moisture-absorbing layer. The flexible roll material is rolled into a wheel-shaped structure.

8. The preparation method according to claim 7, characterized in that, The coating method is either film scraping with a film scraper or coating with a coating machine; Alternatively, the substrate may be treated with acid or alkali, resulting in chemically active groups on its surface and exhibiting chemical reactivity.

9. The application of the drying rotor according to any one of claims 1-6 in a household appliance with dehumidification function.

10. A dishwasher, characterized in that, The device is equipped with a drying impeller as described in any one of claims 1-6.

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