KR20220125053A - Eco-friendly face mask with an electrostatic thin film filter module and manufacturing process of the same - Google Patents

Abstract

The present invention relates to an air purifying mask which is eco-friendly and has improved filtration performance, and a manufacturing method thereof. The mask of the present invention is a pulp-based air mask manufactured by mounting a filter module which is manufactured by laminating various functional thin films such as a thin film with static electricity. Through the electrostatic effect, the mask can effectively filter ultra-fine particles such as yellow dust, fine dust, and infectious droplets or aerosols.

Description

Eco-friendly face mask with an electrostatic thin film filter module and manufacturing process of the same}

The present invention relates to a mask made of an eco-friendly material for purifying air by blocking ultra-fine particles such as fine dust and aerosols in the air. It relates to an air purifying mask manufactured by attaching a thin-film electrostatic filter module to an air purifier and a method for manufacturing the same.

With the development of industry, air pollution in residential areas as well as industrial areas is becoming more serious due to urban concentration and the rapid spread of automobiles. to be. The reality is that such fine dust and air pollution greatly increase the frequency of respiratory and skin-related diseases such as colds, bronchitis, and atopic dermatitis.

In addition, in recent years, due to the worldwide spread and spread of the coronavirus, the number of confirmed cases of the coronavirus at home and abroad has increased significantly, and the death of people with underlying diseases is also increasing proportionally. The possibility of the spread of the infection is higher than ever.

Accordingly, various air purification devices to purify the air are rapidly spreading to various large buildings, industrial sites, as well as general households, and various types of masks are provided to prevent inhalation of ultrafine dust when going out.

The air purifier or mask above must necessarily include an air filter to filter out ultra-fine dust. Conventional air filters are simply manufactured to have fine pores so that air can pass through, but dust over a certain size cannot pass through. It is generally configured so that the filtration performance is determined according to the pore size.

Therefore, the smaller the pore size of the air filter is, the more fine dust can be filtered out. There are disadvantages.

In addition, when the pores of the air filter become smaller, the filtration performance of filtering out dust increases, but the air permeability is lowered, which causes a problem in that the usability is deteriorated. For example, when a mask is made with an air filter with very small pores, it becomes very difficult for a user wearing the mask to breathe, so it is inconvenient to wear the mask for a long time.

An electrostatic air filter that attracts and filters fine dust using static electricity to solve the above problems, that is, to increase the filtration performance while maintaining the size of the pores above a certain size (Republic of Korea Patent No. 10-0310274) has been proposed Since the conventional air filter has pores of 20 to 30 μm, it is impossible to remove fine dust. Therefore, when such a conventional air filter is used, not only the dust flows out at the beginning of operation, but also the dust remains on the filter surface even after exhaustion. This happens frequently. The electrostatic air filter is configured so that static electricity is generated in the fibers when the filter fiber is manufactured, so that even fine dust smaller than the pores of the fiber fabric is blocked by static electricity to filter out fine dust, that is, even if the pores are not very small. There are advantages to being able to

However, in order to manufacture the conventional electrostatic air filter as described above, the process of fusing the plastic non-woven resin and the corona discharge process are essential, so the manufacturing process is not simple, the production facility investment burden is high, and the manufacturing cost is somewhat high, which limits commercialization. There is a disadvantage that there is.

In order to solve the above problems, that is, in order to improve the filtration performance while maintaining the size of the pores above a certain size, a material having an adhesive property instead of static electricity is sprayed on the air filter fabric, and when the curing is completed, it becomes a gel (gelation) and flows in. An air filter (Korean Patent Registration No. 10-1808115) in which fine dust in the air is adsorbed and removed by an adhesive gel has been proposed. Although the above-mentioned adhesive air filter can remove fine dust by an operation principle different from static electricity, the manufacturing process may be complicated and there is a sense of distance from consumer demand for a mask that can be washed and reused.

On the other hand, a mask air filter (Korean Patent Registration No. 10-1923106) has been proposed that improves the problems of the existing mask air purification filter, mounts a washed filter, and applies static electricity from both ends using piezoelectric elements. As for the replaceable air filter, a simple piezoelectric device is combined with the mask to add a new electrostatic function from time to time, so it is possible to continuously manage the air purification ability. It has the characteristic of being able to continuously supply air.

However, in order to manufacture the mask with the air filter attached as described above, many attachments are required, the manufacturing process such as power connection is very complicated, productivity is low, and the manufacturing cost increases as the number of attachments increases. Difficulty in mass supply is inevitable.

On the other hand, household goods made of plastic, consumed and discarded, are on the rise every year, raising concerns about limiting reprocessing capacity and accelerating environmental pollution. According to the recent BelVG global online e-commerce, more than 1 ^million plastic bottles are purchased worldwide every minute, and 83 km2 of paper is thrown away every year in the UK during the Christmas season, and more than 5 trillion plastic bags are consumed worldwide every year. ( Go Green: Top 20 Environment Friendly Products | BelVG Blog ).

In addition, it was reported that China, the world's largest population, began to regulate the use of disposable products in earnest, and plans to gradually expand measures such as the ban on the production, sale, and use of plastic products by 2026 (Korea Trade News). In Korea, according to the policy direction press release of the Ministry of Environment, a plan to reduce the amount of plastic waste in half by 2030 has been announced (Resource Circulation Policy and Press Release of the Ministry of Environment of Korea, 2018-05-10)

Masks are a big fire street at the center of the garbage crisis that has risen sharply at this point in the Corona era, and it is estimated that 7.8 billion people worldwide use 129 billion non-woven (polypropylene) masks every month (Dong-A Science 2020.10.31). Recycling of resources is reluctant due to concerns about secondary infection of personal protective equipment.

Republic of Korea Patent Publication 10-1923106 Republic of Korea Patent Publication No. 10-0310274 Republic of Korea Patent Publication 10-1808115

An object of the present invention is to greatly reduce the risk of environmental pollution due to the increase in plastic use by molding and manufacturing a mask manufactured based on a nonwoven fabric with pulp, which is an eco-friendly material, and at the same time as the problem in the prior art. In order to improve the problem of static electricity dissipation due to high humidity, which is a disadvantage, a natural material-based porous thin-film electrostatic filter with improved filtration characteristics is manufactured, and each functional filter is laminated and modularized and mounted on a mask molded from eco-friendly pulp. To provide a pulp mask.

In order to achieve the above object, the method for manufacturing an eco-friendly air purifying mask equipped with a thin film electrostatic filter module according to the present invention,

preparing a pulp solution for manufacturing a mask composed of an eco-friendly material containing natural pulp;

manufacturing a mask shape from a pulp solution through a vacuum forming pulp mold;

forming cross-links and contours between the formulation components such that the molded mask has elasticity and mechanical durability;

creating a hole in a specific part of the mask to attach the thin film electrostatic filter module to the mask;

attaching a porous thin film electrostatic filter module to the hole so that the mask has an air purification function;

includes

An eco-friendly mask equipped with a thin film electrostatic filter module according to the present invention is a natural pulp mask on which an electrostatic filter module manufactured as a set is mounted by stacking several functional thin films including a functional thin film having static electricity,

Creating an appearance with a formulation in which natural pulp, an intellectual strength enhancer, and a crosslinking agent are mixed in a certain ratio;

inducing cross-linking to the mask shape through pressure and heating, thereby imparting tensile strength and elasticity to the shape body; including,

It is manufactured by creating a hole in a specific part of the natural pulp mask and attaching a breathable electrostatic filter module thereto.

The mounted thin film electrostatic filter module is composed of a single thin film by cross-stacking and fusing porous thin films with positive or negative static electricity produced by chemically combining natural materials.

In the lamination process of the thin film electrostatic filter module, a porous spacer is disposed between each thin film to secure flexible air flow and at the same time can be manufactured to greatly increase the air contact opportunity of the electrostatic filter.

The natural pulp mask according to the present invention is provided with a generous internal space, so it is excellent in breathing ease and can effectively filter out ultra-fine particles such as yellow dust, fine dust, and infectious droplets or aerosols due to the electrostatic effect that lasts even in a high-humidity environment. In particular, it is eco-friendly by using recycled pulp material, and it has the advantage of simplifying the manufacturing process through modularization, improving productivity and reducing manufacturing cost.

1 is a block diagram of a thin film electrostatic filter module according to the present invention.
2 is a dye adsorption test result according to the charged state of the thin film electrostatic filter according to the present invention.
*Left: Negatively charged red dye (Allura red ac) is adsorbed on the surface of the positively charged thin film filter
*Right: The positively charged blue dye (Methylene blue) is adsorbed on the negatively charged thin film filter surface.
3 is an electron micrograph of a vertical cut surface magnified by 2,000 times of the thin film according to the present invention, in which multi-layered microchannels are formed.
4 is an electron micrograph of the porous structure of the surface of the thin film according to the present invention at 2,500 times magnification.
5 is a three-dimensional rendering image of a pulp mask shape according to the present invention.

Hereinafter, a pulp mask and a method for manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram illustrating the configuration of a thin film electrostatic filter module according to the present invention, and FIG. 2 is a moss to which positive and negatively charged dyes are adsorbed according to the electrostatic state of the electrostatic filter thin film according to the present invention. is an electron micrograph showing the micropore channels of the vertical cut surface of the electrostatic filter thin film, FIG. 4 is an electron micrograph showing the pores on the surface of the electrostatic filter thin film, and FIG. 5 is a rendered image of the pulp mask shape according to the present invention.

The pulp mask according to the present invention is an air purifying screen for effectively filtering fine dust, droplets, aerosols, etc. in the air produced based on recycled materials such as pulp, which is an eco-friendly material, and has an average pore size of 5 to 20 microns. It is configured to effectively filter even very small ultrafine dust, and it is relatively simple to manufacture compared to the sought efficacy and has the characteristics of being easily manufactured in an environment-friendly manner.

That is, the mask according to the present invention obtains a shape through a vacuum forming pulp molding process after the resource recycling pulp material, binder, strength enhancer, crosslinking agent, etc. are blended and homogenized in a certain ratio, and then dried and shaped through a heating and pressurizing process. The final pulp mask is prepared via crosslink.

The pulp solution for mask molding according to the present invention may be composed of 3 to 4% pulp, 2 to 3% hydroxyethyl cellulose, and 0.1 to 0.3% citric acid as main raw materials, but if necessary, a catalyst and a sizing agent It can be prepared by selectively adding The present invention is characterized in that the pulp solution is prepared and used mainly from eco-friendly raw materials in order to suppress or minimize the emission of environmental pollutants in the manufacturing process.

In order to attach the air permeable filter to the pulp mask, it is required to create a hole of a certain area on the surface of the mask. Hole generation can be manufactured so that a perforated molded product can be obtained by reflecting the hole area in the mold design stage of the vacuum forming pulp mold.

In order to manufacture the module of the air permeable thin film electrostatic filter attached to the pulp mask according to the present invention and used as an air purification filter, a positively or negatively charged functional thin film is required. In order to make a functional thin film having a positive or negative charge required for manufacturing a filter module, a natural material used as a raw material in this embodiment is chitosan, and collagen, gelatin, etc. may be used as a protein raw material. Natural materials that can be used for manufacturing the functional thin film of the present invention may be polysaccharides derived from nature such as cellulose, starch, alginic acid, in addition to chitosan. On the other hand, although carboxylic acid is used in the embodiment of the present invention as a crosslinking agent for manufacturing a functional thin film, a compound that forms a crosslink by other crosslinking reaction mechanisms can also be used in principle. The final raw material solution is prepared through appropriate dissolution and blending of these components.

The chitosan raw material having a molecular weight of 100,000 to 300,000 is added to 1% acetic acid or formic acid so as to become a final 50 degree 2% chitosan solution, and dissolved by stirring for about 1 hour. Meanwhile, in a separate container, the gelatin raw material is prepared in a final 2% protein solution through the same process.

Each of the raw material solutions is mixed in a 1:1 weight ratio and homogenized through stirring while maintaining the temperature of the solution at 50°C. In this stirring process, the organic acid serving as a crosslinking agent is appropriately added and mixed within a concentration range of 3 to 20 mM. In this embodiment, citric acid is used as an organic acid serving as a crosslinking agent. A final dispensing solution is prepared by further stirring the mixed solution containing citric acid at 50 degrees for 1 hour.

If necessary to lower the temperature of the solution in which all the raw materials are mixed to 40 degrees and secure the flexibility of the thin film, glycerin can be added in the range of 0.3 to 0.6% (w/v) in this step.

An appropriate amount of the mixture is dispensed into a container made of glass, polystyrene, polypropylene, etc. stored at 40°C. The thickness of the final dried thin film may vary depending on the dispensing capacity, and it is possible to control the thickness of the final dried thin film to be manufactured by determining and executing the dispensing capacity per container through this method.

The dispensed mixed solution is left to stand in an environment of 40 degrees for 24 hours to proceed with drying. If necessary, in order to shorten the drying time, the drying temperature of the solution can be appropriately adjusted within the range of 40 to 70 degrees.

As drying proceeds at the above temperature, a crosslinking reaction mediated by organic acids may proceed, and the final dried thin film may be a flat thin film in which pores are not sufficiently formed. If necessary for sufficient pore formation, a thin film is manufactured through a subsequent process. The crosslinking reaction of natural materials strengthens the tensile strength and durability of the thin film, and at the same time gives insolubility when exposed to water. When the thin film drying is completed, the thin film production is completed through curing for an appropriate time within the range of additionally 90 to 110 degrees.

In the porous thin film according to the present invention, ultrafine dust in the air purifies the air by the difference in physical pore size through the pores of the thin film. Therefore, the prepared thin film is treated with a proteolytic enzyme to induce sufficient pore formation.

Industrially useful enzymes such as trypsin, papain, and bromelain may be used as the proteolytic enzyme input for preparing the porous thin film. Also, it is possible to use a pronase proteolytic enzyme produced by a microorganism (Streptomyces griseus).

The concentration of each enzyme is appropriate to be 1-5%, and the dried thin film is put into the enzyme reaction solution prepared in advance, and some protein components constituting the thin film are decomposed and removed while circulating the solution for an appropriate temperature and reaction time. do.

When the reaction is completed, the thin film is transferred to another container, the activity of the remaining enzyme is stopped, and the thin film is recovered through additional washing and dried at room temperature. The pores of the thin film prepared using proteolytic enzymes have non-linear characteristics, and the thicker the thin film, the more multi-layered non-linear pore structure.

As shown in the vertical section of FIG. 3 , the porous thin film of the present invention can be formed with a physical pore size in the range of 5 to 20 μm and has a multi-layered microchannel pore structure. The size of the pores finally created through the change in the composition ratio of the polysaccharide and protein input in the raw material mixing preparation step can be variably controlled. In the weight mixing ratio of chitosan and gelatin in this example, 100% of the weight of gelatin was added relative to the weight of chitosan, but in order to make the pore size of the thin film smaller or larger, the weight of the protein added relative to the weight of polysaccharide can be variably adjusted to produce a thin film. have.

In particular, in the pores of the thin film according to the present invention, the passage time of fine particles is delayed as air passes through the inside of the film in a zigzag path, rather than linear pores passing through the front and rear surfaces of the thin film, and thereby blocking the ultrafine particles You can get results that are more effective.

Fine dust or physical particles larger than the pore size of the thin film according to the present invention do not easily pass through the pores of these zigzag microchannels, and in particular, in the case of droplets defined with a particle size of 5 μm or more, it is not easy to directly pass through the pores . Droplet nuclei or aerosol particles with a diameter of less than 5 μm are collectively referred to as particles suspended in solid or liquid fine particles in a gas, such as smoke or mist, and their size is about 100 nm to 5 μm.

In order to effectively block ultrafine particles smaller than pores, the porous thin film according to the present invention is subjected to a surface modification step through a subsequent process, and a semi-permanent electrostatic function is imparted to the surface of the porous thin film by chemical bonding of a charged compound. can do.

In order to impart static electricity to the surface of the thin film according to the present invention, a material having a positive or negative charge may be selectively added. That is, the surface modification reaction can be initiated by immersing the porous thin film filter in a previously prepared alkali solution. The alkali solution according to the present invention may be a caustic soda solution in a concentration range of 50 to 500 mM, and the concentration of caustic soda used can be variably adjusted according to the target of the surface modification level. The surface modification reaction proceeds while stirring the solution at room temperature or an appropriate temperature.

More specifically, when preparing the alkali solution to positively charge the surface of the thin film according to the present invention, as a molar ratio, a positively charged compound equivalent to about twice the concentration of sodium hydroxide can be added. have. For example, in the case of 50mM aqueous caustic soda solution, use 100mM concentration, which is twice the concentration, to obtain a sufficient positively charged compound concentration.

If a positively charged material is applied to the porous thin film filter, the positively charged material used can be chloro diethylaminoethyl. It is absorbed and blocked by force.

Other materials that can be selected for the positive charge coating purpose include 3-chloro-2-hydroxypropyltrimethylammonium chloride, 2-chloro-N, N'-dimethylethylamine hydrochloride, 2-chloro-N, N'-diethylethylamine hydrochloride, and the like. These are listed by way of example only, and other compounds having similar functions and purposes may be used.

A negatively charged compound may be imparted to the newly prepared porous thin film by a manufacturing method similar to the above, and sodium chloroacetate may be used as the negatively charged compound, and the surface modification process may be performed in a similar manner to the above. As a result, the negatively charged porous thin-film filter with the completed bonding can trap and block positively charged surface particles or ultrafine dust contained in the flowing air by electrostatic force when passing through the pores.

The surface modification reaction may proceed for about 1 hour at room temperature, but reaction parameters such as the applied reaction temperature and the concentration of the compound to be added can be variably controlled according to the purpose such as adjustment of the added charge density and shortening of the reaction time. When the surface modification reaction is completed, the thin film filter is moved to another container, and the bonding reaction process is completed by neutralization reaction and washing with water.

As described above, the eco-friendly air purifying mask equipped with the thin film electrostatic filter module according to the present invention is environmentally friendly and functionally, it can block ultra-fine particles smaller than the pore size by using the surface electrostatic force of the filter and provides excellent cost-effective air purification. have the ability As shown in FIG. 2, it is shown that the positively or negatively charged dye having a positive or negative charge is adsorbed in a moisture environment in the thin film electrostatic filter of the present invention.

On the other hand, in order to easily attach the electrostatic filter for blocking ultra-fine particles to the molded pulp mask, it is preferable to laminate filters having various functions and manufacture them as one module. The filter module according to the present invention may be configured in the order of outer shell - pre-filter - negatively charged thin film filter - spacer - positively charged thin film filter - spacer - endothelial. In more detail, the outer and inner skins can be made of a breathable spun bond material, a 50-100 micron thick non-woven material with porosity can be used for the spacer, and a non-woven material of 10 g (grammage) or more is used for the pre-filter. can be manufactured. 1 shows a state in which each film constituting the filter module is overlapped.

The eco-friendly mask equipped with the above thin-film electrostatic filter module can overcome the functional disappearance of the existing mask electrostatic filter due to the high-humidity environment that occurs in the inhalation and exhalation of respiration, and maintains the surface negative or surface positive charge properties even in a high humidity environment such as water. Due to the characteristics of the thin film, it can be used while expecting a high blocking effect even in rainy weather.

As mentioned above, although the present invention has been described in detail using preferred embodiments, the scope of the present invention is not limited to specific embodiments and should be construed according to the appended claims. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

The pulp mask according to the present invention can maintain the electrostatic filter function even in a high humidity environment other than dry air, so it is possible to fundamentally overcome the problem of loss of the electrostatic filter function due to the humidity of the existing MB filter applied mask. As a clean product, industrial use is possible.

The mask material is also harmless to the human body and is selected as a biodegradable raw material, so it can greatly reduce the risk of environmental pollution in the waste and incineration process, and it is an eco-friendly product suitable for the needs of green consumers considering the environment with high cost performance.

Claims (6)

Air mask based on natural pulp material that purifies incoming air;
forming cross-links between the components of the pulp preparation solution to have mechanical durability in the process of molding and manufacturing the mask;
manufacturing the mask by stacking functional filters on each other in the process of manufacturing the mask and combining them into one module;
creating a hole in a certain portion of the pulp mask so that the mask has an air purification function and attaching a filter module to the created hole portion; including,

The air mask is
It is a pulp-based air mask manufactured with a filter module manufactured by laminating various functional thin films such as thin films with static electricity.
It is manufactured by vacuum forming pulp mold for a formulation in which natural pulp, intellectual strength enhancer, crosslinking agent, etc. are mixed in a certain ratio,
The air filter module is constructed in the form of a single thin film by alternatingly stacking and fusing porous thin films with positive or negative static electricity produced by chemical bonding.
In the lamination process for filter module manufacturing, a porous spacer is placed between each electrostatic porous thin film to increase the smooth air flow and the effect of the electrostatic filter,
The formulation for manufacturing the mask is composed of recycled pulp, a crosslinking agent, an intellectual strength enhancer, a sizing agent, and other natural waste resources,
The crosslinking agent in the pulp mask molding and thin film manufacturing process is an organic acid, which is any one of carboxylic acids,
The filter module includes a porous thin film having a positive charge and a porous thin film having a negative charge, and consists of a total of two or more thin film electrostatic filters,
The mask is a resource recycling pulp mask, characterized in that it is easy to assemble and manufacture by mounting a filter module on a mask molded based on recycled natural pulp resources, and blocks ultra-fine particles in the air introduced by the attached electrostatic filter
The method of claim 1,
In the manufacturing process of the porous thin-film filter constituting the thin-film filter module, the mixing ratio of chitosan and gelatin is 50 to 130% of the weight of chitosan.
The method of claim 1,
The carboxylic acid used as a crosslinking agent of the porous thin film constituting the filter module is a pulp mask, characterized in that it is manufactured using an organic acid compound having at least two or more carboxyl groups.
The method of claim 1,
The positively charged material used for surface modification of the porous thin film filter is any one of 2-chloro-N, N'-diethylethylamine hydrochloride or 3-chloro-2-hydroxypropyltrimethylammonium chloride or 2-chloro-N, N'-dimethylethylamine hydrochloride. Pulp mask, characterized in that it is produced using
The method of claim 1,
The compound used for surface modification of the negatively charged thin film filter constituting the filter module is a pulp mask, characterized in that it is manufactured using chloroacetate.
The method of claim 1,
Pulp mask, characterized in that produced by arranging a porous spacer between each filter in the production of a set by stacking breathable or functional filters for the configuration of the filter module

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