CN113769479A

CN113769479A - Membrane material and preparation method thereof

Info

Publication number: CN113769479A
Application number: CN202010524812.1A
Authority: CN
Inventors: 张一平; 邵钦蓉; 张子琦
Original assignee: Shanghai Rongping International Trade Co ltd
Current assignee: Shanghai Rongping International Trade Co ltd
Priority date: 2020-06-10
Filing date: 2020-06-10
Publication date: 2021-12-10

Abstract

The invention discloses a membrane material and a preparation method thereof, wherein micropores are arranged on the membrane material; the film material comprises coating resin, and the coating resin is coated on the glass fiber composite needle felt cloth. The membrane material has the particle filtration efficiency of 98.8-99.997% or above and the air permeability resistance of 20-200 Pa, can be used for preparing medical and common masks, protective clothing, filter paper and filter cloth for blocking bacteria, viruses, oily and non-oily particles with the particle size of more than 0.001 mu m, and simultaneously ensures the smoothness of ventilation of users.

Description

Membrane material and preparation method thereof

Technical Field

The invention belongs to the technical field of filtration, and particularly relates to a membrane material and a preparation method thereof.

Background

The mask filter element which is specially used for protecting and isolating bacteria, viruses and ultrafine particles in the market at present is not a lot, the mask filter element in the market is mostly prepared by non-woven fabrics, gauze, plastic mesh fabrics and the like, the weave holes or meshes of the mask filter element are large, and the bacteria, the viruses and the particles can still pass through the mask and enter the nasal cavity.

Disclosure of Invention

One of the main objectives of the present invention is to provide a membrane material, which is used to solve the problem of the current filter material with larger pore size.

In order to achieve the purpose, the invention is realized by the following technical scheme: a membrane material is provided with micropores; the film material comprises coating resin, and the coating resin is coated on the glass fiber composite needle felt cloth.

Preferably, the pore size of the micropores is 0.001 to 0.01 μm; the porosity of the membrane material is 60-85%, and the air permeability of the membrane material is 8-50 cm/s.

The invention also provides a preparation method of the membrane material, which comprises the following steps:

step S1: three-dimensionally weaving glass fibers on the needled felt cloth to obtain glass fiber composite needled felt cloth;

step S2: the coating resin is applied to the glass fiber composite needle felt cloth obtained in step S1, and the glass fiber composite needle felt cloth is combined to form a film material.

Preferably, the coating resin is prepared as follows:

step S3: placing food-grade plastic particles in water, adding an initiator, and carrying out first suspension polymerization to obtain a pretreated product;

step S4: heating the pretreated product obtained in the step S3, and realizing the second suspension polymerization in the cooling process to obtain a crude product;

step S5: the crude product obtained in the step S4 is sequentially smashed, ground, washed and dried to obtain powdered resin;

step S6: melting the powdery resin obtained in the step S5, and preparing a liquid coating resin through a biaxial stretching process;

step S7: the liquid coating resin obtained in step S6 is applied to the glass fiber composite needle felt cloth obtained in step S1, and cooled to obtain a film material.

Preferably, the plastic particles consist of 85-95% PTFE and 5-15% PE.

Preferably, the heating temperature in step S3 is between 450 ℃ and 650 ℃.

Preferably, the crude product obtained in step S4 refers to a mixture of a copolymer of PTFE and PE, a PTFE monomer, a PE monomer, a persulfate salt and water.

The technical scheme provided by the invention has the following beneficial effects:

1. the membrane material has the particle filtration efficiency of 98.8-99.997% or more, the air permeability resistance of 20-200 Pa and the gram weight of 25-35 g per square meter, and can ensure smooth breathing.

2. The membrane material can block bacteria, viruses, oily and non-oily particles with the particle size of more than 0.001 mu m, can be used for preparing medical and common masks, protective clothing, filter paper, filter cloth and the like, can ensure the smoothness of ventilation of users and the like, overcomes the defect of suffocating when wearing the masks, and ensures the wearing comfort.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.

Fig. 1 is a schematic view of the mask of the present invention;

fig. 2 is a schematic structural view of a mask with a non-woven fabric laminated filter element according to a ninth embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a supporting frame according to a tenth embodiment of the present invention;

FIG. 4 is a schematic view showing the structure of a first filter layer, a second filter layer and a third filter layer in a tenth example of the present invention;

fig. 5 is a schematic structural diagram of a filter cloth according to an eleventh embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

Example one

A membrane material 3, the surface of the membrane material 3 is provided with micropores 4, and the membrane material 3 comprises coating resin; the coating resin is coated on the glass fiber composite needle felt cloth.

Wherein the pore diameter of the micropores 4 is 0.001 to 0.1 μm; the porosity of the membrane material is 60-85%, and the air permeability of the membrane material is 8-50 cm/s.

The membrane material 3 in the implementation has the advantages of small aperture, high porosity, ventilation and the like, can block bacteria and viruses with the particle size of more than 0.001 mu m, can be used for preparing masks, filter paper, protective clothing and the like, can solve the problem of suffocation when the masks are worn at present, and ensures the smoothness of ventilation. The tensile strength of the membrane material of this application is big, can avoid because of the not high security that influences wearing of intensity of membrane material, and this application compares in the various gauze mask membrane materials of tradition existing usefulness can also filter oiliness and non-oily granule in separation and absorption bacterium and virus.

Example two

This embodiment is a preparation method of embodiment one, including the steps of:

step S2: the coating resin is applied to the glass fiber composite needle felt cloth obtained in step S1, and the cloth is combined to form the film 3.

In this embodiment, the surface of the coating resin is a micro-network structure, which is beneficial to air infiltration and can fully ensure the smoothness of breathing.

EXAMPLE III

This example is the preferred embodiment of the second embodiment, namely a method for preparing a coating resin, comprising the steps of:

the plastic particles consist of 85-95% of PTFE (polytetrafluoroethylene) particles and 5-15% of PE (polyethylene) particles.

In general, methylene blue, sodium thiosulfate and the like are commonly used as initiators, and the suspension system can be more stable by adding calcium phosphate powder, and persulfate is used in the embodiment.

In this step, water is used as the continuous phase, and the heat of polymerization is easily removed. Its advantages are high safety and low viscosity of reaction system. The disadvantage is that it is not suitable for suspension polymerization of the resin in the form of dry powder or granules, so that atomization and secondary polymerization are required.

step S7: the liquid coating resin obtained in step S6 is applied to a felt, and cooled to obtain a film material.

The heating temperature in step S3 is 450-650 ℃, and the crude product obtained in step S4 is a mixture of a copolymer of PTFE and PE, a PTFE monomer, a PE monomer, a persulfate and water.

In this embodiment, through smashing and grinding technology, fully grind plastic granules, reduce plastic granules's diameter, improve plastic granules's quality to adopt biaxial stretching technology can improve the tensile strength of membrane material 3 greatly, avoid the not high security that thereby influences wearing of intensity of membrane material 3. The mask made of the membrane material does not need to depend on a one-way breather valve, the defect of suffocation when the mask is worn is overcome, and the wearing comfort is ensured.

The method comprises the steps of measuring the trapping rate of particles with different particle diameters by using a prepared membrane material 3; the detection experiment was as follows:

the test area is 100cm at the ambient temperature of 23 +/-2.0 ℃, the relative humidity of 40 +/-10 percent²And under the condition that the air volume is 58L/min, the collection rate of the particles with different particle diameters is measured:

ultrafine particles, which means particles having a diameter in the range of 0.001 μm to 0.1 μm;

pollen particles having a diameter in the range of 1 μm to 2 μm;

3 μm particles, particles with a diameter in the range of 2.7 μm to 3 μm.

The results of the trapping rate test are shown in tables 1 to 3 below:

TABLE-results of ultrafine particle Capacity

	Particle trapping rate
		①	98.6
②	99.0
		③	98.6
④	99.1
		⑤	98.7
Average	98.8

TABLE Erhua powder particle trapping ratio results

	Particle trapping rate
		①	99.9％
②	99.9％
		③	99.9％
Average	99.9％

TABLE three 3 μm particle Capture Rate results

	Particle trapping rate
		①	99.9％
②	99.9％
		③	99.9％
Average	99.9％

The above table section is selected from the test report (No. LSRL-20011-D127) of the Japanese Living science research institute corporation, and the special membrane material 3 of the present invention has the filtration efficiency of 98.8% -99.997% or more, and can block and adsorb particles with the diameter of 0.001 μm or more.

Example four

As shown in fig. 1, the filter element prepared in this embodiment includes a first nonwoven fabric 1 and a second nonwoven fabric 2, and a membrane material 3 of the first embodiment is disposed between the first nonwoven fabric 1 and the second nonwoven fabric 2.

Wherein the gram weight of the first non-woven fabric 1 and the gram weight of the second non-woven fabric 2 are both 20 to 40 grams per square meter. The nonwoven fabric has a lower grammage than conventional ones, and therefore has better air permeability. In this embodiment, the first nonwoven fabric 1 and the second nonwoven fabric 2 may be PE/PP bicomponent nonwoven fabric or PE/PET bicomponent nonwoven fabric. Therefore, part of the fibers in the first non-woven fabric 1 and the second non-woven fabric 2 can be melted by heating, the melted part plays a role of an adhesive, and the fiber melted part can well adhere the membrane material 3 and the first non-woven fabric 1 and the second non-woven fabric 2 together through external pressure.

EXAMPLE five

A preparation method of a non-woven fabric membrane-covered filter element comprises the following steps:

step S1, placing the film material 3 obtained in the second embodiment between the first nonwoven fabric 1 and the second nonwoven fabric 2, wherein the first nonwoven fabric 1 and the second nonwoven fabric 2 are PE/PP two-component nonwoven fabric or PE/PET two-component nonwoven fabric;

and step S2, melting the PE fibers in the first non-woven fabric 1 and the second non-woven fabric 2 through hot melting point pressing, and better bonding the membrane material 3 with the first non-woven fabric 1 and the second non-woven fabric 2 through pressure action to prepare the membrane-coated non-woven fabric.

The hot-pressing temperature of the hot-melting point pressing is 120 ℃, and the hot-melting point pressing is only stressed in a point shape, so that the membrane and the non-woven fabric are bonded in a point shape, and the damage to the membrane material 3 is reduced.

EXAMPLE six

step S1, placing the film material 3 obtained in the second embodiment between the first nonwoven fabric 1 and the second nonwoven fabric 2, wherein the first nonwoven fabric 1 and the second nonwoven fabric 2 are both PP spunbond nonwoven fabrics;

and step S2, directly bonding the membrane material 3 with the first non-woven fabric 1 and the second non-woven fabric 2 together by a hot-pressing membrane covering process to prepare the membrane-covered non-woven fabric.

The hot-pressing temperature of the hot-melting point pressing is 130 ℃.

EXAMPLE seven

step S1, placing the film material 3 obtained in the second embodiment between the first nonwoven fabric 1 and the second nonwoven fabric 2, wherein the first nonwoven fabric 1 and the second nonwoven fabric 2 are both PET spunbonded nonwoven fabrics;

The hot-pressing temperature of the hot-melting point pressing is 150 ℃. The hot-press coating process used in the third and fourth examples is to apply pressure to the entire film surface, coat the entire film on the surface of the nonwoven fabric, and melt a part of the fibers in the first nonwoven fabric 1 and the second nonwoven fabric 2 by heating, and the melted part functions as a binder.

Example eight

step S1 of placing the film 3 obtained in the second embodiment between the first nonwoven fabric 1 and the second nonwoven fabric 2;

step S2, evenly dispersing eva hot melt adhesive among the first non-woven fabric 1, the second non-woven fabric 2 and the membrane material 3 in a dot shape;

step S3, the membrane material 3 is chemically bonded to the first nonwoven fabric 1 and the second nonwoven fabric 2 by hot pressing, respectively, to prepare a coated nonwoven fabric.

The hot-pressing temperature of the hot-melting point pressing is 80 ℃, in the embodiment, the melting point of the eva hot-melting glue is lower, so that the film coating temperature can be reduced, the bonding effect is better, and the damage of the hot-pressing to the film material 3 can be reduced at low temperature.

The membrane-coated non-woven fabrics prepared in the fifth to eighth embodiments are replaced and matched according to different specifications to form different non-woven fabric membrane-coated filter elements, so that different filtering requirements are met.

The special membrane material 3 has the filtering efficiency of 98.8-99.997% and above, the ventilation resistance of 39-200 Pa and the air permeability of 10.Ocm/s, can block and adsorb bacteria and viruses with the diameter of more than 0.001 mu m and oily and non-oily particles, can be used for preparing a mask filter core for blocking and isolating the bacteria, the viruses and the particles, ensures the smoothness of breathing without depending on a one-way breather valve, solves the problem of oppression when wearing the mask, and ensures the comfort of wearing. The membrane material 3 manufactured by the preparation method has the advantages of long effective service life, good protection and isolation effects, portability and comfort, and is worthy of production and popularization.

Example nine

As shown in fig. 2, a mask applied to a non-woven fabric laminated filter element comprises an inner layer 11, a middle layer and an outer layer 12, wherein the inner layer is made of polypropylene fiber spun-bonded non-woven fabric, the middle layer is the non-woven fabric laminated filter element prepared in any one of the third to sixth embodiments, and the outer layer is made of polyester fiber spun-bonded non-woven fabric. Wherein the gram weight of the polypropylene fiber spunbonded nonwoven fabric and the polyester fiber spunbonded nonwoven fabric is 10g/m2-50g/m 2.

In the embodiment, the lower end edges and the left and right end edges of the inner layer 11 and the outer layer 12 of the mask are bonded together through hot pressing, the upper end edges of the inner layer and the outer layer are provided with opening parts 13, and the middle layer can be placed in the opening parts 13 through the opening parts; the upper end edge of the inner layer is provided with a sealing drape 14, the end of the sealing drape 14 being in contact with the upper end edge of the outer layer 11. Thereby in the gauze mask use, can realize carrying out the effect of trading with the non-woven fabrics tectorial membrane filter core of intermediate level.

Example ten

As shown in fig. 3 to 4, an air conditioner filter element applied to a non-woven fabric membrane-covered filter element comprises a supporting frame 21 and a plurality of filter units, wherein a plurality of rectangular frames 22 are arranged in the supporting frame 21, the filter units are installed in the rectangular frames 22, each filter unit comprises a first filter layer 23 made of the non-woven fabric membrane-covered filter element, a second filter layer 24 made of an activated carbon fiber material and a third filter layer 25 made of a nano silver ion material, and the first filter layer 23, the second filter layer 24 and the third filter layer 25 are sequentially attached.

The first filter layer 23 made of the non-woven fabric membrane-covered filter element can block and adsorb bacteria and viruses with the diameter of more than 0.001 mu m and oily and non-oily particles, thereby effectively reducing PM2.5 in the air, and the second filter layer 24 can filter organic pollutants such as formaldehyde, benzene, TOVC and the like in the indoor air. The third filter layer 25 has the functions of resisting and inhibiting bacteria, filtering bacteria, fungal spores and the like.

EXAMPLE eleven

As shown in fig. 5, the filter cloth applied to the non-woven fabric membrane-covered filter element comprises clamping blocks 32, wherein the clamping blocks 32 are fixedly bonded to two sides of the filter layer 31 made of the non-woven fabric membrane-covered filter element in any one of the third embodiment to the sixth embodiment through viscose 34, the clamping blocks 32 are clamped in the mounting bar 33, and clamping grooves 35 are formed in the end portions of the mounting bar 33. The filter layer 31 is bonded on the clamping block 32 through the adhesive 34, so that the strength of the filter layer 31 can be prevented from being damaged in modes such as hole opening, the clamping block 32 is clamped in the mounting bar 33, the clamping groove 35 formed in the mounting bar 33 is clamped on an external device, and the mounting bar 33 is fixed. Through the position that removes fixture block 32, can adjust the position of filter layer 31, through opening threaded counter bore on fixture block 32, through bolt fixed mounting on mounting bar 33, improve the stability of installation.

The filter layer 31 made of the non-woven fabric film-covered filter element can block and adsorb bacteria and viruses with the diameter of more than 0.001 mu m and oily and non-oily particles, thereby effectively reducing PM2.5 in the air, can filter organic pollutants such as formaldehyde, benzene, TOVC and the like in the indoor air through the filter layer 31, and has better effect when being used in dustproof equipment of factories.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; the pattern filling in the drawings of the invention does not represent the material of the structure, and only distinguishes the structure; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A film, characterized in that: micropores are arranged on the membrane material; the film material comprises coating resin, and the coating resin is coated on the glass fiber composite needle felt cloth.

2. The film according to claim 1, wherein: the pore diameter of the micropores is 0.001 to 0.1 μm; the porosity of the membrane material is 60-85%, and the air permeability of the membrane material is 8-50 cm/s.

3. The method for producing a film according to claim 1 or 2, characterized in that: the method comprises the following steps:

4. The production method according to claim 3, characterized in that: the coating resin is prepared by the following steps:

step S3: placing plastic particles in water, adding an initiator, and carrying out first suspension polymerization to obtain a pretreated product;

5. The method of claim 4, wherein: the plastic particles consist of 85-95% of PTFE and 5-15% of PE.

6. The method of claim 4, wherein: the heating temperature in step S3 is between 450 ℃ and 650 ℃.

7. The method of claim 4, wherein: the crude product obtained in step S4 is a mixture of a copolymer of PTFE and PE, a PTFE monomer, a PE monomer, persulfate, and water.