阅读说明：本技术 一种梯度结构玻璃纤维滤纸及其制备方法和应用 (Glass fiber filter paper with gradient structure and preparation method and application thereof ) 是由 刘铁军 王屹 胡晓侠 王莹 费传军 范凌云 郭晓蓓 陈晓燕 代丰 吴涛 于 2019-09-29 设计创作，主要内容包括：本发明涉及过滤与分离技术领域,公开了一种梯度结构玻璃纤维滤纸及其制备方法和应用,所述方法包括制浆、成型和干燥步骤,成型时通过双层流浆箱的布浆和匀整作用,可精确控制不同层浆料的用量,然后脱水成型,在成型过程中使不同层浆料接触面的纤维发生相互渗透,从而使各过滤层泾渭分明且又有一定的层间结合力,在提高过滤效率的同时,增加了各层之间的吸附力,使形成的湿纸页不易脱落或分层。本发明的方法实现了多级过滤效果滤纸的一次性生产,避免了不同层之间粘合剂的使用,提高了滤纸的综合性能,减少了其他工艺后续的各梯度复合工艺,提高了生产效率。(The invention relates to the technical field of filtration and separation, and discloses glass fiber filter paper with a gradient structure and a preparation method and application thereof. The method of the invention realizes the one-time production of the filter paper with the multi-stage filtering effect, avoids the use of adhesives among different layers, improves the comprehensive performance of the filter paper, reduces the subsequent gradient compound processes of other processes and improves the production efficiency.)

1. The preparation method of the glass fiber filter paper with the gradient structure comprises a first aperture glass fiber filter layer and a second aperture glass fiber filter layer, wherein the first aperture is larger than the second aperture, and comprises the steps of pulping, molding and drying, and is characterized in that the molding comprises the following steps:

and (3) respectively carrying out slurry distribution on the first aperture glass fiber filtering layer slurry and the second aperture glass fiber filtering layer slurry through a double-layer slurry distribution box, and then dehydrating and forming to form the wet paper sheet with the gradient structure.

2. The method according to claim 1, wherein the dewatering forming comprises applying the first pore size glass fiber filter slurry and the second pore size glass fiber filter slurry to 10 to 100m, respectively³And (3) after the sizing amount per hour is distributed through a double-layer flow box, naturally dehydrating and vacuumizing and dehydrating under the vacuum degree of 0.01-0.1 MPa in sequence to enable the moisture content of the wet paper sheet to be 60-80%.

3. The preparation method according to claim 1 or 2, characterized by further comprising the step of filtering and diluting the first pore size glass fiber filter layer slurry and the second pore size glass fiber filter layer slurry to 0.1-0.5 wt% by adding water, respectively, before the forming step.

4. A method according to any one of claims 1-3, characterized in that said pulping comprises the steps of:

preparing slurry of a first aperture glass fiber filtering layer:

and (3) cutting microfiber glass wool and glass fiber short shreds into (50-90): (9-40) defibering and dispersing in water according to the weight ratio, and adjusting the pH of the system to 2-4 to obtain a suspension with the concentration of 0.5-1.5 wt%;

preparing slurry of a second aperture glass fiber filtering layer:

and (2) cutting microfiber glass wool and glass fiber short shreds into (60-95): (4-30) dispersing in water, and adjusting the pH of the system to 2-4 to obtain a suspension with a concentration of 0.5-1.5 wt%.

5. The preparation method according to claim 4, wherein the beating degree of the microfiber glass wool is 10 to 80 ° SR; the length of the short glass fiber shreds is 3-20 mm.

6. The preparation method according to any one of claims 1 to 5, wherein before the drying step, the method further comprises the step of applying an adhesive to the surface of the wet paper web of the gradient structure glass fiber filter paper and dehydrating the wet paper web until the water content of the system is 60 to 80% to obtain a semi-finished product of the gradient structure glass fiber filter paper.

7. The method of claim 6, wherein the binder is a water-soluble acrylic resin emulsion with a concentration of 1-10 wt%, and is applied in an amount of 1-10% of the total mass of the wet paper sheet.

8. The preparation method according to claim 6 or 7, characterized in that the drying is carried out by drying the semi-finished product at 100-200 ℃ for 10-30 min so that the dryness of the paper sheet is more than or equal to 99%.

9. The gradient-structure glass fiber filter paper prepared by the method for preparing the gradient-structure glass fiber filter paper according to any one of claims 1 to 8.

10. Use of the gradient structure glass fiber filter paper prepared by the method according to any one of claims 1 to 8 or the gradient structure glass fiber filter paper according to claim 9 in the manufacture of a liquid filter or an air filter.

Technical Field

The invention relates to the technical field of filtration and separation, in particular to glass fiber filter paper with a gradient structure and a preparation method and application thereof.

Background

With the continuous growth of the global population and the rapid development of scientific technology, human beings also establish a global ecosystem which is deeply influenced by human beings while creating civilization, and the deterioration of the ecological environment brings great harm to the production and the life of the human beings. In recent years, with the development of modern science and technology, the improvement of the requirements of human life quality and increasingly strict environmental regulations, the filtration and separation industry is rapidly developed. In order to achieve the purpose of purification, new high-quality filter materials gradually become research hotspots of researchers.

The glass fiber has the advantages of fine diameter (0.3 mu m), excellent dimensional stability, difficult deformation, non-adhesion, high temperature resistance, corrosion resistance and the like, and the glass fiber filter paper formed by taking the glass fiber as the raw material has extremely high filtering efficiency, excellent chemical stability and lower resistance, so the glass fiber filter paper is widely applied to air and liquid filtration and occupies an unfortunate position in a plurality of filtering and separating materials. However, in the case of a single-layer filter paper, most of the particles are intercepted by the surface layer on one side of the filter paper during filtration to form a filter cake, which causes rapid increase of the resistance of the filter paper in a short time, and thus the pores in the entire thickness of the filter paper cannot be fully utilized, and it is difficult to satisfy the requirements of high filtration efficiency and dust holding capacity at the same time.

In order to solve the contradiction between high filtration efficiency and dust holding capacity, the prior art provides a preparation method of a glass fiber double-layer filter material, wherein the double-layer filter material consists of a coarse glass fiber layer and a fine glass fiber layer, and is obtained by coating glue between a coarse glass fiber layer semi-finished product and a fine glass fiber layer semi-finished product, vacuumizing, compounding and drying. However, in the disclosed technology, the thick and thin glass fiber layers of the double-layer filter material are bonded together under the action of the binder, and the binder can fill the internal pores of the filter material, thereby affecting the dust holding capacity of the filter material, reducing the filtering performance of the product and shortening the service life of the product; in addition, the upper layer and the lower layer are respectively formed and then compounded together, and the requirement on the synchronism of equipment is also high.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defect that the performance of the product is affected by the adhesive between the thick glass fiber layer and the thin glass fiber layer of the double-layer glass fiber filter paper in the prior art, so that the preparation method of the glass fiber filter paper with the gradient structure is provided, and simultaneously, the invention also provides the glass fiber filter paper with the gradient structure prepared by the method and the application thereof.

In order to solve the technical problems, the invention provides a preparation method of glass fiber filter paper with a gradient structure, wherein the filter paper comprises a first aperture glass fiber filter layer and a second aperture glass fiber filter layer, the first aperture is larger than the second aperture, the preparation method comprises the steps of pulping, molding and drying, and the molding comprises the following steps:

and (3) respectively carrying out slurry distribution on the first aperture glass fiber filtering layer slurry and the second aperture glass fiber filtering layer slurry through a double-layer slurry distribution box, and then dehydrating and forming to form the wet paper sheet with the gradient structure.

Further, the dehydration forming comprises the step of respectively using the first aperture glass fiber filtering layer slurry and the second aperture glass fiber filtering layer slurry by 10-100 m³The sizing amount per hour is distributed by a double-layer flow box, and then natural dehydration and vacuum dehydration are sequentially carried out under the vacuum degree of 0.01-0.1 MPaAnd water, and enabling the moisture content of the wet paper sheet to be 60-80%.

Furthermore, before the forming step, the method further comprises the steps of filtering the first aperture glass fiber filtering layer slurry and the second aperture glass fiber filtering layer slurry respectively and adding water to dilute the first aperture glass fiber filtering layer slurry and the second aperture glass fiber filtering layer slurry to 0.1-0.5 wt%.

Further, the pulping comprises the following steps:

preparing slurry of a first aperture glass fiber filtering layer:

and (3) cutting microfiber glass wool and glass fiber short shreds into (50-90): (9-40) defibering and dispersing in water according to the weight ratio, and adjusting the pH of the system to 2-4 to obtain a suspension with the concentration of 0.5-1.5 wt%;

preparing slurry of a second aperture glass fiber filtering layer:

and (2) cutting microfiber glass wool and glass fiber short shreds into (60-95): (4-30) dispersing in water, and adjusting the pH of the system to 2-4 to obtain a suspension with a concentration of 0.5-1.5 wt%.

Furthermore, in order to fully disperse the microfiber glass wool into a uniform suspension, the pulping time of the first aperture glass fiber filter layer slurry is 5-30 min, and the pulping time of the second aperture glass fiber filter layer slurry is 5-20 min.

Furthermore, the beating degree of the microfiber glass wool is 10-80 DEG SR, and more preferably 14-60 DEG SR.

Further, the microfiber glass wool may be alkali-free glass or borosilicate glass 475 #.

Furthermore, the length of the short glass fiber shreds is 3-20 mm, and the short glass fiber shreds can be alkali-free glass or medium-alkali fiber.

Further, before the drying step, a step of applying an adhesive to the surface of the wet paper web of the glass fiber filter paper with the gradient structure, and dehydrating until the water content of the system is 60-80% to obtain a semi-finished product of the glass fiber filter paper with the gradient structure.

Furthermore, the adhesive is water-soluble acrylic resin emulsion with the concentration of 1-10 wt%, and the application amount of the water-soluble acrylic resin emulsion accounts for 1-10% of the total mass of the wet paper sheet.

Still further, the water-soluble acrylic resin emulsion is selected from at least one of an anionic acrylic resin emulsion, a cationic acrylic resin emulsion, or a non-ionic acrylic resin emulsion.

Furthermore, the acrylic resin emulsion comprises 1-10 parts by weight of A series acrylic resin emulsion; 1-5 parts of a B series acrylic resin emulsion; 1-10 parts of a surfactant; 75-95 parts of water.

Further, the surfactant is at least one of a water repellent agent, an oil repellent agent, or an antifouling agent.

Further, the drying is to dry the semi-finished product at 100-200 ℃ for 10-30 min, so that the dryness of the paper sheet is more than or equal to 99%.

The invention also provides the glass fiber filter paper with the gradient structure prepared by the preparation method of the glass fiber filter paper with the gradient structure.

Further, the gram weight of the filter paper is 70-120 g/m²The gram weight of the first aperture glass fiber filtering layer is 20-110 g/m²The gram weight of the second aperture fine glass fiber filtering layer is 20-80 g/m²。

The invention also provides application of the glass fiber filter paper with the gradient structure prepared by the preparation method or the glass fiber filter paper with the gradient structure in manufacturing a liquid separation filter or a gas separation filter.

The technical scheme of the invention has the following advantages:

1. the preparation method of the glass fiber filter paper with the gradient structure comprises the steps of pulping, forming and drying, wherein during forming, the first aperture glass fiber filter layer slurry and the second aperture glass fiber filter layer slurry are respectively subjected to slurry distribution through a double-layer slurry box, the use amounts of different layers of slurry can be accurately controlled through the slurry distribution and leveling action of a double-layer head box, then dehydration forming is carried out, and the fibers of the contact surfaces of the different layers of slurry are subjected to mutual permeation in the forming process, so that the filter layers are clear in size and have certain interlayer binding force, the filtration efficiency is improved, meanwhile, the adsorption force among the layers is increased, and the formed wet paper is not easy to fall off or delaminate. The method of the invention realizes the one-time production of the filter paper with the multi-stage filtering effect, avoids the use of adhesives among different layers, improves the comprehensive performance of the filter paper, reduces the subsequent gradient processes of other processes and improves the production efficiency.

2. The preparation method of the glass fiber filter paper with the gradient structure provided by the invention controls the sizing amount of the sizing agent of the upper glass fiber filter layer on the lower glass fiber filter layer by controlling the sizing distribution speed of the upper glass fiber filter layer and the lower glass fiber filter layer through the double-layer flow box, so that the obtained glass fiber filter paper with the gradient structure has the advantages of high porosity, high dust holding capacity, high efficiency and low resistance, and is suitable for the geometric structure corresponding to the filtration mode with the diffusion mechanism in the leading position.

3. The preparation method of the glass fiber gradient structure filter paper provided by the invention has the advantages that the slurry is subjected to deslagging and dilution treatment before forming, and favorable conditions are provided for uniform forming.

4. According to the preparation method of the glass fiber filter paper with the gradient structure, provided by the invention, the fibers in the slurry are interwoven into a good three-dimensional network structure by controlling the pH value and the pulping time of the slurry, so that a stable suspension state is formed, the settling time of the fibers in water is prolonged, and the dispersion effect of the fibers is improved.

5. According to the preparation method of the glass fiber filter paper with the gradient structure, provided by the invention, the surface of the wet paper sheet is sprayed with the water-based acrylic resin emulsion, and the fine particles in the emulsion are utilized to permeate and cross-link among fibers to form point connection among the fibers, so that the use of adhesives among different layers is avoided.

6. The glass fiber filter paper with the gradient structure comprises a first aperture glass fiber filter layer and a second aperture fine glass fiber filter layer, wherein the first aperture is larger than the second aperture, and the filter layer with the gradient structure with the aperture gradually decreasing from top to bottom can reasonably adjust the relation between the filter efficiency and the dust holding capacity, so that an ideal filter separation effect is achieved, and the service life of the filter is prolonged. The gradient structure filter paper combines filter layers with different thicknesses by interweaving fibers, avoids the influence of a binder on the performance of the filter paper, correspondingly increases the effective pore volume, and generates good filtering effect, so that the filter paper has the characteristics of high porosity, high dust holding capacity and high efficiency, and has the advantage of low resistance.

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, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic structural diagram of a gradient-structured glass fiber filter paper according to the present invention.

Reference numerals:

1-a first pore size glass fiber filter layer; 2-second aperture glass fiber filtering layer.

Detailed Description

The following examples are provided to further understand the present invention, not to limit the scope of the present invention, but to provide the best mode, not to limit the content and the protection scope of the present invention, and any product similar or similar to the present invention, which is obtained by combining the present invention with other prior art features, falls within the protection scope of the present invention.