TWI811086B - Preparation method and finished product of tubular filter membrane - Google Patents

Abstract

The invention proposes a method, from winding forming to soaking process, realize at least one non-woven fabric being wound multiple times around the mold; melting the adjacent edges or overlaps of two circles of non-woven fabric to form a welded part; of semi-finished products. After two procedures of washing and drying, a tubular filter membrane (also known as tubular membrane) suitable for tangential flow (also known as cross-flow) filtration method is obtained.

Description

Preparation method and finished product of tubular filter membrane

The invention relates to filtration technology, especially a preparation method for producing a finished product of a tubular filtration membrane.

The separation field of traditional membranes can be divided into tubular membranes, flat sheet membranes, spiral wound membranes, capillary membranes, hollow fiber membranes and other polymer separation membranes according to their types.

Wherein, after the spiral-wound membrane is filtered, it has the disadvantage of being clogged and difficult to clean, so the spiral-wound membrane is suitable for filtration with low pollution sources. The pores of the hollow fiber membranes are less than 0.5 mm, which also has the disadvantage of being clogged and difficult to clean, and is also suitable for filtration with low pollution sources. The flat membrane is vertical to the flow direction and belongs to the dead end (Dead End) filtration method of the pollution source. Although the clogged dirt can be removed by cleaning, it has the disadvantage of low filtration efficiency. The tubular membrane or capillary membrane adopts tangential flow (also known as cross flow, originally Tangential Flow Filtration, TFF for short) filtration method, because the flow direction is parallel to the tube wall, so the dirt blocked by the tube wall is taken away by the pollution source , effectively solve the clogging degree, and the filtration efficiency is better.

The inventor of this case proposes a preparation method, the main purpose of which is to use simple steps to produce tubular membranes suitable for tangential flow filtration, switch from the external procurement mode to the domestic demand production mode, and improve the efficiency of technology and stimulate economic demand.

According to the above-mentioned preparation method, the inventor of the present case produced a tubular filter membrane, which is suitable for tangential flow filtration.

From the achievement of the above-mentioned purpose, the method of the present invention performs the following steps in sequence: at least one non-woven fabric is wound around the mold for multiple turns; the adjacent edges or overlaps of the two circles of non-woven fabric are melted to form a welded part; the non-woven fabric is separated from the mold and becomes tubular and the inner side is attached to the formula A semi-finished product of the feed liquid; and, soaking the semi-finished product in the liquid in the container.

In a preferred embodiment, the non-woven fabric is a non-woven fabric made of one of polypropylene (PP), polyethylene terephthalate (PET), nylon (Nylon) and polylactic acid (PLA) or weaving.

In a preferred embodiment, fusion equipment is used to realize the welding position at the adjacent edge or overlap of the two loops of non-woven fabric. Of course, the melting device is selected from one of ultrasonic welding equipment and hot pressing molds.

In a preferred embodiment, the formulation liquid is polyvinylidene fluoride (PVDF), polyphenylene ether (PES), polyarylene (PSU), polyacrylonitrile (PAN), acetate fiber (Acetate Fiber), poly One of the organic polymers of tetrafluoroethylene (PTFE), nylon (Nylon) and polyvinyl chloride (PVC).

In a preferred embodiment, the formula material liquid is transported from the formula tank to the hollow mold through a pump, and turns to the outlet and falls on the drop portion of the mold. When the non-woven fabric leaves the mold through the drop portion, the formula material liquid adheres to the inner side of the tubular semi-finished product.

Alternatively, the formula material liquid is transported from the formula tank to the discharge port of the hollow mold through a pump, and the high-voltage power supply outputs power to the mould. The charged conical droplet Taylor Cone (Taylor Cone) generates a repulsive force in response to the voltage rise to overcome the surface tension, and then sprays nanofibers towards the grounded collector plate, and stacks them on the inside of the non-woven fabric leaving the mold to form a tubular semi-finished product.

The method further includes: taking out the semi-finished product from the container for physical or chemical cleaning; and drying the cleaned semi-finished product into a finished tubular membrane.

In this way, the preparation method of the present invention adopts simple steps to produce tubular membranes suitable for tangential flow filtration, transforms from the external procurement mode to the domestic demand production mode, and improves technology while stimulating economic demand.

According to the above-mentioned method, a tubular filter membrane is produced, which is suitable for tangential flow filtration. The tubular filter membrane includes: an outer layer with multiple turns of welds; and an inner layer disposed inside the outer layer. The tubular filter membrane further includes: an intermediate layer with multiple turns of welding positions, the intermediate layer is laminated on the inner side of the outer layer and attached to the outer side of the inner layer.

Therefore, the present invention produces a tubular filter membrane according to the above method, also known as tubular membrane, which is suitable for tangential flow (also known as cross flow) filtration.

In order to make the purpose, features and advantages of the present invention easy to understand, one or more preferred embodiments will be described in detail as follows in conjunction with the accompanying drawings.

Next, in conjunction with the accompanying drawings, describe the embodiment of this case. In the drawings, the same or similar structures or units are denoted by the same reference numerals. It is foreseeable that the described embodiments are only some examples of this case, not all embodiments. Other embodiments that can be deduced based on the examples described above, or structures that can be modified or changed as needed, all belong to the scope of protection of this case.

In the following descriptions, directional terms such as "upper", "lower", "left", "right", "front", "rear", "inner", "outer" and "side" refer only to the directions of the drawings . The use of directional terms is for better and clearer description and understanding of this case, and does not express or imply that the devices or components described must have a specific orientation, structure and operation, so it cannot be understood as a limitation on the technical content of this case.

In the following descriptions, "mounted", "connected", "connected" or "set on" should be interpreted in a broad sense, such as fixed connection, detachable connection, integral connection, mechanical connection, unless there are specific and clear specifications and limitations , directly connected, indirectly connected, or internally connected between two elements. Those skilled in the field of this case can understand the specific meanings of the above terms in each embodiment and even this case by virtue of common knowledge or experience.

Unless otherwise specified, in the following description, "plurality" means two or more.

The present invention proposes a method to obtain a finished product 45 as shown in FIG. 8 through processes such as winding forming, soaking, cleaning and drying. Both the winding formula and the soaking conditions are the core of the method, and it is better to be handled by the producer himself. As for the existing technology that the two steps of washing and drying are roughly the same, distributing other manufacturers to implement it with existing equipment can reduce the burden on the producer.

As shown in Figure 1, the method starts from the 10 steps of winding and forming to the end of the 16 steps of drying, and then goes through the two procedures of soaking in the water tank 14 and soaking in the cleaning tank 15 in sequence. Wherein, the winding forming 10 steps are subdivided into three procedures: winding 11 , melting 12 and forming filter layer 13 . Next, the process or action of each step is clarified in conjunction with Figs. 2 to 7.

In the step of winding 11, two non-woven fabrics 24, 25 are wound on the same mold 23 for multiple turns. Each non-woven fabric 24 or 25 is a non-woven or woven fabric made of one of polypropylene (PP), polyethylene terephthalate (PET), nylon (Nylon) and polylactic acid (PLA). Cloth, with a width of 15mm~35mm.

During the fusing 12 step, the adjoining edges or overlaps of the nonwoven turns 24 , 25 are fused to form welds 27 . The welding position 27 is implemented by using one or more melting devices 26 . The melting device 26 is an ultrasonic welding device, which melts the adjacent edges or overlaps of the two circles of non-woven fabrics 24 and 25 through high-frequency vibration to form a welded part 27 . The melting device 26 can also be a hot pressing mold, which melts the adjacent edges or overlaps of the two circles of non-woven fabrics 24 and 25 at high temperature to form the welded part 27 .

The step of forming the filter layer 13 is to let the non-woven fabrics 24 and 25 separate from the mold 23 to become a semi-finished product 30 in a tubular shape with the formula material liquid 31 attached to the inside. Therefore, obtaining the screening and filtering effect of the pore structure is the main purpose of the step of forming the filter layer 13, so the formula of the formula material liquid 31 is very important, such as using polyvinylidene fluoride (PVDF), polyphenylene ether (PES) ), polyarylene (PSU), polyacrylonitrile (PAN), acetate fiber (Acetate Fiber), polytetrafluoroethylene (PTFE), nylon (Nylon) and polyvinyl chloride (PVC), one of the organic polymers is good. Of course, implementing the known wet phase inversion method or electrospinning technology is one of the preferred options of the present invention.

In Figures 2 and 3, the formula material liquid 31 is transported 22 from the formula tank 20 to the hollow mold 23 via the pump 21 , and turns to the discharge port 28 and falls on the drop portion 29 of the mold 23 . This non-woven fabric 24 is stacked on the periphery of other non-woven fabrics 25. When the two leave the mold 23 along the arrow 32 direction, they will pass through the drop portion 29, so that the formula material liquid 31 adheres to the inner side of the non-woven fabric 25, thereby obtaining a tubular semi-finished product 30. Of course, the formula material liquid 31 adheres to the inner side of the semi-finished product 30 .

In Figures 4 and 5, the formula material liquid 31 is transported 22 from the formula tank 20 to the discharge port 28 of the hollow mold 23 via the pump 21 . The high-voltage power supply 40 outputs power to the mold 23, and in the electric field from the mold 23 to the grounded collecting plate 41, the formula 31 will form charged conical droplets at the outlet 28, Taylor Cone (Taylor Cone), The repulsive force generated by the voltage rise overcomes the surface tension, and then the nanofibers are sprayed toward the grounded collecting plate 41 . The non-woven fabric 24 is stacked on the periphery of other non-woven fabrics 25, and the two leave the mold 23 along the direction of the arrow 32, and just pass between the mold 23 and the grounded collecting plate 41, so that the nanofibers are stacked on the inside of the non-woven fabric 25 to form a tubular semi-finished product together 30. Similarly, the inner side of the semi-finished product 30 is also equipped with a formula material liquid 31 .

In the soaking step, as in FIG. 6 , the semifinished product 30 is soaked in a liquid 34 in a container 33 . The present invention adopts the soaking water tank 14 program, for example, the semi-finished product 30 is soaked in water at a temperature of 25° C. to 85° C. for 4 to 12 hours (h).

In the cleaning step, the semi-finished product 30 is taken out from the container 33 for physical cleaning or chemical cleaning. In terms of physical cleaning, use various physical effects such as force, heat, sound, light and electricity to remove dirt from the semi-finished product 30 . In terms of chemical cleaning, various acids, alkalis, organic solvents, surfactants, corrosion inhibitors (also known as corrosion inhibitors) and chelates are used to prepare cleaning agents to clean or remove dirt from the semi-finished product 30 . The present invention adopts the program of soaking into the cleaning tank 15, which belongs to the category of chemical cleaning. Of course, the present invention does not exclude the possibility of physical cleaning.

In the step of drying 16 , the cleaned semi-finished product 30 is put into a heating device 35 . As shown in Figure 7, a heat source 36 is installed inside the heating device 35, and the heat source 36 evaporates water, and the semi-finished product 30 is dried into a finished product 45 (see Figure 8) and taken out.

In FIG. 8 the finished product 45 is a tubular membrane 46 . The outer layer 42 of the tubular membrane 46 is a support structure made of non-woven fabric, which is provided with multiple turns of welding positions 27 (see Fig. 2 or Fig. 4 ). The inner layer 44 of the tubular membrane 46 is disposed inside the outer layer 42 and has an asymmetric hole structure. The middle layer 43 of the tubular membrane 46 is also a supporting structure made of non-woven fabric, and also has a multi-turn welding position 27 (seeing the second or 4 figures), and the middle layer 43 is stacked on the inner side of the outer layer 42 and attached to the outer layer 42. the outer side of the inner layer 44 .

To sum up, the preparation method of the present invention converts from the external procurement mode to the domestic demand production mode, adopts simple steps to improve the filtration technology, and has the effect of stimulating economic demand. Thus, the tubular membrane 46 manufactured according to the above method, also known as tubular filter membrane, is suitable for tangential flow (also known as cross flow) filtration.

In some embodiments, there is no intermediate layer, and the support structure of the outer layer of the tubular membrane is directly attached to the inner layer of the filter structure, which is also within the allowable scope of the present invention. In other words, the aforementioned preparation method wraps a single non-woven fabric in a single mold, which belongs to the technical scope of the present invention.

Those skilled in the art can understand and make changes to the above-disclosed embodiments without departing from the broad concepts of the present invention. Therefore, this case is not limited to the specific embodiments disclosed in the specification, and all modifications made according to the spirit and technical scope of this case shall be covered and protected by the textual content defined in the scope of the patent application.

10: winding forming

11: winding

12: Molten

13: Form a filter layer

14: Soaking sink

15: Soak into the cleaning tank

16: drying

20: Recipe Slot

21: pump

22: Conveying

23: Mold

24, 25: non-woven fabric

26: Melting equipment

27: Welding part

28: Outlet

29: drop department

30:Semi-finished products

31: Formulation liquid

32: Arrow

33: container

34: Liquid

35: Heating equipment

36: heat source

40:High voltage power supply

41: Ground collector plate

42: outer layer

43: middle layer

44: inner layer

45: Finished product

46: Tubular membrane

Figure 1 shows a preferred manufacturing process of the present invention. Figure 2 is a schematic diagram of a first embodiment of the roll forming step. Figure 3 shows the action of obtaining semi-finished products in Figure 2. Figure 4 depicts a schematic diagram of a second embodiment of the winding forming step. Figure 5 presents a schematic diagram of the semi-finished product obtained in Figure 4. Figure 6 simply shows the soaking process of the semi-finished product. Figure 7 simply depicts the drying process of semi-finished products. Figure 8 shows the finished product in three dimensions.

10: winding forming

11: winding

12: Molten

13: Form a filter layer

14: Soaking sink

15: Soak into the cleaning tank

16: drying

Claims (7)

A method for preparing a tubular filter membrane, the following steps are performed in sequence: at least one non-woven cloth (24 or 25) is wound multiple times on a mold (23); the adjacent edges or overlaps of the two rings of non-woven cloth (24 or 25) are melted to form a welded part (27 ); the non-woven fabric (24 or 25) breaks away from the mold (23) and becomes a tubular semi-finished product (30); the formulation material liquid (31) is transported (22) to the hollow mold (23) from the formulation tank (20) via the pump (21) The discharge port (28), the high-voltage power supply (40) outputs power to the mold (23), and in the electric field from the mold (23) to the ground collecting plate (41), the formula material liquid (31) will be in the discharge port (28) Form charged conical droplet Taylor Cone (Taylor Cone), generate repulsion in response to voltage rise to overcome surface tension, and spray nanofibers towards the grounded collecting plate (41), so that the formulation liquid (31) adheres to the semi-finished product (30); and immerse the semi-finished product (30) in the liquid (34) of the container (33). The preparation method of tubular filter membrane as claimed in item 1, wherein, the non-woven fabric (24 or 25) is polypropylene (PP), polyethylene terephthalate (PET), nylon (Nylon) and polylactic acid (PLA) ) One of the non-woven or woven fabrics made of organic polymers. The method for preparing a tubular filter membrane as claimed in claim 1, wherein the welding position (27) is realized at the adjacent side or overlap of the two circles of non-woven fabrics (24 or 25) by means of a melting device (26). The method for preparing a tubular filter membrane as claimed in claim 3, wherein the melting device (26) is selected from one of ultrasonic welding equipment and hot pressing molds. The method for preparing a tubular filter membrane as claimed in claim 1, wherein the formulation liquid (31) is polyvinylidene fluoride (PVDF), polyphenylene ether (PES), polyarylene (PSU), polyacrylonitrile (PAN), Acetate Fiber (Acetate Fiber), polytetrafluoroethylene (PTFE), nylon (Nylon) and polyvinyl chloride (PVC), one of the organic polymers. The method for preparing tubular filter membrane as claimed in claim 1, wherein the formula liquid (31) is transported (22) from the formula tank (20) to the hollow mold (23) via the pump (21), and turned to the discharge port (28 ) falls on the drop portion (29) of the mold (23), and when the non-woven fabric (24 or 25) leaves the mold (23) through the drop portion (29), the formula material liquid (31) is attached to the inside of the tubular semi-finished product (30). The preparation method of the tubular filter membrane as described in claim item 1, further comprising: taking out the semi-finished product (30) from the container (33) for physical or chemical cleaning; and drying the cleaned semi-finished product (30) into a tubular membrane (46) Finished product (45).

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