CN107754493A - A kind of transparent PM2.5 filter membranes with photocatalytic and preparation method thereof - Google Patents

Abstract

The invention discloses a photocatalytic transparent PM2.5 filter membrane and a preparation method thereof. The PM2.5 filter membrane is a composite nanofiber membrane with a sandwich structure, including polyacrylonitrile @TiO ₂ and polyamide-6, The nanofiber diameter distribution of the composite nanofiber membrane is 60-100nm. The composite film has a tight cross-linked network, photocatalytic function, high transparency and efficient PM2.5 filtration performance. It can not only effectively prevent outdoor PM2.5 from entering the room when used in anti-nano screens, but also under the action of sunlight Photocatalyze the low concentration of harmful gases in the atmosphere while maintaining good lighting and ventilation effects.

Description

A kind of transparent PM2.5 filter film with photocatalysis and preparation method thereof

technical field

The invention belongs to the technical field of filter material preparation, in particular to a photocatalytic transparent PM2.5 high-efficiency filter membrane and a preparation method thereof.

Background technique

With the development of industrialization, the pollution of the environment and air has further intensified, and the harm caused by PM2.5 has attracted worldwide attention. PM2.5 is called "particulate matter that can enter the lungs", which can directly enter the lungs of people. Because it contains toxic and harmful substances, stays in the air for a long time, and is transported over a long distance, it will inevitably affect the quality of the air environment and human health. Negative impact. In addition, the indoor air quality has also attracted people's attention, especially during severe smog, the PM2.5 value in the indoor air is even higher than that in the outdoor air, and at the same time, the indoor VOCs concentration is significantly increased due to the interior decoration, which seriously affects people's health. . Therefore, the research and development of high-efficiency PM2.5 filter materials with high-efficiency degradation of VOCs in the air has received extensive attention. Wu Rui et al. prepared a photocatalytic anti-PM2.5 nano-screen, which is composed of nano-air filtration membrane, photocatalytic membrane and carbon intercalated non-woven fabric, wherein the nano-air filtration membrane is composed of dispersed nano-acetic acid Composed of fiber filaments, many nanopores with a diameter of 0.5-1 μm are formed, and the porosity of the nanofiltration membrane is 85%-98%. The photocatalytic membrane is composed of TiO2/SiO2 composite nanotubes. The nano window screen is composed of a photocatalytic membrane and a nanofiltration membrane with filtration performance. The preparation process is relatively long, and the nano-acetic acetate fiber has a large pore size, and the PM2.5 filtration efficiency is only about 75%. Light transmission is not high.

Contents of the invention

The technical problem to be solved by the present invention is to provide a kind of transparent PM2.5 filter film with photocatalysis and its preparation method for the deficiencies in the above-mentioned prior art, and improve the low light transmittance and poor air permeability of the existing air filter film And the problem of single function is applicable to fields such as indoor air purification devices and window screen materials.

The present invention adopts following technical scheme:

A transparent PM2.5 filter membrane with photocatalysis, the PM2.5 filter membrane is a composite nanofiber membrane with a sandwich structure, including polyacrylonitrile@TiO ₂ and polyamide-6, polyamide-6 is set in The upper and lower layers of the sandwich-like structure, polyacrylonitrile @TiO ₂ is arranged in the middle layer of the sandwich-like structure, and the nanofiber diameter distribution of the composite nanofiber membrane is 60-100 nm.

Further, the porosity of the polyacrylonitrile@TiO ₂ is 80-85%, and the surface pore diameter is 0.05-0.1 μm.

Further, the light transmittance of the composite nanofiber film is 70-75%, and the gas permeability is 14450-14912 mL/(cm ² ·h).

A preparation method of a photocatalytic transparent PM2.5 filter film, comprising the following steps:

S1. Prepare a PAN@TiO ₂ spinning solution with a mass percentage of 6-10% and a polyamide-6 spinning solution with a mass percentage of 12-16%, respectively, wherein the PAN@TiO ₂ spinning solution is doped with TiO ₂ with a mass fraction of 20%;

S2. Inject the PAN@TiO ₂ spinning solution and the polyamide-6 spinning solution prepared in step S1 into the two liquid storage cylinders of the textile nozzle in the electrospinning machine respectively, and set the textile nozzle on the electrospinning machine to receive On the left side of the device, the flow rate of the spinning solution is controlled by a syringe pump. Tin foil paper is set on the receiving device of the electrospinning machine, and then single-needle spinning is started to spin different polymers in the liquid storage cylinder respectively. Obtain a uniform and transparent PAN@TiO ₂ /PA6 nanocomposite fiber film;

S3. Vacuum-dry the PAN@TiO ₂ /PA6 nanocomposite fiber membrane obtained in step S2 together with tinfoil at 60°C for 18h-24h to prepare a sandwich-like transparent PM2.5 filter membrane with photocatalytic properties.

Further, in step S1, slowly add polyacrylonitrile powder into the N,N-dimethylformamide solution, stir magnetically at 20-25°C for 8-12h, then slowly add nano-titanium dioxide powder TiO ₂ , and continue at 20-25°C After stirring for 8-12 hours, a PAN@TiO ₂ spinning solution accounting for 6%-10% of the total spinning solution mass fraction is prepared.

Further, the molecular weight of the polyacrylonitrile powder is 150,000, and the average particle diameter of the nano titanium dioxide powder is 40-50 nm.

Further, in step S1, polyamide-6 particles are dissolved in formic acid solution, and magnetically stirred at 25°C for 18-24 hours until the polyamide-6 particles are completely dissolved, and polyamide-6 spinning with a mass percentage of 12-16% is prepared. liquid, spare.

Further, the molecular weight of the polyamide-6 particles is 18000-20000.

Further, in step S2, the polyamide-6 spinning solution is first opened for spinning, and a layer of polyamide-6 nanofiber membrane is obtained after collecting for 20 to 30 minutes; then the PAN/TiO ₂ spinning solution is opened for spinning, Collect for 15 to 20 minutes; finally turn on the polyamide-6 spinning solution for spinning, and collect for 20 to 30 minutes.

Further, the spinning voltage is 18-20kV, the spinning distance is 18-20cm, and the feeding speed is 0.5-0.8mL/h.

Compared with the prior art, the present invention has at least the following beneficial effects:

The present invention is a transparent PM2.5 filter membrane with photocatalysis, and obtains a composite nano-air filter with a sandwich structure composed of polyacrylonitrile/ _TiO2 nanofibers and polyamide-6 nanofibers through a simple electrospinning method The material, the composite film has a tight cross-linked network, and has photocatalytic function, high transparency and efficient PM2.5 filtration performance. It can not only effectively prevent outdoor PM2.5 from entering the room when applied to anti-nano screens, but also protect against sunlight. Under the action, it can photocatalyze the low concentration of harmful gases in the atmosphere, while maintaining good lighting and ventilation effects.

Further, the porosity of polyacrylonitrile@TiO ₂ is 80-85%, the average surface pore diameter is 0.05-0.1 μm, the specific area is large, the porosity is high, the filtration rate of PM2.5 in the air is high, the transparency is high, and it is breathable Good performance.

Further, the light transmittance of the composite nanofiber membrane is 70-75%, and the air permeability is 14450mL/(cm ² ·h)-14912mL/(cm ² ·h), which has good filtration performance, high light transmittance, and air permeability Well, the filtration efficiency of PM2.5 in the air is 97.97% to 99.89%, and it has a good photocatalytic effect on indoor VOCs.

The invention also discloses a method for preparing a photocatalytic transparent PM2.5 filter membrane, respectively preparing PAN@TiO ₂ spinning solution and polyamide-6 spinning solution, and then spinning through a double-needle electrostatic spinning machine. to obtain a uniform and transparent PAN@TiO ₂ /PA6 nanocomposite fiber membrane, and finally vacuum-dried at 60°C for 18-24 hours to obtain a sandwich-like transparent PM2.5 filter membrane with photocatalytic properties. The preparation method is simple to operate It is easy to operate, and the prepared PM2.5 filter membrane has the functions of transparency, high-efficiency filtration of PM2.5, and photocatalytic degradation of VOCs.

Furthermore, in this method, the hydrophilic nano-TiO ₂ is directly added to the PAN spinning solution, the configuration process is simple and easy, and the prepared PAN@TiO ₂ spinning solution is homogeneous and transparent, and has stable properties.

Further, in this method, PA6 particles are directly dissolved in formic acid solvent, and stirred at 25°C for a certain period of time to obtain a homogeneous and transparent PA6 spinning solution. The method is simple and easy, and the raw materials are easy to obtain.

Further, in this method, alternate spinning is carried out through a double-needle spinning machine, and the spinning time of different pipeline needles is controlled respectively. First, PA6 spinning is started, and the spinning is collected for 20 minutes to 30 minutes, and then the PAN/TiO2 spinning solution is turned on. Spinning and collecting for 15 to 20 minutes, and finally polyamide-6 spinning, and spinning and collecting for 20 to 30 minutes. The obtained nanofiber filter membrane has good light transmittance and filtering effect.

Further, when the spinning voltage is 18-20kV, the spinning distance is 18-20cm, and the feeding speed is 0.5mL/h-0.8mL/h, the spinning process is stable and the average diameter of the obtained nanofibers is small. The pore size is small, the porosity is high, the thickness of the obtained nanofiber membrane is uniform, and the performance is stable.

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

Description of drawings

Fig. 1 is the schematic diagram of the electrospinning machine device of preparation method of the present invention;

Fig. 2 is a scanning electron micrograph of the composite nanofiber air filter membrane obtained in Example 3 of the present invention.

Among them: 1. High-voltage power supply; 2. Syringe; 3. Micro-volume dual-channel injection pump; 4. Spinneret; 5. Receiving device.

Detailed ways

The invention discloses a transparent PM2.5 filter membrane with photocatalysis. The PM2.5 filter membrane is a composite nanofiber membrane with a sandwich structure, which is polyamide-6 and polyacrylonitrile@TiO ₂ from top to bottom. And polyamide-6, PM2.5 filter membrane is PAN@TiO ₂ /PA6 composite nanofiber membrane, and its nanofiber diameter distribution is 60nm～100nm.

Among them, the light transmittance of PAN@TiO ₂ /PA6 composite nanofiber membrane is 70%~75%, the air permeability is 14450mL/(cm ² h)~14912mL/(cm ² h), and the porosity is 80%~ About 85%, the surface pore diameter is 0.05-0.1μm.

The present invention also discloses a method for preparing a photocatalytic transparent PM2.5 filter membrane, comprising the following steps:

S1. Prepare a PAN@TiO ₂ spinning solution with a mass percentage of 6% to 10% and a polyamide 6 spinning solution with a mass percentage of 12% to 16%, respectively, wherein the PAN@TiO ₂ spinning solution is mixed with TiO ₂ mixed with a mass fraction of 20%;

Among them, slowly add polyacrylonitrile powder (PAN) into N,N-dimethylformamide (DMF) solution, stir magnetically at 25°C for 8-12 hours, and then slowly add nanometer titanium dioxide powder (TiO ₂ ) into the solution, Continue stirring at 25°C for 8-12 hours to prepare a PAN@TiO ₂ spinning solution with a mass fraction of 6%-10%;

Preferably, the molecular weight of polyacrylonitrile is 150,000, and the average particle diameter of hydrophilic nano _TiO2 is 40nm～50nm;

Dissolve polyamide-6 particles (PA6) in formic acid solution, stir magnetically at 25°C for 18-24 hours until the polyamide-6 particles are completely dissolved, and prepare polyamide-6 (PA6) spinning with a mass percentage of 12% to 16%. liquid, spare;

Preferably, the molecular weight of polyamide-6 is 18000-20000.

S2. Inject the PAN@TiO ₂ and PA6 spinning solution into the two liquid storage tanks of the textile nozzle of the electrospinning machine respectively, set the textile nozzle on the left side of the receiving device of the electrospinning machine and control the spinning solution through a syringe pump Set the tin foil paper on the receiving device of the electrospinning machine, and then start the single-needle spinning to spin the different polymers in the liquid storage cylinder respectively, and a layer of uniform and transparent PAN@TiO can be obtained on the surface of the receiving device. ₂ / PA6-like sandwich structure nanocomposite fiber membrane;

Among them, first turn on the PA6 spinning solution for spinning, and collect for 20 minutes to 30 minutes; then turn on the PAN/TiO ₂ spinning solution for spinning, and collect for 15 minutes to 20 minutes; then turn on the PA6 spinning solution for spinning, and collect for 20 minutes to 30 minutes;

Preferably, the spinning voltage is 18-20kV, the spinning distance is 18-20cm, and the feeding speed is 0.5mL/h-0.8mL/h.

S3. Vacuum-dry the PAN@TiO ₂ /PA6 nanocomposite fiber film obtained in step S2 together with tinfoil at 60°C for 18h to 24h to obtain a PAN@TiO ₂ /PA6 composite nanofiber with a sandwich-like structure and stable performance PM2.5 filter material.

Example 1:

S1, spinning solution preparation

Weigh 3g of polyacrylonitrile powder (PAN), 0.6g of nano-titanium dioxide powder (TiO ₂ ), 47g of N,N-dimethylformamide (DMF), slowly add the PAN powder into the DMF solution, and magnetically Stir for 8h, then slowly add nano- _TiO2 into the solution, continue to stir at 25°C for 8h, and prepare a PAN@ _TiO2 spinning solution with a mass fraction of 6%; weigh 6g of polyamide-6 particles (PA6) and dissolve in 44g of formic acid solution was magnetically stirred at 25°C for 18 hours until the PA6 particles were completely dissolved, and a PA6 spinning solution with a mass percentage of 12% was prepared and set aside.

S2. Preparation of PAN@TiO ₂ /PA6 composite nanofibers

Inject the above-mentioned PAN@TiO ₂ spinning solution and PA6 spinning solution into the two liquid storage cylinders of the syringe 2 in the micro-injection pump 3, place the tinfoil on the receiving device 5, start the high-voltage power supply 1, spinneret 4 Start working (as shown in Figure 1).

First turn on the PA6 spinning solution for spinning, the spinning voltage is 18KV, the spinning distance is 18cm, the feeding speed of the spinning solution is 0.5mL/h, and the collection is 30min; then turn on the PAN/TiO ₂ spinning solution for spinning, adjust The spinning voltage is 20KV, the spinning distance is 18cm, the feeding speed of the spinning solution is 0.5mL/h, and the collection is 15min; finally, the PA6 spinning solution is turned on for spinning, the spinning voltage is 18KV, the spinning distance is 18cm, and the spinning solution The liquid feeding rate is 0.5mL/h, and the collection time is 30min;

S3. Post-treatment of PAN@TiO ₂ /PA6 composite nanofibers

After the shutdown, the obtained PAN@TiO ₂ /PA6 composite electrospun fiber membrane with tinfoil was vacuum-dried at 60°C for 24 hours to fully evaporate the solvent, and a PAN@TiO ₂ /PA6 composite nanostructure with a sandwich-like structure and stable performance was obtained. Fiber PM2.5 filter material.

The PAN@TiO ₂ /PA6 composite nanofiber membrane is tightly cross-linked, the average nanofiber diameter is 70nm, the porosity is 80%, the average surface pore size is 0.06μm, and the filtration efficiency of PM2.5 in the air is 97.97%. The light transmittance is 72%, the air permeability is 14688mL/(cm ² ·h), and it has a good photocatalytic effect on indoor VOCs.

Example 2:

S1, spinning solution preparation

4g of polyacrylonitrile powder (PAN), 0.8g of nano titanium dioxide powder (TiO ₂ ), and 46g of N,N-dimethylformamide (DMF) were weighed respectively. Slowly add PAN powder into the DMF solution, stir magnetically at 25°C for 12h, then slowly add nano-TiO ₂ into the solution, continue stirring at 25°C for 12h, and prepare a PAN@TiO ₂ spinning solution with a mass fraction of 8%; weigh Take 7g of polyamide-6 particles (PA6) and dissolve them in 43g of formic acid solution, stir magnetically at 25°C for 24h until the PA6 particles are completely dissolved, and prepare a PA6 spinning solution with a mass percentage of 14%.

S2. Preparation of PAN@TiO ₂ /PA6 composite nanofibers

Inject the above-mentioned PAN@TiO ₂ spinning solution and PA6 spinning solution into the two liquid storage cylinders of the syringe 2 in the micro-injection pump 3, place the tinfoil on the receiving device 5, start the high-voltage power supply 1, spinneret 4 Start working (as shown in Figure 1).

First turn on the PA6 spinning solution for spinning, the spinning voltage is 20KV, the spinning distance is 20cm, the feeding speed of the spinning solution is 0.6mL/h, and the collection is 20min; then the polyacrylonitrile/TiO ₂ blended spinning solution is turned on for spinning Silk, the spinning voltage is 20KV, the spinning distance is 18cm, the feeding speed of the spinning solution is 0.6mL/h, and the collection is 10min; finally, the PA6 spinning solution is turned on for spinning, the spinning voltage is 20KV, the spinning distance is 20cm, the spinning The feeding speed of the silk liquid is 0.6mL/h, and the collection time is 20min;

S3. Post-treatment of PAN@TiO ₂ /PA6 composite nanofibers

After shutdown, the obtained composite electrospun fiber membrane with tinfoil was vacuum-dried at 60°C for 24 hours to fully volatilize the solvent, and a PAN@TiO ₂ /PA6 composite nanofiber PM2.5 filter material with a sandwich-like structure and stable performance was obtained .

The PAN@TiO ₂ /PA6 composite nanofiber membrane has a tight cross-linked network, the average nanofiber diameter is 60nm, the porosity is 83%, the average surface pore size is 0.1μm, and the filtration efficiency of PM2.5 in the air is 98.89%. The light transmittance is 75%, the air permeability is 14912mL/(cm ² ·h), and it has a good photocatalytic effect on indoor VOCs.

Example 3:

S1, spinning solution preparation

5g of polyacrylonitrile powder (PAN), 1g of nano titanium dioxide powder (TiO ₂ ), and 45g of N,N-dimethylformamide (DMF) were weighed respectively. Slowly add the PAN powder into the DMF solution, stir magnetically at 25°C for 12h, then slowly add nano- _TiO2 into the solution, and continue stirring at 25°C for 12h to prepare a PAN@TiO2 spinning solution with a mass fraction of 10%; weigh 8 g of polyamide-6 particles (PA6) were dissolved in 42 g of formic acid solution, and magnetically stirred at 25°C for 24 hours until the PA6 particles were completely dissolved, and a PA6 spinning solution with a mass percentage of 16% was prepared.

S2. Preparation of PAN@TiO ₂ /PA6 composite nanofibers

Inject the above-mentioned PAN@TiO ₂ and polyamide-6 spinning solution into the two liquid storage cylinders of the syringe 2 in the micro-injection pump 3, place the tinfoil on the receiving device 5, start the high-voltage power supply 1, spinneret 4 Start working (as shown in Figure 1).

First turn on the polyamide-6 spinning solution for spinning, the spinning voltage is 20KV, the spinning distance is 20cm, the feeding speed of the spinning solution is 0.8mL/h, and the collection is 20min; then the PAN/TiO ₂ blended spinning solution is turned on. Spinning, the spinning voltage is 20KV, the spinning distance is 20cm, the feeding speed of the spinning liquid is 0.5mL/h, and the collection is 10min; finally, the polyamide-6 spinning liquid is turned on for spinning, the spinning voltage is 20KV, and the spinning The distance is 20cm, the feeding speed of spinning solution is 0.8mL/h, and the collection time is 20min;

S3. Post-treatment of PAN@TiO ₂ /PA6 composite nanofibers

After shutdown, the obtained composite electrospun fiber membrane with tinfoil was vacuum-dried at 60°C for 24 hours to fully volatilize the solvent, and a PAN@TiO ₂ /PA6 composite nanofiber PM2.5 filter material with a sandwich-like structure and stable performance was obtained .

The PAN@TiO ₂ /PA6 composite nanofiber membrane has a tight cross-linked network, an average nanofiber diameter of 100nm, a porosity of 85%, and an average pore diameter of 0.05μm. The filtration efficiency of PM2.5 in the air is 99.89%. The light rate is 70%, the air permeability is 14450mL/(cm ² ·h), and it has a good photocatalytic effect on indoor VOCs.

Table 1 is the comparison before and after the effect of the composite nanofiber air filter material of Example 3 of the present invention on several indoor Vocs

The scanning electron microscope image of the PAN@TiO ₂ /PA6 composite nanofiber membrane obtained in Example 3 is shown in Figure 2. In the figure, the nanofiber network is tightly cross-linked, with an average diameter of 100 nm, a porosity of 85%, and an average pore diameter of 0.05 μm.

The above content is only to illustrate the technical ideas of the present invention, and cannot limit the protection scope of the present invention. Any changes made on the basis of the technical solutions according to the technical ideas proposed in the present invention shall fall within the scope of the claims of the present invention. within the scope of protection.

Claims (10)

1. a kind of transparent PM2.5 filter membranes with photocatalytic, it is characterised in that PM2.5 filter membranes are class sandwich structure Composite nano-fiber membrane, including polyacrylonitrile@TiO₂With polyamide -6, polyamide -6 is arranged on the upper strata of class sandwich structure And lower floor, polyacrylonitrile@TiO₂It is arranged on the intermediate layer of class sandwich structure, the nanofiber diameter point of composite nano-fiber membrane Cloth is 60~100nm.

2. a kind of transparent PM2.5 filter membranes with photocatalytic according to claim 1, it is characterised in that described poly- Acrylonitrile@TiO₂Porosity be 80~85%, surface apertures be 0.05~0.1 μm.

3. a kind of transparent PM2.5 filter membranes with photocatalytic according to claim 1 or 2, it is characterised in that described The light transmittance of composite nano-fiber membrane is 70~75%, and gas permeability is 14450~14912mL/ (cm²·h)。

A kind of 4. method for preparing the transparent PM2.5 filter membranes with photocatalytic described in claim 1, it is characterised in that bag Include following steps：

S1, PAN@TiO are prepared respectively₂Spinning solution and the spinning solution of polyamide -6, wherein, the PAN@TiO₂In spinning solution doped with Account for PAN@TiO₂The TiO of spinning solution mass percent 20%₂；

S2, the PAN@TiO for preparing step S1₂Spinning solution and the spinning solution of polyamide -6 are injected separately into electrostatic spinning machine weaving spray In two liquid storage cylinders of head, weaving shower nozzle is arranged on electrostatic spinning machine reception device side and spinning solution is controlled by syringe pump Flow velocity, masking foil is set in the reception device of electrostatic spinning machine, then start single needle spinning respectively in liquid storage cylinder Different polymer carry out spinning, and the PAN@TiO of one layer of homogeneous transparent are obtained on reception device surface₂/ PA6 nano-composite fibers Film；

S3, the PAN@TiO by gained in step S2₂The related masking foil of/PA6 nano-composite fiber films together do at 60 DEG C by vacuum Dry 18h~24h, class sandwich structure, which is made, has the transparent PM2.5 filter membranes of photocatalytic.

5. a kind of preparation method of transparent PM2.5 filter membranes with photocatalytic according to claim 4, its feature exist In, in step S1, the fine powder of polypropylene is slowly added in DMF solution, 20~25 DEG C of magnetic agitations 8~ 12h, it is slow added into nano titanium dioxide powder TiO₂, continue 20~25 DEG C of 8~12h of stirring, be prepared and account for total spinning solution The PAN@TiO of mass fraction 6%~10%₂Spinning solution.

6. a kind of preparation method of transparent PM2.5 filter membranes with photocatalytic according to claim 5, its feature exist In the molecular weight of, the fine powder of polypropylene be 150,000, the average grain diameter of the nano titanium dioxide powder for 40~ 50nm。

7. a kind of preparation method of transparent PM2.5 filter membranes with photocatalytic according to claim 4, its feature exist In in step S1, the particle of polyamide -6 being dissolved in into formic acid solution, 25 DEG C of 18~24h of magnetic agitation are complete to the particle of polyamide -6 Dissolving, the spinning solution of polyamide -6 that mass percent is 12~16% is prepared, it is standby.

8. a kind of preparation method of transparent PM2.5 filter membranes with photocatalytic according to claim 7, its feature exist In the molecular weight of the particle of polyamide -6 is 18000~20000.

9. a kind of preparation method of transparent PM2.5 filter membranes with photocatalytic according to claim 4, its feature exist In in step S2, first unlatching polyamide -6 spinning solution carries out spinning, collects 20~30min and obtains the Nanowire of a strata acid amides -6 Film is tieed up as substrate；It is then turned on PAN/TiO₂Spinning solution carries out spinning, collects 15~20min；Finally it is then turned on the spinning of polyamide -6 Silk liquid carries out spinning, collects 20~30min.

10. a kind of preparation method of transparent PM2.5 filter membranes with photocatalytic according to claim 9, its feature It is, spinning voltage is 18~20kV, and spinning distance is 18~20cm, and it is 0.5~0.8mL/h to feed liquid speed degree.