CN111850710A

CN111850710A - Anti-blocking electrostatic spinning nozzle and manufacturing method thereof

Info

Publication number: CN111850710A
Application number: CN202010636423.8A
Authority: CN
Inventors: 程楚云; 刘颖波; 彭宇川; 胡昭宇
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-07-04
Filing date: 2020-07-04
Publication date: 2020-10-30

Abstract

The invention provides an anti-blocking electrostatic spinning nozzle and a manufacturing method thereof. The sprayer comprises a shell made of a strong conductive material, and a channel for the polymer solution to flow through is formed in the shell; and an inner liner made of a weakly conductive material disposed on an inner wall of the housing. The spray head can continuously work in a high-voltage electrostatic field without blockage, and the prepared fiber has uniform thickness and can be widely applied to the existing needle type electrostatic spinning equipment.

Description

Anti-blocking electrostatic spinning nozzle and manufacturing method thereof

Technical Field

The patent relates to a method for manufacturing an anti-blocking spray head (needle point) which can be widely applied to needle type electrostatic spinning.

Background

With the wide application of nanofibers and products thereof, the electrospinning technology and equipment thereof are gradually receiving attention from people. Needle type electrostatic spinning equipment has the characteristics of simple equipment, various spinning raw materials, controllable fiber diameter, uniform distribution and the like, and more people continuously develop various needle type electrostatic (melt) spinning equipment. For example, patent documents having application numbers 201610839245.2, 201510063309.X, 201410185429.2 and the like disclose needle electrospinning apparatuses. Because the inner diameters of the spinning nozzles (needle points) are smaller and the spinning nozzles are easy to block under the action of a high-voltage electrostatic field, the equipment cannot realize continuous and stable production; even if the spray head is cleaned regularly, the stability and uniformity of the product are affected.

Due to the requirement of electrostatic spinning, spray heads of needle type electrostatic spinning equipment are made of metal materials, and pipelines connected with the spray heads are made of various plastics. In a high-voltage electrostatic field, plastic and metal have larger potential difference, and the higher the voltage is, the larger the potential difference is. The polymer solution slowly solidifies continuously under the influence of the potential difference, eventually causing clogging.

Therefore, the blockage of the nozzle becomes a problem to be solved in needle type electrostatic spinning.

Disclosure of Invention

Aiming at the problems mentioned in the background technology, the invention provides an anti-blocking electrostatic spinning spray head and a manufacturing method thereof. The spray head and the connecting pipeline thereof have no obvious potential difference in a high-voltage electrostatic field, so that the blockage of the spray head is avoided, and the smooth use of the spray head for a long time is ensured.

The invention provides an anti-blocking electrostatic spinning nozzle, which comprises:

a housing made of a strongly conductive material, said housing having formed therein a passage for the polymer solution to flow through;

and the inner lining is arranged on the inner wall of the shell and made of a weak conductive material.

Further, the strong conductive material may be various metal materials such as iron, stainless steel, copper, aluminum alloy, etc., a good conductor, a semiconductor, or a composite material thereof.

Further, the weakly conductive material may be various insulating materials such as PP, PE, PET, PVC, PTFE, etc., poor conductors, or composite materials thereof, according to the use requirements of the polymer solution or the solvent thereof.

Further, the thickness of inside lining is 0.1 ~ 5 mm.

Further, at the outlet of the channel, the distance between the end part of the lining and the end part of the shell is 0-10 mm.

Further, the number of the channels is plural.

Further, the number of the channels is one or four.

Furthermore, the anti-blocking electrostatic spinning nozzle also comprises a protective layer arranged on the outer wall of the shell.

Furthermore, the material of the protective layer can be various insulating materials such as PP, PE, PET, PVC, PTFE, etc., poor conductors or composite materials thereof.

The manufacturing method of the anti-blocking electrostatic spinning nozzle comprises the following steps:

processing the strong conductive material to manufacture a shell, wherein a channel for the circulation of a polymer solution is formed in the shell;

the weak conductive material is molded by injection to form a lining with the shape matched with the inner wall of the shell;

inserting the liner into the shell such that the liner mates with the shell.

In addition, the method for manufacturing the anti-clogging electrostatic spinning nozzle may further include the steps of:

performing injection molding on the weak conductive material to form a lining;

the strong conductive material is formed into an outer shell outside the inner liner by an electroplating or deposition method.

The invention has the beneficial effects that: the nozzle can continuously work in a high-voltage electrostatic field without blockage, and the prepared fiber has uniform thickness and can be widely applied to the existing needle type electrostatic spinning equipment.

Drawings

Fig. 1 is a schematic structural view (longitudinal section) of an anti-clogging electrospinning nozzle according to an embodiment of the present invention.

Fig. 2 is a schematic structural view (bottom view) of a four-needle anti-blocking electrostatic spinning nozzle according to another embodiment of the present invention.

Fig. 3 is a schematic sectional view along the direction a-a in fig. 2.

Fig. 4 is a photomicrograph of PU nanofibers prepared using the anti-blocking electrospinning nozzle of the present invention.

Fig. 5 is a photomicrograph of PAA nanofibers prepared using the anti-blocking electrospinning nozzle of the present invention.

Fig. 6 is a photomicrograph of PA nanofibers prepared using the anti-blocking electrospinning nozzle of the present invention.

The reference signs explain: 1. a liner; 2. a housing; 3. a channel; a. distance between the end of the outer shell and the end of the inner liner.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of "first," "second," and similar terms in the description and in the claims does not indicate any order, quantity, or importance, but rather is used to distinguish one element from another. Also, the use of the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships are changed accordingly. The thicknesses and shapes of the various film layers in the drawings are not to be considered true proportions, but are merely intended to illustrate the invention.

As shown in fig. 1, the anti-blocking electrostatic spinning nozzle of the present invention comprises a liner 1 and an outer shell 2. The housing 2 has a passage 3 for the polymer solution to flow through. The upper part of the housing 2 has a larger diameter and the middle part is contracted, so that the lower part has a smaller diameter. In this embodiment, the upper portion of the housing 2 has a diameter of 20mm and the lower portion has a diameter of 5 mm. The lining 1 is tightly attached to the inner wall of the shell 2, so that the polymer solution can flow along the inner wall of the lining 1. In the present embodiment, the thickness of the liner 1 is 1 mm. The bottom end of the shell 2 with the larger diameter is used as an inlet of the polymer solution, and the top end of the shell 2 with the smaller diameter is used as an outlet of the polymer solution. At the outlet, the end of the liner 1 is at a distance a, which may be ± 10mm, from the end of the shell 2; that is, the inner wall of the outer shell 2 is spaced a distance a without the liner 1, or the liner 1 extends a distance a beyond the outer shell 2. In this embodiment, a is +0.5mm, i.e. the inner wall of the outer shell 2 is 0.5mm free of the liner 1. In the present embodiment, the outer shell 2 is made of stainless steel and the inner liner 1 is made of PP. In this embodiment, the anti-blocking electrostatic spinning nozzle is a single-tube (one-needle) nozzle, stainless steel is processed to form a housing 2, and a passage 3 for polymer solution to flow is formed in the housing 2; then, carrying out injection molding on PP to form a lining 1 of which the shape is matched with the inner wall of the shell 2; finally, the liner 1 is inserted into the outer shell 2, so that the liner 1 is tightly matched with the outer shell 2.

In other embodiments, the housing 2 has a plurality of channels 3 therein through which the polymer solution flows. For example, figures 2 and 3 show a four needle anti-clogging electrospinning jet head comprising a liner 1 and a shell 2, the shell 2 having four channels 3 for the polymer solution to flow through. The diameter of the upper part of the shell 2 is larger and is 20 mm; the lower part is four needles, and the diameter of each needle is 2 mm. The lining 1 is tightly attached to the inner wall of the shell 2, so that the polymer solution can flow along the inner wall of the lining 1. The thickness of the liner 1 in the four needles is 0.5 mm. The top end of the upper part of the shell 2 with larger diameter is used as an inlet of the polymer solution, and the bottom ends of the four needles with smaller diameter at the lower part of the shell 2 are used as outlets of the polymer solution. At the four outlets, the ends of the liner 1 are all at a distance a, of ± 10mm from the ends of the shell 2.

In other embodiments, the materials of the outer shell 2 and the inner liner 1 may be changed as long as the material of the outer shell 2 is a strong conductive material and the material of the inner liner 1 is a weak conductive material.

In other embodiments, the outer wall of the housing 2 is further provided with a protective layer for protection (e.g., corrosion protection) for use in a particular use environment. The protective layer can be made of various insulating materials such as PP, PE, PET, PVC, PTFE and the like, poor conductors or composite materials thereof.

The liner 1 is manufactured in different ways according to the type of the spray head. If a single tube (needle) nozzle is used, the liner 1 can be sleeved or pre-molded to a desired form and then matched with the shell 2. If a multi-tube (multi-needle) spray head is adopted, the shell 2 can be manufactured by adopting an injection molding mode or directly on the outer layer of the lining 1 through an electroplating or other metal deposition method according to the complexity of the spray head.

In use, the inner liner 1 is connected with a polymer solution supply pipeline, and the outer shell 2 is used as a conductor to be connected with a high-voltage static electricity source. Because the anti-blocking electrostatic spinning nozzle comprises a two-layer structure, the inner layer is made of anticorrosive plastics, the outer layer is made of metal, and the potential difference of the electrospinning solution at the nozzle is about 1/3 of a common nozzle, so that the polymer solution is not easy to solidify in the nozzle, and the anti-blocking effect is achieved. Therefore, the anti-blocking electrostatic spinning spray head can not be blocked in a high-voltage electrostatic field and is smooth after long-term use.

The performance of the anti-clogging electrostatic spinning nozzle of the present invention was tested.

Test 1:

and (3) testing conditions are as follows: polyurethane (PU) solution is used, the flow rate is 5ml/min, 20 four-needle anti-blocking electrostatic spinning nozzles are adopted, the a value is adjusted to be-0.5 mm, and the spinning voltage is +/-45 KV; after the nozzles continuously work for 20 days, all the nozzles smoothly spin without blockage, and the thickness of the obtained PU nano fiber is relatively uniform, as shown in figure 4.

Test 2:

and (3) testing conditions are as follows: using polyamic acid (PAA) solution with flow rate of 5ml/min, adopting 100 four-needle anti-blocking electrostatic spinning nozzles, adjusting a value to be 0mm, and spinning voltage to be +/-40 KV; after the spray heads continuously work for 30 days, all the spray heads smoothly spin without blockage, and the thickness of the obtained PAA nano fiber is relatively uniform, as shown in figure 5.

Test 3:

and (3) testing conditions are as follows: using Polyamide (PA) solution, the flow rate is 5ml/min, adopting 50 four-needle anti-blocking electrostatic spinning nozzles, adjusting the value of a to be 1mm, and the spinning voltage to be +/-35 KV; after the nozzles continuously work for 30 days, all the nozzles smoothly spin without blockage, and the obtained PA nano-fiber has uniform thickness, as shown in figure 6.

Therefore, the anti-blocking electrostatic spinning spray head can continuously work in a high-voltage electrostatic field without blocking, and the prepared fibers are uniform in thickness.

The above embodiments are only for illustrating the invention and are not to be construed as limiting the invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention, therefore, all equivalent technical solutions also fall into the scope of the invention, and the scope of the invention should be defined by the claims.

Claims

1. An anti-clogging electrostatic spinning nozzle comprising:

2. The anti-clogging electrostatic spinning nozzle according to claim 1, characterized in that: the strong conductive material is one or a composite material of at least two of iron, stainless steel, copper, aluminum and aluminum alloy.

3. The anti-clogging electrostatic spinning nozzle according to claim 2, characterized in that: the weak conductive material is one or a composite material of at least two of PP, PE, PET, PVC and PTFE.

4. The anti-clogging electrostatic spinning nozzle according to claim 3, characterized in that: the thickness of inside lining is 0.1 ~ 5 mm.

5. The anti-clogging electrostatic spinning nozzle according to claim 4, characterized in that: at the outlet of the channel, the distance between the end part of the lining and the end part of the shell is 0-10 mm.

6. The anti-clogging electrostatic spinning nozzle according to claim 1, characterized in that: the number of the channels is multiple.

7. The anti-clogging electrostatic spinning nozzle according to claim 6, characterized in that: the number of the channels is one or four.

8. The anti-clogging electrostatic spinning nozzle according to any one of claims 1 to 7, characterized in that: the anti-blocking electrostatic spinning nozzle further comprises a protective layer arranged on the outer wall of the shell.

9. The anti-clogging electrostatic spinning nozzle according to claim 8, characterized in that: the protective layer is made of one or a composite material of at least two of PP, PE, PET, PVC and PTFE.

10. The method for manufacturing the anti-clogging electrostatic spinning nozzle according to claim 1, comprising the steps of:

inserting the liner into the shell such that the liner mates with the shell.

11. The method for manufacturing the anti-clogging electrostatic spinning nozzle according to claim 1, comprising the steps of:

performing injection molding on the weak conductive material to form a lining;