A printing method

Abstract

The present invention relates to a printing method, which uses a spray needle. The tip of the spray needle is provided with a liquid outlet. The spray needle vibrates the liquid to be printed in the spray needle out of the liquid outlet and atomizes it. The minimum thickness of the outer edge of the needle tip is greater than the amplitude of the needle tip when the spray needle vibrates; the outer edge of the needle tip is transitioned by a rounded corner so that the minimum thickness is greater than the amplitude of the needle tip when the spray needle vibrates; the spray needle is composed of a C-shaped groove I and a C-shaped groove II; or, the spray needle is composed of a cylindrical tube and a half-sectioned cylinder; or, the spray needle is a truncated hollow cylinder, and the truncated hollow cylinder is a geometric body obtained by cutting the hollow cylinder with a plane that intersects all generatrixes of the hollow cylinder but is not parallel to the bottom surface of the hollow cylinder, and the intersection area of ​​the cross section and the hollow part is the liquid outlet. The present invention can effectively solve the problem of the spray needle spray diverging upward and downward.

Description

Technical Field

[0001] The invention belongs to the technical field of inkjet printing and dyeing, and relates to a printing method. Background Art

[0002] Water is a limited and irreplaceable natural resource essential for human survival. Globally, water availability is in critical demand. my country's per capita water availability is only one-third of the global average, making it a water-scarce country. A prominent theme in the development of the international textile printing and dyeing industry today is the focus on resources, the environment, and health, with a strong emphasis on developing and applying clean textile production technologies. Traditional textile printing and dyeing finishing processes primarily utilize dyes, chemical auxiliaries, and water. Reducing water use, minimizing the discharge of toxic and hazardous chemicals, and reducing waste generation, shifting pollution treatment from end-of-pipe to initial and intermediate treatment, and achieving clean processing and production, are key to the sustainable development of the textile printing and dyeing industry. Since the 1970s, significant human and material resources have been invested internationally in developing environmentally friendly dyes, auxiliaries, and new technologies and equipment that are energy-efficient and require little or no water.

[0003] Currently developed spray needles (such as Figure 1 As shown in the figure, a technology for dyeing with little or no water can be realized. A large droplet enters the liquid storage needle 3 through the liquid inlet at the rear end. A pulse current is applied to the piezoelectric ceramic resonator plates 2 on both sides of the metal plate 1 at different frequencies. The piezoelectric ceramic resonator plates 2 on both sides vibrate simultaneously, causing the droplet at the front end of the steel needle 3 to fall onto the surface of the medium, completing the dyeing process.

[0004] However, the droplets at the needle tip do not flow out as quickly as a jet, but form independent droplets one after another at the needle tip under the control of the intelligent negative pressure ink path system and the combined action of the droplet surface tension. The needle tip is very thin and sharp. Driven by the vibration of the ceramic resonator, the needle tip performs high-frequency reciprocating motion in the vertical direction. Even if the water flows downward, when the water droplets hang on the needle tip, as long as the amplitude of the needle tip is greater than the thickness of the needle tip, the E surface (such as Figure 2 As shown) can also contact water, D surface (as shown) Figure 3 As shown in the figure, the water droplets are quickly vibrated and beaten to form a downward spray 5. On the contrary, the E surface is quickly vibrated and beaten to form an upward spray 4. Therefore, the water mist sprayed by the spray needle is divided into two upward and downward sprays (as shown in the figure). Figure 4 As shown in FIG. 1 ). Since the distance between the needle tip and the fabric to be printed and dyed is very small, the downward spray 5 can be well controlled to be sprayed onto the fabric to be printed and dyed. However, the upward spray 4 is sprayed away from the fabric and will float and fall unevenly on the fabric to be printed and dyed, causing uneven printing and dyeing of the fabric, thereby affecting the printing and dyeing effect.

[0005] Patent CN115635775A discloses a multi-needle printhead comprising a metal sheet, multiple needles, and a piezoelectric resonator. The needles are positioned parallel to the edge of the metal sheet, circulating the liquid to be printed. The piezoelectric resonator, located on the side of the metal sheet, vibrates the sheet under the control of a drive signal, causing the needles to vibrate and eject the liquid within them. While this multi-needle printhead can adjust the amount of liquid discharged per shot and enable proportional mixing and sequential printing of different liquids, it still cannot prevent vertical dispersion of the spray.

[0006] Therefore, it is of great significance to study a printing method that can effectively avoid the spray from dispersing up and down. Summary of the Invention

[0007] The purpose of the present invention is to solve the problems existing in the prior art and provide a printing method.

[0008] To achieve the above object, the present invention adopts the following scheme:

[0009] A printing method uses a spray needle with a liquid outlet at the tip of the spray needle. The spray needle vibrates to vibrate the liquid to be printed out of the liquid outlet and atomizes it. The minimum thickness of the outer edge of the needle tip is greater than the amplitude of the needle tip when the spray needle vibrates (about several hundred nanometers).

[0010] like Figure 5 As shown in the figure, H is the minimum thickness of the outer edge of the needle tip, and h is the amplitude of the needle tip when the needle vibrates. When the needle sprays, the needle tip vibrates back and forth within the range of h, so when H>h, the water droplets will not touch the E surface, and no upward water mist will be generated.

[0011] As the preferred technical solution:

[0012] In the above-mentioned printing method, the outer edge of the needle tip is transitioned through a rounded corner so that the minimum thickness is greater than the amplitude of the needle tip when the needle vibrates.

[0013] In the above-described printing method, the nozzle comprises a C-shaped groove I and a C-shaped groove II; the notch of the C-shaped groove I is downward, the notch of the C-shaped groove II is upward, the C-shaped groove I is located above the C-shaped groove II, the lower surface of the C-shaped groove I is in contact with the upper surface of the C-shaped groove II, and the two are arranged to form a cylindrical tube, the central axis of which is denoted as axis X;

[0014] One end of the C-shaped groove I and the C-shaped groove II is end a, and the other end is end b; the ends a of the C-shaped groove I and the C-shaped groove II are flush, and the length of the C-shaped groove II is greater than that of the C-shaped groove I;

[0015] The end face of the b end of the C-shaped groove I is recorded as surface A, the end face of the b end of the C-shaped groove II is recorded as surface C, and the portion of the upper surface of the C-shaped groove II located between surface A and surface C is recorded as surface B; surface B is parallel to axis X, the angle between surface A and surface B is greater than or equal to 90° and less than 180°, and the angle between surface C and surface B is greater than 90° and less than 180°; surface B is used to pat the liquid to be printed after it is vibrated out of the liquid outlet and before it drips, so as to atomize it; when the angle between surface A and surface B is greater than 90° and less than 180°, surface A and surface C both serve as auxiliary surfaces to pat the liquid to be printed to atomize it; when the angle between surface A and surface B is equal to 90°, only surface C serves as an auxiliary surface to pat the liquid to be printed to atomize it; the former has a larger amount of vertical downward spray than the latter;

[0016] The intersections of surface B and surface C with the outer wall of the C-shaped groove II are chamfered.

[0017] In the above-mentioned printing method, the nozzle is composed of a cylindrical tube and a half-cylinder, the half-cylinder being a geometric body obtained by cutting the cylinder with a plane parallel to the central axis of the cylinder; the central axis of the cylindrical tube is denoted as axis X;

[0018] One end of the cylindrical tube and the half-split cylinder is end a, and the other end is end b; end a of the half-split cylinder fits with end b of the cylindrical tube, and does not completely seal the hollow part of the cylindrical tube;

[0019] The end face of the cylindrical tube at end b is recorded as face A, the cross section of the half-sectioned cylinder is recorded as face B, and the end face of the half-sectioned cylinder at end b is recorded as face C; face B is parallel to axis X, the angle between face A and face B is greater than or equal to 90° and less than 180°, and the angle between face C and face B is greater than 90° and less than 180°; face B is used to pat the liquid to be printed after it is vibrated out of the liquid outlet and before it drips, so as to atomize it; when the angle between face A and face B is greater than 90° and less than 1 When the angle between surfaces A and B is 80°, both surfaces A and C act as auxiliary surfaces to atomize the liquid to be printed. When the angle between surfaces A and B is 90°, only surface C acts as an auxiliary surface to atomize the liquid to be printed. The former sprays a larger amount of vertical downward spray than the latter. In addition, the area of ​​surface B of the nozzle composed of a cylindrical tube and a half-cylinder is larger than the area of ​​surface B of the nozzle composed of C-shaped groove I and C-shaped groove II, which can achieve a larger amount of atomized liquid to be printed.

[0020] The areas where surfaces B and C intersect with the cylindrical surface of the half-section cylinder are filleted.

[0021] In the above-mentioned printing method, the nozzle needle is an integrally formed part.

[0022] In a printing method as described above, the nozzle is an obliquely cut hollow cylinder, and the obliquely cut hollow cylinder is a geometric body obtained by cutting the hollow cylinder with a plane that intersects all the generatrixes of the hollow cylinder and is not parallel to the bottom surface of the hollow cylinder. The intersection area of ​​the cross section and the hollow part is the liquid outlet, and the position where the cross section intersects with the outer wall of the hollow cylinder is chamfered.

[0023] In the printing method described above, the shape of the liquid outlet is circular or semi-elliptical, and the number of liquid outlets is 1; the circular or semi-elliptical shape of the liquid outlet can increase the area of ​​the vibrating water droplets, thereby increasing the width / area of ​​the downward water mist.

[0024] In the printing method described above, the shape of the liquid outlet is semi-elliptical, the number of liquid outlets is 2 and they are symmetrically distributed on the cross section; this can increase the area of ​​the vibrating water droplets and increase the width / area of ​​the downward water mist.

[0025] In the printing method described above, the distance between the liquid outlet and the farthest end of the nozzle is greater than or equal to 1.2 mm, so that the liquid to be printed can be kept away from the farthest end of the nozzle, further preventing the liquid to be printed from contacting the cylindrical surface of the oblique hollow cylinder, thereby further avoiding the generation of upward spray.

[0026] In a printing method as described above, a barrier is provided at the farthest end of the nozzle needle, and the barrier is used to prevent the liquid to be printed from contacting the cylindrical surface of the oblique hollow cylinder. This can further prevent the liquid to be printed from contacting the cylindrical surface of the oblique hollow cylinder, thereby further avoiding the generation of upward spray.

[0027] In the printing method described above, the wall thickness of the obliquely cut hollow cylinder is uniform, which can improve the consistency of the spray needles, especially when multiple spray needles are combined together, thereby improving the printing and dyeing uniformity.

[0028] Beneficial effects

[0029] The printing method of the present invention can effectively solve the problem of the spray needle spray diverging upward and downward, so that the spray is all directed toward the cloth, ensuring a good printing and dyeing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The spray needle of the prior art;

[0031] Figures 2 and 3 It is a structural schematic diagram of the spray needle of the prior art;

[0032] Figure 4 This is a diagram showing the actual use effect of the spray needle in the prior art;

[0033] Figure 5 Schematic diagram of the needle tip structure of a spray needle in the present invention; in the figure, H is the minimum thickness of the outer edge of the needle tip, and h is the amplitude of the needle tip when the spray needle vibrates;

[0034] Figure 6 Schematic diagram of the spray needle structure in Example 1;

[0035] Figure 7 Dimensional diagram of the spray needle in Example 8; the numerical dimensions in the figure are in mm, (a) is a front view of the spray needle, (b) is a top view of the spray needle, and (c) is a top view of the sectional view taken along the FF direction in (b);

[0036] Figure 8 This is a diagram showing the actual use effect of the spray needle in Example 8;

[0037] Figure 9 Schematic diagram of the spray needle structure of Example 2 of the present invention;

[0038] Figure 10 Dimensional drawing of the spray needle in Example 9; the numerical dimensions in the figure are in mm, (a) to (c) are the front view, bottom view, and left view of the spray needle, respectively;

[0039] Figure 11 This is a diagram showing the actual use effect of the spray needle in Example 9;

[0040] Figure 12 Schematic diagram of the structure of the spray needle in Example 3;

[0041] Figure 13 Schematic diagram of the spray effect of the spray needle in Example 10;

[0042] Figure 14 Dimensions of the spray needle in Example 10; wherein the numerical dimensions in the figure are in mm;

[0043] Figure 15 This is a diagram showing the actual use effect of the spray needle in Example 10;

[0044] Figure 16 Schematic diagram of the structure of the spray needle in Example 4;

[0045] Figure 17 Schematic diagram of the spray effect of the spray needle in Example 13;

[0046] Figure 18 Dimensions of the spray needle in Example 13; wherein the numerical dimensions in the figure are in mm;

[0047] Figure 19 This is a diagram showing the actual use effect of the spray needle in Example 13;

[0048] Figure 20 Schematic diagram of the structure of the spray needle in Example 5;

[0049] Figure 21Schematic diagram of the spray effect of the spray needle in Example 14; in the figure, (a) is a schematic diagram of the side view effect, and (b) is a schematic diagram of the front view effect;

[0050] Figure 22 Dimensions of the spray needle in Example 14; wherein the numerical dimensions in the figure are in mm;

[0051] Figure 23 This is a diagram showing the actual use effect of the spray needle in Example 14;

[0052] Figure 24 Schematic diagram of the structure of the spray needle in Example 6;

[0053] Figure 25 Schematic diagram of the structure of the spray needle in Example 7;

[0054] Figure 26 Schematic diagram of the spray effect of the spray needle in Example 11;

[0055] Figure 27 Schematic diagram of the spray effect of the spray needle in Example 12;

[0056] Among them, 1-metal sheet, 2-piezoelectric ceramic resonant plate, 3-steel needle, 4-upward spray, 5-downward spray, 6-barrier. DETAILED DESCRIPTION

[0057] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0058] Method for detecting K / S value of fabric after printing in the embodiment:

[0059] The test was conducted using a Datacolor SF1050 colorimeter under D65 illuminant, a 10° field of view, a 30mm aperture, and within the visible light range (400-700nm, with a wavelength interval of 10nm). The fabric apparent depth (K / S) was calculated by measuring the spectral reflectance of the fabric at the wavelength of maximum absorption using the following formula:

[0060]

[0061] Where R is the spectral reflectance of the sample;

[0062] Take 9 points at random on the dyed fabric for measurement, take the average of the color measurement results, and calculate the standard deviation of the K / S value. If the standard deviation is ≤0.8, it can be considered that the printing and dyeing uniformity is good.

[0063] Example 1

[0064] A needle, such as Figure 6 As shown, it consists of a C-shaped groove I and a C-shaped groove II; the notch of the C-shaped groove I is downward, the notch of the C-shaped groove II is upward, the C-shaped groove I is located above the C-shaped groove II, the lower surface of the C-shaped groove I is in contact with the upper surface of the C-shaped groove II, and the two form a cylindrical tube, the central axis of the cylindrical tube is denoted as axis X;

[0065] One end of the C-shaped groove I and the C-shaped groove II is end a, and the other end is end b; the ends a of the C-shaped groove I and the C-shaped groove II are flush, and the length of the C-shaped groove II is greater than that of the C-shaped groove I;

[0066] The end surface of the b-end of the C-shaped groove I is denoted as surface A, the end surface of the b-end of the C-shaped groove II is denoted as surface C, and the portion of the upper surface of the C-shaped groove II located between surface A and surface C is denoted as surface B; surface B is parallel to the axis X, the angle between surface A and surface B is greater than or equal to 90° and less than 180°, and the angle between surface C and surface B is greater than 90° and less than 180°;

[0067] The intersection of surface B and surface C with the outer wall of C-shaped groove II is chamfered;

[0068] The spray needle is a one-piece molded part.

[0069] Comparative Example 1

[0070] A spray needle is basically the same as embodiment 1, except that the intersection of surface B and surface C with the outer wall of the C-shaped groove II is not chamfered.

[0071] Example 2

[0072] A needle, such as Figure 9 As shown, it consists of a cylindrical tube and a half-sectioned cylinder. The half-sectioned cylinder is a geometric body obtained by cutting the cylinder with a plane parallel to the central axis of the cylinder; the central axis of the cylindrical tube is denoted as axis X;

[0073] One end of the cylindrical tube and the half-split cylinder is end a, and the other end is end b; end a of the half-split cylinder fits with end b of the cylindrical tube, and does not completely seal the hollow part of the cylindrical tube;

[0074] The end face of the cylindrical tube at end b is recorded as surface A, the cross section of the half-sectioned cylinder is recorded as surface B, and the end face of the half-sectioned cylinder at end b is recorded as surface C; surface B is parallel to axis X, the angle between surface A and surface B is greater than or equal to 90° and less than 180°, and the angle between surface C and surface B is greater than 90° and less than 180°;

[0075] The intersection of surface B and surface C with the cylindrical surface of the half-section cylinder is rounded and transitioned;

[0076] The spray needle is a one-piece molded part.

[0077] Example 3

[0078] A needle, such as Figure 12 As shown, it is an obliquely truncated hollow cylinder. The obliquely truncated hollow cylinder is a geometric body obtained by cutting the hollow cylinder with a plane that intersects all the generatrixes of the hollow cylinder and is not parallel to the bottom surface of the hollow cylinder. The intersection area of ​​the cross section and the hollow part is the liquid outlet. The shape of the liquid outlet is circular, the number of liquid outlets is 1, and the position where the cross section intersects with the outer wall of the hollow cylinder is chamfered.

[0079] Comparative Example 2

[0080] A spray needle is basically the same as Example 3, except that the intersection of the cross section and the outer wall of the hollow cylinder is not chamfered.

[0081] Example 4

[0082] A needle, such as Figure 16 As shown, it is basically the same as embodiment 3, with the only difference being that the shape of the liquid outlet is semi-elliptical.

[0083] Example 5

[0084] A needle, such as Figure 20 As shown, it is basically the same as Example 3, with the only difference being that the shape of the liquid outlet is semi-elliptical, the number of the liquid outlets is 2, and the 2 liquid outlets are symmetrically distributed.

[0085] Example 6

[0086] A needle, such as Figure 24 As shown, it is basically the same as embodiment 3, with the only difference being that a barrier 6 is provided at the farthest end of the spray needle, and the barrier 6 is used to prevent the liquid to be printed from contacting the cylindrical surface of the obliquely truncated hollow cylinder.

[0087] Example 7

[0088] A needle, such as Figure 25 As shown, it is basically the same as embodiment 3, with the only difference being that the shape of the liquid outlet is semi-elliptical.

[0089] Example 8

[0090] A printing method, the steps are as follows:

[0091] (1) Preparation;

[0092] The overall structure of the printing device is basically the same as the printing device in the Chinese patent publication number CN114683701A (single needle nozzle and printing device for printing), the only difference is that the nozzle needle in the printing device of this embodiment is the nozzle needle of the above embodiment 1, and the size of the nozzle needle is as follows: Figure 7 As shown;

[0093] Liquid to be printed: a dye solution with a concentration of 10 g / L, wherein the dye in the dye solution is Longsheng Reactive Red 3BSN 150% (manufacturer: Zhejiang Longsheng Group Co., Ltd.);

[0094] The fabric to be sprayed is pure cotton rib fabric (manufacturer: Huzhou Zhang Chaoming Knitting Rib Co., Ltd., specification: 200g / m 2 );

[0095] (2) The liquid to be printed is sprayed onto the fabric using an inkjet device. The relevant process parameters are: piezoelectric resonator frequency 180 kHz, voltage 2.5 V, impedance 5 Ω; the minimum thickness of the outer edge of the needle tip is greater than the amplitude of the needle tip when the needle vibrates.

[0096] During the printing process, there is only one downward spray at the tip of each needle. Figure 8 As shown; the relevant parameters of the fabric after printing are shown in the table below:

[0097]

[0098] According to the data in the table, the standard deviation is less than 0.8, indicating that the printing and dyeing uniformity is good.

[0099] Comparative Example 3

[0100] A printing method is basically the same as Example 8, except that the spray needle is the spray needle of Comparative Example 1, and the minimum thickness of the outer edge of the needle tip is less than the amplitude of the needle tip when the spray needle vibrates.

[0101] During the printing process, there is a downward spray and an upward spray at the tip of the needle; the average K / S value of the fabric after printing is 8.6, and the standard deviation of the K / S value is 0.84, indicating that the printing and dyeing uniformity is poor.

[0102] Comparing Example 8 with Comparative Example 3, it can be seen that the present invention effectively avoids the generation of upward spray by controlling the minimum thickness of the outer edge of the needle tip to be greater than the amplitude of the needle tip when the spray needle vibrates, thereby improving printing and dyeing uniformity.

[0103] Example 9

[0104] A printing method is basically the same as that in Example 8, except that the nozzle needle used in the printing device of this embodiment is the nozzle needle in Example 2; the size of the nozzle needle is as follows: Figure 10 As shown, the minimum thickness of the outer edge of the needle tip is greater than the amplitude of the needle tip when the needle vibrates;

[0105] During the printing process, there is only one spray jet downward from the tip of each needle. Figure 11 As shown in the figure, the average K / S value of the fabric after printing is 8.85, and the standard deviation of the K / S value is 0.11, indicating that the printing and dyeing uniformity is good.

[0106] Example 10

[0107] A printing method is basically the same as that in Example 8, except that the nozzle needle used in the printing device of this embodiment is the nozzle needle in Example 3, and the size of the nozzle needle is as follows: Figure 14 As shown, the minimum thickness of the outer edge of the needle tip is greater than the amplitude of the needle tip when the needle vibrates. The schematic diagram of the spray effect is shown in Figure 13 As shown;

[0108] During the printing process, there is only one spray jet downward from the tip of each needle. Figure 15 As shown in the figure, the average K / S value of the fabric after printing is 8.5, and the standard deviation of the K / S value is 0.08, indicating that the printing and dyeing uniformity is good.

[0109] Comparative Example 4

[0110] A printing method is basically the same as Example 10, except that the spray needle is the spray needle of Comparative Example 2, and the minimum thickness of the outer edge of the needle tip is less than the amplitude of the needle tip when the spray needle vibrates.

[0111] During the printing process, there is a downward spray and an upward spray at the tip of the needle; the average K / S value of the fabric after printing is 8.5, and the standard deviation of the K / S value is 1.4, indicating that the printing and dyeing uniformity is poor.

[0112] Comparing Example 10 with Comparative Example 4, it can be seen that the present invention effectively avoids the generation of upward spray by controlling the minimum thickness of the outer edge of the needle tip to be greater than the amplitude of the needle tip when the spray needle vibrates, thereby improving printing and dyeing uniformity.

[0113] Example 11

[0114] A printing method is basically the same as that in Example 8, except that the nozzle used in the printing device of this embodiment is the nozzle in Example 6, and the minimum thickness of the outer edge of the nozzle tip is greater than the amplitude of the nozzle tip when the nozzle tip vibrates. The spray effect diagram is shown in FIG. Figure 26 As shown;

[0115] During the printing process, only one spray is emitted downward from the tip of each needle; the standard deviation of the K / S value of the fabric after printing is 0.06, indicating good printing and dyeing uniformity.

[0116] Example 12

[0117] A printing method is basically the same as that in Example 8, except that the nozzle used in the printing device of this embodiment is the nozzle in Example 7, the distance between the liquid outlet and the farthest end of the nozzle is 1.2 mm, the minimum thickness of the outer edge of the nozzle tip is greater than the amplitude of the nozzle tip when the nozzle tip vibrates, and the spray effect diagram is shown in FIG. Figure 27 As shown;

[0118] During the printing process, only one spray is emitted downward from the tip of each needle; the standard deviation of the K / S value of the fabric after printing is 0.07, indicating good printing and dyeing uniformity.

[0119] By comparing Example 8, Example 11 and Example 12, it can be seen that the printing and dyeing uniformity of Example 11 and Example 12 is better. This is because a barrier is added to the spray needle in Example 11, which can further prevent the liquid to be printed from contacting the cylindrical surface of the oblique hollow cylinder, thereby further avoiding the generation of upward spray. In Example 12, the distance between the liquid outlet and the farthest end of the spray needle is larger, which further prevents the liquid to be printed from contacting the cylindrical surface of the oblique hollow cylinder, thereby further avoiding the generation of upward spray.

[0120] Example 13

[0121] A printing method is basically the same as that in Example 8, except that the nozzle needle used in the printing device of this embodiment is the nozzle needle in Example 4, and the size of the nozzle needle is as follows: Figure 18 As shown, the minimum thickness of the outer edge of the needle tip is greater than the amplitude of the needle tip when the needle vibrates. The schematic diagram of the spray effect is shown in Figure 17 As shown;

[0122] During the printing process, there is only one spray jet downward from the tip of each needle. Figure 19 As shown in the figure, the average K / S value of the fabric after printing is 8.81, and the standard deviation of the K / S value is 0.11, indicating that the printing and dyeing uniformity is good.

[0123] Example 14

[0124] A printing method is basically the same as that in Example 8, except that the nozzle needle used in the printing device of this embodiment is the nozzle needle in Example 5, and the size of the nozzle needle is as follows: Figure 22 As shown, the minimum thickness of the outer edge of the needle tip is greater than the amplitude of the needle tip when the needle vibrates. The schematic diagram of the spray effect is shown in Figure 21 As shown;

[0125] During the printing process, there is only one spray jet downward from the tip of each needle. Figure 23 As shown in the figure, the average K / S value of the fabric after printing is 8.8, and the standard deviation of the K / S value is 0.09, indicating that the printing and dyeing uniformity is good.

Claims

1. A printing method, using a spray needle, wherein the tip of the spray needle is provided with a liquid outlet, and the spray needle vibrates to vibrate the liquid to be printed in the spray needle out of the liquid outlet and atomizes it, characterized in that: The nozzle needle is an obliquely truncated hollow cylinder. The obliquely truncated hollow cylinder is a geometric body obtained by cutting the hollow cylinder with a plane that intersects all the generatrixes of the hollow cylinder and is not parallel to the bottom surface of the hollow cylinder. The intersection area of ​​the cross section and the hollow part is the liquid outlet. The position where the cross section intersects with the outer wall of the hollow cylinder is chamfered so that the minimum thickness of the needle tip is greater than the amplitude of the needle tip when the nozzle vibrates, so as to avoid the generation of upward water mist.

2. A printing method according to claim 1, characterized in that: The shape of the liquid outlet is circular or semi-elliptical, and the number of the liquid outlet is one.

3. A printing method according to claim 1, characterized in that: The shape of the liquid outlet is semi-elliptical, the number of the liquid outlets is 2 and they are symmetrically distributed on the cross section.

4. A printing method according to claim 1, characterized in that: The distance between the liquid outlet and the farthest end of the spray needle is greater than or equal to 1.2 mm.

5. A printing method according to claim 1, characterized in that: A barrier is provided at the farthest end of the spray needle, and the barrier is used to prevent the liquid to be sprayed from contacting the cylindrical surface of the obliquely cut hollow cylinder.

6. A printing method, using a spray needle, wherein the tip of the spray needle is provided with a liquid outlet, and the spray needle vibrates to vibrate the liquid to be printed in the spray needle out of the liquid outlet and atomizes it, characterized in that: The spray needle consists of a C-shaped groove I and a C-shaped groove II; the notch of C-shaped groove I faces downward, and the notch of C-shaped groove II faces upward. C-shaped groove I is located above C-shaped groove II, and the lower surface of C-shaped groove I fits with the upper surface of C-shaped groove II, forming a cylindrical tube. The central axis of the cylindrical tube is denoted as axis X. One end of the C-shaped groove I and the C-shaped groove II is end a, and the other end is end b; the ends a of the C-shaped groove I and the C-shaped groove II are flush, and the length of the C-shaped groove II is greater than that of the C-shaped groove I; The end surface of the b-end of the C-shaped groove I is denoted as surface A, the end surface of the b-end of the C-shaped groove II is denoted as surface C, and the portion of the upper surface of the C-shaped groove II located between surface A and surface C is denoted as surface B; surface B is parallel to the axis X, the angle between surface A and surface B is greater than or equal to 90° and less than 180°, and the angle between surface C and surface B is greater than 90° and less than 180°; The chamfered transition at the intersection of surface B and surface C with the outer wall of the C-shaped groove II makes the minimum thickness of the needle tip greater than the amplitude of the needle tip when the needle vibrates, so as to avoid the generation of upward water mist.

7. A printing method according to claim 6, characterized in that: The spray needle is a one-piece molded part.

8. A printing method, using a spray needle, wherein the tip of the spray needle is provided with a liquid outlet, and the spray needle vibrates to vibrate the liquid to be printed in the spray needle out of the liquid outlet and atomizes it, characterized in that: The nozzle consists of a cylindrical tube and a half-sectioned cylinder. The half-sectioned cylinder is a geometric body obtained by cutting the cylinder with a plane parallel to the central axis of the cylinder. The central axis of the cylindrical tube is denoted as axis X. One end of the cylindrical tube and the half-split cylinder is end a, and the other end is end b; end a of the half-split cylinder fits with end b of the cylindrical tube, and does not completely seal the hollow part of the cylindrical tube; The end face of the cylindrical tube at end b is recorded as surface A, the cross section of the half-sectioned cylinder is recorded as surface B, and the end face of the half-sectioned cylinder at end b is recorded as surface C; surface B is parallel to axis X, the angle between surface A and surface B is greater than or equal to 90° and less than 180°, and the angle between surface C and surface B is greater than 90° and less than 180°; The chamfered transition at the intersection of surface B and surface C with the cylindrical surface of the half-section cylinder makes the minimum thickness of the needle tip greater than the amplitude of the needle tip when the needle vibrates, so as to avoid generating upward water mist.

9. A printing method according to claim 8, characterized in that: The spray needle is a one-piece molded part.

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