Wide-width ultrasonic atomization linear spraying equipment

Abstract

The utility model belongs to the technical field of coating equipment, and relates to wide-width ultrasonic atomization linear spraying equipment which comprises a vacuum adsorption system, an atomization nozzle and an air knife, an atomizing cavity, an ultrasonic transducer and a water cooling cavity are arranged in the atomizing nozzle, the atomizing cavity is communicated with an air outlet opening outwards through a slit channel, the transverse length of the slit channel is larger than the longitudinal length, and the air outlet direction of the slit channel is in the horizontal direction; the air knife is positioned above the air outlet direction of the atomizing nozzle and is fixed relative to the atomizing nozzle; the air knife is provided with a slit air outlet with a downward air outlet direction; the atomizing nozzle can move in the direction opposite to the air outlet direction of the atomizing nozzle relative to the base plate. According to the equipment, fogdrops are prevented from being condensed into large liquid drops again due to gathering in a small range, the fineness of the fogdrops after ultrasonic atomization is ensured, a wide product with the width of more than 10cm is coated with a film more uniformly, and the non-uniformity can be controlled below 6%.

Description

Technical Field

[0001] The utility model relates to the technical field of coating equipment, in particular to wide-width ultrasonic atomization linear spraying equipment. Background Art

[0002] With the development of nanomaterial technology, the application of nano-scale thin films has become more and more extensive, and the requirements for nano-scale coating equipment have become higher and higher. Traditional thin film preparation methods include two-fluid spraying, CVD coating, vacuum evaporation and sputtering. However, these traditional thin film preparation methods have problems such as low raw material utilization, low coating efficiency, and high equipment cost. Ultrasonic atomization spraying is a process in which the ultrasonic amplitude emitted by the ultrasonic transducer is amplified by an ultrasonic horn, and the high-frequency ultrasonic vibration energy is used to atomize the liquid into tiny droplets. The droplets reach the surface of the coated material by gravity or purge gas to achieve the coating process. Compared with traditional coating equipment, ultrasonic atomization spraying has the following significant advantages: uniform spraying, controllable flow, adjustable droplet diameter, low equipment cost, and can be prepared at room temperature and pressure.

[0003] However, the application of ultrasonic atomization spraying technology is also greatly limited. At present, most atomizing nozzles are point nozzles, such as a segmented injector for electrostatic powder spraying disclosed in announcement number CN201913019U. The point-shaped liquid discharge limits its maximum effective spraying width, and the limited spraying width limits its application in large-area spraying. At present, the application of spraying on large areas is often through linear arrangement of multiple nozzles or multiple reciprocating spraying operations of a single nozzle. The reciprocating continuous spraying of a single nozzle is slow and the beat is long, while the series connection of multiple nozzles leads to high costs and poor film uniformity, which is not conducive to industrial preparation.

[0004] Publication No. CN108472676A discloses a droplet coating film forming device and a droplet coating film forming method, in which an ultrasonic vibrator is used to atomize the coating liquid into very fine droplets, and the droplets are sent to the droplet coating head through an airflow, and then directly sprayed onto the surface of the substrate. Although it is claimed that a film layer with a thickness of less than 100nm can be obtained, in fact, when it is used on a wide product with a width of more than 10cm, the following two problems still occur:

[0005] 1. Because the droplet coating head is always close to the spraying surface, the gas-liquid mixture gathers in a small space between the droplet coating head and the spraying surface. However, in this way, the very small droplets that have been ultrasonically atomized can easily condense to form large droplets, resulting in the failure to achieve the purpose of ultrasonic atomization, unsatisfactory coating uniformity, and unevenness. Often between 10-20%;

[0006] 2. To ensure wide-width spraying, there must be a sufficiently large air pressure in the droplet coating head, but this will cause the coating liquid droplets to be sprayed out too quickly. However, it is impossible to increase the moving speed of the substrate indefinitely to increase the spraying area per unit time. Therefore, when the spraying volume is large and the spraying area cannot be reduced, the film thickness is difficult to control.

[0007] Therefore be necessary to improve spraying equipment to solve the above problems. Utility Model Content

[0008] A main purpose of the utility model is to provide a wide-width ultrasonic atomization linear spraying device, which can ensure the fineness of droplets after ultrasonic atomization and make the coating on wide-width products with a width of more than 10 cm more uniform.

[0009] The utility model achieves the above-mentioned purpose through the following technical scheme: a wide-width ultrasonic atomization linear spraying device, including a vacuum adsorption system, an atomization nozzle and an air knife;

[0010] The vacuum adsorption system includes an adsorption platform for adsorbing the substrate, a negative pressure generating mechanism, and an air suction pipeline connected from the negative pressure generating mechanism to the adsorption platform;

[0011] The atomizing nozzle is provided with an atomizing chamber, an ultrasonic transducer and a water cooling chamber, the ultrasonic transducer is located between the atomizing chamber and the water cooling chamber and is not connected to the latter two, the atomizing chamber is connected to an outwardly opened air outlet through a slit channel, the lateral length of the slit channel is greater than the longitudinal length and the air outlet direction thereof is along the horizontal direction;

[0012] The wind knife is located above the atomizing nozzle in the air outlet direction and is relatively fixed to the atomizing nozzle, and the wind knife has a slit air outlet with the air outlet direction downward;

[0013] The atomizing nozzle can move relative to the substrate in a direction opposite to its air outlet direction.

[0014] Specifically, it also includes a frame, which includes a workbench and two transmission belts arranged on both sides of the workbench, and the adsorption platform is located between the two transmission belts.

[0015] Furthermore, it also includes the gantry standing above the workbench, the atomizing nozzle and the wind knife are arranged below the top plate of the gantry, the two feet of the gantry are respectively located on the outside of the two transmission belts and the lower end is provided with a walking mechanism that moves along the transmission direction of the transmission belt.

[0016] Furthermore, the gantry is provided with a lifting servo mechanism for controlling the synchronous lifting and lowering of the atomizing nozzle and the air knife, and a laser thickness gauge for detecting the actual height of the upper surface of the substrate.

[0017] Specifically, it also includes an injection system for providing the coating liquid to the atomizing chamber, the injection system includes a liquid storage tank for storing the coating liquid, a liquid delivery pipeline connected from the liquid storage tank to the atomizing chamber, and an injection pump and a liquid inlet valve arranged on the liquid delivery pipeline.

[0018] Furthermore, the liquid storage tank and the injection pump are fixed to the upper part of the gantry.

[0019] Furthermore, the atomization chamber is a linear rectangular chamber, the slit channel is connected to the highest position of the atomization chamber, the inner wall of the atomization chamber is provided with a mist detector and a liquid level monitoring controller, and the control system of the equipment controls the flow rate of the carrier gas through the detection result of the mist detector, and controls the injection pump to replenish the liquid through the detection result of the liquid level monitoring controller.

[0020] Specifically, the air supply system includes an air compressor, a first air path connected from the air compressor to the air knife, and a second air path connected from the air compressor to the atomization chamber. The first air path is provided with an air knife valve, and the second air path is provided with a carrier gas valve; a plurality of branches are provided at the end of the second air path, all of which are connected to the atomization chamber at equal intervals, and the entry position of the branch is located at a relative position to the slit channel.

[0021] Specifically, the condensing water circulation system includes a water chiller, a circulation pipeline connected from the water chiller to the inlet and outlet of the water cooling chamber respectively, and a cold water valve arranged on the circulation pipeline.

[0022] The beneficial effects of the technical solution of the utility model are:

[0023] This equipment can use ultrasound to atomize the coating liquid, and then spray it horizontally from the atomizing nozzle to a wider range, and then apply it to the surface of the substrate under the action of the wind knife, avoiding the droplets from gathering in a small range and re-condensing into large droplets, ensuring the fineness of the droplets after ultrasonic atomization, making the coating more uniform on wide products with a width of more than 10cm, and the unevenness can be controlled below 6%. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the orthographic projection of the wide-width ultrasonic atomization linear spraying equipment of the embodiment as viewed from the conveying direction (the thick solid lines in the figure represent the outlines of the parts, the thin solid lines represent the liquid pipelines, and the thin dotted lines represent the gas pipelines);

[0025] Figure 2 It is a spraying principle diagram of a wide-width ultrasonic atomization linear spraying device (the thick solid line in the figure represents the outline of the substrate and its fixed structure, the thin solid line represents the outline of the spraying part, the thin arrow represents the spraying direction of the droplets, and the thick arrow represents the moving direction of the spraying part);

[0026] Figure 3This is the pipeline diagram of the atomizing nozzle, air knife and its auxiliary system (the thick solid lines in the figure represent the outlines of the components, the thin solid lines represent the liquid pipelines, and the thin dotted lines represent the gas pipelines).

[0027] The numbers in the figure represent:

[0028] 1-Wide range ultrasonic atomization linear spraying equipment,

[0029] 11-frame, 111-workbench, 112-drive belt,

[0030] 12-gantry, 121-lifting servo mechanism, 122-laser thickness gauge, 123-travel mechanism,

[0031] 13- vacuum adsorption system, 131- adsorption platform, 132- negative pressure generating mechanism, 133- suction pipeline,

[0032] 14-atomizing nozzle, 141-atomizing chamber, 142-ultrasonic transducer, 143-water cooling chamber, 144-slit channel, 145-air outlet, 146-fog volume detector, 147-liquid level detection controller,

[0033] 15- wind knife, 151- slit air outlet,

[0034] 16-liquid injection system, 161-liquid storage tank, 162-liquid delivery pipeline, 163-injection pump, 164-liquid inlet valve;

[0035] 17- condensate circulation system, 171- chiller, 172- circulation pipeline, 173- chilled water valve;

[0036] 18-air supply system, 181-air compressor, 182-first air path, 1821-air knife valve, 183-second air path, 1831-carrier gas valve;

[0037] 2-Substrate. DETAILED DESCRIPTION

[0038] The utility model is further described in detail below in conjunction with specific embodiments.

[0039] Example:

[0040] like Figure 1 As shown, a wide-width ultrasonic atomization linear spraying device 1 of the utility model includes a frame 11, a gantry 12, a vacuum adsorption system 13, an atomizing nozzle 14, an air knife 15, a liquid injection system 16, a condensed water circulation system 17 and an air supply system 18.

[0041] like Figure 1 and Figure 2As shown, the frame 11 includes a workbench 111 and two transmission belts 112 arranged on both sides of the workbench 111 , and the transmission belts 112 are used to transport the substrate 2 .

[0042] The transmission belt 12 can be docked with the front and rear workstations to realize the automatic loading and unloading of the substrate. If there is no transmission belt 12, the substrate can also be loaded manually.

[0043] like Figure 1 and Figure 2 As shown, the vacuum adsorption system 13 includes an adsorption platform 131 located between two driving belts 12 , a negative pressure generating mechanism 132 located at the lower part of the frame 11 , and an air suction pipeline 133 connected from the negative pressure generating mechanism 132 to the adsorption platform 131 .

[0044] There are many suction holes on the adsorption platform 131 for sucking the lower surface of the substrate 2. The negative pressure of the suction is generated by the negative pressure generating mechanism 132, and the size of the suction force can be adjusted to prevent the position of the substrate 2 from moving easily during spraying, and to avoid excessive suction force to damage the surface of the substrate 2.

[0045] like Figure 2 As shown, an atomizing chamber 141, an ultrasonic transducer 142 and a water-cooling chamber 143 are provided in the atomizing nozzle 14. The ultrasonic transducer 142 is located between the atomizing chamber 141 and the water-cooling chamber 143 and is not connected to the latter two. The atomizing chamber 141 is connected to an outwardly opened air outlet 145 through a slit channel 144. The lateral length of the slit channel 144 is greater than the longitudinal length and its air outlet direction is along the horizontal direction.

[0046] The coating liquid and air are mixed in the atomizing chamber 141, the coating liquid comes from the injection system 16, and the air comes from the air supply system 18. The ultrasonic transducer 142 can ultrasonically atomize the gas-liquid mixture in the atomizing chamber 141, breaking it into extremely small droplets. Because the coating liquid and air are continuously added, the gas-liquid mixture can only flow out along the slit channel 144, and then spray out from the air outlet 145 at a certain initial velocity. Because the air outlet 145 is open, the sprayed droplets will expand in the up and down directions and on both sides. Because the space where the droplets are located is expanded, the droplets are prevented from re-condensing into large droplets due to gathering in a small range, ensuring the fineness of the droplets after ultrasonic atomization, so that the coating liquid is more uniform when applied to the substrate. The ultrasonic transducer 142 will emit a lot of heat when working, so in order to avoid overheating of the atomizing nozzle 14, the water-cooling chamber 143 must continuously pass and discharge cooling water, and the cooling water is supplied and recovered by the condensed water circulation system 17.

[0047] like Figure 2 As shown, the wind knife 15 is located above the atomizing nozzle 14 in the air outlet direction and is relatively fixed to the atomizing nozzle 14. The wind knife 15 has a slit air outlet 151 with the air outlet direction downward.

[0048] When the atomizing nozzle 14 moves in the opposite direction of the air outlet direction relative to the substrate 2, the mist droplets are sprayed out from the air outlet 145 of the atomizing nozzle 14, and then affected by the airflow blown downward from the slit air outlet 151, the mist droplets will fall linearly onto the substrate 2, and the airflow direction of the wind knife 15 can have a certain slope. During operation, the atomizing nozzle 14 moves backward relative to the substrate 2 while the wind knife 15 sprays until the entire surface of the substrate 2 is covered. This method can be applied to wide products with a width of more than 10 cm. The mist droplets of the coating liquid are finer, making the coating on wide products with a width of more than 10 cm more uniform, and the unevenness can be controlled below 6%.

[0049] like Figure 1 and Figure 2 As shown, the gantry 12 straddles the top of the workbench 111, the atomizing nozzle 14 and the wind knife 15 are arranged below the top plate of the gantry 12, and the gantry 12 is provided with a lifting servo mechanism 121 for controlling the synchronous lifting and lowering of the atomizing nozzle 14 and the wind knife 15, and a laser thickness gauge 122 for detecting the actual height of the upper surface of the substrate 2. The two feet of the gantry 12 are respectively located on the outside of the two transmission belts 112, and the lower end is provided with a walking mechanism 123 that moves along the conveying direction of the transmission belt 112.

[0050] In order to complete the spraying, the atomizing nozzle 4 needs to move in the opposite direction of the spraying direction relative to the substrate 2. In the embodiment, the atomizing nozzle 4 is moved in a different manner than the substrate 2. The specific solution is that the entire gantry 12 uses the walking mechanism 123 to move along the conveying direction of the transmission belt 112, so the atomizing nozzle 14 and the wind knife 15 can be translated along with the gantry 12. In other embodiments, the atomizing nozzle 14 and the wind knife 15 can remain stationary, while the substrate 2 is translated along the air outlet direction of the atomizing nozzle 14, which is equivalent in terms of the spraying effect. It’s just that the front and rear range of the gantry 12 is often shorter than the length of the substrate 2, and moving the substrate 2 requires a larger workbench 111 area than moving the gantry 12, and there is no embodiment to save space. Theoretically, while maintaining a safe distance, the higher the atomizing nozzle 14 is relative to the upper surface of the substrate 2, the easier it is for the droplets to fly to the outside and be wasted, which is not conducive to the coating liquid adhering to the substrate 2. Therefore, when dealing with substrates 2 of different thicknesses, in order to ensure the stability of the coating effect, it is necessary to rely on a laser thickness gauge 122 to measure the height of the atomizing nozzle 14 and the wind knife 15 relative to the upper surface of the substrate 2, and then the lifting servo mechanism 121 makes height adjustments to the two.

[0051] like Figure 1 and Figure 3As shown, the injection system 16 includes a liquid storage tank 161 for storing the coating liquid, a liquid delivery pipeline 162 connected from the liquid storage tank 161 to the atomization chamber 142, and an injection pump 163 and a liquid inlet valve 164 arranged on the liquid delivery pipeline 162. The liquid storage tank 161 and the injection pump 163 are fixed to the upper part of the gantry 12.

[0052] The liquid storage tank 161 is used to store the coating liquid. The injection pump 163 draws the coating liquid from the liquid storage tank 161 and supplies it to the atomizing chamber 142. The injection pump 12 can accurately control the injection amount and injection speed, and the liquid inlet valve 164 is used to control the on-off of the liquid delivery pipeline 162. The entire liquid injection system 16 is fixed to the gantry 12, and the liquid delivery pipeline 162 is connected to a section of the atomizing nozzle 14 with a selected hose, so that the height adjustment of the atomizing nozzle 14 is not affected.

[0053] like Figure 3 As shown, the atomization chamber 141 is a linear rectangular chamber, the slit channel 144 is connected to the highest position of the atomization chamber 141, and the inner wall of the atomization chamber 141 is provided with a mist detector 146 and a liquid level monitoring controller 147. The control system of the equipment controls the flow rate of the carrier gas through the detection result of the mist detector 146, and controls the injection pump 163 to replenish the liquid through the detection result of the liquid level monitoring controller 147.

[0054] A certain volume of coating liquid needs to be retained in the atomization chamber 141. The liquid level in the chamber is detected by the liquid level monitoring controller 147 and cannot be lower than the set height. If the liquid level of the coating liquid is lower than the set height, the control system of the equipment controls the injection pump 163 to replenish the liquid. The mist volume detector 146 can detect the volume ratio of the gas-liquid mixture droplets in the gas above the liquid level. The droplet volume ratio is inversely proportional to the flow rate of the carrier gas, so as to ensure that the flow rate of the coating liquid per unit time is a constant value, thereby satisfying the uniformity of the film thickness in the coating direction.

[0055] like Figure 1 and Figure 3 As shown, the air supply system 18 includes an air compressor 181 disposed at the lower part of the frame 11, a first air path 182 connected from the air compressor 181 to the air knife 15, and a second air path 183 connected from the air compressor 181 to the atomizing chamber 141. The first air path 182 is provided with an air knife valve 1821, and the second air path 183 is provided with a carrier gas valve 1831. A plurality of branches (not marked) are provided at the end of the second air path 183, all of which are connected to the atomizing chamber 142 at equal intervals, and the entry position of the branch is located at a relative position of the slit channel 144.

[0056] The airflow of the wind knife 15 and the carrier gas of the atomizing nozzle 14 are both provided by the air compressor 181. The wind knife valve 1821 and the carrier gas valve 1831 can control the start and stop of the blowing. Because the structure of the slit channel 144 is very narrow and long, if the carrier gas only enters from one point of the atomizing chamber 142, the flow rate of the gas-liquid mixture at the air outlet 145 will be very uneven, with a fast flow rate near the entry position and a slow flow rate far away, which will be detrimental to the uniformity of the coating. Therefore, the second air path 183 must first be divided into multiple branches and then enter from multiple equidistant positions inside the atomizing chamber 142, so that the droplet flow rate distribution through the slit channel 144 will be more uniform, so that the film thickness is uniform in the direction perpendicular to the coating.

[0057] like Figure 1 and Figure 3 As shown, the condensing water circulation system 17 includes a chiller 171 disposed at the lower part of the frame 11 , a circulation pipeline 172 connected from the chiller 171 to the inlet and outlet of the water cooling chamber 143 , and a cold water valve 173 disposed on the circulation pipeline 172 .

[0058] The water chiller 171 can inject cooling water with a relatively low temperature into the water cooling chamber 143 , and then return the cooling water to the water chiller 171 through the circulation pipeline 172 after absorbing the heat, thereby ensuring the safety of ultrasonic atomization. The water chiller 173 is used to control the on-off of the circulation pipeline 172 .

[0059] The working process of wide-width ultrasonic atomization linear spraying equipment 1 is:

[0060] S1. Substrate positioning: two conveyor belts 112 transport the substrate 2 to the top of the adsorption platform 131. The negative pressure generating mechanism 132 enables the adsorption platform 131 to generate suction to adsorb and position the lower surface of the substrate 2. The laser thickness gauge 122 can detect the height to the upper surface of the substrate 2 at this time, so that the lifting servo mechanism 121 pre-adjusts the height of the atomizing nozzle 14 and the air knife 15.

[0061] S2, ultrasonic atomization: the injection pump 163 draws the coating liquid from the liquid storage tank 161, and then passes it into the atomization chamber 141 until the liquid level is higher than the liquid level detection controller 147, the ultrasonic transducer 142 is started, and the chiller 171 passes cooling water into the water cooling chamber 143 to cool the ultrasonic transducer 142. Under the monitoring of the mist amount detector 146, the ultrasonic transducer 142 atomizes the coating liquid into droplets of appropriate size;

[0062] S3, spraying: turn on the air compressor 181, open the air knife valve 1821 and the carrier gas valve 1831, and blow the droplets out from the air outlet 145 through the carrier gas. When the atomizing nozzle 14 moves in the opposite direction of the air outlet direction, the droplets are blown to the upper surface of the substrate 2 by the air flow blown by the air knife 15, thereby completing the spray coating.

[0063] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A wide-width ultrasonic atomization linear spraying equipment, characterized in that: Including vacuum adsorption system, atomizing nozzle and air knife; The vacuum adsorption system includes an adsorption platform for adsorbing the substrate, a negative pressure generating mechanism, and an air suction pipeline connected from the negative pressure generating mechanism to the adsorption platform; The atomizing nozzle is provided with an atomizing chamber, an ultrasonic transducer and a water cooling chamber, the ultrasonic transducer is located between the atomizing chamber and the water cooling chamber and is not connected to the latter two, the atomizing chamber is connected to an outwardly opened air outlet through a slit channel, the lateral length of the slit channel is greater than the longitudinal length and the air outlet direction thereof is along the horizontal direction; The wind knife is located above the atomizing nozzle in the air outlet direction and is relatively fixed to the atomizing nozzle, and the wind knife has a slit air outlet with the air outlet direction downward; The atomizing nozzle can move relative to the substrate in a direction opposite to its air outlet direction.

2. The wide-width ultrasonic atomization linear spraying equipment according to claim 1 is characterized in that: The machine also includes a frame, which includes a workbench and two transmission belts arranged on both sides of the workbench, and the adsorption platform is located between the two transmission belts.

3. The wide-width ultrasonic atomization linear spraying equipment according to claim 2 is characterized in that: It also includes a gantry frame straddling the workbench, the atomizing nozzle and the wind knife are arranged below the top plate of the gantry frame, the two feet of the gantry frame are respectively located on the outside of two transmission belts and the lower end is provided with a walking mechanism that moves along the transmission direction of the transmission belt.

4. The wide-width ultrasonic atomization linear spraying equipment according to claim 3 is characterized in that: The gantry is provided with a lifting servo mechanism for controlling the synchronous lifting and lowering of the atomizing nozzle and the air knife, and a laser thickness gauge for detecting the actual height of the upper surface of the substrate.

5. The wide-width ultrasonic atomization linear spraying equipment according to claim 1 is characterized in that: It also includes a liquid injection system for providing the coating liquid to the atomizing chamber, the liquid injection system includes a liquid storage tank for storing the coating liquid, a liquid delivery pipeline connected from the liquid storage tank to the atomizing chamber, and an injection pump and a liquid inlet valve arranged on the liquid delivery pipeline.

6. The wide-width ultrasonic atomization linear spraying equipment according to claim 5 is characterized in that: The liquid storage tank and the injection pump are fixed on the upper part of the gantry.

7. The wide-width ultrasonic atomization linear spraying equipment according to claim 5 is characterized in that: The atomization chamber is a linear rectangular chamber, the slit channel is connected to the highest position of the atomization chamber, and the inner wall of the atomization chamber is provided with a fog volume detector and a liquid level monitoring controller. The control system of the equipment controls the flow rate of the carrier gas through the detection result of the fog volume detector, and controls the liquid replenishment of the injection pump through the detection result of the liquid level monitoring controller.

8. The wide-width ultrasonic atomization linear spraying equipment according to claim 1 is characterized in that: It also includes an air supply system, which includes an air compressor, a first air path connected from the air compressor to the air knife, and a second air path connected from the air compressor to the atomization chamber, the first air path is provided with an air knife valve, and the second air path is provided with a carrier gas valve; a plurality of branches are provided at the end of the second air path, all of which are connected to the atomization chamber at equal intervals, and the entry position of the branch is located at a relative position to the slit channel.

9. The wide-width ultrasonic atomization linear spraying equipment according to claim 1 is characterized in that: It also includes a condensed water circulation system, which includes a chiller, a circulation pipeline connected from the chiller to the inlet and outlet of the water cooling chamber respectively, and a cold water valve arranged on the circulation pipeline.

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