CN111976344A

CN111976344A - Projectable blackboard and its making equipment

Info

Publication number: CN111976344A
Application number: CN202010899662.2A
Authority: CN
Inventors: 吴准; 林岚云
Original assignee: Fuzhou Shenluo Information Technology Co ltd
Current assignee: Fuzhou Shenluo Information Technology Co ltd
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2020-11-24

Abstract

The invention relates to the field of blackboard processing, in particular to a projectable blackboard and manufacturing equipment thereof, wherein the projectable blackboard comprises a substrate and a blackish green display coating, the display coating has the functions of writing and projecting, and comprises the following materials in parts by mass, 40-50 parts of polyurethane resin; 0.1-0.3 part of color paste; 0.4-0.7 part of nano powder; 1-2 parts of microcrystalline cellulose; 1.5-2.5 parts of spherical silver powder particles; 0.2-0.3 part of defoaming agent; 0.3-0.4 part of dispersant; 0.1-0.2 part of leveling agent; 3-5 parts of ethylene glycol; 8-10 parts of deionized water; the invention can improve the reflection performance of the blackboard during projection, improve the visual angle balance, have the optical characteristics of strong light resistance and high gain, improve the projection effect, ensure the original chalk writing habit and the visual performance of the blackboard, directly put multimedia contents into a picture by using a projector, and present the picture with high brightness, high contrast and high resolution.

Description

Projectable blackboard and its making equipment

Technical Field

The invention relates to the technical field of blackboard processing, in particular to a projectable blackboard and manufacturing equipment thereof.

Background

The multimedia teaching is that in the teaching process, according to the characteristics of a teaching target and a teaching object, modern teaching media are reasonably selected and applied through teaching design, and are organically combined with the traditional teaching means to jointly participate in the whole teaching process, and various media information acts on students to form a reasonable teaching process structure so as to achieve the optimized teaching effect.

The existing blackboard (black or dark green) is only used for erasing and writing chalk, can not be used for displaying projected images, and in order to give consideration to the functions of chalk writing and multimedia projection, at present, two structural forms are mainly used respectively:

1. the blackboard is divided into a plurality of pieces, the whiteboard is exposed through push-pull to display multimedia contents in a projection mode, and when the blackboard is applied, the blackboard needs to be pushed and pulled back and forth to be used in a switching mode, and chalks and whiteboard pens need to be used in a switching mode to write;

2. the LCD TV is combined with a push-pull type; namely, the blackboard is used for erasing and writing the chalk, and the liquid crystal screen is exposed by pushing and pulling to display multimedia content; similarly, the chalk and the electronic pen are required to be switched for writing, the cost is high, a certain fault rate exists, and the teaching is influenced;

the conventional blackboards of the above two forms have the following disadvantages:

1. the existing traditional blackboard (black \ dark green) can not combine with projection display to understand clear picture;

2. the existing projection white board generates overflow light interference and glare interference due to reflected light, and writing contents cannot be seen clearly;

3. the teachers and students are easy to fatigue eyes and damage eyesight in a mode of white background and black characters for a long time;

4. the size of the liquid crystal screen is limited, and the cost is high.

5. Teachers need to frequently push and pull the blackboard and the whiteboard to be switched, characters are not smoothly written and displayed in the teaching process, and the teaching quality is affected.

Disclosure of Invention

The invention aims to provide a projectable blackboard and a preparation process thereof, which aim to solve the technical problems of the existing blackboard.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the invention provides a projectable blackboard which comprises a substrate and a blackish green display coating, wherein the display coating has the functions of writing and projection, and comprises the following materials in parts by mass:

40-50 parts of polyurethane resin;

0.1-0.3 part of color paste;

0.4-0.7 part of nano powder;

1-2 parts of microcrystalline cellulose;

1.5-2.5 parts of spherical silver powder particles;

0.2-0.3 part of defoaming agent;

0.3-0.4 part of dispersant;

0.1-0.2 part of leveling agent;

3-5 parts of ethylene glycol;

8-10 parts of deionized water.

Further, the polyurethane resin is prepared by polymerizing polyester polyol and isophorone diisocyanate.

Further, the nano powder comprises the following components: the nano titanium oxide, nano aluminum oxide and nano silicon dioxide comprise the following components in parts by mass: 1-2.5:0.5-1:0.5-1.5.

Further, the preparation method of the display coating comprises the following steps:

s1, taking polyurethane resin, microcrystalline cellulose, a defoaming agent, a dispersing agent and a flatting agent according to parts by weight, stirring and mixing for 5 minutes to obtain a mixture 1;

s2, taking the nano powder according to the mass part, adding the nano powder into the mixture 1, and continuously stirring for 30-40 minutes uniformly to obtain a mixture 2;

s3, taking the spherical silver powder particles according to the mass parts, carrying out high-shear mixing, uniformly stirring for 30-50 minutes, and finally adding a proper amount of color paste to adjust to a target color value to obtain the water-based paint;

s4, spraying the prepared coating on the flat surface of the base material through a spraying mechanism, and drying to form a display coating with the thickness of 0.1-0.3 mm.

Further, the base material is selected from any one of toughened glass, acrylic plates, galvanized plates, stainless steel plates, gypsum boards, density boards, glue-free PVC films and glue-carrying PVC films, and the thickness of the base material is 2mm-10 mm.

The invention also provides a manufacturing device of the projectable blackboard, which is used for processing the projectable blackboard and comprises a rack, and a conveying mechanism, a spraying mechanism, a movable supporting mechanism and a dust collection mechanism which are arranged on the rack;

the conveying mechanism is used for conveying the projectable blackboard,

the movable support mechanism is positioned above the conveying mechanism and comprises a plurality of guide rails which are arranged at intervals along the width direction of the projectable blackboard, a lead screw is assembled in each guide rail through a bearing, the spraying mechanism is assembled with the lead screw through a connecting block, and the lead screw is driven to rotate through a motor so that the connecting block drives the spraying mechanism to reciprocate along the length direction of the guide rails;

the spraying mechanism is used for spraying materials onto the substrate to form a display coating, and comprises a material storage tank, a material conveying pump, a high-pressure air pump and a spray gun;

the spray gun comprises a shell, a material channel and a gas transmission channel are axially arranged in the shell, the gas transmission channel surrounds the periphery of the material channel, and outlets of the material channel and the gas transmission channel are communicated with a nozzle at the bottom of the shell;

the dust collection mechanisms are positioned on two sides of the conveying mechanism and used for collecting materials.

Furthermore, the outer side of the shell is movably connected with a baffle, and the angle between the baffle and the shell is adjustable.

Further, dust absorption mechanism includes a plurality of dust absorption mouths, the dust absorption mouth is the horn mouth form, and the inside of dust absorption mouth is provided with the cavity, and the inner wall of dust absorption mouth sets up a plurality of gas pockets that communicate with the cavity, and updraft ventilator passes through pipeline and cavity intercommunication.

Furthermore, the bottom passageway of dust absorption mouth passes through the pipeline and communicates the water pump, the water pump is used for carrying water and material mixture to waste liquid collection tank.

Further, including the dustcoat, the dustcoat sets up the frame is outside for keep apart conveying mechanism, spraying mechanism, removal supporting mechanism and dust absorption mechanism with the external world, the inner wall of dustcoat sets up the guiding gutter, the guiding gutter is arranged along the week side of dustcoat and is formed the loop, the guiding gutter is just right the position of dust absorption mouth is provided with the opening, the import and the exit position of casing set up hydrojet device respectively for form the water curtain in the import and the exit of casing, the rivers that the water curtain formed collect extremely in the guiding gutter.

By adopting the technical scheme, compared with the prior art, the projectable blackboard has the advantages that:

1. the invention improves the blackboard and chalk using habit of people without changing the blackboard and chalk, does not need to increase the entity and operation of push-pull switching screen, and has higher availability and usability.

2. The coating can be adhered to various surfaces in a water-based coating spraying mode, and the application range is wide; the cost is low; easy to process, manufacture or modify; the water-soluble and pollution-free environment-friendly material is energy-saving and environment-friendly.

3. The nano powder material is used as an additive to prepare a display coating, so that the display coating is obviously enhanced and toughened, and the addition of a proper amount of nano material improves the volume filling density of pigment and filler in the coating, reduces the capillary effect and improves the shielding effect of the coating on a corrosive medium; at the same time, the rheological properties and the thermal stability of the coating used for the coating are improved. The addition of the nano powder material can effectively improve the surface adhesive force, surface hardness, smoothness and aging resistance of the blackboard/green board, and the chalk is easier to erase and write.

4. The spherical silver powder particles with uniform particle size are uniformly and tightly distributed under the action of a water-based nano system, the surface light reflection characteristic is favorable for displaying a projection picture, and the bright part is pure high light reflection, so that the gain can be greatly improved; the dark part inhibits the ambient light and effectively controls the black position; the contrast between brightness and darkness is very high, so that the projection display effect of high gain, high light resistance and high contrast can be achieved.

5. The uniform coating density ensures high brightness uniformity and no solar effect. Wider horizontal and vertical field angles can be provided.

Drawings

Fig. 1 is a schematic structural diagram of a projectable blackboard manufacturing apparatus according to an embodiment of the present invention;

fig. 2 is a schematic side structure view of a projectable blackboard manufacturing apparatus according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a spray mechanism in an embodiment of the present invention;

FIG. 4 is a schematic structural view of a spray gun in an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a conveying mechanism in an embodiment of the present invention;

FIG. 6 is a schematic view of a dust suction port according to an embodiment of the present invention;

fig. 7 is another schematic structural diagram of a projectable blackboard manufacturing apparatus according to an embodiment of the present invention;

FIG. 8 is a schematic structural view of a housing in an embodiment of the present invention;

fig. 9 is a schematic structural view of a liquid ejecting apparatus in an embodiment of the present invention.

In the figure, 10-rack; 20-a conveying mechanism; 30-a spraying mechanism; 31-a storage tank; 32-a delivery pump; 33-a high-pressure air pump; 34-a spray gun; 341-a housing; 342-a material channel; 343-a gas transmission channel; 344-spout; 345-a baffle plate; 40-moving the support mechanism; 41-a guide rail; 42-mounting grooves; 43-lead screw; 44-connecting block; 50-a dust suction mechanism; 51-a dust suction port; 511-cavity; 512-air holes; 513-channel; 52-air draft device; 53-water pump; 54-a waste liquid collection tank; 55-cloth bag; 60-an outer cover; 61-a diversion trench; 70-a liquid spraying device; 71-a liquid spray conduit; 72-infusion pump.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. 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.

The embodiment of the invention provides a projectable blackboard which comprises a substrate and a blackish green display coating, wherein the display coating has the functions of writing and projection, and comprises the following materials in parts by mass:

40-50 parts of polyurethane resin;

0.1-0.3 part of color paste;

0.4-0.7 part of nano powder;

1-2 parts of microcrystalline cellulose;

1.5-2.5 parts of spherical silver powder particles;

0.2-0.3 part of defoaming agent;

0.3-0.4 part of dispersant;

0.1-0.2 part of leveling agent;

3-5 parts of ethylene glycol;

8-10 parts of deionized water.

Preferably, the polyurethane resin is polymerized using polyester polyol and isophorone diisocyanate. In addition, the water-based polyurethane resin can be replaced by other base materials, such as acrylic acid and other system resins, PVC, PET and other base materials, and the water-based polyurethane resin is mixed and sprayed or extruded to form finished products in the shapes of plates, films, curtains and the like.

Preferably, mill bases are used to adjust the finished color. The color paste in the embodiment is adjusted to be dark green, and certainly, according to practical application, the color paste can be replaced by other color pastes with different colors to manufacture products with different color appearances.

The added spherical silver powder particles with uniform particle size are uniformly and tightly distributed under the action of a water-based nano system, the surface light reflection characteristic is favorable for displaying a projection picture, and the bright part is pure high light reflection, so that the gain can be greatly improved; the dark part inhibits the ambient light and effectively controls the black position; the contrast between brightness and darkness is very high, so that the projection display effect of high gain, high light resistance and high contrast can be achieved.

Preferably, the nano powder comprises the following components: the nano titanium oxide, nano aluminum oxide and nano silicon dioxide comprise the following components in parts by mass: 1-2.5:0.5-1:0.5-1.5. The nano powder material is used as an additive to prepare a display coating, is obviously strengthened and toughened,

the nano titanium oxide can effectively improve the reflectivity of light, the nano silicon dioxide plays a role of a delustering agent, when the coating is dry, the nano silicon dioxide enables the display layer to form a micro rough surface, slow scattering is achieved after incident light reaches the display layer, a strong matte effect is achieved, the volume filling density of pigment and filler in the coating is improved by adding a proper amount of nano materials, the capillary effect is reduced, and the shielding effect of the coating on a corrosive medium is improved; at the same time, the rheological properties and the thermal stability of the coating used for the coating are improved. The addition of the nano powder material can effectively improve the surface adhesive force, surface hardness, smoothness and aging resistance of the blackboard/green board, and the chalk is easier to erase and write.

The microcrystalline cellulose can obviously improve the adhesive force of the coating;

preferably, the antifoaming agent may employ polyoxyethylene polyoxypropylene amine ether, polyoxypropylene glycerol ether, and the like;

preferably, the dispersant can be BH616, DP983, BYKP-105, Disper710, and the like;

preferably, the leveling agent may be RM series of Rohm and Haas, RHELATE series of Jinhui, SUNFYNOL series of gas chemical industry, TEGO series of Germany Digao, or the like;

the glycol plays a role in preventing freezing;

preferably, the substrate is selected from any one of toughened glass, acrylic plates, galvanized plates, stainless steel plates, gypsum plates, density plates, non-adhesive PVC films and adhesive PVC films, and the thickness of the substrate is 2mm-10 mm.

The display coatings described above have a number of different formulation schemes when applied:

example 1

40 parts of polyurethane resin;

0.1 part of color paste;

0.4 part of nano powder;

1 part of microcrystalline cellulose;

1.5 parts of spherical silver powder particles;

0.2-part of defoaming agent;

0.3 part of a dispersant;

0.1 part of a leveling agent;

3 parts of ethylene glycol;

8 parts of deionized water.

Example 2

45 parts of polyurethane resin;

0.2 part of color paste;

0.6 part of nano powder;

1.5 parts of microcrystalline cellulose;

2 parts of spherical silver powder particles;

0.25 part of defoaming agent;

0.35 part of a dispersant;

0.15 part of a leveling agent;

4 parts of ethylene glycol;

and 9 parts of deionized water.

Example 3

50 parts of polyurethane resin;

0.3 part of color paste;

0.7 part of nano powder;

2 parts of microcrystalline cellulose;

2.5 parts of spherical silver powder particles;

0.3 part of defoaming agent;

0.4 part of a dispersant;

0.2 part of a leveling agent;

5 parts of ethylene glycol;

10 parts of deionized water.

The projectable blackboard provided by the embodiment of the invention can improve the reflection performance of the blackboard (black or dark green) during projection, improve the visual angle balance, has the optical characteristics of strong light resistance and high gain, and has no solar effect, so that the projection effect is further improved, and the coating is environment-friendly, good in adhesive force, high in surface strength and good in stability. Particularly, the display layer is arranged to be a dark green matte surface, the eye fatigue is not prone to being observed for a long time, chalk can be erased and written repeatedly, the original chalk writing habit and visual performance of the blackboard are guaranteed, multimedia contents can be directly put in the picture by using a projector, and the picture with high brightness, high contrast and high resolution is presented. The invention has the writing and projection functions, so that the whole body does not need to be divided, and the writing and the multimedia display do not need to be switched.

Preferably, the preparation method of the display coating of the projectable blackboard comprises the following steps:

s4, spraying the prepared coating on the flat surface of the substrate through a spraying mechanism 30, and drying to form a display coating with the thickness of 0.1-0.3 mm.

In addition, referring to fig. 1 and 2, an embodiment of the present invention further provides a projectable blackboard manufacturing apparatus, for processing the projectable blackboard in the above embodiment, the manufacturing apparatus includes a frame 10, and a conveying mechanism 20, a spraying mechanism 30, a moving support mechanism 40, and a dust suction mechanism 50 which are arranged on the frame 10;

the conveying mechanism 20 is used for conveying and supporting the projectable blackboard; the conveying mechanism 20 can adopt transmission structures such as conveying rollers, conveying belts, conveying chains and the like;

the movable support mechanism 40 is used for supporting the spraying mechanism 30 and driving the spraying mechanism 30 to move.

Specifically, refer to fig. 5; the movable supporting mechanism 40 is positioned above the conveying mechanism 20, the movable supporting mechanism 40 comprises a plurality of guide rails 41 which are arranged at intervals along the width direction of the projectable blackboard, each guide rail 41 is provided with a mounting groove 42, a lead screw 43 is assembled in the mounting groove 42 of each guide rail 41 through a bearing, the spraying mechanism 30 is assembled with the lead screw 43 through a connecting block 44, and the lead screw 43 is driven to rotate through a motor, so that the connecting block 44 drives the spraying mechanism 30 to reciprocate along the length direction of the guide rails 41; therefore, the substrate is sprayed simultaneously by the plurality of spraying mechanisms 30 arranged at intervals, and the conveying mechanism 20 is in a static state during spraying, so that the spraying uniformity of the display layer can be greatly improved, the processing efficiency is improved, and the product quality is improved; in the conventional spraying system, the spraying quality of the display layer is affected by the vibration of the substrate caused by the static state of the spray gun 34 and the running state of the conveying mechanism 20;

the spraying mechanism 30 is used for spraying the material on the substrate to form a display coating;

specifically, referring to fig. 3 and 4, the spraying mechanism 30 includes a storage tank 31, a delivery pump 32, a high-pressure air pump 33, and a spray gun 34;

the spray gun 34 comprises a shell 341, the shell 341 is fixed on the connecting block 44 through a connecting piece and can move synchronously with the connecting block 44, a material channel 342 and a gas transmission channel 343 are coaxially arranged in the shell 341 along the axial direction, the gas transmission channel 343 surrounds the periphery of the material channel 342, and the outlet of the material channel 342 and the outlet of the gas transmission channel 343 are communicated with a nozzle 344 at the bottom of the shell 341;

the paint is stored in the material storage tank 31, the paint is conveyed to a material channel 342 in the spray gun 34 by the material conveying pump 32 through a pipeline, the high-pressure air pump 33 conveys high-pressure air to a gas conveying channel 343 of the spray gun 34 through a pipeline and the high-pressure air is mixed and sprayed out of a nozzle 344, so that a uniform display coating is formed on the surface of a substrate;

the dust suction mechanisms 50 are located at two sides of the conveying mechanism 20, and are used for collecting material particles diffused in the air to avoid air pollution.

Preferably, the outer side of the housing 341 of the spray gun 34 is movably connected with a baffle 345 through a rotating shaft, and the angle between the baffle 345 and the housing 341 is adjustable, so that the spraying range of the materials can be adjusted during application, the spraying overlapping range of the spray guns 34 is reduced, and in addition, for blackboards with different width sizes, the angle between the baffle 345 and the housing 341 can be adjusted in a targeted manner, and the waste of the materials is avoided.

Preferably, with reference to fig. 1, 2 and 6; dust absorption mechanism 50 includes a plurality of dust absorption mouths 51, dust absorption mouth 51 is the horn mouth form, the inside of dust absorption mouth 51 is provided with cavity 511, the inner wall of dust absorption mouth 51 sets up a plurality of gas pockets 512 that communicate with cavity 511, updraft ventilator 52 passes through the pipeline and communicates with cavity 511, can make dust absorption mouth 51 department form the negative pressure through updraft ventilator 52, absorb the material of dispersion in the air, updraft ventilator still communicates with sack 55 or collection tank for the material storage with the suction, avoid causing the pollution to the air.

In addition, the bottom channel 513 of the dust suction port 51 is communicated with the water pump 53 through a pipeline, the water pump 53 is used for conveying water and the material mixture entering the dust suction port 51 to the waste liquid collecting tank 54, the waste liquid is heated through the corresponding heating device subsequently, the coating is collected again, and secondary recycling of resources can be achieved.

Refer to fig. 7 and 8; the projectable blackboard manufacturing equipment provided by the embodiment further comprises an outer cover 60, wherein the outer cover 60 is arranged outside the rack 10 and used for isolating the conveying mechanism 20, the spraying mechanism 30, the moving support mechanism 40 and the dust suction mechanism 50 from the outside, so that the pollution to the external environment is avoided.

The inner wall of dustcoat 60 sets up guiding gutter 61, guiding gutter 61 arranges along the week side of dustcoat 60 and forms the loop, guiding gutter 61 is provided with the opening just to the position of dust absorption mouth 51, make the liquid in guiding gutter 61 can flow into dust absorption mouth 51, mix with material in the air, the bottom passageway of rethread dust absorption mouth 51, water pump 53, carry the material mixture to the waste liquid collecting tank, the import and the exit position of casing 341 set up hydrojet device 70 respectively, be used for forming the water curtain in the import and the exit of casing 341, the rivers that the water curtain formed converge to guiding gutter 61.

Specifically, refer to fig. 9; the liquid spraying device 70 comprises a liquid spraying pipeline 71 and a liquid conveying pump 72, the liquid conveying pump 72 is communicated with the liquid spraying pipeline 71 through a pipeline, the liquid spraying pipeline 71 is installed on the rack 10, the length of the liquid spraying pipeline 71 is larger than that of an inlet and an outlet of the shell 341, a plurality of water outlet holes are formed below the liquid spraying pipeline 71, so that a water curtain is formed at the inlet and the outlet of the shell 341, harmful substances in the shell 341 are prevented from being diffused to the outside, the water curtain falls in the flow guide groove 61, flows into the dust suction port 51 through the opening of the flow guide groove 61 and is mixed with the materials, and finally the materials are collected in the waste liquid.

The manufacturing equipment of the projectable blackboard provided by the embodiment of the invention has the following characteristics:

1. the guide rails 41 are used for assembling the spraying mechanisms 30, so that the spray guns 34 are used for spraying the substrate, the conveying mechanism 20 is in a static state during spraying, the uniformity of spraying of the display layer can be greatly improved, the processing efficiency is improved, and the product quality is improved.

2. The outer side of the shell 341 is movably connected with a baffle 345 through a rotating shaft, and the angle between the baffle 345 and the shell 341 is adjustable, so that the spraying range of the materials can be adjusted during application, and the spraying overlapping range of the plurality of spray guns 34 is reduced.

3. Negative pressure can be formed at the dust suction port 51 through the air draft device 52, and materials dispersed in the air are absorbed, so that the materials are recycled, and the air pollution is avoided.

4. The liquid spraying device 70 forms a water curtain at the inlet and outlet of the housing 341 to prevent harmful substances in the housing 341 from being diffused to the outside, and the water curtain falls in the guide groove 61, flows into the dust suction port 51 through the opening of the guide groove 61 to be mixed with the materials, and is finally collected in the waste liquid collecting tank.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. The projectable blackboard is characterized by comprising a substrate and a blackish green display coating, wherein the display coating has the functions of writing and projection, and comprises the following materials in parts by mass:

40-50 parts of polyurethane resin;

0.1-0.3 part of color paste;

0.4-0.7 part of nano powder;

1-2 parts of microcrystalline cellulose;

1.5-2.5 parts of spherical silver powder particles;

0.2-0.3 part of defoaming agent;

0.3-0.4 part of dispersant;

0.1-0.2 part of leveling agent;

3-5 parts of ethylene glycol;

8-10 parts of deionized water.

2. The projectable blackboard of claim 1, wherein the polyurethane resin is polymerized from polyester polyol and isophorone diisocyanate.

3. The projectable blackboard of claim 2, wherein the nano-powder comprises the following components: the nano titanium oxide, nano aluminum oxide and nano silicon dioxide comprise the following components in parts by mass: 1-2.5:0.5-1:0.5-1.5.

4. The projectable blackboard of claim 1, wherein the display coating is prepared by the following method:

5. The projectable blackboard of claim 1, wherein the substrate is selected from any one of tempered glass, acrylic board, galvanized board, stainless steel board, gypsum board, density board, adhesive-free PVC film and adhesive-containing PVC film, and the thickness of the substrate is 2mm to 10 mm.

6. A projectable blackboard manufacturing equipment is used for processing the projectable blackboard as claimed in any one of claims 1 to 5, and is characterized by comprising a frame, and a conveying mechanism, a spraying mechanism, a movable supporting mechanism and a dust suction mechanism which are arranged on the frame;

the conveying mechanism is used for conveying the projectable blackboard,

7. The projectable blackboard of claim 6, wherein a baffle is movably connected to the outer side of the housing, and the angle between the baffle and the housing is adjustable.

8. The projectable blackboard of claim 6, wherein the dust suction mechanism comprises a plurality of dust suction ports, the dust suction ports are in a bell mouth shape, a cavity is arranged inside the dust suction ports, a plurality of air holes communicated with the cavity are arranged on the inner wall of the dust suction ports, and the air draft device is communicated with the cavity through a pipeline.

9. The projectable blackboard of claim 8, wherein the bottom channel of the dust suction port is communicated with a water pump through a pipeline, and the water pump is used for conveying the mixture of water and materials to the waste liquid collecting tank.

10. The projectable blackboard of claim 9, comprising an outer cover, wherein the outer cover is disposed outside the chassis and used for isolating the conveying mechanism, the spraying mechanism, the moving support mechanism and the dust suction mechanism from the outside, a diversion trench is disposed on the inner wall of the outer cover and arranged along the peripheral side of the outer cover to form a loop, an opening is disposed at the position of the dust suction port opposite to the diversion trench, liquid spraying devices are respectively disposed at the inlet and outlet positions of the casing and used for forming a water curtain at the inlet and outlet of the casing, and water flow formed by the water curtain is collected into the diversion trench.