An inkjet state detection device and method for binder jet 3D printing

Abstract

The present invention relates to the technical field of 3D printing, and specifically discloses an inkjet state detection device and method for binder jet 3D printing, wherein the inkjet state detection device comprises a loading platform, a material storage box, a first guide roller, a first lifting roller, a weighing platform, a second lifting roller, a second guide roller and a traction device; the first guide roller and the second guide roller are respectively arranged on both sides of the weighing platform; a test paper is arranged in the material storage box; the weighing platform is used to detect the pressure of the test paper on the weighing platform; the first lifting roller and the second lifting roller can be lifted and lowered. The present invention can automatically collect, weigh and record the ink jet from the nozzle without manual intervention, thereby reducing detection errors.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to an inkjet state detection device and method for binder jet 3D printing. Background Art

[0002] Binder jet 3D printing is a technology that uses a nozzle to spray binder (or ink) to bind the powder layers at the specified position to form a three-dimensional green body / model. It can print and form a variety of powder materials, including polymers, metals, ceramics, composite materials, sand, etc. For metal and ceramic powders, it is usually necessary to degrease and sinter the printed green body to obtain a final product that meets the requirements. Therefore, the quality of the green body directly affects the quality of the final product. For binder jet 3D printing technology, one of the key factors affecting the quality of printed green bodies / models is the inkjet state of the nozzle. Before 3D printing of green bodies / models, the inkjet state of the nozzle is usually tested, including jet stability (whether the nozzle is blocked, whether the ink droplets drift and splash, etc.), the amount of inkjet, and the ink amount stability of multi-layer printing inkjet. According to the test results, the printing parameters and jet parameters should be adjusted. Only when the nozzle sprays stably and the inkjet amount is constant can the quality and density uniformity of the green body / model be ensured. In addition, the binder content in the green body can also be calculated based on the actual amount of inkjet, and the subsequent degreasing process can be formulated accordingly.

[0003] The existing inkjet status detection method usually places a medium for receiving ink under the nozzle, manually removes the medium after inkjet, analyzes the inkjet stability by observing the ink droplets distributed on it through a microscope, and weighs the medium to analyze the amount of inkjet. This method requires manual operation, is time-consuming and labor-intensive, and is not very accurate in detecting the amount of inkjet, which will affect the formulation of the subsequent green body degreasing process; and this method is difficult to detect the ink volume stability of continuous multi-layer printing inkjet. Summary of the invention

[0004] In order to solve the defects of the prior art, the present invention provides an inkjet status detection device and method for binder jet 3D printing, which can automatically collect, weigh and record the inkjet of the nozzle without manual intervention, thereby reducing detection errors.

[0005] In order to solve the above technical problems, the embodiment of the present invention provides an inkjet state detection device for binder jet 3D printing, comprising a loading platform, a material storage box, a first guide roller, a first lifting roller, a weighing platform, a second lifting roller, a second guide roller and a traction device, wherein the material storage box, the first guide roller, the first lifting roller, the weighing platform, the second lifting roller, the second guide roller and the traction device are arranged on the loading platform; the first guide roller and the second guide roller are respectively arranged on both sides of the weighing platform, the first lifting roller is arranged between the first guide roller and the weighing platform, and the second lifting roller is arranged between the second guide roller and the weighing platform; the highest points of the first guide roller and the second guide roller are lower than the upper surface of the weighing platform. The material storage box is provided with a test paper, and the test paper passes through the first guide roller, the first lifting roller, the weighing platform, the second lifting roller and the second guide roller in sequence under the pulling action of the traction device; the weighing platform is used to detect the pressure of the test paper on the weighing platform; the first lifting roller and the second lifting roller can be lifted and lowered to ensure that the test paper enters the weighing platform from a position lower than the upper surface of the weighing platform and leaves from a position lower than the upper surface of the weighing platform during the test.

[0006] As an improvement of the above-mentioned scheme, the inkjet status detection equipment also includes a base, on which a platform lifting mechanism is provided, and the platform lifting mechanism is connected to the loading platform, and the storage box, the first guide roller, the first lifting roller, the weighing platform, the second lifting roller, the second guide roller and the traction device can be lifted and lowered together with the loading platform.

[0007] As an improvement of the above solution, the first lifting roller and the second lifting roller are connected to a roller lifting mechanism, and the roller lifting mechanism is used to drive the corresponding first lifting roller and / or second lifting roller to rise and fall.

[0008] As an improvement of the above scheme, the roller lifting mechanism includes a lifting cylinder, and the piston rod of the lifting cylinder is connected to the corresponding first lifting roller and / or second lifting roller; or, the roller lifting mechanism is a screw lifting mechanism, including a screw and a drive nut, the screw is connected to the corresponding first lifting roller and / or second lifting roller, and the drive nut is connected to the drive motor, and the drive nut drives the screw to rise and fall by its own rotation.

[0009] As an improvement of the above solution, the test paper is composed of an upper layer of cotton fiber paper and a lower layer of plastic hard film, wherein the cotton fiber paper is used to absorb the sprayed adhesive, and the plastic hard film is used to prevent the adhesive from penetrating and contaminating the weighing platform.

[0010] Accordingly, an embodiment of the present invention further provides an inkjet state detection method for binder jet 3D printing, using the inkjet state detection device for binder jet 3D printing as described above, comprising the following steps:

[0011] Step 1: driving the test paper to pass through the first guide roller, the first lifting roller, the weighing platform, the second lifting roller and the second guide roller in sequence, and controlling the heights of the first lifting roller and the second lifting roller so that the highest points of the first lifting roller and the second lifting roller are lower than the upper surface of the weighing platform, and the highest points of the first guide roller and the second guide roller are lower than the upper surface of the weighing platform;

[0012] Step 2: Obtain the current weight of the test paper through a weighing platform, which is recorded as the initial weight W0;

[0013] Step 3: Use a 3D printer to spray a layer of adhesive on the surface of the test paper, obtain the current weight of the test paper through a weighing platform, record it as the weight after inkjet W1, and then obtain the weight of one inkjet △W through a controller, △W=W1-W0.

[0014] Accordingly, an embodiment of the present invention further provides an inkjet state detection method for binder jet 3D printing, using the inkjet state detection device for binder jet 3D printing as described above, comprising the following steps:

[0015] Step 1: driving the test paper to pass through the first guide roller, the first lifting roller, the weighing platform, the second lifting roller and the second guide roller in sequence, and controlling the heights of the first lifting roller and the second lifting roller so that the highest points of the first lifting roller and the second lifting roller are lower than the upper surface of the weighing platform, and the highest points of the first guide roller and the second guide roller are lower than the upper surface of the weighing platform;

[0016] Step 2: Obtain the current weight of the test paper through a weighing platform, which is recorded as the initial weight;

[0017] Step 3: spray a layer of adhesive on the surface of the test paper through a 3D printer, obtain the current weight of the test paper through a weighing platform, record it as the weight after inkjet, and then obtain the weight of a single inkjet through a controller;

[0018] Repeat steps 1 to 3 to obtain the weight of a single inkjet of different test papers;

[0019] Calculating an average of the weights of a plurality of single ink jets;

[0020] The weight of each single inkjet is compared with the average value, and the state of the nozzle is adjusted according to the comparison result.

[0021] Accordingly, an embodiment of the present invention further provides an inkjet state detection method for binder jet 3D printing, using the inkjet state detection device for binder jet 3D printing as described above, comprising the following steps:

[0022] Step 1: driving the test paper to pass through the first guide roller, the first lifting roller, the weighing platform, the second lifting roller and the second guide roller in sequence, and controlling the heights of the first lifting roller and the second lifting roller so that the highest points of the first lifting roller and the second lifting roller are lower than the upper surface of the weighing platform, and the highest points of the first guide roller and the second guide roller are lower than the upper surface of the weighing platform;

[0023] Step 2: Obtain the current weight of the test paper through a weighing platform, which is recorded as the initial weight;

[0024] Step 3: spray a layer of adhesive on the surface of the test paper through a 3D printer, adjust the height of the stage and / or the distance between the stage and the base, obtain the current weight of the test paper through a weighing table, record it as the weight after inkjet, and then obtain the weight of a single inkjet through a controller;

[0025] Repeat steps 1 to 3 to obtain the weight of a single inkjet of different test papers;

[0026] Calculating an average of the weights of a plurality of single ink jets;

[0027] The weight of each single inkjet is compared with the average value, and the state of the nozzle is adjusted according to the comparison result.

[0028] Preferably, a layer of adhesive is sprayed on the surface of the test paper by a 3D printer, and the distance between the lower surface of the nozzle of the 3D printer and the upper surface of the test paper is 3-6 mm.

[0029] Preferably, the highest points of the first lifting roller and the second lifting roller are 1-3 mm lower than the upper surface of the weighing platform.

[0030] Implementing the embodiments of the present invention has the following beneficial effects:

[0031] By adopting the above detection equipment and detection method, the ink jetting of the nozzle can be automatically collected, weighed and recorded without manual intervention, thereby reducing detection errors.

[0032] The above-mentioned detection equipment and detection method can also detect the ink volume stability of continuous multi-layer printing inkjet, truly reflect the inkjet state of the nozzle during continuous printing, and provide a reference for adjusting process parameters to achieve long-term stable printing and formulate green body degreasing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1It is a structural schematic diagram of an inkjet state detection device for binder jet 3D printing according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It is hereby stated that the directional terms such as up, down, left, right, front, back, inside, outside, etc. that appear or will appear in the text of the present invention are only based on the accompanying drawings of the present invention, and are not specific limitations of the present invention.

[0035] like Figure 1 As shown, an embodiment of the present invention provides an inkjet state detection device for binder jet 3D printing, comprising a loading platform 1, a material storage box 2, a first guide roller 3, a first lifting roller 4, a weighing platform 5, a second lifting roller 6, a second guide roller 7 and a traction device 8, wherein the material storage box 2, the first guide roller 3, the first lifting roller 4, the weighing platform 5, the second lifting roller 6, the second guide roller 7 and the traction device 8 are arranged on the loading platform 1; the first guide roller 3 and the second guide roller 7 are respectively arranged on both sides of the weighing platform 5, the first lifting roller 4 is arranged between the first guide roller 3 and the weighing platform 5, and the second lifting roller 6 is arranged between the first guide roller 3 and the weighing platform 5. Between the second guide roller 7 and the weighing platform 5, the highest points of the first guide roller 3 and the second guide roller 7 are lower than the upper surface of the weighing platform 5; the storage box 2 is provided with a test paper 9, and the test paper 9 passes through the first guide roller 3, the first lifting roller 4, the weighing platform 5, the second lifting roller 6 and the second guide roller 7 in sequence under the pulling action of the traction device 8; the weighing platform 5 is used to detect the pressure of the test paper 9 on the weighing platform 5; the first lifting roller 4 and the second lifting roller 6 can be lifted and lowered to ensure that the test paper 9 enters the weighing platform 5 from a position lower than the upper surface of the weighing platform 5 and leaves from a position lower than the upper surface of the weighing platform 5 during the test. The first guide roller 3 and / or the second guide roller 7 are connected to the loading platform 1 through a roller bracket 10, and the roller bracket 10 can be made of an elastic metal sheet to provide a stable tension for the test paper.

[0036] The above-mentioned detection equipment can automatically collect, weigh and record the ink from the nozzle without manual intervention, thereby reducing detection errors. It can also detect the ink volume stability of continuous multi-layer printing inkjet and truly reflect the inkjet status of the nozzle during continuous printing, providing a reference for adjusting process parameters to achieve long-term stable printing and formulating green body degreasing process.

[0037] Preferably, the inkjet state detection device further comprises a base 11, on which a platform lifting mechanism 12 is provided, and the platform lifting mechanism 12 is connected to the loading platform 1 and is used to drive the loading platform 1 to rise and fall. The material storage box 2, the first guide roller 3, the first lifting roller 4, the weighing platform 5, the second lifting roller 6, the second guide roller 7 and the traction device 8 can rise and fall together with the loading platform 1. The platform lifting mechanism 12 can be an existing screw lifting mechanism or a hydraulic lifting mechanism, etc.

[0038] Preferably, the first lifting roller 4 and the second lifting roller 6 are respectively arranged on the corresponding roller lifting mechanism 13, and the roller lifting mechanism 13 is used to drive the corresponding first lifting roller 4 or second lifting roller 6 to rise and fall. The roller lifting mechanism 13 includes a lifting cylinder 131, and the piston rod of the lifting cylinder 131 is connected to the corresponding first lifting roller 4 or second lifting roller 6; or, the roller lifting mechanism 13 is a screw lifting mechanism (not shown in the figure), including a screw and a drive nut, the screw is connected to the corresponding first lifting roller 4 or second lifting roller 6, and the drive nut is connected to the drive motor, and the drive nut drives the screw to rise and fall by rotating itself. It should be noted that the function of the roller lifting mechanism 13 is to drive the first lifting roller 4 and the second lifting roller 6 to rise and fall independently. In addition to the above two specific embodiments, other existing mechanical and electrical components can also be used to achieve this.

[0039] In order to prevent the test papers 9 from contaminating each other after measurement and to prevent the weighing platform 5 from being contaminated by the liquid sprayed from the nozzle, the test paper 9 is composed of an upper layer of cotton fiber paper and a lower layer of plastic hard film, wherein the cotton fiber paper is used to absorb the sprayed adhesive and the plastic hard film is used to prevent the adhesive from penetrating and contaminating the weighing platform 5. After the test is completed, the test paper 9 can be stored in a roll, and each layer of the test paper 9 is isolated by a plastic hard film to prevent mutual contamination.

[0040] Accordingly, the present invention also provides an embodiment of a method for detecting inkjet status of binder jet 3D printing, using the inkjet status detection device for binder jet 3D printing as described above, comprising the following steps:

[0041] Step 1: Place the inkjet state detection device for binder jet 3D printing in the forming cylinder of the binder jet 3D printer. In some embodiments, the test paper 9 in the storage box 2 is sequentially passed through the upper surface of the first guide roller 3, the lower surface of the first lifting roller 4, the lower surface of the second lifting roller 6, and the upper surface of the second guide roller 7, and connected to the traction device 8; the height of the first lifting roller 4 and the second lifting roller 6 is controlled so that the highest point of the first lifting roller 4 and the second lifting roller 6 is 1-3mm lower than the upper surface of the weighing platform 5; the distance from the upper surface of the test paper on the weighing platform 5 to the lower surface of the nozzle is 3-6mm.

[0042] Step 2: Obtain the current weight of the test paper through the weighing platform 5, which is recorded as the initial weight W0;

[0043] Step 3: The nozzle sprays a layer of adhesive onto the test paper 9 on the weighing platform 5, and obtains the current weight of the test paper through the weighing platform, which is recorded as the weight after inkjet W1; then obtains the weight of one inkjet △W through the controller, △W=W1-W0.

[0044] The controller may be an existing single chip microcomputer, PLC or server etc. with data acquisition, recording and computing capabilities.

[0045] In this embodiment, the above method can be used to automatically collect, weigh and record the ink sprayed from the nozzle without manual intervention, thereby reducing detection errors.

[0046] The present invention also provides another embodiment of a method for detecting inkjet status of binder jet 3D printing, using the inkjet status detection device for binder jet 3D printing as described above, comprising the following steps:

[0047] Step 1: Place the inkjet state detection device for binder jet 3D printing in the forming cylinder of the binder jet 3D printer. In some embodiments, the test paper 9 in the storage box 2 is sequentially passed through the upper surface of the first guide roller 3, the lower surface of the first lifting roller 4, the lower surface of the second lifting roller 6, and the upper surface of the second guide roller 7, and connected to the traction device 8; the height of the first lifting roller 4 and the second lifting roller 6 is controlled so that the highest point of the first lifting roller 4 and the second lifting roller 6 is 1-3mm lower than the upper surface of the weighing platform 5; the distance from the upper surface of the test paper on the weighing platform 5 to the lower surface of the nozzle is 3-6mm.

[0048] Step 2: Obtain the current weight of the test paper through the weighing platform 5, which is recorded as the initial weight W0;

[0049] Step 3: The nozzle sprays a layer of adhesive onto the test paper 9 on the weighing platform 5, and obtains the current weight of the test paper through the weighing platform, which is recorded as the weight after inkjet W1; then obtains the weight of one inkjet △W through the controller, △W=W1-W0.

[0050] Repeat steps 1 to 3 to obtain the weight of a single inkjet of different test papers;

[0051] Calculating an average of the weights of a plurality of single ink jets;

[0052] The weight of each single inkjet is compared with the average value, and the state of the nozzle is adjusted according to the comparison result.

[0053] In this embodiment, the following steps are taken after a single test to prepare for the next test: the first lifting roller 4 and the second lifting roller 6 are driven to rise so that the lowest points of the first lifting roller 4 and the second lifting roller 6 are 1-3 mm higher than the upper surface of the weighing platform 5; the traction device 8 pulls the test paper 9 downward, and pulls the part of the test paper 9 that already contains the adhesive to one side of the weighing platform 5, and a new section of the test paper 9 is covered on the surface of the weighing platform 5.

[0054] Preferably, in order to realize continuous testing of the inkjet of the nozzle, steps one to three of the inkjet state detection method of binder jet 3D printing described above can be repeated to obtain a test paper 9 containing multiple printing records and the weight of a single inkjet of different test papers 9; the sample on the test paper 9 can show the change of the inkjet state of the nozzle for a long time, which is convenient for subsequent analysis.

[0055] After obtaining a sufficient number of test paper samples, the average weight of multiple single ink jets can be calculated;

[0056] The weight of each single inkjet is compared with the average value, and the state of the nozzle is adjusted according to the comparison result. When the deviation of the weight of a single inkjet exceeds ±5% of the average value of the inkjet weight, the nozzle is adjusted or repaired. In order to reduce the error, at least 5 or more inkjet samples are taken before judgment. More preferably, a microscope can be used to analyze the inkjet sample on the test paper 9, and the nozzle parameters and printing parameters are adjusted and optimized accordingly, and the green body degreasing process is formulated according to the total amount of inkjet.

[0057] In order to detect continuous multi-layer printing inkjet, the present invention also provides another embodiment of a method for detecting inkjet status of binder jet 3D printing, using the inkjet status detection device for binder jet 3D printing as described above, comprising the following steps:

[0058] Step 1: driving the test paper to pass through the first guide roller, the first lifting roller, the weighing platform, the second lifting roller and the second guide roller in sequence, and controlling the heights of the first lifting roller and the second lifting roller so that the highest points of the first lifting roller and the second lifting roller are lower than the upper surface of the weighing platform, and the highest points of the first guide roller and the second guide roller are lower than the upper surface of the weighing platform;

[0059] In some embodiments, the inkjet state detection device for binder jet 3D printing is placed in the forming cylinder of the binder jet 3D printer. The test paper 9 in the storage box 2 is sequentially passed through the upper surface of the first guide roller 3, the lower surface of the first lifting roller 4, the lower surface of the second lifting roller 6, and the upper surface of the second guide roller 7, and connected to the traction device 8; the height of the first lifting roller 4 and the second lifting roller 6 is controlled so that the highest point of the first lifting roller 4 and the second lifting roller 6 is 1-3mm lower than the upper surface of the weighing platform 5; the distance from the upper surface of the test paper on the weighing platform 5 to the lower surface of the nozzle is 3-6mm.

[0060] Step 2: Obtain the current weight of the test paper through a weighing platform, which is recorded as the initial weight W0;

[0061] Step three: The nozzle sprays a layer of adhesive onto the test paper 9 on the weighing platform 5, adjusts the height of the stage 1 and / or the distance between the stage 1 and the base 11, obtains the current weight of the test paper through the weighing platform 5, and records it as the weight after inkjet W1; then obtains the weight △W of one inkjet through the controller, △W=W1-W0.

[0062] In some embodiments, the height of the stage 1 and / or the distance between the stage 1 and the base 11 can be adjusted to keep the distance from the nozzle to the weighing platform 5 unchanged. For example, in order to simulate a printer in which the forming cylinder descends by a printing layer thickness for each layer printed during normal printing, the forming cylinder can be descended by a printing layer thickness, and the stage 1 can be raised by a printing layer thickness relative to the base 11 to keep the distance from the nozzle to the weighing platform 5 unchanged.

[0063] Repeat steps 1 to 3 several times to obtain the weight of a single inkjet of different test papers in a continuous multi-layer printing state;

[0064] Calculating an average of the weights of a plurality of single ink jets;

[0065] The weight of each single inkjet is compared with the average value, and the state of the nozzle is adjusted according to the comparison result.

[0066] Preferably, a microscope may be used to analyze the inkjet sample on the test paper 9, and the nozzle parameters and printing parameters may be adjusted and optimized accordingly, and a green body degreasing process may be formulated according to the total amount of inkjet.

[0067] In this embodiment, the above method can simulate the printing state of the printing device during normal operation, thereby truly reflecting the nozzle state, the lifting accuracy and stability of the forming cylinder, and the influence of tiny vibrations in the lifting process of the forming cylinder on the printing effect. Combined with the weight data after each inkjet, it can objectively reflect the printing state of the printing device, which is convenient for early intervention before problems occur, and adjustment of the nozzle state before each printing.

[0068] Embodiment 1

[0069] The first embodiment of the present invention uses a binder jet 3D printer to print 316L stainless steel powder, the nozzle uses a Starlight SG1024LA nozzle, the binder uses a water-based single-component binder, the ink volume is 80%, and the print layer thickness is 0.15mm. This embodiment provides a continuous single-layer detection method for the inkjet state of binder jet 3D printing, using the inkjet state detection device for binder jet 3D printing as described above, including the following steps:

[0070] Step 1: Pass the test paper 9 in the storage box 2 through the upper surface of the first guide roller 3, the lower surface of the first lifting roller 4, the lower surface of the second lifting roller 6 and the upper surface of the second guide roller 7 in turn, and connect to the traction device 8; control the height of the first lifting roller 4 and the second lifting roller 6 so that the highest point of the first lifting roller 4 and the second lifting roller 6 is 2mm lower than the upper surface of the weighing platform 5; the weighing platform 5 obtains the current weight and records it as the initial weight; the weighing accuracy of the weighing platform 5 is 0.0001 grams, and the weighing value can be automatically stored and calculated each time. The material of the plastic film is polyvinyl chloride. The thickness of the test paper 9 is 0.5mm.

[0071] Step 2: Place the inkjet state detection device for binder jet 3D printing in the forming cylinder of the binder jet 3D printer, and make the distance from the upper surface of the test paper on the weighing table 5 to the lower surface of the nozzle be 3 mm;

[0072] Step 3: The nozzle sprays a layer of adhesive onto the test paper 9 of the weighing platform 5. The weighing platform 5 automatically detects the current weight and records it as the weight after inkjet. The weight after inkjet is subtracted from the initial weight to obtain the inkjet weight and display and store it.

[0073] Step 4: Drive the first lifting roller 4 and the second lifting roller 6 to rise, so that the lowest point of the first lifting roller 4 and the second lifting roller 6 is 2 mm higher than the upper surface of the weighing platform 5; the traction device 8 pulls the test paper 9 downward, and pulls the part of the test paper 9 that already contains the adhesive to one side of the weighing platform 5, and a new section of the test paper 9 is covered on the surface of the weighing platform 5.

[0074] Step 5: Repeat steps 1 to 4 of the inkjet state detection method for binder jet 3D printing described above for 6 times to obtain a test paper 9 containing multiple printing records.

[0075] Step 6: Observe the state of the droplets of the adhesive on the test paper 9 obtained by the six tests under a microscope, and analyze the inkjet state and inkjet stability according to the uniformity of the droplet state and the fluctuation degree of the inkjet weight in one test in combination with the corresponding inkjet weight. The results of the six tests show that the weight of each inkjet amount is within ±5% of the average value, so the inkjet is stable.

[0076] Embodiment 2

[0077] The second embodiment of the present invention uses a binder jet 3D printer to print PA12 nylon powder, the nozzle uses a XAARGS12 nozzle, the binder uses a water-based single-component binder, the ink volume is 100%, and the print layer thickness is 0.1mm. This embodiment provides a continuous multi-layer detection method for the inkjet state of binder jet 3D printing, using the inkjet state detection device for binder jet 3D printing as described above, including the following steps:

[0078] Step 1: Pass the test paper 9 in the storage box 2 through the upper surface of the first guide roller 3, the lower surface of the first lifting roller 4, the lower surface of the second lifting roller 6 and the upper surface of the second guide roller 7 in turn, and connect to the traction device 8; control the height of the first lifting roller 4 and the second lifting roller 6 so that the highest point of the first lifting roller 4 and the second lifting roller 6 is 1.5mm lower than the upper surface of the weighing platform 5; the weighing platform 5 obtains the current weight and records it as the initial weight; the weighing accuracy of the weighing platform 5 is 0.0001 grams, and the weighing value of each weighing can be automatically stored and calculated. The material of the plastic film is polyethylene. The thickness of the test paper 9 is 0.6mm.

[0079] Step 2: Place the inkjet state detection device for binder jet 3D printing in the forming cylinder of the binder jet 3D printer, and make the distance from the upper surface of the test paper on the weighing table 5 to the lower surface of the nozzle be 4 mm;

[0080] Step 3: The nozzle sprays a layer of adhesive onto the test paper 9 of the weighing platform 5. The weighing platform 5 automatically detects the current weight and records it as the weight after inkjet. The weight after inkjet is subtracted from the initial weight to obtain the inkjet weight and display and store it.

[0081] Step 4: Drive the first lifting roller 4 and the second lifting roller 6 to rise, so that the lowest point of the first lifting roller 4 and the second lifting roller 6 is 2 mm higher than the upper surface of the weighing platform 5; the traction device 8 pulls the test paper 9 downward, and pulls the part of the test paper 9 that already contains the adhesive to one side of the weighing platform 5, and a new section of the test paper 9 is covered on the surface of the weighing platform 5.

[0082] Step 5: lower the forming cylinder by a distance of 0.1 mm in thickness of the printing layer, and at the same time raise the stage 1 by a distance of 0.1 mm in thickness of the printing layer, so as to keep the distance from the nozzle to the weighing platform 5 unchanged;

[0083] Step 6: Repeat steps 1 to 5 50 times to obtain printing samples in a continuous multi-layer printing state and the inkjet weight of each print.

[0084] Step 7: Take out the test paper 9, observe the droplet state of the adhesive on the test paper 9 under a microscope, and analyze the inkjet state and inkjet stability according to the uniformity of the droplet state and the fluctuation degree of the inkjet weight in combination with the record of one inkjet weight: the results of multi-layer continuous tests show that the weight of each inkjet amount is within ±5% of the average value, the inkjet is stable, and continuous printing operations can be performed.

[0085] The above method can simulate the printing state of the printing device during normal operation, so as to truly reflect the state of the nozzle, the lifting accuracy and stability of the forming cylinder, and the influence of the tiny vibrations in the lifting process of the forming cylinder on the printing effect. Combined with the weight data after each inkjet, it can objectively reflect the printing state of the printing device, which is convenient for early intervention before problems occur, and adjustment of the nozzle state before each printing.

[0086] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An inkjet state detection device for binder jet 3D printing, characterized in that: It includes a loading platform, a material storage box, a first guide roller, a first lifting roller, a weighing platform, a second lifting roller, a second guide roller and a traction device, wherein the material storage box, the first guide roller, the first lifting roller, the weighing platform, the second lifting roller, the second guide roller and the traction device are arranged on the loading platform; The first guide roller and the second guide roller are respectively arranged on both sides of the weighing platform, the first lifting roller is arranged between the first guide roller and the weighing platform, and the second lifting roller is arranged between the second guide roller and the weighing platform; the highest points of the first guide roller and the second guide roller are lower than the upper surface of the weighing platform; The storage box is provided with a test paper, and the test paper passes through the first guide roller, the first lifting roller, the weighing platform, the second lifting roller and the second guide roller in sequence under the pulling action of the traction device; The weighing platform is used to detect the pressure of the test paper on the weighing platform; The first lifting roller and the second lifting roller can be lifted and lowered to ensure that the test paper enters the weighing platform from a position lower than the upper surface of the weighing platform and leaves the weighing platform from a position lower than the upper surface of the weighing platform during the test; It also includes a base, on which a platform lifting mechanism is provided, and the platform lifting mechanism is connected to the loading platform, and the storage box, the first guide roller, the first lifting roller, the weighing platform, the second lifting roller, the second guide roller and the traction device can be lifted and lowered together with the loading platform.

2. The inkjet state detection device for binder jet 3D printing according to claim 1, characterized in that: The first lifting roller and the second lifting roller are connected to a roller lifting mechanism, and the roller lifting mechanism is used to drive the first lifting roller and / or the second lifting roller to move up and down.

3. The inkjet state detection device for binder jet 3D printing according to claim 2, characterized in that: The roller lifting mechanism comprises a lifting cylinder, and a piston rod of the lifting cylinder is connected to the first lifting roller and / or the second lifting roller; Alternatively, the roller lifting mechanism is a screw lifting mechanism, including a screw and a drive nut, the screw is connected to the first lifting roller and / or the second lifting roller, the drive nut is connected to the drive motor, and the drive nut drives the screw to rise and fall by rotating itself.

4. The inkjet state detection device for binder jet 3D printing according to claim 1, characterized in that: The test paper is composed of cotton fiber paper and plastic hard film, and the thickness of the test paper is 0.1-1 mm.

5. A method for detecting inkjet status in binder jet 3D printing, characterized in that: The inkjet state detection device for binder jet 3D printing according to any one of claims 1 to 4 comprises the following steps: Step 1: driving the test paper to pass through the first guide roller, the first lifting roller, the weighing platform, the second lifting roller and the second guide roller in sequence, and controlling the heights of the first lifting roller and the second lifting roller so that the highest points of the first lifting roller and the second lifting roller are lower than the upper surface of the weighing platform, and the highest points of the first guide roller and the second guide roller are lower than the upper surface of the weighing platform; Step 2: Obtain the current weight of the test paper through a weighing platform, which is recorded as the initial weight; Step 3: spray a layer of adhesive on the surface of the test paper through a 3D printer, obtain the current weight of the test paper through a weighing platform, record it as the weight after inkjet, and then obtain the weight of one inkjet through a controller; Step 4: Observe the droplet state of the adhesive on the test paper under a microscope, and analyze the inkjet state and inkjet stability according to the uniformity of the droplet state and the fluctuation of the inkjet weight.

6. A method for detecting inkjet status in binder jet 3D printing, characterized in that: Using the inkjet state detection device for binder jet 3D printing as described in any one of claims 1 to 4, the inkjet state detection method for binder jet 3D printing comprises the following steps: Step 1: driving the test paper to pass through the first guide roller, the first lifting roller, the weighing platform, the second lifting roller and the second guide roller in sequence, and controlling the heights of the first lifting roller and the second lifting roller so that the highest points of the first lifting roller and the second lifting roller are lower than the upper surface of the weighing platform, and the highest points of the first guide roller and the second guide roller are lower than the upper surface of the weighing platform; Step 2: Obtain the current weight of the test paper through a weighing platform, which is recorded as the initial weight; Step 3: spray a layer of adhesive on the surface of the test paper through a 3D printer, obtain the current weight of the test paper through a weighing platform, record it as the weight after inkjet, and then obtain the weight of a single inkjet through a controller; Repeat steps 1 to 3 to obtain the weight of a single inkjet of different test papers; Calculating an average of the weights of a plurality of single ink jets; Comparing the weight of each single inkjet with the average value, and adjusting the state of the nozzle according to the comparison result; The droplet state of the adhesive on the test paper obtained by the test is observed under a microscope, and combined with the corresponding inkjet weight, the inkjet state and inkjet stability are analyzed according to the uniformity of the droplet state and the fluctuation degree of the inkjet weight.

7. A method for detecting inkjet status in binder jet 3D printing, characterized in that: Using the inkjet state detection device for binder jet 3D printing as described in any one of claims 1 to 4, the inkjet state detection method for binder jet 3D printing comprises the following steps: Step 1: driving the test paper to pass through the first guide roller, the first lifting roller, the weighing platform, the second lifting roller and the second guide roller in sequence, and controlling the heights of the first lifting roller and the second lifting roller so that the highest points of the first lifting roller and the second lifting roller are lower than the upper surface of the weighing platform, and the highest points of the first guide roller and the second guide roller are lower than the upper surface of the weighing platform; Step 2: Obtain the current weight of the test paper through a weighing platform, which is recorded as the initial weight; Step 3: spray a layer of adhesive on the surface of the test paper through a 3D printer, adjust the height of the stage and / or the distance between the stage and the base, obtain the current weight of the test paper through a weighing table, record it as the weight after inkjet, and then obtain the weight of a single inkjet through a controller; Repeat steps 1 to 3 to obtain the weight of a single inkjet of different test papers; Calculating an average of the weights of a plurality of single ink jets; Comparing the weight of each single inkjet with the average value, and adjusting the state of the nozzle according to the comparison result; The droplet state of the adhesive on the test paper obtained by the test is observed under a microscope, and combined with the corresponding inkjet weight, the inkjet state and inkjet stability are analyzed according to the uniformity of the droplet state and the fluctuation degree of the inkjet weight.

8. The inkjet state detection method for binder jet 3D printing according to any one of claims 5 to 7, characterized in that: A layer of adhesive is sprayed on the surface of the test paper by a 3D printer, and the distance between the lower surface of the nozzle of the 3D printer and the upper surface of the test paper is 3-6 mm.

9. The inkjet state detection method for binder jet 3D printing according to any one of claims 5 to 7, characterized in that: The highest points of the first lifting roller and the second lifting roller are 1-3 mm lower than the upper surface of the weighing platform.

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