A material-saving type light-curing printer and a printing method

Abstract

The application discloses a kind of material-saving type light-cured printer and printing method, including rack, the liquid tank is installed in the bottom layer of rack, platform is placed horizontally in liquid tank, a plurality of holes are arranged on platform, platform is connected with screw lifting system, realize the up-and-down movement of platform;The remaining three sides except the side where screw lifting system is located are all connected with protection plate through telescopic device on the inside of liquid tank, air bag is placed between the side wall of liquid tank and protection plate;A group of guide rails are installed in the middle layer of rack, scraper is installed between two guide rails, scraper has telescopic tool bit, scraper is above liquid tank, scraper moves back and forth along guide rail, and liquid level in liquid tank is scraped flat;Laser is installed in the top layer of rack.In the scheme, when platform is lowered to the lowest end, liquid level is lifted by inflation, then printing is continued, liquid photopolymer around printing model can be fully utilized, the utilization rate of liquid photopolymer is improved, and it is also applicable to printing model with larger height.

Description

TECHNICAL FIELD

[0001] The present application relates to light-cured 3D printing technology, in particular to a material-saving light-cured printer and a printing method. BACKGROUND

[0002] Light-cured 3D printing, also known as stereolithography (SLA), is the earliest and most in-depth 3D printing technology discovered in the world. The working principle of SLA is based on the photopolymerization principle of liquid photosensitive resin. The commonly used in industry is a sinking type light-cured printer, which is provided with a light source device above the resin tank. The ultraviolet light beam is deflected by a fast-moving deflection mirror to solidify the resin on the platform. The reflection control system controls the movement of the mirror in the X and Y directions to guide the ultraviolet light beam emitted by the light source to the corresponding area. The liquid resin irradiated will be solidified from point to line and from line to plane. The platform starts from the top of the resin tank and is solidified layer by layer to obtain the final model.

[0003] At present, after each printing of the sinking type light-cured printer, a large amount of old liquid will be left in the liquid tank. The general practice is to leave these photosensitive resins in the liquid tank for the next printing. However, if exposed to light during storage, the resins will easily solidify, causing material failure and waste. Resin materials are expensive, which puts great pressure on the control of production costs.

[0004] In recent years, the SLA printer of the pull-up type has appeared. The light source is placed below the resin tank, and the resin tank is transparent from the bottom. Although the pull-up type SLA printer greatly reduces the waste of resin and improves the utilization rate, it is prone to problems such as solidified resin sticking to the bottom of the tank, limited printing size, and the pulling force during stripping may cause printing failure. Moreover, the pull-up type SLA printer is commonly used for desktop printing, and the sinking type SLA printer with very large printing size and high precision is needed in industry.

[0005] Patent No. 201510807896.9 discloses a resin tank assembly and a laser rapid prototyping equipment with the assembly. The piston transmission device is installed at the bottom of the resin tank. The thin film between the piston and the resin tank is used to hold the resin. The volume of the resin tank can be changed by the piston device, so that the resin material is saved when printing small models, and the thin film facilitates the quick replacement of the resin material. However, this device cannot utilize the liquid resin around the model, and it has no obvious advantage when printing large models.

[0006] Therefore, it is necessary to develop a light-cured printer that can improve the utilization rate of liquid resin, reduce waste, and reduce costs. SUMMARY

[0007] The purpose of the present application is to provide a material-saving light-curing printer and printing method.

[0008] The technical scheme of the present application comprises a frame, a liquid tank is installed at the bottom of the frame, a platform is horizontally placed in the liquid tank, a plurality of holes are arranged on the platform, the platform is connected with a screw lifting system to realize the up-and-down movement of the platform, the inner side of the liquid tank is connected with a protection plate through a telescopic device except for the side where the screw lifting system is located, the protection plate is above the platform, and an air bag is placed between the side wall of the liquid tank and the protection plate, a group of guide rails are installed at the middle layer of the frame, a scraper is installed between the two guide rails, the scraper has a telescopic head, the scraper is above the liquid tank, and the scraper moves back and forth along the guide rails to scrape the liquid surface in the liquid tank flat, and a laser is installed at the top layer of the frame.

[0009] The platform is fixedly installed above the bottom surface of an L-shaped bracket, the top of the L-shaped bracket is connected with the screw lifting system, and the screw lifting system drives the platform to move up and down.

[0010] One side of the air bag close to the side wall of the liquid tank is connected with a gas filling connector embedded in the side wall of the liquid tank, the other end of the gas filling connector is connected with one end of an air conveying pipe outside the liquid tank to realize the air filling in the air bag.

[0011] The other end of the air conveying pipe is connected with a gas filling pump installed on the outer side wall of the liquid tank, the gas filling pump fills air into the air bag in the liquid tank through the air conveying pipe, and a flow control table is arranged on the gas filling pump to control the air volume filled in the air bag.

[0012] The air bag is made of high-molecular polyphthalate fabric material, and the inner wall is coated with a layer of polychloroprene to seal the gas, the outer surface of the air bag has corrosion resistance, and has good plasticity after air filling.

[0013] When the scraper works, the head of the scraper is retracted by one layer thickness when the liquid surface in the liquid tank rises by one layer thickness, and then the liquid surface is scraped flat.

[0014] The present application also comprises a material-saving light-curing printing method, which comprises the following steps:

[0015] S1: before printing, a certain amount of liquid photosensitive resin is poured into the liquid tank;

[0016] S2: the printer reads a slicing file output by slicing software processing to obtain scanning path and slicing layer thickness data information of the model;

[0017] S3: the platform rises to a slice layer thickness away from the liquid surface, the scraper works to flatten the liquid surface, at this time the laser starts to work to print the first layer;

[0018] S4: the first layer is printed, the laser is turned off, the platform is lowered by a slice layer thickness, the scraper continues to flatten the liquid surface, and the laser continues to start printing;

[0019] S5: repeat step S4 until the platform is lowered to the bottom of the liquid tank and the current layer printing is completed, the protection plate is extended until the interval between the protection plate and the model reaches the preset distance;

[0020] S6: according to the set amount of inflation, the three air bags are uniformly inflated with gas to make the liquid surface rise by a slice layer thickness; at the same time, the scraper adjusts the height of the cutter head and flattens the liquid surface; the laser continues to start printing and is turned off after the current layer is printed;

[0021] S7: repeat step S6 until the model is printed;

[0022] S8: release the air in the air bag, retract the protection plate to the side wall of the liquid tank, and take out the model.

[0023] In step S1, the amount of liquid resin poured into the liquid tank is determined according to the height of the model, and the initial pouring height of the liquid resin is 3 / 5 of the height of the model to be printed. If the air bag is exposed during printing, the photosensitive resin is supplemented accordingly.

[0024] In step S6, the total volume of air filled into the three air bags each time is calculated according to the following formula:

[0025] V = Δh·S

[0026] Wherein, Δh is the slice layer thickness, and S represents the bottom area of the liquid tank.

[0027] Beneficial effects: compared with the prior art, the technical scheme of the present application has the beneficial effects that through the internal protection plate, air bag and scraper with retractable cutter head and other devices, when the platform is lowered to the bottom end, the protection plate is responsible for protecting the printed model and providing space for the air bag, and the air bag and the scraper work together to lift and utilize the liquid resin originally difficult to utilize around the printed model. Greatly reduces the deterioration caused by subsequent storage, saves new resin, and reduces cost. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a structural schematic diagram of the present application;

[0029] Figure 2 is a structural schematic diagram of the front of the present application;

[0030] Figure 3 is a top view of the present application;

[0031] Figure 4 This is a cross-sectional view of the connection between the airbag and the air delivery tube.

[0032] Figure 5 This is a schematic diagram of the scraper's structure;

[0033] Figure 6 This is a schematic diagram of the internal state of the liquid tank during the printing process. Detailed Implementation

[0034] The technical solution of the present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0035] like Figures 1-5 As shown, the material-saving photopolymerization printer of the present invention includes a frame 1, a laser 2, a doctor blade 3, a retractable blade head 31, a liquid tank 4, an air bladder 5, a protective plate 6, a telescopic rod 61, an L-shaped bracket 7, a platform 8, an air supply pipe 9, an inflation connector 91, an air pump 10, and a flow control meter 101. The frame 1 is made of aluminum profile or stainless steel and includes a bottom layer, a middle layer, and a top layer. The laser 2 is installed on the crossbar of the top layer of the frame 1. The laser 2 is a conventional component of an SLA printer, and its specific structure can be referred to in the prior art. The liquid tank 4 is installed at the bottom of the frame 1, and the platform 8 is placed horizontally in the liquid tank 4. Several holes are arranged on the platform 8. The platform 8 is connected to a screw lifting system to realize the up and down movement of the platform 8. Specifically, the platform 8 is fixedly installed above the bottom surface of the L-shaped bracket 7. The bottom of the L-shaped bracket 7 supports the platform 8 and the two are fixed by bolts. The top of the L-shaped bracket 7 is connected to the screw lifting system by bolts. Other lifting systems can also be used, as long as they can achieve the lifting movement of platform 8. The three sides of the inner side of the liquid tank 4, excluding the side where the screw lifting system and L-shaped bracket 7 are located, are connected to the protective plate 6 via telescopic devices. The protective plate 6 is positioned above platform 8. Specifically, the telescopic device is a telescopic rod 61. Two telescopic rods 61 are installed between the bottom of the protective plate 6 and the side wall of the liquid tank 4. One extendable end of the telescopic rod 61 is installed on the protective plate 6, and the other end is installed on the inner side wall of the liquid tank 4. The two telescopic rods 61 are spaced apart. An airbag 5 is placed between the side wall of the liquid tank 4 and the protective plate 6, positioned between the two telescopic rods 61. The telescopic device is not limited to the telescopic rods in this solution; other telescopic devices can also be used, as long as they can push the protective rod 6 back and forth. The protective plate 6 can be brought close to the maximum size of the printed model on platform 8 by the telescopic rods 61, to a distance of 5mm from the maximum size of the printed model, to prevent the airbag 5 from touching the printed model and affecting printing. Figure 2 and Figure 4As shown, the air bag 5 is connected to the inflation joint 91 embedded in the side wall of the liquid tank 4 on one side of the side wall of the liquid tank 4, and the other end of the inflation joint 91 is connected to one end of the gas conveying pipe 9 outside. The other end of the gas conveying pipe 9 is connected to the inflation pump 10 installed on the outer side of the liquid tank 4. The inflation pump is connected to the gas conveying pipe 9 in three directions. The inflation pump 10 can inflate the air bag 5 in the liquid tank through the gas conveying pipe 9. The flow control table 101 is arranged on the inflation pump 10 to control the volume of air filled into the air bag 5. The inflation joint 91 is embedded in the side wall of the liquid tank 4 as an intermediate part for connecting the air bag 5 and the gas conveying pipe 9, and the two ends thereof are sealedly connected to the air bag 5 and the gas conveying pipe 9 respectively, so that the air output by the inflation pump 10 can be smoothly filled into the air bag 5 through the gas conveying pipe 9. In the embodiment, the air bag 5 is made of high-molecular polyphthalate fabric material, and the inner wall is coated with a layer of polychloroprene to seal the gas.

[0036] As shown in Figure 1 and Figure 5 A set of guide rails are installed at both ends of the middle layer of the rack 1, and a scraper 3 is installed between the two guide rails. The scraper 3 has a telescopic blade head 31. The scraper 3 is above the liquid tank 4 and can adjust the height of the blade head in time according to the height of the liquid surface during the process of lifting the liquid resin surface by the air bag 5. The scraper 3 moves back and forth along the guide rails to ensure that the liquid surface in the liquid tank 4 is scraped flat.

[0037] The present application also includes a material-saving type light-curing printing method, which specifically includes the following steps:

[0038] S1: Before printing starts, a certain amount of liquid photosensitive resin is poured into the liquid tank 4. Specifically, according to the height of the printing model, a photosensitive resin with a height of 3 / 5 of the model height is poured into the liquid tank 4;

[0039] S2: The printer reads the slicing file processed and output by the slicing software to obtain data information such as the scanning path and slicing layer thickness of the model. In the embodiment, the magics software is used to slice the model and generate a slicing file;

[0040] S3: The platform 8 rises to a position one slicing layer thickness away from the liquid surface, the scraper 3 works to scrape the liquid surface flat, and at this time the laser 2 starts to work to print the first layer;

[0041] S4: After the first layer is printed, the laser 2 is turned off, the platform 8 is lowered by one slicing layer thickness, the scraper 3 continues to scrape the liquid surface flat, and the laser 2 continues to start printing;

[0042] S5: Repeat step S4 until the platform 8 is lowered to the bottom layer of the liquid tank 4 and the printing of the current layer is completed, and the protection plate 6 is extended until the interval between the protection plate 6 and the printing model reaches the preset distance. In the embodiment, the interval between the protection plate 6 and the printing model is set to 5 mm.

[0043] S6: according to the set amount of inflation, the three air bags 5 are uniformly inflated, so that the liquid level rises by one slice layer thickness; at the same time, the scraper 3 adjusts the height of the cutter head, and the liquid level is scraped flat; the laser 2 continues to start printing, and is turned off after the current layer is printed; wherein, the total volume of air filled in the three air bags 5 each time is calculated according to the following formula:

[0044] V = Δh S

[0045] In the formula, Δh is the slice layer thickness, and S represents the bottom area of the liquid tank 4.

[0046] S7: repeat step S6 until the model is printed;

[0047] S8: release the air in the air bag 5, retract the protection plate 6 to the side wall of the liquid tank 4, and take out the model.

[0048] The technical scheme of the present application can utilize the liquid photosensitive resin that is difficult to utilize around the model printed by the ordinary printer, improve the utilization rate of the photosensitive resin at one time, reduce the loss caused by the deterioration of a large amount of residual resin in storage, save a large amount of new photosensitive resin, and effectively reduce the printing cost.

Claims

1. A material-saving photopolymerization printing method, characterized in that, This method is applied to a material-saving photopolymer printer, which includes a frame (1), a liquid tank (4) installed at the bottom of the frame (1), a platform (8) placed horizontally in the liquid tank (4), a number of holes arranged on the platform (8), and the platform (8) is connected to a screw lifting system to realize the up and down movement of the platform (8). The three sides of the inner side of the liquid tank (4), except for the side where the screw lifting system is located, are connected to the protective plate (6) through a telescopic device. The protective plate (6) is located above the platform (8), and an airbag (5) is placed between the side wall of the liquid tank (4) and the protective plate (6). A set of guide rails is installed at both ends of the middle layer of the frame (1), and a scraper (3) is installed between the two guide rails. The scraper (3) has a retractable blade head (31). The scraper (3) is located above the liquid tank (4). The scraper (3) moves back and forth along the guide rail to scrape the liquid surface in the liquid tank (4) flat. A laser (2) is installed on the top layer of the frame (1). When the airbag (5) is working, the scraper (3) retracts the blade (31) upwards by one layer thickness every time the liquid level in the liquid tank (4) rises by one layer thickness, and then scrapes the liquid level again. This material-saving photopolymer printing method includes the following steps: S1: Before printing begins, pour a certain amount of liquid photosensitive resin into the liquid tank (4); In step S1, the amount of liquid resin poured into the liquid tank (4) is determined according to the height of the model. The initial amount of liquid resin poured in is 3 / 5 of the height of the model to be printed. If the airbag (5) is exposed on the liquid surface during the printing process, liquid photosensitive resin is added accordingly. S2: The printer reads the slice file output by the slicing software and obtains the data information of the model's scanning path and slice layer thickness. S3: The platform (8) rises to a position one slice thickness away from the liquid surface, the scraper (3) works to level the liquid surface, and at this time the laser (2) starts to work and prints the first layer; S4: After the first layer is printed, the laser (2) is turned off, the platform (8) drops by one slice thickness, the scraper (3) continues to smooth the liquid surface, and the laser (2) continues to start printing; S5: Repeat step S4 until the platform (8) descends to the bottom of the liquid tank (4) and the printing of the current layer is completed, and the protective plate (6) extends until the gap between the protective plate (6) and the model reaches the preset distance; S6: Inflate the three airbags (5) evenly according to the set inflation volume, so that the liquid level rises by one slice thickness; at the same time, the scraper (3) adjusts the height of the scraper head and scrapes the liquid level; the laser (2) continues to start printing, and turns off the laser after the current layer is printed; S7: Repeat step S6 until the model is printed; S8: Release the air from the airbag (5), retract the protective plate (6) into the side wall of the liquid tank (4), and remove the model.

2. The material-saving photopolymerization printing method according to claim 1, characterized in that: The platform (8) is fixedly installed above the bottom surface of the L-shaped bracket (7), and the top of the L-shaped bracket (7) is connected to the screw lifting system.

3. The material-saving photopolymerization printing method according to claim 1, characterized in that: The airbag (5) is connected to the inflation connector (91) embedded in the side wall of the liquid tank (4) on one side; the other end of the inflation connector (91) is connected to one end of the external air supply pipe (9).

4. The material-saving photopolymerization printing method according to claim 3, characterized in that: The other end of the gas supply pipe (9) is connected to an air pump (10) installed on the outer wall of the liquid tank (4). The air pump (10) inflates the air bag (5) in the liquid tank through the gas supply pipe (9). A flow control meter (101) is installed on the air pump (10) to control the volume of air inflated into the air bag (5).

5. The material-saving photopolymerization printing method according to claim 1, characterized in that: The airbag (5) is made of high molecular weight polyamide fabric material, and the inner wall is coated with a layer of polychloroprene to seal the gas.

6. The material-saving photopolymerization printing method according to claim 1, characterized in that, In step S6, the formula for calculating the total volume of air inflated into the three airbags (5) each time is as follows: ； In the formula, For slice layer thickness, This indicates the bottom area of ​​the liquid tank (4).

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