CN114147964A

CN114147964A - Active bearing tray of photocuring 3D printer and photocuring forming method

Info

Publication number: CN114147964A
Application number: CN202010936325.6A
Authority: CN
Inventors: 黄海洲; 林文雄; 葛燕; 黄见洪; 阮开明; 李锦辉; 翁文
Original assignee: Fujian Institute of Research on the Structure of Matter of CAS
Current assignee: Fujian Institute of Research on the Structure of Matter of CAS
Priority date: 2020-09-08
Filing date: 2020-09-08
Publication date: 2022-03-08
Anticipated expiration: 2040-09-08
Also published as: CN114147964B

Abstract

The invention discloses an active bearing tray of a photocuring 3D printer and a photocuring forming method. The active carrier tray includes: the tray comprises a tray main body, a mechanical clamping piece arranged in the tray main body, and a hanging part connected with the bottom surface of the tray main body, wherein the hanging part is connected with a tray bracket. The active bearing tray bears and actively clamps a large-size (printing breadth is more than 50cm x 50cm, filling ratio is more than 50%) photocuring printing object under high-speed 3D printing (more than 180mm/h), so that the 3D printing process can be smoothly carried out. The method can overcome the defects that the self weight of the printing object and the bonding force between the resin material and the tray are insufficient, the attraction of the bottom of the resin tank to the printing object and the attraction of resin which is not filled in time and forms vacuum between the bottom of the resin tank and the printing object to the printing object in the high-speed 3D printing of the large-size object, so that the large-size object can be cured and molded at a high printing speed.

Description

Active bearing tray of photocuring 3D printer and photocuring forming method

Technical Field

The invention belongs to the field of 3D printing, and particularly relates to an active bearing tray of a photocuring 3D printer and a photocuring forming method.

Background

The principle of photocuring 3D printing is to cure a liquid photosensitive resin layer by layer on a carrying tray (platform) to form a complete printed object.

At present, the load-bearing platform is made of metal or other functional film layers coated on the surface of the metal, and is a passive platform. During printing, the adhesive force between the printed object and the surface of the platform is only used for overcoming the self-gravity of the object, the adhesive force of the bottom of the resin tank to the object during printing and the vacuum attraction force generated to the object when the resin is not completely filled so as to maintain the upward printing process of the object. In the 3D printing process of large-size objects, the weight of the objects is gradually increased, the vacuum attraction force caused by the fact that the large printing breadth is not filled with resin in time is increased, and the adhesive force of the bearing platform to the objects is insufficient, so that the printed objects fall off and the printing process fails. This phenomenon is more pronounced in high speed (pull rate > 180mm/h)3D printing of large size objects, due to the faster weight gain of the molded object and the faster formation of the resin filled vacuum. More importantly, in order to meet the requirements of specific properties such as mechanical or high temperature resistance, some resin materials for printing have insufficient adhesion with a metal platform and are more likely to be peeled off with the increase of the printing size.

Disclosure of Invention

In order to solve the problems existing in the prior art in high-speed 3D printing of large-size objects, the invention provides an active bearing tray of a photocuring 3D printer, wherein the active bearing tray comprises: the tray comprises a tray main body, a mechanical clamping piece arranged in the tray main body, and a hanging part connected with the bottom surface of the tray main body, wherein the hanging part is connected with a tray bracket.

The active tray has a function of actively clamping a printed object through a mechanical clamping piece compared with a traditional tray.

According to an embodiment of the present invention, the material of the tray main body is a metal alloy (e.g., an aluminum alloy or stainless steel) or a polymer material.

According to an embodiment of the invention, the number of said mechanical clamps is at least 2, such as 3, 4 or more. Those skilled in the art will appreciate that the number and distribution of mechanical clips on the active carrier tray may be adjusted according to the size of the printed object being held.

According to an embodiment of the present invention, the active carrier tray further comprises a standard printing base, the standard printing base is clamped by the mechanical clamp and is connected with a printed object. Preferably, the standard printing base is printed out simultaneously with the printing object.

According to an embodiment of the present invention, a piston is disposed inside the mechanical clamp, and the piston can protrude from the inside of the mechanical clamp under an external force to provide clamping for a printed object or the standard printing base.

According to one embodiment of the invention, an air passage is arranged inside the mechanical clamp, and compressed air is introduced into the air passage to serve as external force for extending the piston.

According to another embodiment of the present invention, a micro motor is disposed inside the mechanical clamp, and the piston is extended out of the mechanical clamp under the driving force of the motor provided by the micro motor. A piston, which may extend with other mechanical clamps, may provide clamping of the printed object or the standard printing base. The clamping force on the printed object or the standard printing base can be adjusted according to the change of the motor driving current parameter.

According to an embodiment of the invention, the sides of the standard printing base have a regular shape, able to be gripped by the mechanical gripper, preferably by the piston; or, the side of the standard printing base is provided with a hole, and the hole is used for accommodating the piston and is matched with the piston in size. For example, the sides of the standard printing base may be flat or curved, and the outer surface of the piston may be adapted to the sides of the standard printing base.

According to an embodiment of the present invention, the overall shape of the standard printing base is not particularly limited, and is, for example, a cube, such as a rectangular body or a cylinder.

Illustratively, the standard printing base is shaped as a rectangular body, and the mechanical clips are distributed around four sides of the standard printing base. And the piston synchronously extends out of the mechanical clamping piece under the action of external force to prop against the side surface of the standard printing base so as to provide clamping for the standard printing base and a printed object on the standard printing base.

Illustratively, the standard printing base is in the shape of a cylinder, the mechanical clamps are distributed around the side face of the standard printing base, and the outer surface of the piston synchronously extending under the action of external force can be matched with the side face of the standard printing base. The piston can be withstood the side of the standard printing base under the action of external force, and provides clamping for the base and a printed object on the base.

According to an embodiment of the present invention, the hanging portion may be a hanger. The shape of the suspension bracket is not limited, and it is preferable that the suspension bracket can be fitted to the tray holder.

According to an embodiment of the invention, the active carrying tray further comprises fastening elements for enabling fixation of the suspension with the tray support. For example, the fastening element may be a fixing element known in the art, such as a bolt or the like.

According to the embodiment of the invention, the tray support is connected with a z-axis stepping motor of the photocuring 3D printer, and the active bearing tray is driven to move by the z-axis stepping motor through the tray support.

According to an embodiment of the invention, the standard printing base is connected to the printing object by a support. For example, the supporting part is a supporting strip which is obtained by photocuring 3D printing.

The invention also provides a photocuring 3D printing system containing the active bearing tray.

The invention also provides application of the active bearing tray in high-speed printing of large-size printing objects. Wherein the high speed is printing speed more than 180mm/h, for example, the printing speed is more than or equal to 190 mm/h. Wherein the large-size printed object is a photocuring printed object with a printing breadth of more than 50cm multiplied by 50cm and a filling ratio of more than 50%.

The invention also provides a photocuring forming method utilizing the active bearing tray, which comprises the following steps: providing a grip for a printed object without a printing base by a mechanical clamp of the active carrier tray (preferably by the piston) during photocuring 3D printing;

or, in the process of photocuring 3D printing of the integrated printing model, when a standard printing base in the integrated printing model is printed to completely expose the surface of the active carrying tray, the integrated printing model is clamped by a mechanical clamp (preferably by the piston) of the active carrying tray;

the integrated printing model comprises the standard printing base and a printing object.

According to an embodiment of the invention, the printing speed of the printing process is > 180mm/h, e.g. the printing speed is > 190 mm/h.

According to an embodiment of the invention, the integrated printing model further comprises a support connecting the standard printing base and the printing object. Preferably, the support has the meaning as described above.

According to an embodiment of the present invention, the unified printing model may be constructed by computer-aided software prior to photocuring 3D printing.

According to an embodiment of the invention, the piston extends from the mechanical clamp under the action of an external force. For example, the external force may be provided by compressed gas or motor drive.

The invention has the beneficial effects that:

the active bearing tray provided by the invention can actively clamp and bear the standard printing base and/or the photocuring printing object through the mechanical clamping piece, further provides larger release force on the basis that the lower surface of the active bearing tray is mutually adhered to the printing object or the standard printing base, overcomes the defects of insufficient self weight of the printing object, insufficient adhesive force between the resin material and the tray, attractive force of the bottom of the resin tank to the printing object and attractive force of resin which is not filled to the printing object and is generated by vacuum formed between the bottom of the resin tank and the printing object in high-speed 3D printing, enables the large-size object to be cured and molded at high printing speed, and maintains high-speed operation of the whole printing process.

Drawings

FIG. 1 is a schematic structural diagram of an active bearing tray of a photocuring 3D printer in embodiment 1;

FIG. 2 is a plan view of the mechanical clip and the printing base on the tray body in example 1;

FIG. 3 is a schematic structural view of a mechanical clip according to embodiment 1;

fig. 4 is a schematic view of the printing effect in embodiment 1.

Reference numerals: 1-pallet body, 2-mechanical clamp, 3-standard printing base, 4-suspension bracket, 5-pallet support, 6-fastening element, 7-piston, 8-air path, 9-pneumatic connector, 10-support bar, 11-printing object.

Detailed Description

Embodiments of the present invention will be described in further detail with reference to specific examples. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.

Unless otherwise indicated, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.

Example 1

The active load-bearing pallet of the structure shown in fig. 1-3 comprises a pallet body 1, and 4 sets of mechanical clamps 2 embedded in the pallet body 1, wherein the mechanical clamps 2 internally contain pistons 7 capable of extending out of the body. A suspension bracket 4 is fixedly arranged on the upper surface of the tray main body 1, and hole positions corresponding to the end parts of a tray bracket 5 fixed on a z-axis stepping motor of the 3D printer are reserved in the suspension bracket 4. The tray support 5 can be inserted into the suspension bracket 4 through the hole sites, and the tray main body 1 is horizontally suspended on the tray support 5.

In order to make the connection between the suspension bracket 4 and the tray support 5 more secure, threaded holes are provided in both the upper wall of the suspension bracket 4 and the end of the tray support 5, and the fastening elements 6 have threads matching the threaded holes. The tray support 5 is fastened to the suspension bracket 4 by rotating the fastening element 6.

As shown in fig. 2, in order to make the mechanical clamping device 2 provide effective clamping for the large-size printing object with irregular bottom side surface, a standard printing base 3 matched with the mechanical clamping device 2 is provided, the standard printing base 3 is shaped as a rectangular body, and the mechanical clamping device 2 is distributed around four side surfaces of the standard printing base 3. And the piston synchronously extends out of the mechanical clamping piece under the action of external force to prop against the side surface of the standard printing base so as to provide clamping for the standard printing base and a printed object on the standard printing base. The supporting strip 10 (as shown in fig. 4) between the standard printing base 3 and the printing object 11 can be constructed by computer-aided software, so that the standard printing base 3 and the printing object 11 form a printing body.

When the high-speed photocuring 3D printing is started, a gap of 30-300 mu m is reserved between the lower surface of the printing tray embedded with the active mechanical clamp and the bottom of the resin groove according to whether a continuous liquid level 3D printing method (CLIP) or a liquid level-constrained DLP printing method is adopted as a printing method, so that the printing of a standard printing base or a first layer of a printing object is started. At this time, the mechanical clip 2 protrudes from the tray body 1 by a distance equal to the predetermined gap and abuts against the bottom of the resin tank under the action of its own gravity, and the piston 7 inside the mechanical clip 2 does not protrude (fig. 3).

In one embodiment, as shown in fig. 3, the mechanical clamp 2 includes an air channel 8 and a pneumatic connector 9 capable of connecting with an external compressed air conduit, and is capable of ejecting the piston 7 under the action of compressed air to contact with a side surface of the print object 11 or a standard print base 3 thereof, so as to clamp the print object.

In another embodiment, the print length of the print object 11 or its standard print base 3 is greater than 5mm, namely, when the mechanical clamping pieces 2 are exposed out of the lower surface of the tray main body 1 by more than 5mm, the extending condition of the piston 7 under the action of external force can be met, the piston 7 in each mechanical clamping piece 2 extends out of the mechanical clamping piece 2 under the action of external force and is attached to the outer surface of the printed object 11 or the standard printing base 3, provides clamping for the printing object being printed, so that the printing object can not increase due to the self weight in the high-speed printing process, the attractive force of the bottom of the resin tank to the printing object is increased along with the increase of the printing section, and the increase of the attractive force to the printing object caused by the fact that the resin is not filled in time and vacuum is formed between the bottom of the resin tank and the printing object, so that the printing object is separated from the printing tray, and printing failure is caused.

In another embodiment, the first 1-10 layers of the printing main body (including the standard printing base 3, the supporting bar 10 and the printing object 11) are printed at an average speed of less than 180mm/h, and the rest is printed at a constant speed of more than 180 mm/h.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An active tray that bears of photocuring 3D printer, its characterized in that, the active tray that bears includes: the tray comprises a tray main body, a mechanical clamping piece arranged in the tray main body, and a hanging part connected with the bottom surface of the tray main body, wherein the hanging part is connected with a tray bracket.

2. The active carrier tray of claim 1, wherein the tray body is made of a metal alloy or a polymer material.

Preferably, the number of said mechanical clamps is at least 2;

preferably, the number and the distribution position of the mechanical clamps on the active carrying tray can be adjusted according to the size of the printed object to be clamped.

3. The active carrier tray of claim 1 or 2, further comprising a standard printing base that accepts the mechanical clamp grip and connects to a printed object. Preferably, the standard printing base is printed out simultaneously with the printing object.

4. The active carrier tray of any one of claims 1-3, wherein the mechanical clamp has a piston disposed therein, the piston being capable of protruding from the interior of the mechanical clamp under an external force to provide a grip for a printed object or the standard printing base.

Preferably, an air passage is arranged inside the mechanical clamping piece, and compressed air is introduced into the air passage to serve as external force for extending the piston.

Preferably, a micro motor is arranged inside the mechanical clamping piece, and the piston extends out of the mechanical clamping piece under the action of motor driving force provided by the micro motor.

5. Active carrying tray according to any of claims 3-4, characterized in that the sides of the standard printing base have a regular shape, able to be gripped by the mechanical gripper, preferably by the piston; or, the side of the standard printing base is provided with a hole, and the hole is used for accommodating the piston and is matched with the piston in size. Preferably, the side face of the standard printing base is a plane or an arc face, and the outer surface of the piston can be matched with the side face of the standard printing base.

Preferably, the standard printing base is a cube, such as a cuboid or a cylinder.

Preferably, the standard printing base is rectangular, and the mechanical clamps are distributed around four sides of the standard printing base; and the piston synchronously extends out of the mechanical clamping piece under the action of external force to prop against the side surface of the standard printing base so as to provide clamping for the standard printing base and a printed object on the standard printing base.

Preferably, the standard printing base is in the shape of a cylinder, the mechanical clamps are distributed around the side face of the standard printing base, and the outer surfaces of the pistons which synchronously extend under the action of external force can be matched with the side face of the standard printing base.

6. The active carrier tray of any of claims 1-5, wherein the suspension is a suspension.

Preferably, the active carrying tray further comprises a fastening element for achieving the fixation of the hanging portion with the tray support.

Preferably, the tray support is connected with a z-axis stepping motor of the photocuring 3D printer, and the z-axis stepping motor drives the active bearing tray to move through the tray support.

Preferably, the standard printing base is connected with the printing object through a support part. Preferably, the supporting part is a supporting strip, and the supporting strip is obtained by photocuring 3D printing.

7. A photocuring 3D printing system containing the active carrying tray of any one of claims 1-6.

8. Use of the active carrier tray of any one of claims 1-6 for high speed printing of large size printed objects.

Preferably, the high speed is a printing speed > 180 mm/h;

preferably, the large-size printed object is a photocuring printed object with a printing width of more than 50cm multiplied by 50cm and a filling ratio of more than 50%.

9. A method of stereolithography using the active carrier tray of any of claims 1-6, said method comprising the steps of: in the photocuring 3D printing process, a printed object without a printing base is clamped by the mechanical clamp of the active bearing tray;

or in the process of photocuring 3D printing of the integrated printing model, when a standard printing base in the integrated printing model is printed to the surface of the active bearing tray, the integrated printing model is clamped by a mechanical clamping piece of the active bearing tray;

10. The photocuring molding method according to claim 9, wherein the printing speed of the printing process is greater than 180 mm/h.

Preferably, the integrated printing model further comprises a support part connecting the standard printing base and the printing object. Preferably, the support has the meaning as claimed in claim 6.

Preferably, the integrated printing model is built by computer-aided software prior to photocuring 3D printing.

Preferably, the piston extends from the mechanical clamp under the action of an external force. Preferably, the external force is provided by compressed gas or motor driving force.