KR20220038569A - 3D printer and its control for printing of high viscosity edible materials - Google Patents

Abstract

The present invention relates to a 3D edible substance printer including an extrusion unit driven on a Z axis where an edible substance is printed and a controller controlling the same. The edible substance is composed of rice or a high-viscosity edible substance and a hydrocolloid composed of natural starch dough or starch. The extrusion unit includes an extruder (or nozzle) and a screw feeding unit communicating therewith. For extruder drive inertia minimization, the screw feeding unit is mounted in a printer body other than the extruder. The controller is capable of XY-axis driving including the Z-axis extruder and includes a controller compatible with a CNC machine controller. A feed rate (v) of the extruder is proportional to the diameter of the nozzle and the height of an extruded edible substance layer and inversely proportional to the diameter of a filament and the extrusion flow velocity of the edible substance.

Description

{3D printer and its control for printing of high viscosity edible materials}

The present invention relates to a 3D printer for edible substances (hereinafter 'printer' refers to a 3D printer), and more particularly, to a dough of edible substances such as rice, starch paste, wheat flour, vegetables, fruits, etc. It relates to a 3D printer device for edible substances capable of efficiently 3D printing, and a method for controlling the same.

In general, a 3D printer refers to a three-dimensional injection molding machine that three-dimensionally molds a desired product by stacking up very thin layers one by one based on three-dimensional modeling.

Most 3D printers are FFF (fused filament fabrication) or FDM (fused deposition modeling) methods. FDM 3D printer that does not have an extruder over 300C and a heating chamber can be used at 190C such as PLA (polylactic acid), ABS (acrylonitrile butadiene styrene), PETG (Glycolmodified Polyethylene Terephthalate), HIPS (high impact polystyrene), FPE (flexible polyester), etc. Only plastics that melt between ~250C can be used.

Recently, technologies for printing various composite materials have been developed. Composite materials include cement mixtures, ceramic resin materials, various building materials to which inorganic materials such as metal powder or carbon are added, medical composite materials, reinforced plastics, etc., and other food or drinkable food materials.

However, these composite materials, especially edible materials, have relatively high viscosity and lower fluidity compared to filament-type thermoplastics or resins, so frequent device failures such as clogging of nozzles or pipelines of existing 3D printers and disadvantages in device maintenance there was

In order to solve the fluidity problem of the printer material, a cylinder-type printer that presses the printing material or a screw-type 3D printer that presses the printing material with a rotary blade and extrudes it (see Patent Publication No. 10-2019-0065622) is commercially available there is.

However, in such a conventional filament-type, cylinder-type or screw-type printer, an extrusion driving part (cylinder-piston driving part or cylinder-screw driving part) for extruding the printing material is mounted on the extruder, and due to its inertia, There is a problem in that the printing precision of composite materials, especially edible substances, is lowered.

In addition, the thickness of the printing layer of the conventional composite material printer is several tens of times greater than that of the filament printer, so that the controller driving the Z-axis cannot be used interchangeably, so there is a problem that a controller of the composite material printer needs to be newly developed.

Furthermore, the precision and efficiency of printing are affected by the viscosity and flow characteristics of the printing material, structural characteristics such as the diameter of the extruder nozzle, the extrusion pressure characteristics, the extruder moving speed, and the thickness of the layer. There is a problem in that the printing precision and efficiency are lowered because the flow characteristics of the

The present invention has been proposed to solve the above problems, and improves response accuracy by reducing the inertia of the extruder, provides a control method suitable for the behavioral characteristics of edible printing materials such as rice, and is compatible with the controller of the CNC machine A 3D printer apparatus and method for printing an edible printing material that can easily control a Z-axis extruder using a possible controller are provided.

Edible material 3D printer according to the present invention for achieving the above object, in the conventional 3D printer using the drive method of Cartesian, CoreXY, Delta, H-bot, consists of an extrusion unit driven on the Z-axis, The extruder feed rate is proportional to the diameter of the nozzle and the height of the layer of extruded edible material layer, and the extruder feeds in inverse proportion to the filament diameter and the extruder flow rate of the edible material. As the controller for driving, a controller compatible with the controller of the CNC machine can be used.

The extrusion unit is composed of an extruder (or nozzle) and a screw feeding unit communicating therewith, and in order to minimize the driving inertia of the extruder, the screw feeding unit may be mounted on a printer body other than the extruder.

The edible material may be a hydrocolloid composed of starch dough in its natural state, rice (rice is a food that is boiled in a way that grains of rice and barley are put in water so as not to lose moisture or become loose), and starch.

A controller compatible with the controller of the CNC machine may be a commercially available 'Mach3' or the like.

The 3D printer for edible materials according to the present invention increases the response accuracy by reducing the inertia of the extruder, provides a control method suitable for the behavioral characteristics of edible printing materials such as rice, and uses a controller compatible with the controller of the CNC machine Accordingly, there is an effect of providing a 3D printer apparatus and method for printing an edible printing material that can easily control the Z-axis extruder.

1 is an overall perspective view of a 3D printer using a screw-type extruder as a prior art.
2 is an overall perspective view of a 3D printer for edible substances according to an embodiment of the present invention.
3 is a partially cutaway view of the screw feeding part in the 3D printer for edible substances according to an embodiment of the present invention.

Hereinafter, an embodiment of the 3D printer for edible substances according to the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in each figure indicate like elements.

The terms used in the present invention are defined as follows. Rice is a food made by boiling rice and barley grains in water so that they do not lose moisture or become loose. The main chemical component of rice may be starch or starch. Starch may contain repeating glucose units linked by α (1-4) and α (1-6) glycosidic bonds. The physical properties of the rice may be in the form of a dough, and a desirable behavior may have a viscosity to the extent that the shear strength is greater than that of general bread dough or hotcake dough and it does not fall freely due to its own weight. In addition, starch molecules may contain many hydroxyl groups that can interact with water through hydrogen bonds, which can increase the viscosity of starch molecules. Hereinafter, rice or high-viscosity edible material is used as the same concept.

1 is an overall perspective view of a 3D printer using a screw-type extruder as a prior art, FIG. 2 is an overall perspective view of a 3D printer for edible substances according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention It is a partial cutaway view of the screw feeding part in the 3D printer for edible substances according to

The 3D printer according to the embodiment of the present invention has a Cartesian driving device as shown in FIG. 2, but is not limited thereto. The 3D printer according to the present invention may include an extrusion unit 10 and a controller 20 compatible with the controller of the CNC machine.

The extruder 11 as shown in Figure 3 of the extrusion unit 20; screw feeding unit 12; It is comprised by the conveyance pipe 13 which communicates them.

A controller compatible with the controller of the CNC machine may be a commercially available 'Mach3' or the like. Mach3 transforms a regular computer into a CNC machine controller. Mach3 processes G-code on most Windows PCs to control the motion of motors (steppers and servos). A typical 3D printer is identical to a CNC machine in that it is a numerical control device controlled by G code. Therefore, many G code changes were required to use the conventional 3D printer controller that melts the filament with heat to the food material printer, but if a CNC controller is used instead, it is possible to easily control the edible material printer without changing the G code.

The edible material may be a raw starch dough, rice or a high viscosity edible material. Therefore, the precision and efficiency of printing high-viscosity edible materials are affected by the viscosity and flow characteristics of the printing material, structural characteristics such as the diameter of the extruder nozzle, extrusion pressure characteristics, the extruder moving speed, and the thickness of the layer.

The printing of high-viscosity edible materials requires that the extrusion speed of the edible material and the extruder's movement speed can be controlled independently due to the high viscosity. Using the traditional slicer method of observing the printed output, examine the G code that produced the slicer that reached a certain reference value to derive all the variables that the printing process affects.

G code has the following format. G1*X(x1)*Y(y1)*Z(z1)*E(e)*F(f). G1 is the print command, and the X, Y and Z fields determine the nozzle position. The E field represents the length (e) of the extruded filament and the F field represents the filament extrusion rate (f). The values of e and f are in mm and mm/min, respectively. The following equation is established (hereinafter referred to as ‘(1) equation’)

e = ((D _{nozzle diameter} ) ² * (layer layer height) * extrusion coefficient * extruder travel distance * 1.273)/((D _filament ) ² * D _nozzle ) --(1) formula

Therefore, the extruder's moving speed (v) is determined by the following equation (hereinafter referred to as '(2) equation'). Here, the unit of extruder speed is mm/sec. Here, the extruder's movement path is the distance the nozzle must travel to move from the current position (x ₀ , y ₀ , z ₀ ) to the new coordinates (x ₁ , y ₁ , z ₁ ). The extrusion duration in minutes can be calculated from the values of e and f.

v = (Extruder's movement path)/(e/f) = √(x ₁ - x ₀ ) ² + (y ₁ - y ₀ ) ² + (z ₁ - z ₀ ) ² /(e/f) ----------(2) formula

The diameter or height of the layer of printed edible material is determined by the extruder's travel speed (v) and the layer's extrusion speed (Q). Here, the unit of the extrusion rate (Q) of the layer is mm3/sec. When the width of the extruded layer with an elliptical cross section is a and the height is b, the following formula (hereinafter referred to as ‘Equation (3)’) holds.

Q/v = (π*a*b)/4 -----------------------(3)Equation

According to the formulas (1) to (3), the relationship between the layer extrusion speed (Q) and the extruder moving speed (v) is expressed by the following formula (hereinafter referred to as '(4) formula') do.

Q = (π*a*b)/4*(extruder's path)/(e/f) = √(x ₁ - x ₀ ) ² + (y ₁ - y ₀ ) ² + (z ₁ - z ₀ ) ² /(e/f)--(4)

In summary, the edible material 3D printer according to the present invention includes an extrusion unit driven on the Z-axis for printing an edible material and a controller for controlling the same, wherein the edible material is rice or high-viscosity edible material, starch dough in a natural state, or composed of hydrocolloids composed of starch; the extrusion unit is composed of an extruder (or nozzle) and a screw feeding unit communicating therewith, and the screw feeding unit is mounted on a printer body other than the extruder in order to minimize the driving inertia of the extruder; The controller includes a controller capable of XY-axis driving including a Z-axis extruder and compatible with a controller of a CNC machine, and the feed rate (v) of the extruder depends on the diameter of the nozzle and the layer of the layer of edible material being extruded. It is characterized in that it is proportional to the height and inversely proportional to the diameter of the filament and the extrusion flow rate of the edible material.

The controller compatible with the controller of the CNC machine may be a commercially available 'Mach3', and the extrusion flow rate (Q) of the extruder is characterized in that the above expression (4) is satisfied.

As mentioned above, although the present invention has been described in detail using preferred embodiments, the scope of the present invention is not limited to specific embodiments and should be construed according to the appended claims. In addition, those skilled in the art will understand that many modifications and variations are possible without departing from the scope of the present invention.

10: extrusion unit
11: Extruder
12: screw feeding part
13: transfer pipe
20: controller
30: edible substances
40 :GUI
100: discharge unit
120: discharge housing
150: discharge drive part
200: vertical transfer unit
300: horizontal transfer unit

Claims (3)

A 3D printer comprising: an extrusion unit driven on the Z-axis for printing edible substances and a controller for controlling the same; said edible material is composed of rice or high viscosity edible material, starch dough in its natural state or hydrocolloid composed of starch; the extrusion unit is composed of an extruder (or nozzle) and a screw feeding unit communicating therewith, and the screw feeding unit is mounted on a printer body other than the extruder in order to minimize the driving inertia of the extruder; The controller is capable of driving the XY axis including the Z-axis extruder, and a 3D printer device for edible substances, characterized in that it comprises a controller compatible with the controller of the CNC machine. The method of claim 1,
The feed rate (v) of the extruder is proportional to the diameter of the nozzle and the height of the extruded edible material layer layer and is inversely proportional to the diameter of the filament and the extrusion flow rate (Q) of the edible material 3D printer for edible substances Device. 3. The method of claim 2,
The controller compatible with the controller of the CNC machine may be a commercially available 'Mach3', and the extrusion flow rate (Q) of the extruder is a 3D printer device for edible substances, characterized in that it satisfies the following (4) equation.

Q = (π*a*b)/4*(extruder's path)/(e/f) = √(x ₁ - x ₀ ) ² + (y ₁ - y ₀ ) ² + (z ₁ - z ₀ ) ² /(e/f)

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