CN110742294B

CN110742294B - Microwave-assisted three-dimensional printing device and accurate and efficient printing method for plant gel system

Info

Publication number: CN110742294B
Application number: CN201911002864.6A
Authority: CN
Inventors: 张慜; 刘振彬; 陈慧芝
Original assignee: Jiangnan University
Current assignee: Jiangnan University
Priority date: 2019-10-22
Filing date: 2019-10-22
Publication date: 2021-07-23
Anticipated expiration: 2039-10-22
Also published as: WO2021077561A1; AU2019471247B2; AU2019471247A1; CN110742294A

Abstract

A microwave-assisted three-dimensional printing device and an accurate and efficient printing method for a plant gel system belong to the technical field of food processing. The device comprises a three-dimensional printer, a built-in real-time microwave heating and curing device, a flexible microwave shielding box body, an embedded online microwave real-time controller and the like. The microwave source is a solid microwave source, and the power is continuously adjustable within the range of 20-200W. Microwave energy feedback is realized by adopting a rotary antenna mode, and the microwave can be uniformly absorbed by the material layer in the printing process. The device can realize the real-time heating solidification of printing in-process microwave at 3D, reaches the fast curing and improves and print the precision, shortens 3D under the full flow and prints the efficiency of production food. According to material properties such as rheological properties and dielectric properties, a matching relation is established between the printing extrusion speed of the material and the microwave real-time heating power in the 3D printing process, so that the material is cured at a proper speed, the printing precision of more than 95% is realized, and deformation does not occur in the subsequent process.

Description

Microwave-assisted three-dimensional printing device and accurate and efficient printing method for plant gel system

Technical Field

The field belongs to the technical field of food, and particularly relates to a three-dimensional printing device and an accurate and efficient printing method for food under the microwave synergistic condition.

Background

The 3D printing technology, also known as additive manufacturing technology and rapid prototyping technology, is a technology for producing three-dimensional structural objects in a continuous physical stacking form by computer modeling. Although the 3D printing is used in the food field, the requirements of people on personalized food can be well met, food with different nutritional ingredients can be made according to target people, and the range of food materials can be enlarged, the technology still faces some technical problems, such as how to realize accurate printing, how to print a complex three-dimensional structure by using a conventional pasty material, how to keep the shape of the printed food in the subsequent processing process and the like, and the development of the printed food industry is well promoted by solving the problems.

The plant gel system is an important component of a food system for 3D printing. The 3D food printing technology can realize the customization of the shape and texture of food, develop easily swallowed old food, widen the range of available food materials and the like, but the biggest problem faced by the existing 3D food printing technology is that the speed is relatively slow, the printing efficiency is relatively low, and the large-scale application of the 3D printing technology in the food field is greatly limited. At present, the commonly used method for improving the 3D printing efficiency is to increase the diameter of a printing nozzle and improve the moving speed of a printing shaft, but increasing the diameter of the printing nozzle often causes the reduction of the 3D printing precision, increasing the moving speed often causes the reduction of the printing stability, and the effects of the diameter of the printing nozzle and the moving speed on the aspect of improving the 3D printing efficiency are limited.

The microwave heating technology is a related technology for heating materials by using the principle that polar molecules in the materials are polarized and alternate orientation is carried out along with the change of the polarity of an external alternating electromagnetic field under the action of the external alternating electromagnetic field as a result of the interaction between the polar molecules in the materials and a microwave electromagnetic field absorbed by the materials, so that the electromagnetic energy is converted into heat energy due to frequent mutual friction loss of a plurality of polar molecules. Microwave heating has many advantages. Instantaneity, simultaneous heating inside and outside, and the heating rate is fast. The whole body is realized, the heating process is simultaneously carried out in the whole object, the temperature is rapidly increased, the temperature is uniform, the temperature gradient is small, and the heating device is a 'body heat source', and the heat conduction time in the conventional heating is greatly shortened. Selectivity, different materials respond differently to microwaves due to their own dielectric properties. High efficiency, in conventional heating, the preheating of the equipment, the radiation heat loss and the heat loss of the high-temperature medium occupy a large proportion of the total energy consumption, when the microwave is used for heating, the medium material can absorb the microwave and convert the microwave into heat energy, and the metal material of the equipment shell is a microwave reflection type material which can only reflect but not absorb the microwave (or absorb the microwave very little).

According to the invention, the microwave technology and the 3D printing technology are combined, and the microwave power is timely adjusted according to the printing speed and the dielectric property of the material in the 3D printing process to realize real-time curing of the material, so that the accuracy of a 3D printed object can be prevented from being reduced due to the action of gravity in the printing process, and meanwhile, the 3D printing process and the later curing stage can be unified and integrated in the same process, so that the 3D printing efficiency can be greatly improved.

The invention discloses a petrology intelligence (2018) and a microwave-assisted 3D food printing device and method (CN 109363221A). The device comprises a 3D printing box body, wherein a scanning area and a mixing area are respectively arranged above the inside of the 3D printing box body, a cooling area and a printing area are respectively arranged below the scanning area and the mixing area, an abrasive device and a storage tank are respectively arranged on two sides of the upper end of the 3D printing box body, a feeding port of the storage tank is arranged above the mixing area, and a computer digital control panel is arranged on one side of the 3D printing box body. Although the invention introduces microwaves as heat sources, the device has significant difference from the invention in both structure and microwave action. The invention emphasizes microwave curing and microwave heating of a cured material layer so as to improve the 3D printing precision, and simultaneously the microwave power can be timely adjusted and controlled according to the dielectric and curing characteristics of the material. While the contrast patent focuses on cooling and solidifying the printed object in the cooling zone to improve printing accuracy, microwaves are only used as a curing means. In conclusion, there is a significant difference between the two.

Guo yun et al (2018) invented an intelligent food 3D thermal printer (CN109645538A) with a semiconductor cooling and heating control system built in the device for heating and cooling the showerhead system. This is significantly different from the present invention which uses microwaves as a heat source.

Bin and the like (2016) invented a 3D food printing method and a 3D food printer (CN105595386A), which mainly solve the problems that the existing printer can not print and ripen food immediately and the material is difficult to convey. According to the invention, the material is made into a specific shape through the 3D food printer, and is heated on the conveying path of the material so as to be cured, so that the rapid conversion from raw to cooked of the material can be realized, and the cured food can be obtained instantly and continuously. The invention is obviously different from the invention which adopts microwave as a heat source. In addition, the heating and curing are carried out after the 3D printing process is finished, which is obviously different from the timely heating in the printing process of the invention.

Zhanhong et al (2018) invented a collaborative 3D printing system and method for accurate nutritious food, which can realize the automatic processing of accurate nutritious 3D printed food constructed by various food materials, and the invention does not introduce a heating device, which is obviously different from the invention which introduces microwave to heat at the right time.

Zang (2016) invented a 3D food printer (CN206403183U), which has a heating and cooking device inside, to cook the printed food and improve the taste and formability of the food. However, the present invention focuses mainly on conventional electrical heating for curing, and is significantly different from the present invention which adopts microwave heating for realizing endogenous rapid heating. In addition, while the microwave is taken as a curing means in the invention, the microwave is more focused on the rapid curing performance of the microwave so as to improve the precision of 3D printing.

Great thousand (2017) have announced a utility model patent (CN207140357U) of "food printer", divide into X axle subassembly, Y axle subassembly and Z axle subassembly with the printer, aim at solving food 3D printing apparatus structure complicacy, and is bulky, prints the shortcoming that the precision is low. This invention is significantly different from the present invention that realizes high precision 3D printing by virtue of the rapid curing property of microwaves.

Guo Yun (2018) discloses an intelligent thermoelectric heating sprayer of a food 3D printer (CN108402506A), which structurally comprises a semiconductor refrigerating and heating device, and can accelerate cooling of a printing model after discharging of a nozzle, reduce energy consumption and improve printing precision. The microwave source is not arranged in the printing nozzle, but is embedded on the printing platform to realize the effect of instant heating, and the two have obvious difference in the thought.

Disclosure of Invention

The invention aims to provide a microwave-assisted three-dimensional printing device and an accurate and efficient printing method for a plant gel system.

The technical scheme of the invention is as follows:

the utility model provides a three-dimensional printing device in coordination with microwave, the device include that 3D prints box, X axle horizontal migration axle 1, Z axle and reciprocates tank tower 2, prints shower nozzle 3, microwave case 4, prints object 5, print platform 6, microwave generator and antenna 7 and embedded microwave on-line controller 8, microwave generator and antenna 7 set up in 3D and print the bottom half, be located print platform 6 below, microwave generator and antenna 7 evenly release the microwave, heat the object 5 of printing on the print platform 6. In the 3D printing process, the printing object 5 can move along with the printing platform 6; an X-axis horizontal moving shaft 1 and a Z-axis vertical moving box frame 2 are arranged in the 3D printing box body; the microwave box 4 is made of flexible shielding materials to prevent microwave leakage and can move up and down along with the printing platform 6 and the Z-axis up-down moving frame 2 in a front-back and left-right mode; the embedded microwave online controller 8 is arranged in the 3D printing box body and used for controlling the microwave power of the microwave generator and visually displaying the working state.

The microwave box 4 is made of flexible shielding materials, can move the frame 2 up and down along with the Z axis, namely, the printing nozzle 3 moves up and down to stretch and elongate, and moves along with the printing platform 6 moving left and right, so that the phenomenon of microwave leakage in the whole printing process is prevented.

Set up infrared online temperature sensor in the 3D prints the box for real-time supervision prints the temperature, its temperature measurement scope: 0-500 degrees.

The microwave generator adopts a solid microwave source, the frequency is 2450MHz, the power is continuously adjustable within 20-200W, and the power of the power supply is 500VA and 220V/50 Hz.

A method for accurately and efficiently printing a plant gel system of a microwave-assisted three-dimensional printing device comprises the following steps: firstly, preparing a plant gel system, then selecting proper printing spray head diameter, printing distance, printing speed, extrusion speed and microwave power, and finally controlling the printing process through the embedded microwave online controller 8 to finish printing.

When the extrusion speed is 0.002-0.005 cm³When the microwave power is 25-45W/s; when the extrusion speed is 0.005-0.008 cm³When the microwave power is 45-65W per second; when the extrusion speed is 0.008-0.010 cm³The microwave power is 65-80W at/s.

The diameter of the printing nozzle is 1.0-1.5 mm; the printing distance is 1.0-2.0 mm.

The moving speed of the spray head is 20-30 mm/s.

The invention has the beneficial effects that: a microwave generator and an embedded microwave online controller are arranged in the 3D printer to realize real-time heating and curing in the 3D printing process, and the microwave power can be adjusted in real time according to the properties (such as dielectric characteristics) of the material to realize proper-speed curing of the material. In the 3D printing process, microwave energy is input in a rotating antenna mode, and a microwave generator and the antenna uniformly release microwaves in real time, so that a printing workpiece is uniformly heated by the microwaves. In order to realize real-time curing of the material, under the given printing speed and extrusion speed, the microwave power can be adjusted in real time through the embedded microwave online controller according to the properties (such as dielectric property, rheological property and the like) of the material, so that the material can be cured at a proper speed. If the microwave power and the material printing extrusion speed are not matched, the material can be cured and dehydrated and shrunk too fast, so that a subsequent material layer cannot be deposited on a previous extruded layer well, and printing failure is caused. In addition, real-time adjustment and control of microwave power are also greatly related to material properties, materials with strong absorption capacity can be cured at a proper speed by using smaller microwave power, and materials with weak microwave absorption capacity conversely need higher microwave power. The invention unifies the 3D printing process and the curing/curing process in one process, thereby improving the efficiency of the whole 3D printing process.

The invention adopts the solid microwave source, can accurately control the power to be continuously adjustable between 20 and 200W, has good linearity, more accurate control and good reproducibility. In addition, the adoption of the continuously adjustable low-power level can prevent the discontinuous adhesion of front and back printing material layers caused by the rapid evaporation of material moisture in the 3D printing process, and the printing failure is caused.

Drawings

FIG. 1 is a schematic illustration of the present invention.

In the figure: 1X axis horizontal movement axis; 2, moving the box frame up and down along a Z axis; 3, printing a spray head; 4, a microwave box; 5 printing the object; 6, printing a platform; 7, a microwave generator and an antenna; 8, an in-line microwave controller is embedded.

Detailed Description

EXAMPLE 1 accurate, efficient microwave three-dimensional printing of yam flour gel systems

Mixing commercially available rhizoma Dioscoreae powder, butter and tap water to obtain uniform paste, wherein the rhizoma Dioscoreae powder is 50% of tap water, and butter is added into the system after softening and foaming at room temperature, and the weight is 25% of the total weight of the rhizoma Dioscoreae powder and tap water. And printing and molding the material by using a 3D printer. Selecting a printing nozzle with diameter of 1.5mm, printing distance of 1.5mm, nozzle moving speed of 25mm/s, and extrusion speed of 0.007cm³Printing is performed under the condition of/s. In the printing process, the printed matter moves along with the movement of the printing platform, the power of the microwave generator is set to 63W, the printed matter is relatively uniformly absorbed by the material layer being printed, and the Chinese yam powder is pasted while the Chinese yam powder is solidified. In the process, the control of the microwave power is crucial, and the larger microwave power can cause the material of the previous printing layer to be quickly dehydrated and shrunk, so that the subsequent printing layer can not be well jointed. If the microwave power is too low, the printed layer material cannot be quickly solidified, and is deformed under the action of gravity, so that the printing effect is influenced. Tests show that the printing precision under the conditions can reach more than 95 percent, and the printing precision does not deform in the subsequent storage process. In addition, compared with the mode of firstly printing and then subsequently performing microwave curing treatment, the microwave real-time heating curing method in the printing process can improve the production efficiency by 20-30% under the whole process.

EXAMPLE 2 accurate, high efficiency microwave printing of mashed potato systems

Firstly, cleaning and peeling potatoes, cutting the potatoes into slices with the thickness of about 5mm, cooking the slices for 22min, and then pulping the slices for 5.5min until the pulp is fine and shiny. Taking mashed potato after pulping as a reference, adding 3% of colloid (pectin, carrageenan and the like) to be uniformly mixed, and then cooking for 23min to fully dissolve the colloid, thereby improving the rheological property and the corresponding forming characteristics of the mashed potato. Selecting printing nozzle with diameter of 1.5mm, printing distance of 1.7mm, nozzle moving speed of 25mm/s, and extrusion speed of 0.009cm³And s. Since the mashed potatoes are pre-cured during printing, the smaller microwave power can realize the accelerated curing of the material layer being printed. Through experiments, the power of the microwave generator is set to78W, under the condition, the rapid solidification of the materials can be ensured, and the rapid dehydration and shrinkage of the materials of the previous printing layer caused by larger microwave power can be prevented, so that the subsequent printing layers can not be well jointed. In the printing process, the printed matter moves along with the movement of the printing platform so as to ensure that the material can uniformly absorb microwaves. The printing precision under the scheme is more than 95%, and the printing precision is not deformed in the subsequent storage process.

Example 3 precision high efficiency microwave three-dimensional printing of purple sweet potato flour gel System

The method comprises the following steps of uniformly mixing commercially available purple sweet potato powder, butter and tap water to form uniform paste, wherein the purple sweet potato powder accounts for 48% of the tap water, and the butter is softened and beaten at room temperature and then added into a system, wherein the weight of the butter is 17% of the total weight of the purple sweet potato powder and the tap water. And printing and molding the material by using a 3D printer. Selecting a printing nozzle with diameter of 1.0mm, printing distance of 1.2mm, nozzle moving speed of 24mm/s, and extrusion speed of 0.006cm³Printing is performed under the condition of/s. During printing, the printed matter moves with the movement of the printing platform, and the power of the microwave generator is set to 48W and is relatively uniformly absorbed by the material layer being printed. In the process, the control of the microwave power is crucial, and the larger microwave power can cause the material of the previous printing layer to be quickly dehydrated and shrunk, so that the subsequent printing layer can not be well jointed. If the microwave power is too low, the printed layer material cannot be quickly solidified, and is deformed under the action of gravity, so that the printing effect is influenced. Tests show that the printing precision under the conditions can reach more than 95 percent, and the printing precision does not deform in the subsequent storage process.

Example 4 precision high efficiency microwave three-dimensional printing of Soy protein isolate gel System

Uniformly mixing commercially available soybean protein isolate powder and tap water to form uniform paste, wherein the ratio of water to protein powder is 2.3: 1. adding 1% salt, mixing, steaming for 18min to denature protein, cooling to room temperature to form gel system for 3D printing. Selecting a printing nozzle with diameter of 1.0mm, printing distance of 1.1mm, nozzle moving speed of 24mm/s and extrusion speed of 0.010cm³Printing is performed under the condition of/s.During printing, the printed matter moves along with the movement of the printing platform, and the power of the microwave generator is set to 80W and is relatively uniformly absorbed by the material layer being printed. In the process, the control of the microwave power is crucial, and the larger microwave power can cause the material of the previous printing layer to be quickly dehydrated and shrunk, so that the subsequent printing layer can not be well jointed. If the microwave power is too low, the printed layer material cannot be quickly solidified, and is deformed under the action of gravity, so that the printing effect is influenced. Tests show that the printing precision under the conditions can reach more than 95 percent, and the printing precision does not deform in the subsequent storage process.

Claims

1. The device for three-dimensional microwave collaborative printing of the plant gel system is characterized by comprising a 3D printing box body, an X-axis horizontal moving shaft (1), a Z-axis up-and-down moving box frame (2), a printing spray head (3), a microwave box (4), a printed object (5), a printing platform (6), a microwave generator and antenna (7) and an embedded microwave online controller (8), wherein the microwave generator and antenna (7) are arranged at the bottom of the 3D printing box body and are positioned below the printing platform (6), and the microwave generator and antenna (7) uniformly release microwaves to heat the printed object (5) on the printing platform (6); in the 3D printing process, the printing object (5) can move along with the printing platform (6); an X-axis horizontal moving shaft (1) and a Z-axis vertical moving box frame (2) are arranged in the 3D printing box body; the microwave box (4) is made of flexible shielding materials, can move up and down the box frame (2) along with the Z axis, namely the printing nozzle (3) moves up and down to stretch and elongate, and moves along with the printing platform (6) moving left and right, so that the microwave leakage phenomenon in the whole printing process is prevented; the embedded microwave online controller (8) is arranged in the 3D printing box body and is used for controlling the microwave power of the microwave generator and visually displaying the working state, the 3D printing process and the curing/curing process are unified in one process, and the efficiency of the whole 3D printing process is improved;

2. The device for microwave cooperative three-dimensional printing of a plant gel system according to claim 1, wherein an infrared online temperature measuring sensor is arranged in the 3D printing box body for monitoring the printing temperature in real time, and the temperature measuring range is as follows: 0-500 ℃.

3. The method for accurately and efficiently printing the plant gel system by adopting the device for three-dimensionally printing the plant gel system by microwave cooperation according to claim 1 or 2 is characterized by comprising the following steps of: firstly, a plant gel system is prepared, then a proper printing spray head diameter, a printing distance, a printing spray head moving speed, an extrusion speed and microwave power are selected, and finally the printing process is controlled through an embedded microwave online controller (8) to finish printing.

4. The method of claim 3, wherein the extrusion rate is 0.002-0.005 cm³When the microwave power is 25-45W/s; when the extrusion speed is 0.005-0.008 cm³When the microwave power is 45-65W per second; when the extrusion speed is 0.008-0.010 cm³The microwave power is 65-80W at/s.

5. The accurate and efficient printing method according to claim 3, wherein the diameter of the printing nozzle is 1.0-1.5 mm; the printing distance is 1.0-2.0 mm.

6. The accurate and efficient printing method according to claim 4, wherein the diameter of the printing nozzle is 1.0-1.5 mm; the printing distance is 1.0-2.0 mm.

7. The accurate and efficient printing method according to claim 3 or 4, wherein the moving speed of the printing spray head is 20-30 mm/s.

8. The accurate and efficient printing method according to claim 5, wherein the moving speed of the printing nozzle is 20-30 mm/s.