CN116348275A

CN116348275A - Crystallization control device and method for producing 3D printing wire

Info

Publication number: CN116348275A
Application number: CN202280005342.5A
Authority: CN
Inventors: 苗振兴; 戈弋; 罗小帆
Original assignee: Suzhou Jufu Technology Co ltd
Current assignee: Suzhou Jufu Technology Co ltd
Priority date: 2022-12-08
Filing date: 2022-12-08
Publication date: 2023-06-27

Abstract

The utility model discloses a crystallization controlling means and method, 3D printing wire rod, and winding wheel for producing 3D printing wire rod, crystallization controlling means makes the 3D printing wire rod in production when reciprocating the winding in the wire casing of two winding wheels, and the linear velocity when each wire casing of process is all faster than when the previous wire casing, and makes 3D printing wire rod have the extension to keep tension in every section. The wire rod in the middle of this application is mainly through the groove depth of every wire casing in two winding wheels of control for between two adjacent two positions of two winding wheels only have slight tensile tension, has both ensured the tension of 3D printing wire rod between first winding wheel and second winding wheel like this, and furthest has avoided the wire rod tensile again, and then has ensured the size homogeneity of wire rod diameter.

Description

Crystallization control device and method for producing 3D printing wire

Technical Field

The application relates to the technical field of 3D printing, in particular to a crystallization control device and method for producing a 3D printing wire, the 3D printing wire and a winding wheel.

Background

In recent years, the rising 3D printing, also called additive manufacturing, is an advanced manufacturing method based on the principle of layer-by-layer material accumulation, which has been rising and rapidly developing in recent 30 years. One of the multiple technical routes for 3D printing is material extrusion type 3D printing, which has been widely used in recent years due to the advantages of lower equipment cost, wider material selection, better molding performance, and the like. The material extrusion type 3D printing process is based on the construction of 3D objects by extruding the material under pressure in a flowing state (e.g. molten state, solution, etc.), accumulating layer by layer and solidifying (e.g. glass transition, crystallization, solvent evaporation, etc.). One process that is widely used in material extrusion type 3D printing is called fused deposition modeling (fused deposition modeling, FDM for short) or fused wire manufacturing (fused filament fabrication, FFF for short), and the basic principle is that: the wire of thermoplastic polymer is transferred to a high-temperature hot end by a gear to melt the polymer, the hot end moves along the section outline and the filling track of the part under the control of a computer motion control system, and meanwhile, the melted material is extruded, rapidly solidified and locally fused with surrounding materials; this process is repeated layer by layer to build up a three-dimensional object.

Material extrusion 3D printing mostly uses continuous wire as its raw material form. The average diameter of the wire is typically between about 1.75mm and 2.85mm and it is necessary to ensure a good dimensional uniformity. The largest class of materials currently used in 3D printing wires is polylactic acid (PLA). The PLA wire for 3D printing is generally prepared through an extrusion process, namely, thermoplastic polymers are extruded through a screw extruder, cooled and shaped through a water tank, and then wound. For polymeric materials such as PLA, which have a relatively slow crystallization rate, there is not enough time to crystallize because of the rapid cooling after extrusion, and the wire produced is usually in an amorphous (amorphorus) state, or has only a very low crystallinity. The low crystallinity results in poor heat resistance of the wire and is more prone to premature softening at the cold end of the printhead, resulting in extrusion failure and even clogging of the printhead. Most 3D printed PLA wires in the market today are of this type.

Patent CN106715100B discloses a method for preparing high crystallinity 3D printed PLA wire. The method achieves high crystallinity of the wire by post-treating (annealing) the wire. However, it has been found after production practice that this method requires additional post-treatment steps, which increases the complexity of the production process and leads to lower yields.

Patent applications CN109483844a and CN209454120U disclose a crystallinity control device and method, which increases the residence time of the wire in the water bath, i.e. multi-stage temperature control, by means of a roller set, and implements "on-line crystallization" of the polymer extruded product (without post-treatment steps). However, the method is found to be complicated to operate in actual use after production practice, and the dimensional accuracy of the extruded product cannot be effectively controlled.

Disclosure of Invention

In view of the above-mentioned drawbacks of the related art, an object of the present application is to provide a crystallization control device and method for producing a 3D printing wire, and a winding wheel, which are used for solving the technical problems that the operation is complicated when the 3D printing wire is prepared, and the dimensional accuracy of an extruded product cannot be effectively controlled.

To achieve the above and other related objects, a first aspect of the present application provides a crystallization control device for producing a 3D printing wire, comprising: the temperature control tank comprises a tank body for containing fluid, and a 3D printing wire rod in the tank body is used for achieving crystallization temperature by controlling the temperature control path of the fluid; the tension control mechanism is arranged in the temperature control groove and comprises a first winding wheel arranged at the proximal end of the groove body and a second winding wheel arranged at the distal end of the groove body, and is used for enabling the 3D printing wire to wind back and forth between the first winding wheel and the second winding wheel so as to increase the residence time and residence length of the 3D printing wire in the groove body; the device comprises a first winding wheel and a second winding wheel, wherein a plurality of wire grooves are formed in the first winding wheel or/and the second winding wheel, the groove depth of all or part of the wire grooves of the plurality of wire grooves is sequentially increased, and tension control is conducted on the 3D printing wire rods in the groove bodies through configuring the winding direction of the 3D printing wire rods on the first winding wheel and the second winding wheel or/and configuring the relative rotating speed of the first winding wheel and the second winding wheel.

A second aspect of the present application provides a crystallization control method for producing a 3D printing wire, the crystallization control method comprising the steps of: melting crystalline polymer and extruding to form wire rod; enabling the extruded 3D printing wire rod to pass through a first temperature control groove to be cooled and shaped; winding the shaped 3D printing wire on a tension control mechanism positioned in the second temperature control groove so that the 3D printing wire stays in the temperature control groove for a preset time in a state of keeping preset tension to obtain a crystallized high polymer material wire; the 3D printing wire is pulled out from the tension control mechanism, and is rolled and stored after being cooled; the tension control mechanism comprises a first winding wheel arranged at the near end of the temperature control groove and a second winding wheel arranged at the far end of the temperature control groove, wherein a plurality of wire grooves are formed in the first winding wheel or/and the second winding wheel, the groove depth of all or part of the wire grooves is sequentially increased, so that tension control is carried out on the 3D printing wire in the temperature control groove through configuring the winding direction of the 3D printing wire on the first winding wheel and the second winding wheel or/and configuring the relative rotating speed of the first winding wheel and the second winding wheel.

A third aspect of the present application provides a winding wheel for being installed in pairs on a crystallization control device for producing 3D printing wires, the winding wheel comprising a wheel body and a plurality of wire grooves formed on the wheel body for winding wires, the groove depths of all or part of the plurality of wire grooves being sequentially increased so as to tension-control the 3D printing wires on the crystallization control device by configuring the 3D printing wires in the winding direction of the pair of winding wheels or/and by configuring the relative rotational speeds of the pair of winding wheels.

In summary, the crystallization control device and method for producing 3D printing wires and the winding wheel provided by the present application enable the 3D printing wires in the tension control mechanism to be wound in the wire grooves of the two winding wheels in a reciprocating manner, and the wire speed of each wire groove passing through the device is faster than that of the previous wire groove, so that the 3D printing wires are stretched in each section to maintain tension. The wire rod in the middle of this application is mainly through the groove depth of every wire casing in two winding wheels of control for between two adjacent two positions of two winding wheels only have slight tensile tension, has both ensured the tension of 3D printing wire rod between first winding wheel and second winding wheel like this, and furthest has avoided the wire rod tensile again, and then has ensured the size homogeneity of wire rod diameter.

Drawings

The specific features referred to in this application are set forth in the following claims. The features and advantages of the invention that are related to the present application will be better understood by reference to the exemplary embodiments and the accompanying drawings that are described in detail below. The drawings are briefly described as follows:

FIG. 1 is a schematic flow chart of a crystallization control method according to an embodiment of the present application.

FIG. 2 is a schematic diagram of a crystallization control device according to an embodiment of the present application.

FIG. 3 is a schematic diagram showing a structure of a crystallization control device according to another embodiment of the present application.

Fig. 4 is a schematic structural view of the tension control mechanism in an embodiment of the present application.

FIG. 5 is a schematic view of section A-A of FIG. 2.

Fig. 6 shows a schematic structural view of the winding wheel of the present application in an embodiment.

FIG. 7 is a schematic view of section B-B of FIG. 6.

Fig. 8 shows a schematic structural view of a winding wheel according to the present application in another embodiment.

Fig. 9 shows a schematic view of the formation of a wire web between a first winding wheel and a second winding wheel in the present application.

Fig. 10 shows a schematic structural view of a winding wheel of the present application in yet another embodiment.

Fig. 11 shows a schematic structural view of a winding wheel of the present application in yet another embodiment.

Detailed Description

Further advantages and effects of the present application will be readily apparent to those skilled in the art from the present disclosure, by describing the embodiments of the present application with specific examples.

In the following description, reference is made to the accompanying drawings, which describe several embodiments of the present application. It is to be understood that other embodiments may be utilized and that mechanical, structural, electrical, and operational changes may be made without departing from the spirit and scope of the present disclosure. The following detailed description is not to be taken in a limiting sense, and the scope of embodiments of the present application is defined only by the claims of the issued patent. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Spatially relative terms, such as "upper," "lower," "left," "right," "lower," "upper," and the like, may be used herein to facilitate a description of one element or feature as illustrated in the figures as being related to another element or feature.

Furthermore, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including" specify the presence of stated features, steps, operations, elements, components, items, categories, and/or groups, but do not preclude the presence, presence or addition of one or more other features, steps, operations, elements, components, items, categories, and/or groups. The terms "or" and/or "as used herein are to be construed as inclusive, or meaning any one or any combination. Thus, "A, B or C" or "A, B and/or C" means "any of the following: a, A is as follows; b, a step of preparing a composite material; c, performing operation; a and B; a and C; b and C; A. b and C). An exception to this definition will occur only when a combination of elements, functions, steps or operations are in some way inherently mutually exclusive.

The present application will be described in further detail with reference to the accompanying drawings and detailed description. The technical solutions in the embodiments of the present application are clearly and completely described, and it is obvious that the described embodiments are only some of the embodiments of the present application, but not all of the embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

As described in the background art, extrusion processes commonly used in the field of polymer processing and manufacturing do not allow for very good control of the crystallinity of crystalline polymers, which results in: the crystallinity of the final extruded product of crystalline polymers is often not controllable, thus resulting in unstable or unsatisfactory product properties. That is, the conventional process cannot directly obtain a 3D printed PLA wire with high crystallinity after the process molding. For example, the method disclosed in the above patent document CN106715100B is to store a wire in a large roll, heat-crystallize the large roll, and then divide the large roll into small rolls. The production practice shows that the method increases the post-treatment time and the coil separating time, has certain wire loss and affects the production efficiency. In addition, by adopting the solutions of the patent documents CN109483844A and CN209454120U, the production practice finds that the length of the wire rod which is intended to be increased and stopped in the hot water tank is limited, and the production speed of the wire rod is slower in order to ensure the stop time of the wire rod; moreover, the resistance of each wheel to rotation requires wire pulling to overcome, which can cause excessive wire stretching and thus affect wire size uniformity. The scheme can meet the performance requirement at a lower production speed, and cannot be effectively used when the speed is further increased, so that the production efficiency is not improved, and the production cost is reduced.

Therefore, the present application provides a crystallization control device for producing a 3D printing wire and a crystallization control method for producing a 3D printing wire, which are used for directly obtaining a high crystallinity of a 3D printing wire in the extrusion process, that is, synchronously completing crystallization in the wire production process without any post-treatment step, and ensuring good uniformity of dimensions of the wire under the condition of ensuring the production efficiency.

In this application, the term "amorphous" or "crystalline" can be generally measured by the level of crystallinity. When the crystallinity is large, attractive forces between the polymer molecules tend to interact, so that the strength is large, but the transparency is poor; on the contrary, the glass has smaller strength and better transparency, and the volume change is not large when the glass is melted, and the glass is not easy to shrink.

In this application, the term "wire" generally refers to a formed material having a shape with a smaller cross-sectional diameter and a longer length. For example, the wire may be circular, square or oval in cross-section.

In this application, the term "comprising" is generally intended to include the features specifically recited, but does not exclude other elements.

In this application, the term "about" generally means ranging from 0.5% to 10% above or below the specified value, e.g., ranging from 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, or 10% above or below the specified value.

"polylactic acid", sometimes abbreviated "PLA", is a high molecular weight polymer synthesized by the polymerization of lactide, which is a cyclic dimer of lactic acid, or 2-hydroxypropionic acid. Lactic acid is a chiral molecule with two optical isomers, l-lactic acid and d-lactic acid. Normally both l-lactic acid and d-lactic acid are present in PLA. The composition ratio of l-lactic acid and d-lactic acid is a key factor in determining the crystallization behavior (including crystallinity and crystallization kinetics) of PLA. The l-lactic acid content of most commercially available PLAs predominates. As the d-lactic acid content increases, the crystallinity, melting temperature, and crystallization rate decrease accordingly. When the d-lactic acid content exceeds 15%, the crystallization ability of PLA becomes very weak. Suitable for the PLA described in this application, its l-lactic acid content preferably ranges between 85% and 100%. Examples of such PLA materials are 2500HP, 4032D, 2003D, 4043D, 7001D, etc. supplied by Nature Works LLC.

The process of cooling and crystallizing the polymer melt is approximately as follows: the plastic particles are extruded to form polymer melt, and the microstructure is composed of random entangled polymer chains. In the process of cooling the polymer melt in the outlet die, some polymer chains are kept in a disordered state to form an amorphous region; and some macromolecular chains are regularly arranged to form a crystal region. The proportion of the crystallization area is the crystallinity of the polymer material.

The crystallization of the polymer material mainly comprises two steps: (1) Nucleation, i.e., the formation of nuclei of polymer chains or other components under certain conditions; (2) And (3) growing crystals, namely arranging polymer chains around crystal nucleus regularly to form crystals. For a particular material, there will be a temperature dependence of nucleation and crystal growth, i.e., there will be temperatures T 'and T "(where T' < T"), corresponding to the temperature at which the nucleation rate is the fastest and the temperature at which the crystal grows the fastest, respectively. In the cooling process of the melt, part of the polymer material can only form crystal nucleus and can not grow into crystals. This is because when the temperature of the melt is gradually cooled from a high temperature, it reaches the vicinity of T "(the temperature at which the crystal grows most rapidly) first, at which time the molecular chain activity tends to grow the crystal, but the crystal nuclei for crystal attachment growth are lacking in the melt, so that no crystallization region is formed in the melt; when the temperature is further reduced to the vicinity of T', a large number of crystal nuclei are formed in the melt, but the temperature is smaller than the subsequent temperature, the molecular chains are difficult to move, and crystals cannot grow in a regular arrangement around the crystal nuclei. When the cooled material is heated for a second time and the temperature reaches the vicinity of T', the polymer chain starts to grow crystals from the crystal nucleus. This crystallization behavior is often referred to as cold crystallization, and a polymer material having cold crystallization behavior may also be referred to as a cold crystallized polymer. Common cold-crystallized polymers include: polylactic acid, dimethyl terephthalate, polyamide as a part thereof, and the like.

The behaviour of the cold crystallization can generally be characterized by differential scanning calorimetry (differential scanning calorimetry or DSC). The characterization method is as follows:

1. weighing an appropriate amount of sample (typically several milligrams to tens of milligrams) as required by the particular DSC instrument;

2. the samples were placed in a DSC instrument and measured using the following temperature procedure:

a. primary temperature rise: heating the sample to a specific temperature at a constant temperature rise rate (10-20C/min), T _h ，T _h Above the highest melting point T of the material _m And can make all crystal areas of the material completely melt to form melt;

b. and (3) cooling: cooling the sample to a specific temperature T at a constant cooling rate (10-20C/min) _l ，T _l Below the glass transition temperature T of the material _g And can completely transform the material into a solid state without fluidity;

c. and (3) secondary temperature rise: the sample is heated again to a specific temperature T at a constant temperature rising speed (10-20C/min) _h ’，T _h ' above the highest melting point T of the material _m And can completely melt all crystal areas of the material to form a melt. T (T) _h ' and T _h May be the same or different;

d. the heat flow (heat flow) of the primary warming, cooling, and secondary warming process was recorded.

Wherein T is _h ，T _l And T _h ' flexible selection can be made for the characteristics of different materials. If the material exhibits a crystallization peak (typically an exothermic peak having a temperature lower than the melting peak temperature) with a non-zero area during the secondary temperature rise, it can be judged that the material has cold crystallization behavior. The temperature corresponding to the crystallization peak in the secondary temperature rising process is the cold crystallization temperature T _cold 。

And the other part of the high polymer material is T '> T', or the two parts are close to each other, so that the nucleation of the material melt in the cooling process occurs before the crystal growth or the nucleation and the crystal growth occur simultaneously. Such polymers generally do not exhibit a cold crystallization peak, i.e., no significant crystallization peak during the second temperature increase, under testing using the same DSC method as described above. The crystallization peak usually only occurs during the cooling process. The temperature corresponding to the crystallization peak during the cooling process can be generally considered as the crystallization temperature of the material, or Tc.

Most PLA strands used for FDM/FFF type 3D printing are prepared by a melt extrusion process. In the melt extrusion process, the fully dried PLA pellets, along with other formulation components, are fed into a screw-type polymeric extruder (single screw or twin screw) with a cylindrical die for continuous extrusion. The extruded material is then cooled, drawn by a tractor to the desired physical dimensions, and finally collected. The process may also use equipment such as melt pumps/gear pumps (ensuring stable output), laser calipers (real time measurement of wire physical dimensions), etc.

Referring to fig. 1, which is a schematic flow chart of a crystallization control method according to an embodiment of the present application, as shown in the drawing, the crystallization control method for producing a 3D printing wire according to the present application includes the following steps:

Step S10: melting crystalline polymer and extruding to form wire rod; in an example, a crystalline polymer was melted and extrusion-molded into a wire by an extruder for producing a 3D printing wire. The crystalline polymer comprises one or more of Polyethylene (PE), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polypropylene (PP), polyamide (PA), polybutylene terephthalate (PBT), polyoxymethylene (POM), polyvinyl chloride (PVC), polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyvinylidene fluoride (PVDF), polycaprolactone (PCL), polylactic acid (PLA), and copolymers of any of the above polymers; wherein the crystalline polymer further comprises one or more of the following components: colorants, pigments, fillers, fibers, plasticizers, nucleating agents, thermal/UV stabilizers, processing aids, impact modifiers;

in embodiments, the processes disclosed herein are applicable to most polymer extrusion equipment. Specifically, the extrusion apparatus such as an extruder may be selected by an operator according to actual conditions. Common extrusion equipment comprises: single screw extruder, twin screw extruder, multi screw extruder, ram extruder, vane plasticizing extruder, etc. Meanwhile, operators can also select additional equipment such as a melt metering pump and the like according to actual requirements.

Step S11: enabling the extruded 3D printing wire rod to pass through a first temperature control groove to be cooled and shaped; in an embodiment, the temperature control interval of the first temperature control groove is between 50 ℃ and 60 ℃, for example, water with the temperature of 50 ℃ to 60 ℃ is contained in the first temperature control groove so as to cool the high-temperature wire just coming out of the extruder, thereby playing a role in shaping and rapid nucleation of the melt of the wire, and further realizing shaping of the wire.

Step S12: winding the shaped 3D printing wire on a tension control mechanism positioned in the second temperature control groove so that the 3D printing wire stays in the temperature control groove for a preset time under the state of keeping the preset tension to obtain the crystallized high polymer material wire.

Referring to fig. 2, a schematic structural diagram of an embodiment of a crystallization control device according to the present application is shown, and as shown in the drawing, the crystallization control device 1 includes a second temperature control tank 11 and a tension control mechanism 12.

The second temperature-controlled tank 11 includes a tank body 110 for containing a fluid, and is used for controlling the temperature of the 3D printing wire in the tank body 110 by controlling the temperature control path of the fluid. In an embodiment, the second temperature control tank 11 is installed on a frame 10 and keeps a certain height on the ground, so as to facilitate the production operation or maintenance of the second temperature control tank 11 by an operator.

In an embodiment, the temperature control range of the second temperature control tank 11 is between 80 ℃ and 100 ℃, for example, the second temperature control tank 11 contains water with a preset temperature range of about 80 ℃ to 100 ℃, and in a preferred embodiment, the temperature of the water contained in the second temperature control tank 11 is between 85 ℃ and 95 ℃, for example, 85 ℃,86 ℃,87 ℃,88 ℃,89 ℃,90 ℃,91 ℃,92 ℃,93 ℃,94 ℃, or 95 ℃; in a more preferred embodiment, the temperature of the water contained in the second temperature-control tank 11 is about 90 ℃, so as to promote the link activity of the polymer in the wire and promote the growth of the crystal area.

In some embodiments, for example, when the preset temperature in the tank body 110 of the second temperature-control tank 11 is higher, for example, exceeds 100 ℃, for example, when the preset temperature in the tank body 110 of the second temperature-control tank 11 is required to reach between 150 ℃ and 300 ℃ during the production of a certain type of wire rod, the tank body 110 of the second temperature-control tank 11 may be oil meeting the preset temperature, or molten low-temperature alloy liquid (such as solder alloy solution) meeting the preset temperature, or high-temperature salt solution (such as salt solution) meeting the preset temperature, or air flow meeting the preset temperature, or steam or mist meeting the preset temperature, etc.

In other embodiments, for example, in some manufacturing processes, it is required to perform pretreatment on the wire shaped in the second temperature-control groove 11, for example, coating some materials on the surface of the wire or performing micro-hole etching on the surface of the wire, then the fluid contained in the groove body 110 of the second temperature-control groove 11 may be a liquid or vapor containing a wire coating agent or a liquid or vapor containing a surface etching agent, and of course, the fluid may also include a wire coating agent and a liquid or vapor containing a surface etching agent.

In the above embodiment, in order to monitor the temperature in the second temperature-control tank 11 in real time, the tank body 110 is provided with the temperature sensor 15 for sensing the temperature of the fluid, and in one embodiment, the temperature sensor 15 is disposed near an overflow port on one side, such as the distal side or the proximal side, of the second temperature-control tank 11, such as the overflow tank 111 shown in fig. 2, but not limited thereto, and in practical implementation, the temperature sensor 15 may be disposed at any position where the temperature of the fluid in the tank body 110 of the second temperature-control tank 11 can be detected.

In an embodiment, one side or both sides of the tank body 110 of the second temperature control tank 11 are provided with a fluid pipeline 14 for inputting the fluid with a preset temperature into the internal space of the tank body 110. In the embodiment shown in fig. 2, the pipe is disposed at one side of the tank body 110 of the second temperature control tank 11 and extends along a long side thereof, and the pipe includes an inlet 140 for communicating with an external input pipe and a plurality of outlets (not shown) located at an inner side of the tank body 110.

In still other embodiments, for example, in some manufacturing processes, it is necessary to pre-process the wires shaped in the second temperature-control tank 11 at the same time, and one or more devices of infrared radiation, microwave radiation, and alternating magnetic field for radiating the space inside the tank 110 are disposed in the tank 110 of the second temperature-control tank 11.

In an embodiment, the second temperature-controlling groove 11 is an elongated groove, for example, an elongated groove with a length of 3-6m, and in a preferred embodiment, the second temperature-controlling groove 11 is an elongated groove with a length of 4m, and for clarity of explanation of the positional relationship between the devices, components, structures, or mechanisms in the embodiments of the present application, an end of the second temperature-controlling groove 11 adjacent to the first temperature-controlling groove is a proximal end, and an end of the second temperature-controlling groove 11 distant from the first temperature-controlling groove is a distal end, where it should be understood that the proximal end or the distal end may also be referred to as a proximal end side or a distal end side.

In an embodiment, the proximal side and the distal side of the second temperature control groove 11 are respectively provided with an overflow groove 111 for overflowing the fluid, such as water, in the groove 110, a gap 1110 for passing the 3D printing wire is provided on a side wall shared by the overflow groove 111 and the groove 110, and the gap 1110 is provided corresponding to the guide wheel.

Referring to fig. 3, a schematic structural diagram of another embodiment of the crystallization control device of the present application is shown, and in the embodiment shown in fig. 3, a openable cover is disposed at a notch of the tank body 110 of the second temperature control tank 11, so as to cover the cover 16 on the notch of the tank body 110 during production, so that the water temperature in the tank body 110 is stabilized while the liquid, such as water, in the tank body 110 overflows. In this embodiment, the cover 16 is disposed on one side of the slot 110 through a plurality of hinge members 17, and one or more handles are disposed on the cover 16 for facilitating the operation of the cover 16 by an operator.

In experiments, it was found that the residence time of the melt in each of the polymer material crystallinity control devices was an important factor affecting crystallinity. The specific residence time can be selected and adjusted by the crystallization speed of the material, the crystallization requirement on the final product, the extrusion speed, the length of each high polymer material crystallization control device, the material/implementation mode of the high polymer material crystallization control device and other factors, so that one of the purposes of the crystallization control device of the application is to increase the residence time of the 3D printing wire in the second temperature control groove by increasing the storage space of the 3D printing wire.

Referring to fig. 4, a schematic structural diagram of a tension control mechanism according to an embodiment of the present application is shown, and in this embodiment, the tension control mechanism 12 includes: a first winding wheel 121 and a second winding wheel 122, wherein the first winding wheel 121 is disposed at the proximal end of the second temperature-controlled tank 11 and is adjacent to the overflow tank 111 at the proximal end side of the second temperature-controlled tank 11. The second winding wheel 122 is disposed at the distal end of the second temperature control tank 11 and is adjacent to the overflow tank 111 at the distal end side of the second temperature control tank 11, and the second winding wheel 122 and the first winding wheel 121 maintain a certain distance, so that the wire passing through the second temperature control tank 11 is wound between the first winding wheel 121 and the second winding wheel 122 in a reciprocating manner, so as to provide a longer storage space for the 3D printing wire, so as to meet the residence time of the 3D printing wire in the tank 110 and realize the high crystallinity of the wire.

As shown in fig. 9, a first winding wheel 121 and a second winding wheel 122 are respectively disposed at two ends of the second temperature-control groove 11 of the water tank, the distance between the first winding wheel 121 and the second winding wheel 122 is l, the 3D printing wire passing through the second temperature-control groove 11 sequentially goes from the first turn of the distal second winding wheel 122 to the first turn of the proximal second winding wheel 122, then returns to the second turn of the distal second winding wheel 122, and then the second turn of the proximal second winding wheel 122, so that two webs are formed between the first winding wheel 121 and the second winding wheel 122, even if the 3D printing wire runs at a certain speed (such as 100 m/min) under the traction of the tractor, the length of the 3D printing wire in the second temperature-control groove 11 is long enough to satisfy the high crystallinity achieved by the retention time of the 3D printing wire in the groove 110, see the test example and table 1 described later.

In this embodiment, the crystallization control device for producing a 3D printing wire of the present application further includes a first driving motor (not shown) for driving the first winding wheel 121 and a second driving motor (not shown) for driving the second winding wheel 122. In this embodiment, the first driving motor and the second driving motor are both servo motors, and are used for executing the work of preset rotation speed by inputting a control command by an operator. Specifically, the first and second drive motors achieve wheel specific speed rotation through

mechanical structures

1211 and 1222 such as drive rods and bevel gears.

In order to avoid that adjacent wires in the lower wire mesh are contacted or stuck to each other between the first winding wheel 121 and the second winding wheel 122, the bottom of the tank body 110 of the second temperature control tank 11 is provided with a plurality of grooves 111 extending from the proximal end to the distal end, please refer to fig. 5, which is a schematic cross-sectional view A-A in fig. 2, each groove of the plurality of grooves 111 is used for one wire to pass through, so that the plurality of grooves 111 can be wound at intervals on adjacent 3D printing wires in the bottom wire mesh/lower wire mesh formed between the first winding wheel 121 and the second winding wheel 122.

As mentioned above, after the 3D printing wire is cooled and shaped by the first temperature control groove, the wire needs to enter the second temperature control groove 11 for a certain time to achieve high crystallinity of the wire, so that the wire from the first temperature control groove needs to be introduced into the second temperature control groove 11, in an embodiment, a first proximal guide wheel 1212 for introducing or extracting the 3D printing wire into or from the first winding wheel 121 is disposed at a proximal end of the groove body 110 of the second temperature control groove 11; and a second proximal guide wheel 1222 for guiding the 3D printing wire into or out of the second winding wheel 122 is provided at the distal end of the slot 110. In one embodiment, the

guide wheel

1212 or 1222 is mounted on one end of a movable swing arm, the other end of which is mounted on a rotating shaft, the swing arm providing a degree of freedom of movement to accommodate high speed wire.

In order to make the two winding wheels of the tension control mechanism completely immersed in the liquid in the second temperature control tank 11, or in another embodiment, make a part (such as an upper part) of the two winding wheels of the tension control mechanism exposed out of or immersed in the liquid in the second temperature control tank 11 (such as making the lower wire mesh of the upper and lower wire meshes wound on the first winding wheel 121 and the second winding wheel 122 immersed in the liquid in the second temperature control tank 11, and the upper wire mesh exposed out of the liquid level in the second temperature control tank 11), it is necessary to adjust the heights of the two winding wheels of the tension control mechanism in the tank body 110 of the second temperature control tank 11, and in an embodiment, the proximal end of the tank body 110 of the second temperature control tank 11 is provided with a first adjusting mechanism 1213 for adjusting the set height of the first winding wheel 121; and a second adjusting mechanism 1223 for adjusting the setting height of the second winding wheel 122 is provided at the distal end of the tub 110. Specifically, the first adjusting mechanism 1213 and the second adjusting mechanism 1223 are, for example, a combination of a slider and a sliding rail, and are fixed after being adjusted to a certain height so as to achieve the height adjustment of the winding wheel.

In the following embodiments, the first winding wheel 121 and the second winding wheel 122 are immersed in the fluid contained in the tank 110.

Because the inner space of the tank body 110 of the second temperature control tank 11 is limited, the wires are wound back and forth between the first winding wheel 121 and the second winding wheel 122 to form an upper wire mesh and a lower wire mesh, the distance between the adjacent wires in the wire mesh is smaller, if the wire mesh or the wires are free of tension, the wires in water can bend and shake along with water flow, the adjacent wires can contact or adhere in the shaking process, and further the forming size of the wires is affected, but because the just-shaped wires are heated through the second temperature control tank 11, the just-shaped wires still have certain softening, if the wires are tensioned or slightly more tension is applied, the wires are thinned, and the forming size of the wires can be affected.

Referring to fig. 6 and 7, fig. 6 is a schematic structural view of a winding wheel according to an embodiment of the present application, fig. 7 is a schematic sectional view of B-B of fig. 6, and for convenience of explanation, a first winding wheel 121 is temporarily exemplified in fig. 6 and 7, in this embodiment, the first winding wheel 121 has a plurality of wire grooves, for example, n+1 wire grooves, the groove depths of which are increased according to a predetermined ratio, such that the diameters of two adjacent wire grooves differ by a fixed ratio or a predetermined ratio The fixed preset value is, for example, in one embodiment, a fixed length, e.g., e, and the diameter of the deepest wire groove (the wire groove of the smallest diameter) is r as shown in FIG. 7 ₁ The shallowest wire slot (wire slot with the largest diameter) has a diameter r ₂ The relationship between the number of slots n+1 and the fixed length e is expressed as: r is (r) ₂ -r ₁ =n·e, in some embodiments, the diameter r of the deepest wire groove ₁ Diameter r designed in shallowest wire slot ₂ 80% -99% of (a), for example: 80%,81%,82%,83%,84%,85%,86%,87%,88%,89%,90%,91%,92%,93%,94%,95%,96%,97%,98%, or 99%, in a preferred embodiment, the diameter r of the deepest wire groove ₁ Diameter r designed as shallowest wire slot ₂ About 90%.

In another embodiment, the depths of the wire grooves on the first winding wheel 121 or the second winding wheel 122 are sequentially deepened, but may not follow a fixed value, for example, the depth variation amplitude of a certain wire groove or a certain number of wire grooves may be adjusted accordingly according to actual requirements, for example, in an embodiment, since the softening degree of the 3D printing wire when the 3D printing wire is just wound around the first wire groove in the winding wheel is greater than the softening degree of the 3D printing wire when the last wire groove in the winding wheel (i.e. the wire exhibits the characteristic of gradually hardening), in order to ensure the tension of the wire in each section, when designing, the depth variation of the last wire slot on the first winding wheel 121 or the second winding wheel 122 may be different from the depth variation of the other wire slots, for example, the depth variation of the last wire slot is smaller, please refer to fig. 8, which shows a schematic structural diagram of the winding wheel in another embodiment of the present application, and as shown in the drawing, the winding wheel is provided with 9 wire slots, and the radius variation of the 9 wire slots in the winding wheel is exemplified by a fixed value of 0.4mm, and the radius of the first winding wheel is 50mm, and sequentially 50.4mm,50.8mm,51.2mm,51.6mm,52mm,52.4mm,52.8mm, but the wire slot with the shallowest depth from the last wire slot has a radius of 53mm, that is, the depth variation of the last wire slot is smaller.

As can be seen from the above, the groove depth of each wire groove on the first winding wheel 121 or the second winding wheel 122 is different, and the wire speeds of the wire grooves at different positions of the same winding wheel are different at the fixed angular speed of the winding wheel, so that the tension of the 3D printing wire in the second temperature control groove 11 is controlled by configuring the winding direction of the 3D printing wire on the first winding wheel 121 and the second winding wheel 122 or by configuring the relative rotational speeds of the first winding wheel 121 and the second winding wheel 122, or by configuring the winding direction of the 3D printing wire on the first winding wheel 121 and the second winding wheel 122, or by configuring the relative rotational speeds of the 3D printing wire on the first winding wheel 121 and the second winding wheel 122. For example, in a specific embodiment, by reasonably setting the speed ratio of the first winding wheel 121 and the second winding wheel 122, the linear speed can be gradually increased when the wire passes through each groove of the two winding wheels in sequence. The difference of the front and back linear speeds provides the tension of each section of wire rod in the upper wire net and the lower wire net, so that the controllable and uniform tension of each section of wire rod is ensured, and better dimensional accuracy and uniformity can be realized.

The first winding wheel 121 shown in fig. 6 and 7 has 12 wire grooves in which the 3D printing wire is wound, and the 12 wire grooves sequentially increase in groove depth from the right side to the left side of fig. 6 and 7, i.e., the diameters or radii of the 12 wire grooves sequentially decrease from the right side to the left side. When the first winding wheel 121 is driven to rotate, the linear velocity of the rightmost first wire groove is smaller than the linear velocity of the right second wire groove, the linear velocity of the right second wire groove is smaller than the linear velocity of the right third wire groove, and so on, the linear velocity of the right eleventh wire groove is smaller than the linear velocity of the right twelfth wire groove, in other words, when the 12 wire grooves are all wound with 3D printing wire and are driven to rotate by the first winding wheel 121, the velocity of the 3D printing wire located in each wire groove is from the right first turn to the left, the linear velocity of the 12 wire grooves of the first winding wheel 121 is a phenomenon of acceleration, and thus, when the 3D printing wire is wound between the first winding wheel 121 and the second winding wheel 122, the wire wound in the 12 wire grooves of the first winding wheel 121 is a process of acceleration, see the description of fig. 9, which will be described later.

It should be understood that, when the second winding wheel 122 also adopts the same wire slot design as the first winding wheel 121, and the deepest wire slot of the first winding wheel 121 and the deepest wire slot of the second winding are located on the same side of the slot body 110, the speed of each wire in the wire forming up and down two wire meshes between the first winding wheel 121 and the second winding wheel 122 is greater than that of the previous wire, i.e. the tension of each wire in the wire forming up and down two wire meshes between the first winding wheel 121 and the second winding wheel 122 is greater than that of the previous wire.

In an embodiment, the rotational speeds of the first winding wheel 121 and the second winding wheel 122 may also be bound by setting the rotational speed ratio or the rotational speed difference of the first driving motor and the second driving motor, specifically, setting the rotational speeds of the first winding wheel 121 and the second winding wheel 122 is achieved, for example, by an input item or a selection item provided by a display interface provided by a touch display screen of a control device.

In one embodiment, the 3D printing wire is wound around the deepest wire groove (i.e., the wire groove having the smallest diameter) of the second winding wheel 122, then wound around the deepest wire groove of the first winding wheel 121, and then wound back and forth between the second winding wheel 122 and the first winding wheel 121 in the order of the wire grooves from deep to shallow, and led out through the shallowest wire groove (i.e., the wire groove having the largest diameter) of the first winding wheel 121. In the present embodiment, the rotational speed of the first winding wheel 121 is set to be greater than the rotational speed of the second winding wheel 122.

In another embodiment, the wire speed difference of each section is flexibly adjusted according to the state of the wire in the forming process, and the rotational speeds of the first winding wheel 121 and the second winding wheel 122 can be kept equal by setting the first driving motor and the second driving motor, that is, the rotational speed of the first winding wheel 121 can be set to be equal to the rotational speed of the second winding wheel 122 based on the winding manner.

Referring to fig. 9, a schematic diagram of a wire mesh formed between a first winding wheel and a second winding wheel is shown, and is assumed to be located in a second temperature control grooveThe wire groove at the maximum diameter position of the first winding wheel 121 at the proximal end in 11 has a linear velocity v _a The linear velocity of the wire groove at the maximum diameter position of the second winding wheel 122 located at the distal end in the second temperature control groove 11 is set to v _b The 3D printing wire has a pulling speed v (e.g., the pulling speed is a speed provided by a tractor), and in an embodiment, the speed ratio k of the first winding wheel 121 to the second winding wheel 122 is programmed _a And k _b Respectively represent:

and

since the first winding wheel 121 and the second winding wheel 122 are all a moving unit, the angular velocities of the corresponding positions of all the wire grooves in the first winding wheel 121 or the second winding wheel 122 are the same, and the linear velocity of the corresponding wire groove position is in proportional relation with the diameter or radius of the winding wheel. Thus, the linear velocity of each groove position in the first winding wheel 121 can be calculated, v in order from the groove position of the maximum diameter to the groove position of the minimum diameter _a 、v _a ·(1-e)、……、v _a ·(1-n·e)。

Accordingly, the linear velocity of each groove position in the second winding wheel 122 is also obtained, and the positions of the grooves starting from the position of the groove with the largest diameter and proceeding from the position of the groove with the smallest diameter are as follows: v _b 、v _b ·(1-e)、……、v _b ·(1-n·e)。

In a specific implementation, after the traction speed of the tractor is obtained, the speed ratio k of the first winding wheel 121 to the second winding wheel 122 is determined _a And k _b The linear speeds of the first winding wheel 121 and the second winding wheel 122 at the plurality of wire grooves are as follows:

the plurality of wire grooves in the first winding wheel 121 start from the wire groove of the largest diameter up to the wire groove of the smallest diameter, and the linear velocity of each wire groove is expressed in turn as: v.k _a 、v·k _a ·(1-e)、……、v·k _a ·(1-n·e)。

The plurality of wire grooves in the second winding wheel 122 start from the wire groove of the largest diameter up to the wire groove of the smallest diameter, and the linear velocity of each wire groove is expressed in turn as: v.k _b 、v·k _b ·(1-e)、……、v·k _b ·(1-n·e)。

By setting the values of the rotational speed parameters of the first and second winding

wheels

121, 122, for example by setting the rotational speed of the first winding wheel 121 to be controlled to be greater than the rotational speed of the second winding wheel 122, assuming that the traction speed of the traction machine is v, the following is achieved as shown in fig. 9:

v≥v·k _a ≥v·k _b ≥v·k _a ·(1-e)≥v·k _b ·(1-e)≥……≥v·k _a ·(1-n·e)≥v·k _b ·(1-n·e)。

as can be seen, when the 3D printing wire between the first winding wheel 121 and the second winding wheel 122 is wound reciprocally in the wire grooves of the two winding wheels, the 3D printing wire passes through each wire groove at a faster linear speed than the previous wire groove, so that the 3D printing wire is stretched to maintain tension in each section.

From the above relation, it can be seen that: the smaller the difference e setting, k _a And k _b The closer to 1 the arrangement is, the larger the number n of wire slots is arranged, and the closer the linear speeds of two adjacent positions are. In this way, only slight stretching tension of the wire between the two adjacent positions of the first winding wheel 121 and the second winding wheel 122 can be ensured, so that the tension of the 3D printing wire between the first winding wheel 121 and the second winding wheel 122 is ensured, the wire stretching is avoided to the greatest extent, and the uniformity of the wire diameter is ensured.

Step S13: the 3D printing wire is pulled out from the tension control mechanism, and is rolled and stored after being cooled; in an embodiment, a third temperature control groove is further disposed near the distal end of the second temperature control groove 11, and in an embodiment, the temperature control interval of the second temperature control groove 11 is between 15 ℃ and 30 ℃, for example, the second temperature control groove 11 contains water with a preset temperature interval of about 15 ℃ to 30 ℃, for example, 15 ℃,16 ℃,17 ℃,18 ℃,19 ℃,20 ℃,21 ℃,22 ℃,23 ℃,24 ℃,25 ℃,26 ℃,27 ℃,28 ℃,29 ℃, or 30 ℃ in the second temperature control groove 11; in a more preferred embodiment, the temperature of the water contained in the third temperature-control tank is about 20 ℃, the water is used for cooling/cooling the 3D printing wire rod passing through the third temperature-control tank, and then the 3D printing wire rod is wound into a finished product by a winding machine arranged in a production line, so that the packaging, the storage or the transportation is facilitated.

To further illustrate the principles and advantages of the present application, the present application provides the following test examples:

by arranging the first winding wheel 121 and the second winding wheel 122 on both sides of the proximal end and the distal end of the second temperature control groove 11, and winding the 3D printing wire material passing through the second temperature control groove 11 between the first winding wheel 121 and the second winding wheel 122 according to a preset sequence, the 3D printing wire material can stay for a long time. Setting the wire drawing speed of 100m/min, and comparing and testing the test model to obtain the retention time of the wires in the following table 1:

table 1:

as can be seen from table 1, in the case of designing the wire grooves of the first winding wheel 121 and the second winding wheel 122 to be 9 circles of grooves, for example, the winding wheel shown in fig. 8 is adopted, the 3D printing wire can stay for 0.693min in the preset temperature environment of the second temperature control groove 11, and the requirement of high crystallinity can be completed according to the stay for 30s of the 3D printing wire at the temperature environment, and this test result shows that the design of the present application can be enough for the wire to crystallize on line in the process of processing and forming.

It will be appreciated that PLA strands of different formulations have different crystallization rates, and that residence times from 30s to 2min are generally required for adequate crystallization. Therefore, in other embodiments, the second temperature control groove may be extended and the distance between the first winding wheel and the second winding wheel may be increased, or the number of the wire grooves on the first winding wheel and the second winding wheel may be increased or reduced appropriately, so that the residence time of the 3D printing wire in the second temperature control groove may be satisfied.

In the test example of designing the wire grooves of the first winding wheel and the second winding wheel as 9-turn grooves shown in fig. 8, setting a wire drawing speed of 100m/min, designing a diameter difference of every two adjacent wire grooves in the first winding wheel and the second winding wheel to be 0.8mm, wherein the diameter of the wire groove with the deepest depth is 100mm, the diameter of the wire groove with the shallowest depth is 106mm, designing the number of turns of the wire groove in the first winding wheel and the second winding wheel to be 9, setting the speed ratio of the first winding wheel and the second winding wheel to be 0.990 and 0.995 respectively, and obtaining the wire speed of each position through actual test: 100. 99.5, 99.3, 99.1, 98.6, 98.3, 97.9, 97.6, … …, 93.9, 93.4. From this test result, the 3D printing wire is improved by about 7% from the inlet to the outlet, and the 3D printing wire can maintain good dimensional stability considering that the wire is gradually drawn over a distance of 69.3m, thereby meeting the design requirements of the process.

In another embodiment, for example, the preset temperature in the second temperature control tank is set to be between 15 ℃ and 30 ℃, based on the teaching of the method steps S10-S13, in view of the technical characteristics that the crystallization control device and the crystallization control method can enable the 3D printing wire to stay in the temperature control tank and stretch at a low temperature, the wire can be fully cooled when being processed at a low temperature, and therefore the processing quality and efficiency of the wire can be effectively improved.

In still another embodiment, for example, the 3D printing wire is required to be wound between the first winding wheel and the second winding wheel, and maintain a slightly relaxed state in the second temperature-control groove to release a part of the stretching deformation of the wire, then the linear speed of the latter position may be set to be slightly lower than the linear speed of the former position, for example, the 3D printing wire is wound around the shallowest groove of the second winding wheel first, then wound around the shallowest groove of the first winding wheel, and then wound back and forth between the second winding wheel and the first winding wheel according to the order of the grooves from shallow to deep, and led out through the deepest groove of the first winding wheel. In this embodiment, the rotational speed of the first winding wheel is set to be less than or equal to the rotational speed of the second winding wheel, so that a state is formed in which the 3D printing wire is slightly relaxed, and a part of the wire stretching deformation is released.

Based on the inventive concept of the present application, in some embodiments, the wheel body of the winding wheel may be further divided into two or more sections, to divide the wheel body of the winding wheel into two examples, where the groove depth of the wire groove in the first section is sequentially reduced according to a preset ratio or a preset value, and the groove depth of the wire groove in the second section is sequentially increased according to a preset ratio or a preset value; referring to fig. 10, there is shown a schematic structural view of a winding wheel according to another embodiment of the present application, wherein the left and right sections of the winding wheel are provided with 6 wire grooves, i.e. 12 wire grooves from left to right, respectively, wherein the groove depths from the 1 st groove to the 6 th groove from left to right are sequentially reduced to have a diameter r as shown in fig. 10 ₁ ＜r ₂ The method comprises the steps of carrying out a first treatment on the surface of the As shown in figure 10 diameter r ₂ ＜r ₃ (the diameter in FIG. 10 is also displaced by r ₂ ＝r ₃ ) The method comprises the steps of carrying out a first treatment on the surface of the The groove depths of the 7 th groove to the 12 th groove are sequentially increased to be the diameter r as shown in fig. 10 ₃ ＞r ₂₄ The method comprises the steps of carrying out a first treatment on the surface of the The pair of winding wheels are arranged at the near end and the far end of the temperature control groove (for example, the second temperature control groove) in the same direction, and 3D printing wires in the temperature control groove are repeatedly wound on the pair of winding wheels and rotate the pair of winding wheels, for example, the 3D printing wires firstly enter from the leftmost 1 st wire groove, at the moment, the linear speed is slowest, the speed is gradually increased to the 6 th wire groove between the pair of winding wheels, the wire is gradually transited from the 7 th wire groove to the gradually deeper 12 th wire groove, and thus, the wires at the back section are all in a speed reduction mode and have slight looseness. Of course, in other embodiments, the 7 th to 12 th wire grooves of the winding wheel in FIG. 10 can be kept constant in groove depth, so that the speed of the rear wire can be kept balanced withoutStretching is free from relaxation.

As another modification example under the concept of the present application, please refer to fig. 11, which shows a schematic structural view of a winding wheel in yet another embodiment of the present application, the left side section and the right side section of the winding wheel as shown have 6 wire grooves, i.e. 12 wire grooves from left to right, wherein the groove depths of the 1 st to 6 th grooves from left to right sequentially increase to have a diameter r as shown in fig. 11 ₁ ＞r ₂ The method comprises the steps of carrying out a first treatment on the surface of the The groove depths of the 7 th groove to the 12 th groove are sequentially reduced to be the diameter r as shown in fig. 11 ₁ ＜r ₂ . The pair of winding wheels are arranged at the near end and the far end of the temperature control groove (for example, the second temperature control groove) in the same direction, and 3D printing wires in the temperature control groove are repeatedly wound on the pair of winding wheels and rotate the pair of winding wheels, for example, the 3D printing wires enter from the leftmost 1 st wire groove, at the moment, the wire speed is fastest, the wire speed gradually falls to the 6 th wire groove between the pair of winding wheels, the wire speed gradually transits from the 7 th wire groove to the gradually shallower 12 th wire groove, so that the wires at the later section are accelerated, and the wires are slightly tensioned.

The present application further provides a 3D printing wire, which is prepared by the crystallization control method and the crystallization control device described in fig. 1 to 9, wherein the 3D printing wire is a semi-crystalline 3D printing wire including polylactic acid (PLA), and in embodiments, the wire may further contain other components besides PLA, for example, including but not limited to: colorants, pigments, fillers, fibers, plasticizers, nucleating agents, thermal/UV stabilizers, processing aids, impact modifiers, and other additives. The average diameter of the 3D printing wire is typically 1.75mm or 2.85mm.

In some embodiments, the 3D printing wire has an average diameter of 1.55mm-1.95mm (e.g., 1.55mm,1.56mm,1.57mm,1.58mm,1.59mm,1.60mm,1.61mm,1.62mm,1.63mm,1.64mm,1.65mm,1.66mm,1.67mm,1.68mm,1.69mm,1.70mm,1.71mm,1.72mm,1.73mm,1.74mm,1.75mm,1.76mm,1.77mm,1.78mm,1.79mm,1.80mm,1.81mm,1.82mm,1.83mm,1.84mm,1.85mm,1.86mm,1.87mm,1.88mm,1.89mm,1.90mm,1.91mm,1.92mm,1.93mm, 1.95mm, or 1.95 mm).

In other embodiments, the 3D printing wire has an average diameter of 2.65mm-3.15mm (e.g., 2.65mm,2.66mm,2.67mm,2.68mm,2.69mm,2.70mm,2.71mm,2.72mm,2.73mm,2.74mm,2.75mm,2.76mm,2.77mm,2.78mm,2.79mm,2.80mm,2.81mm,2.82mm,2.83mm,2.84mm,2.85mm,2.86mm,2.87mm,2.88mm,2.89mm,2.90mm,2.91mm,2.92mm,2.93mm,2.94mm,2.95mm,2.96mm,2.97mm, 2.99mm, 3.75 mm,3.01mm,3.02mm,3.03mm, 3.05mm, 3.79 mm, 3.39 mm,3.09mm, 3.39 mm,3.07mm, 3.11mm, 3.39 mm,3.11mm, 3.09mm, 3.15mm, 3.39 mm).

The application also provides a winding wheel for installing in pairs on crystallization controlling means for producing 3D printing wire, the winding wheel includes a wheel body and forms a plurality of wire casings that are used for supplying the wire winding on the wheel body.

As shown in fig. 2 to 9 described above, the groove depths of all or part of the plurality of wire grooves are sequentially increased so as to control the tension of the 3D printing wire on the crystallization control device by configuring the winding direction of the 3D printing wire in the pair of winding wheels or/and by configuring the relative rotational speeds of the pair of winding wheels.

In an embodiment, the groove depths of all or part of the plurality of grooves are sequentially increased according to a preset ratio or a preset value. Such as the various embodiments shown in fig. 6-8 described above.

In one embodiment, the winding wheel has n+1 wire grooves, wherein the diameters of every two adjacent grooves differ by a length e, and the diameter of the deepest wire groove is r ₁ The diameter of the shallowest wire slot is r ₂ R is then ₂ -r ₁ ＝n·e，r ₁ And r ₂ The ratio of (2) is in the range of 80% -99%. Referring to fig. 6 and 7, in the present embodiment, the winding wheel 121 has a plurality of wire grooves, for example, n+1 wire grooves, and the groove depths of the wire grooves are increased according to a predetermined ratio, such that the diameters of two adjacent wire grooves are different by a fixed ratio or a predetermined value, and the ratio In one embodiment, the fixed preset value is a fixed length, e.g. e, and the diameter of the deepest wire slot (the wire slot with the smallest diameter) is r as shown in FIG. 7 ₁ The shallowest wire slot (wire slot with the largest diameter) has a diameter r ₂ The relationship between the number of slots n+1 and the fixed length e is expressed as: r is (r) ₂ -r ₁ =n·e, in some embodiments, the diameter r of the deepest wire groove ₁ Diameter r designed in shallowest wire slot ₂ 80% -99% of (a), for example: 80%,81%,82%,83%,84%,85%,86%,87%,88%,89%,90%,91%,92%,93%,94%,95%,96%,97%,98%, or 99%, in a preferred embodiment, the diameter r of the deepest wire groove ₁ Diameter r designed as shallowest wire slot ₂ About 90%.

The foregoing embodiments are merely illustrative of the principles of the present application and their effectiveness, and are not intended to limit the application. Modifications and variations may be made to the above-described embodiments by those of ordinary skill in the art without departing from the spirit and scope of the present application. Accordingly, it is intended that all equivalent modifications and variations which may be accomplished by persons skilled in the art without departing from the spirit and technical spirit of the disclosure be covered by the claims of this application.

Claims

1. A crystallization control device for producing a 3D printing wire, comprising:

the temperature control tank comprises a tank body for containing fluid, and a 3D printing wire rod in the tank body is used for achieving crystallization temperature by controlling the temperature control path of the fluid;

the tension control mechanism is arranged in the temperature control groove and comprises a first winding wheel arranged at the proximal end of the groove body and a second winding wheel arranged at the distal end of the groove body, and is used for enabling the 3D printing wire to wind back and forth between the first winding wheel and the second winding wheel so as to increase the residence time and residence length of the 3D printing wire in the groove body;

the device comprises a first winding wheel and a second winding wheel, wherein a plurality of wire grooves are formed in the first winding wheel or/and the second winding wheel, the groove depth of all or part of the wire grooves of the plurality of wire grooves is sequentially increased, and tension control is conducted on the 3D printing wire rods in the groove bodies through configuring the winding direction of the 3D printing wire rods on the first winding wheel and the second winding wheel or/and configuring the relative rotating speed of the first winding wheel and the second winding wheel.

2. The crystallization control device for producing a 3D printing wire according to claim 1, wherein the fluid contained in the tank comprises: water of a preset temperature, oil of a preset temperature, molten low-temperature alloy liquid of a preset temperature, high-temperature salt molten liquid of a preset temperature, air flow of a preset temperature, or steam of a preset temperature.

3. The crystallization control device for producing a 3D printing wire according to claim 1, wherein the preset temperature of the fluid for containing in the tank is between 80 ℃ and 100 ℃ or between 150 ℃ and 300 ℃; or the preset temperature of the fluid in the tank body for containing is 15-30 ℃.

4. The crystallization control device for producing 3D printing wires according to claim 1, wherein the fluid for holding in the tank is a liquid or vapor comprising a wire coating agent and/or a surface etchant.

5. The crystallization control device for producing a 3D printing wire according to claim 1, wherein one or more devices for radiating infrared radiation, microwave radiation, alternating magnetic field of the space inside the tank are provided inside the tank.

6. The crystallization control device for producing a 3D printing wire according to claim 1, wherein one or both sides of the tank body are provided with a pipe through which the fluid is inputted into an inner space of the tank body.

7. The crystallization control device for producing a 3D printing wire according to claim 1, wherein a temperature sensor for sensing the fluid temperature is provided in the tank.

8. The crystallization control device for producing 3D printing wires according to claim 1, wherein the bottom of the tank is provided with a plurality of grooves extending from a proximal end to a distal end for spacing adjacent 3D printing wires formed in a bottom wire mesh formed between the first winding wheel and the second winding wheel.

9. The crystallization control device for producing a 3D printing wire according to claim 1, wherein a notch of the tank body is provided with a cover body that can be opened and closed.

10. The crystallization control device for producing a 3D printing wire according to claim 1, wherein a proximal end of the tank is provided with a first proximal guide wheel for guiding the 3D printing wire into or out of the first winding wheel; and a second proximal guide wheel for guiding the 3D printing wire into or out of the second winding wheel is arranged at the distal end of the groove body.

11. The crystallization control device for producing a 3D printing wire according to claim 1, wherein a proximal end of the tank is provided with a first adjusting mechanism for adjusting a mounting height of the first winding wheel; and a second adjusting mechanism for adjusting the mounting height of the second winding wheel is arranged at the far end of the groove body.

12. The crystallization control device for producing a 3D printing wire according to claim 1, wherein the first winding wheel and the second winding wheel are immersed in a fluid contained in the tank.

13. The crystallization control device for producing a 3D printing wire according to claim 1, further comprising a first driving motor for driving the first winding wheel to rotate, and a second driving motor for driving the second winding wheel to rotate.

14. The crystallization control device for producing a 3D printed wire according to claim 1, wherein the deepest wire groove of the first winding wheel and the deepest wire groove of the second winding are located on the same side within the groove body.

15. The crystallization control device for producing a 3D printing wire according to claim 1, wherein the groove depths of the plurality of wire grooves on the first winding wheel or the second winding wheel are sequentially increased according to a preset ratio or a preset value.

16. The crystallization control device for producing a 3D printing wire according to claim 1, wherein the groove depth of a part of the plurality of wire grooves on the first winding wheel or the second winding wheel sequentially increases according to a preset ratio or a preset value.

17. The crystallization control device for producing 3D printed wire according to claim 15 or 16, wherein the first winding wheel or the second winding wheel has n+1 wire slots, wherein every adjacent two slotsThe diameter of the deepest trunking is r ₁ The diameter of the shallowest wire slot is r ₂ R is then ₂ -r ₁ ＝n·e，r ₁ And r ₂ The ratio of (2) is in the range of 80% -99%.

18. The crystallization control device for producing a 3D printing wire according to claim 1, wherein the 3D printing wire is wound around the deepest slot of the second winding wheel first, then wound around the deepest slot of the first winding wheel, and wound back and forth between the second winding wheel and the first winding wheel in the order of the slots from deep to shallow, and led out through the shallowest slot of the first winding wheel.

19. The crystallization control device for producing a 3D printing wire according to claim 18, wherein a rotational speed of the first winding wheel is greater than or equal to a rotational speed of the second winding wheel.

20. The crystallization control device for producing a 3D printing wire according to claim 1, wherein the 3D printing wire is wound around the shallowest wire slot of the second winding wheel first, then wound around the shallowest wire slot of the first winding wheel, and wound back and forth between the second winding wheel and the first winding wheel in the order of the wire slots from shallow to deep, and led out through the deepest wire slot of the first winding wheel.

21. The crystallization control device for producing a 3D printing wire according to claim 20, wherein a rotational speed of the first winding wheel is less than or equal to a rotational speed of the second winding wheel.

22. A crystallization control method for producing a 3D printing wire, characterized by comprising the steps of:

melting crystalline polymer and extruding to form wire rod;

enabling the extruded 3D printing wire rod to pass through a first temperature control groove to be cooled and shaped;

winding the shaped 3D printing wire on a tension control mechanism positioned in the second temperature control groove so that the 3D printing wire stays in the temperature control groove for a preset time in a state of keeping preset tension to obtain a crystallized high polymer material wire;

The 3D printing wire is pulled out from the tension control mechanism, and is rolled and stored after being cooled;

the tension control mechanism comprises a first winding wheel arranged at the near end of the temperature control groove and a second winding wheel arranged at the far end of the temperature control groove, wherein a plurality of wire grooves are formed in the first winding wheel or/and the second winding wheel, the groove depth of all or part of the wire grooves is sequentially increased, so that tension control is carried out on the 3D printing wire in the temperature control groove through configuring the winding direction of the 3D printing wire on the first winding wheel and the second winding wheel or/and configuring the relative rotating speed of the first winding wheel and the second winding wheel.

23. The crystallization control method for producing a 3D printing wire according to claim 22, wherein the temperature control section of the first temperature control tank is between 50 ℃ and 60 ℃; the temperature control interval of the second temperature control tank is 80-100 ℃; the temperature control interval of the cooling treatment is 15-30 ℃.

24. The crystallization control method for producing a 3D printing wire according to claim 22, wherein the first winding wheel and the second winding wheel of the tension control mechanism are immersed in the fluid contained in the second temperature control tank.

25. The crystallization control method for producing a 3D printing wire according to claim 22, wherein a deepest wire groove of the first winding wheel and a deepest wire groove of the second winding are located on the same side within the second temperature control groove.

26. The crystallization control method for producing a 3D printing wire according to claim 22, wherein the groove depths of the plurality of wire grooves on the first winding wheel or the second winding wheel are sequentially increased according to a preset ratio or a preset value.

27. The crystallization control method for producing a 3D printing wire according to claim 22, wherein the groove depth of a part of the plurality of grooves on the first winding wheel or the second winding wheel is sequentially increased according to a preset ratio or a preset value.

28. The crystallization control method for producing a 3D printing wire according to claim 26 or 27, wherein the first winding wheel or the second winding wheel has n+1 wire grooves, wherein diameters of each adjacent two grooves differ by a length e, and a diameter of a deepest wire groove is r ₁ The diameter of the shallowest wire slot is r ₂ R is then ₂ -r ₁ ＝n·e，r ₁ And r ₂ The ratio of (2) is in the range of 80% -99%.

29. The crystallization control method for producing a 3D printing wire according to claim 22, wherein the step of winding the shaped 3D printing wire on a tension control mechanism located in the second temperature control tank includes: and enabling the 3D printing wire to be wound on the shallowest wire groove of the second winding wheel firstly, then winding the shallowest wire groove of the first winding wheel, and winding the wire grooves back and forth between the second winding wheel and the first winding wheel according to the sequence from shallow to deep, and leading out the wire grooves from the shallowest wire groove of the first winding wheel.

30. The crystallization control method for producing a 3D printing wire according to claim 29, further comprising the step of controlling a rotational speed of the first winding wheel to be greater than or equal to a rotational speed of the second winding wheel.

31. The crystallization control method for producing a 3D printing wire according to claim 22, wherein the step of winding the shaped 3D printing wire on a tension control mechanism located in the second temperature control tank includes: and enabling the 3D printing wire to be wound on the shallowest wire groove of the second winding wheel firstly, then winding the shallowest wire groove of the first winding wheel, and winding the wire grooves back and forth between the second winding wheel and the first winding wheel according to the sequence from shallow to deep, and leading out the wire grooves from the shallowest wire groove of the first winding wheel.

32. The crystallization control method for producing a 3D printing wire according to claim 31, further comprising a step of controlling a rotational speed of the first winding wheel to be less than or equal to a rotational speed of the second winding wheel.

33. A 3D printing wire prepared by the crystallization control method according to any one of the preceding claims 22-32.

34. A winding wheel for mounting in pairs on a crystallization control device for producing 3D printing wires, characterized in that the winding wheel comprises a wheel body and a plurality of wire grooves formed on the wheel body for winding wires, the groove depth of all or part of the plurality of wire grooves is sequentially increased so as to tension-control the 3D printing wires on the crystallization control device by configuring the 3D printing wires in the winding direction of the pair of winding wheels or/and by configuring the relative rotational speeds of the pair of winding wheels.

35. The winding wheel of claim 34, wherein the groove depth of all or a portion of the plurality of grooves increases sequentially according to a predetermined ratio or a predetermined value.

36. A winding wheel according to claim 34 or 35, characterized in that the winding wheel has n+1 wire grooves, wherein the diameters of each adjacent two grooves differ by a length e, the diameter of the deepest wire groove being r ₁ The diameter of the shallowest wire slot is r ₂ R is then ₂ -r ₁ ＝n·e，r ₁ And r ₂ The ratio of (2) is in the range of80％-99％。