阅读说明：本技术 一种环保的双氰胺类复鞣剂、制备方法及系统 (Environment-friendly dicyandiamide retanning agent, preparation method and system ) 是由 范观水 姜本红 季振兴 唐省高 肖丽萍 于 2020-12-28 设计创作，主要内容包括：本发明公开了一种环保的双氰胺类复鞣剂、制备方法及系统,通过将预设质量份双氰胺和亚磷酸二甲酯混合加热,之后加入催化剂,再次混合,得到第一混合液；向所述第一混合液中加入预设质量份丙烯酰胺,进行再次加热混合,得到第二混合液；将预设质量份丙烯酸和丙烯酸乙酯混合,形成融合物；将融合物加入至第二混合液中搅拌均匀,之后加入戊二醛,得到混合物；向混合物中依次加入引发剂和中和剂,之后加热混合,得到双氰胺类复鞣剂,所述双氰胺类复鞣剂能够提升皮革的丰满性、柔软性以及阻燃性,复鞣剂的使用效果更佳。(The invention discloses an environment-friendly dicyandiamide retanning agent, a preparation method and a system, wherein a first mixed solution is obtained by mixing and heating dicyandiamide and dimethyl phosphite in preset mass parts, then adding a catalyst, and mixing again; adding acrylamide in a preset mass part into the first mixed solution, and heating and mixing again to obtain a second mixed solution; mixing acrylic acid and ethyl acrylate in preset parts by mass to form a fusion; adding the fusion into the second mixed solution, uniformly stirring, and then adding glutaraldehyde to obtain a mixture; and sequentially adding an initiator and a neutralizing agent into the mixture, and then heating and mixing to obtain the dicyandiamide retanning agent, wherein the dicyandiamide retanning agent can improve the fullness, softness and flame retardance of leather, and the using effect of the retanning agent is better.)

1. The dicyandiamide retanning agent is characterized by comprising the following raw materials in parts by mass:

40-60 parts of dicyandiamide, 20-30 parts of dimethyl phosphite, 10-16 parts of catalyst, 5-15 parts of acrylamide, 20-30 parts of acrylic acid, 10-12 parts of ethyl acrylate, 6-8 parts of glutaraldehyde, 10-12 parts of initiator and 10-12 parts of neutralizer.

2. The method for preparing the dicyandiamide retanning agent according to claim 1, comprising the steps of:

mixing and heating dicyandiamide and dimethyl phosphite in preset parts by mass, then adding a catalyst, and mixing again to obtain a first mixed solution;

adding acrylamide in a preset mass part into the first mixed solution, and heating and mixing again to obtain a second mixed solution;

mixing acrylic acid and ethyl acrylate in preset parts by mass to form a fusion;

adding the fusion into the second mixed solution, uniformly stirring, and then adding glutaraldehyde to obtain a mixture;

and sequentially adding an initiator and a neutralizing agent into the mixture, and then heating and mixing to obtain the dicyandiamide retanning agent.

3. The method for preparing dicyandiamide retanning agent according to claim 2, wherein in the step of mixing and heating dicyandiamide and dimethyl phosphite in predetermined parts by mass, then adding a catalyst, and mixing again to obtain a first mixed solution:

the heating temperature for mixing and heating dicyandiamide and dimethyl phosphite is 60-80 ℃.

4. The process for producing a dicyandiamide retanning agent according to claim 2,

the catalyst is one or more of toluenesulfonic acid, sulfuric acid and boric acid.

5. The method for preparing a dicyandiamide retanning agent according to claim 2, wherein in the step of adding a predetermined mass part of acrylamide to the first mixed solution and heating and mixing again to obtain a second mixed solution:

and adding acrylamide in a preset mass part into the first mixed solution, wherein the heating temperature is 100-120 ℃ when reheating is carried out.

6. The method for producing a dicyandiamide retanning agent according to claim 2, wherein in the step of adding an initiator and a neutralizing agent to the mixture in this order, and then heating and mixing to obtain a dicyandiamide retanning agent:

the initiator is one or more of azobisisobutyronitrile, azobisisoheptonitrile and cyclohexanone peroxide.

7. The method for producing a dicyandiamide retanning agent according to claim 2, wherein in the step of adding an initiator and a neutralizing agent to the mixture in this order, and then heating and mixing to obtain a dicyandiamide retanning agent:

the neutralizing agent is sodium hydroxide solution.

8. A system for the production of dicyandiamide retanning agent according to claim 2, wherein,

the stirring device comprises a support, a first stirring assembly and a second stirring assembly, wherein the first stirring assembly and the second stirring assembly are fixedly connected with the support, the first stirring assembly is positioned above the second stirring assembly, the first stirring assembly comprises a first shell, a first driving piece, a first rotating shaft and a first mixing part, the first shell is provided with a first inlet pipe and a first outlet pipe, the first driving piece is fixedly connected with the first shell and positioned above the first shell, one end of the first rotating shaft is fixedly connected with the output end of the first driving piece, the other end of the first rotating shaft is inserted into the first shell, the number of the first mixing parts is multiple groups, each group of the first mixing parts comprises an upper inclined rod, a lower inclined rod and two cross rods, one end of the upper inclined rod and one end of the lower inclined rod are respectively fixedly connected with the first rotating shaft, the other ends of the upper inclined rod and the lower inclined rod are fixedly connected with two cross rods;

the second stirring component comprises a second shell, a second driving part, a second rotating shaft, a second mixing part, a heating part and a temperature tester, the second shell is provided with a second inlet pipe and a second outlet pipe, the second driving part is fixedly connected with the second shell and is positioned above the second shell, one end of the second rotating shaft is fixedly connected with the output end of the second driving part, the other end of the second rotating shaft is inserted into the second shell, the quantity of the second mixing part is multiple groups, each group of the second mixing part comprises a first rod body, a second rod body, a third rod body, the first rod body, the second rod body and the third rod body are sequentially arranged from top to bottom along the axial center line direction of the second rotating shaft, the length of the second rod body is greater than that of the first rod body and that of the third rod body, the length of the first rod body is equal to that of the third rod body, the heating member and the temperature tester are both disposed inside the second housing.

Technical Field

The invention relates to the technical field of dicyandiamide retanning agents, in particular to an environment-friendly dicyandiamide retanning agent, a preparation method and a system.

Background

Retanning is a very important position in modern leather-making industry, is a key process in leather-making production, is known as 'gold-making' by the leather industry, and particularly for light leather, the same leather blank can be made into solid vamp leather and soft and plump clothing leather by adopting different retanning methods. The quality of the retanning material determines the quality of the retanning effect, which not only has important influence on the performance of finished leather, but also plays a role in playing a role in improving the quality and the grade of the finished leather. Therefore, various retanning agents have been developed in recent years. However, the existing retanning agents have poor using effect.

Disclosure of Invention

The invention aims to provide an environment-friendly dicyandiamide retanning agent, a preparation method and a system, and aims to solve the technical problem that the retanning agent in the prior art is poor in using effect.

In order to achieve the purpose, the environment-friendly dicyandiamide retanning agent adopted by the invention comprises the following raw materials in parts by mass:

40-60 parts of dicyandiamide, 20-30 parts of dimethyl phosphite, 10-16 parts of catalyst, 5-15 parts of acrylamide, 20-30 parts of acrylic acid, 10-12 parts of ethyl acrylate, 6-8 parts of glutaraldehyde, 10-12 parts of initiator and 10-12 parts of neutralizer.

The invention also provides a preparation method of the dicyandiamide retanning agent, which comprises the following steps:

mixing and heating dicyandiamide and dimethyl phosphite in preset parts by mass, then adding a catalyst, and mixing again to obtain a first mixed solution;

adding acrylamide in a preset mass part into the first mixed solution, and heating and mixing again to obtain a second mixed solution;

mixing acrylic acid and ethyl acrylate in preset parts by mass to form a fusion;

adding the fusion into the second mixed solution, uniformly stirring, and then adding glutaraldehyde to obtain a mixture;

and sequentially adding an initiator and a neutralizing agent into the mixture, and then heating and mixing to obtain the dicyandiamide retanning agent.

Wherein, in the step of mixing and heating dicyandiamide and dimethyl phosphite in preset parts by mass, then adding a catalyst, and mixing again to obtain a first mixed solution:

the heating temperature for mixing and heating dicyandiamide and dimethyl phosphite is 60-80 ℃.

Wherein, the catalyst is one or more of toluenesulfonic acid, sulfuric acid and boric acid.

Adding acrylamide in a preset mass part into the first mixed solution, and heating and mixing again to obtain a second mixed solution:

and adding acrylamide in a preset mass part into the first mixed solution, wherein the heating temperature is 100-120 ℃ when reheating is carried out.

Wherein, in the step of adding the initiator and the neutralizer into the mixture in sequence, and then heating and mixing to obtain the dicyandiamide retanning agent:

the initiator is one or more of azobisisobutyronitrile, azobisisoheptonitrile and cyclohexanone peroxide.

Wherein, in the step of adding the initiator and the neutralizer into the mixture in sequence, and then heating and mixing to obtain the dicyandiamide retanning agent:

the neutralizing agent is sodium hydroxide solution.

The invention also provides a system adopting the preparation method of the dicyandiamide retanning agent, which comprises a support, a first stirring assembly and a second stirring assembly, wherein the first stirring assembly and the second stirring assembly are both fixedly connected with the support, the first stirring assembly is positioned above the second stirring assembly, the first stirring assembly comprises a first shell, a first driving piece, a first rotating shaft and a first mixing part, the first shell is provided with a first feeding pipe and a first discharging pipe, the first driving piece is fixedly connected with the first shell and positioned above the first shell, one end of the first rotating shaft is fixedly connected with an output end of the first driving piece, the other end of the first rotating shaft is inserted into the first shell, the number of the first mixing parts is multiple, and each group of the first mixing parts comprises an upper inclined rod, The first rotating shaft is fixedly connected with the first inclined rod, one end of the first rotating shaft is fixedly connected with the first inclined rod, and the other end of the first rotating shaft is fixedly connected with the first inclined rod;

the second stirring component comprises a second shell, a second driving part, a second rotating shaft, a second mixing part, a heating part and a temperature tester, the second shell is provided with a second inlet pipe and a second outlet pipe, the second driving part is fixedly connected with the second shell and is positioned above the second shell, one end of the second rotating shaft is fixedly connected with the output end of the second driving part, the other end of the second rotating shaft is inserted into the second shell, the quantity of the second mixing part is multiple groups, each group of the second mixing part comprises a first rod body, a second rod body, a third rod body, the first rod body, the second rod body and the third rod body are sequentially arranged from top to bottom along the axial center line direction of the second rotating shaft, the length of the second rod body is greater than that of the first rod body and that of the third rod body, the length of the first rod body is equal to that of the third rod body, the heating member and the temperature tester are both disposed inside the second housing.

The invention has the beneficial effects that: mixing and heating dicyandiamide and dimethyl phosphite in preset parts by mass, then adding a catalyst, and mixing again to obtain a first mixed solution; adding acrylamide in a preset mass part into the first mixed solution, and heating and mixing again to obtain a second mixed solution; mixing acrylic acid and ethyl acrylate in preset parts by mass to form a fusion; adding the fusion into the second mixed solution, uniformly stirring, and then adding glutaraldehyde to obtain a mixture; and sequentially adding an initiator and a neutralizing agent into the mixture, and then heating and mixing to obtain the dicyandiamide retanning agent, wherein the dicyandiamide retanning agent can improve the fullness, softness and flame retardance of leather, and the using effect of the retanning agent is better.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a flow chart of the steps of embodiment 1 of the present invention.

FIG. 2 is a flow chart of the steps of embodiment 2 of the present invention.

FIG. 3 is a flowchart of the steps of embodiment 3 of the present invention.

Fig. 4 is a schematic structural view of a system for producing a dicyandiamide retanning agent of the present invention.

1-bracket, 2-first stirring component, 21-first shell, 211-first feeding pipe, 212-first discharging pipe, 22-first driving piece, 23-first rotating shaft, 24-first mixing part, 241-upper inclined rod, 242-lower inclined rod, 243-transverse rod, 244-vertical rod, 245-stirring piece, 3-second stirring component, 31-second shell, 312-second feeding pipe, 313-second discharging pipe, 32-second driving piece, 33-second rotating shaft, 34-second mixing part, 341-first rod body, 342-second rod body, 343-third rod body, 344-fixing rod, 35-heating part and 36-temperature tester.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships illustrated in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. Further, in the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

The dicyandiamide retanning agent comprises 40-60 parts of dicyandiamide, 20-30 parts of dimethyl phosphite, 10-16 parts of a catalyst, 5-15 parts of acrylamide, 20-30 parts of acrylic acid, 10-12 parts of ethyl acrylate, 6-8 parts of glutaraldehyde, 10-12 parts of an initiator and 10-12 parts of a neutralizer. The dicyandiamide retanning agent also comprises 5-7 parts of pentaerythritol, 6-8 parts of fatty amine and 6-8 parts of an emulsifier;

adding acrylamide in a preset mass part into the first mixed solution, and heating and mixing again to obtain a second mixed solution:

adding acrylamide in a preset mass part into the first mixed solution, heating and mixing again, adding pentaerythritol and fatty amine, and stirring and mixing to obtain a second mixed solution.

Adding an initiator and a neutralizing agent into the mixture in sequence, and then heating and mixing to obtain the dicyandiamide retanning agent, wherein the step of obtaining the dicyandiamide retanning agent comprises the following steps:

sequentially adding an initiator and a neutralizing agent into the mixture, then carrying out primary heating and mixing, standing for 10-12 min, and then heating and mixing again;

and standing and cooling after mixing and heating again, adding an emulsifier, and heating and mixing again to obtain the dicyandiamide retanning agent, wherein the emulsifier is fatty alcohol-polyoxyethylene ether sodium sulfate AES.

Example 1, referring to fig. 1, the present invention provides a method for preparing a dicyandiamide retanning agent, including the following steps:

s1: mixing and heating 40 parts of dicyandiamide and 20 parts of dimethyl phosphite, then adding 10 parts of toluenesulfonic acid, and mixing again to obtain a first mixed solution;

s2: adding 5 parts of acrylamide into the first mixed solution, heating and mixing again, adding 5 parts of pentaerythritol and 6 parts of aliphatic amine, and stirring and mixing to obtain a second mixed solution;

s3: mixing 20 parts acrylic acid and 10 parts ethyl acrylate to form a blend;

s4: adding the fusion into the second mixed solution, uniformly stirring, and then adding 6 parts of glutaraldehyde to obtain a mixture;

s5: and sequentially adding azodiisobutyronitrile and a sodium hydroxide solution into the mixture, then carrying out primary heating and mixing, then standing, then carrying out secondary heating and mixing, standing and cooling after carrying out secondary mixing and heating, then adding 6 parts of fatty alcohol-polyoxyethylene ether sodium sulfate AES, and carrying out secondary heating and mixing to obtain the dicyandiamide retanning agent.

In this embodiment, 40 parts of dicyandiamide and 20 parts of dimethyl phosphite are mixed and heated, the heating temperature is controlled to be 60 ℃, and then toluenesulfonic acid is added and mixed again to obtain a first mixed solution; adding 5 parts of acrylamide into the first mixed solution, heating at 100 ℃ after reheating and mixing, adding 5 parts of pentaerythritol and 6 parts of fatty amine, stirring and mixing to obtain a second mixed solution; mixing 20 parts acrylic acid and 10 parts ethyl acrylate to form a blend; adding the fusion into the second mixed solution, uniformly stirring, and then adding 6 parts of glutaraldehyde to obtain a mixture; the method comprises the steps of sequentially adding azodiisobutyronitrile and a sodium hydroxide solution into a mixture, then carrying out primary heating and mixing, then standing, then carrying out secondary heating and mixing, standing and cooling after carrying out secondary mixing and heating, then adding 6 parts of fatty alcohol-polyoxyethylene ether sodium sulfate AES, and carrying out secondary heating and mixing to obtain the dicyandiamide retanning agent.

Example 2, referring to fig. 2, the present invention provides a method for preparing a dicyandiamide retanning agent, including the following steps:

s1: mixing and heating 60 parts of dicyandiamide and 30 parts of dimethyl phosphite, then adding 16 parts of sulfuric acid, and mixing again to obtain a first mixed solution;

s2: adding 15 parts of acrylamide into the first mixed solution, heating and mixing again, adding 7 parts of pentaerythritol and 8 parts of aliphatic amine, and stirring and mixing to obtain a second mixed solution;

s3: mixing 30 parts acrylic acid and 12 parts ethyl acrylate to form a blend;

s4: adding the fusion into the second mixed solution, uniformly stirring, and then adding 8 parts of glutaraldehyde to obtain a mixture;

s5: sequentially adding azodiisoheptanonitrile and a sodium hydroxide solution into the mixture, then carrying out primary heating and mixing, then standing, then carrying out heating and mixing again, standing and cooling after heating and mixing again, then adding 8 parts of fatty alcohol-polyoxyethylene ether sodium sulfate AES, and carrying out heating and mixing again to obtain the dicyandiamide retanning agent.

In this embodiment, 60 parts of dicyandiamide and 30 parts of dimethyl phosphite are mixed and heated, the heating temperature is controlled to 80 ℃, and then sulfuric acid is added and mixed again to obtain a first mixed solution; adding 15 parts of acrylamide into the first mixed solution, heating at 120 ℃ after reheating and mixing, adding 7 parts of pentaerythritol and 8 parts of fatty amine, stirring and mixing to obtain a second mixed solution; mixing 30 parts acrylic acid and 12 parts ethyl acrylate to form a blend; adding the fusion into the second mixed solution, uniformly stirring, and then adding 8 parts of glutaraldehyde to obtain a mixture; the method comprises the steps of sequentially adding azodiisoheptanonitrile and a sodium hydroxide solution into a mixture, then carrying out primary heating and mixing, then standing, then carrying out secondary heating and mixing, standing and cooling after carrying out secondary mixing and heating, then adding 8 parts of fatty alcohol-polyoxyethylene ether sodium sulfate AES, and carrying out secondary heating and mixing to obtain the dicyandiamide retanning agent.

Example 3, referring to fig. 3, the present invention provides a method for preparing a dicyandiamide retanning agent, including the following steps:

s1: mixing and heating 50 parts of dicyandiamide and 25 parts of dimethyl phosphite, then adding 13 parts of boric acid, and mixing again to obtain a first mixed solution;

s2: adding 10 parts of acrylamide into the first mixed solution, heating and mixing again, adding 6 parts of pentaerythritol and 7 parts of aliphatic amine, and stirring and mixing to obtain a second mixed solution;

s3: mixing 25 parts acrylic acid and 11 parts ethyl acrylate to form a blend;

s4: adding the fusion into the second mixed solution, uniformly stirring, and then adding 7 parts of glutaraldehyde to obtain a mixture;

s5: and sequentially adding cyclohexanone peroxide and a sodium hydroxide solution into the mixture, then carrying out primary heating and mixing, then standing, then carrying out heating and mixing again, standing and cooling after mixing and heating again, then adding 7 parts of fatty alcohol-polyoxyethylene ether sodium sulfate AES, and carrying out heating and mixing again to obtain the dicyandiamide retanning agent.

In this embodiment, a first mixed solution is obtained by mixing and heating 50 parts of dicyandiamide and 25 parts of dimethyl phosphite at a heating temperature of 70 ℃, then adding boric acid, and mixing again; adding 10 parts of acrylamide into the first mixed solution, heating at 110 ℃ after reheating and mixing, adding 6 parts of pentaerythritol and 7 parts of fatty amine, stirring and mixing to obtain a second mixed solution; mixing 25 parts acrylic acid and 11 parts ethyl acrylate to form a blend; adding the fusion into the second mixed solution, uniformly stirring, and then adding 7 parts of glutaraldehyde to obtain a mixture; adding cyclohexanone peroxide and a sodium hydroxide solution into the mixture in sequence, then carrying out primary heating and mixing, then standing, heating and mixing again, standing and cooling after mixing and heating again, then adding 7 parts of fatty alcohol-polyoxyethylene ether sodium sulfate AES, and heating and mixing again to obtain the dicyandiamide retanning agent.

Referring to fig. 4, the present invention further provides a system adopting the above method for preparing a dicyandiamide retanning agent, including a bracket 1, a first stirring assembly 2 and a second stirring assembly 3, wherein the first stirring assembly 2 and the second stirring assembly 3 are both fixedly connected to the bracket 1, the first stirring assembly 2 is located above the second stirring assembly 3, the first stirring assembly 2 includes a first housing 21, a first driving member 22, a first rotating shaft 23 and a first mixing component 24, the first housing 21 is provided with a first feeding pipe 211 and a first discharging pipe 212, the first driving member 22 is fixedly connected to the first housing 21 and located above the first housing 21, one end of the first rotating shaft 23 is fixedly connected to an output end of the first driving member 22, the other end of the first rotating shaft 23 is inserted into the first housing 21, the number of the first mixing parts 24 is multiple, each group of the first mixing parts 24 includes an upper inclined rod 241, a lower inclined rod 242 and two cross rods 243, one end of each of the upper inclined rod 241 and the lower inclined rod 242 is fixedly connected with the first rotating shaft 23, and the other end of each of the upper inclined rod 241 and the lower inclined rod 242 is fixedly connected with two cross rods 243;

the second stirring assembly 3 includes a second casing 31, a second driving member 32, a second rotating shaft 33, a second mixing member 34, a heating member 35 and a temperature tester 36, the second casing 31 is provided with a second feeding pipe 312 and a second discharging pipe 313, the second driving member 32 is fixedly connected to the second casing 31 and is located above the second casing 31, one end of the second rotating shaft 33 is fixedly connected to an output end of the second driving member 32, the other end of the second rotating shaft 33 is inserted into the second casing 31, the number of the second mixing members 34 is multiple groups, each group of the second mixing members 34 includes a first rod 341, a second rod 342, a third rod 343, the first rod 341, the second rod 342 and the third rod 343, which are sequentially arranged from top to bottom along an axial center line direction of the second rotating shaft 33, the length of the second rod 342 is greater than that of the first rod 341 and the third rod 343, the length of the first rod 341 is equal to that of the third rod 343, and the heating member 35 and the temperature tester 36 are both disposed inside the second housing 31.

In this embodiment, dicyandiamide and dimethyl phosphite are put into the second housing 31, mixed by the second stirring component 3, then a catalyst is added, then mixed by the second stirring component 3, then acrylamide is added, then mixed by the second stirring component 3 again with stirring by the second stirring component 3 while being heated by the heating component 35 while being tested for a heating temperature in real time by the temperature tester 36, then a second mixed solution is obtained, acrylic acid and ethyl acrylate are mixed in the first housing 21 by the first stirring component 2 to form a fusion, the fusion sequentially enters the first discharging pipe 212 and the second feeding pipe 312 into the second housing 31, then the second stirring component 3 is operated again to mix the fusion with the second mixed solution, and then glutaraldehyde is added, and (3) obtaining a mixture, sequentially adding an initiator and a neutralizing agent into the mixture, and then heating and mixing again to obtain the dicyandiamide retanning agent. The arrangement of the upper inclined rod 241, the lower inclined rod 242 and the cross rod 243 can make the materials mixed more uniformly. The second rod 342 and the third rod 343 are arranged along the axial center line of the second rotating shaft 33 from top to bottom, so that the mixture in the second shell 31 is more sufficient, and in addition, the length of the second rod 342 is larger than that of the first rod 341 and the third rod 343, the length of the first rod 341 is equal to that of the third rod 343, so that the turbulence effect can be enhanced, and the mixture in the second shell 31 can be rapidly and uniformly mixed.

Further, each set of the first mixing parts 24 further includes a vertical rod 244, and both ends of the vertical rod 244 are respectively fixedly connected to the two cross rods 243 and located between the two cross rods 243. Each group of the first mixing parts 24 further includes a plurality of stirring pieces 245, the number of the stirring pieces 245 is multiple, and the stirring pieces 245 are uniformly arranged on the vertical rod 244.

In this embodiment, the vertical rod 244 and the stirring sheet 245 are arranged to mix the materials more uniformly, so as to improve the stirring effect of the first stirring assembly 2.

Further, each set of the second mixing part 34 further includes a plurality of fixing rods 344, and the fixing rods 344 are disposed on the first rod 341, the second rod 342 and the third rod 343.

In this embodiment, the fixing rod 344 is provided to enable the materials to be mixed more uniformly, so as to improve the stirring effect of the second stirring assembly 3.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.