Production line system and production process of low temperature curing powder

Abstract

The present invention relates to a low-temperature curing powder production line system and its production process, characterized in that the production line system includes a mixer, an extruder, a roller tablet press, a cyclone separator and a stirring tank which are sequentially configured according to the production process route. The production process includes: S1, low-temperature mixing; S2, low-temperature extrusion; S3, low-temperature tableting; S4, separation; S5, stirring; S6, low-temperature grinding. The present invention is modified on the basis of the existing powder coating production line equipment, so that the material temperature in each process node can be controlled and adjusted, and then it can be suitable for the production characteristics of low-temperature curing powder. Different temperature parameters are set in the process of mixing, extrusion and tableting, so that the material always maintains good properties on the above-mentioned process route, and finally the material meets the grinding requirements through the quenching process of first heating and then cooling in the stirring tank.

Description

Technical Field

[0001] The invention relates to the technical field of powder coating production, and in particular to a low-temperature curing powder production line system and a production process thereof. Background Art

[0002] Powder coatings are widely used in modern industrial production due to their advantages of economy, environmental protection, high efficiency and excellent performance, but some of their weaknesses are also obvious. For example, the curing conditions are relatively harsh, and the curing temperature is generally between 180 and 200 degrees Celsius. If the curing temperature can be lowered, energy consumption can be reduced, which is necessary for environmental protection, energy saving and emission reduction.

[0003] In addition to high energy consumption, high curing temperature also limits the coating of some substrates that cannot withstand high temperatures, such as plastics and wood, which greatly affects the expansion of powder coating applications. From the perspective of further improving efficiency, powder coatings that can often be cured at low temperatures can greatly shorten the curing time and improve production efficiency while keeping the temperature constant. Therefore, achieving low-temperature curing of powder coatings has become one of the development directions of the powder coating industry.

[0004] The current production line system for ordinary powder coatings is not suitable for low-temperature curing powder coatings and cannot achieve continuous production. After the material is extruded and crushed, it is in a molten and sticky state and cannot be directly ground into powder, which is not conducive to continuous production. In order to solve the problem of melt adhesion, the current conventional practice is to transfer the tableted and crushed material to a cold storage room for freezing. The freezing time is generally more than 10 hours. After freezing, it is transferred to the workshop for loading and grinding. This causes interruptions in production, making it impossible to achieve continuous production, which is time-consuming and labor-intensive, and greatly reduces production efficiency. Summary of the invention

[0005] The present invention aims to solve the various problems mentioned above, and further provide a production line system and production process of low-temperature curing powder. The structure of the low-temperature curing powder production line is designed for low-temperature curing powder, and combined with the corresponding production process, the industrial production of low-temperature curing powder is more efficient and energy-saving.

[0006] To solve the above problems, the technical solution adopted by the present invention is:

[0007] The special feature of the low temperature curing powder production line system is that it includes the following components that are configured in sequence according to the production process route:

[0008] A mixer, wherein the mixer has a material tank interlayer connected to an ice water machine, and ice water is passed into the material tank interlayer to reduce and cool the friction heat generated by the materials during the mixing and stirring process;

[0009] An extruder, wherein the outer screw sleeve and the inner core shaft of the extruder screw are connected to a water chiller, and ice water is introduced to extrude the material at a low temperature, and the length-to-diameter ratio of the screw of the extruder is 30:1;

[0010] A roller tablet press, wherein the roller of the roller tablet press is connected to a water chiller, and ice water is introduced to press the tablets into low-temperature tablets for output;

[0011] The cyclone separator separates the material after tableting. The separated tablets enter the mixing tank and the separated dust is removed.

[0012] A stirring tank is located at the lower discharge port of the cyclone separator, the stirring tank has an interlayer, and the interlayer is respectively connected to the ice water machine and the mold temperature controller. After the material pieces are left to stand for a period of time under a predetermined temperature condition in the stirring tank, they are sent to the grinding mill.

[0013] A production process of low temperature curing powder, which is special in that it includes the following steps:

[0014] S1, low temperature mixing

[0015] Put the materials into the material tank of the mixer. During the mixing process, ice water is introduced into the interlayer of the material tank through the ice machine to reduce and cool the friction heat generated by the materials during the mixing and stirring process. The premixing time is 5-8 minutes to ensure that the material temperature is less than or equal to 40 degrees;

[0016] S2, low temperature extrusion

[0017] The mixed material is fed into a screw extruder, the screw length-diameter ratio of the screw extruder is 30:1, the extrusion speed is 350-500r / min, the feeding speed is 25-32Hz, and the extruder temperature is set to: 38-42 degrees in zone 1, 52-58 degrees in zone 2, 52-58 degrees in zone 3, and 55-60 degrees in zone 4. The above parameter conditions are controlled to reduce the influence of a large amount of friction heat generated by the high speed of the traditional screw extruder on the material; during the extrusion process, ice water is introduced into the outer screw sleeve and the inner core shaft of the screw extruder through a water chiller, and finally the extrusion temperature is ensured to be a molten material block below 65 degrees;

[0018] S3, low temperature tableting

[0019] The material blocks extruded at low temperature enter the roller tablet press for crushing, and water is passed into the roller of the roller tablet press through the ice water machine to ensure that the output tablet temperature is below 10 degrees;

[0020] S4. Separation

[0021] The rolled pieces are sent to the cyclone separator via the elevator, the dust separated by the cyclone enters the dust removal process, and the pieces separated by the cyclone enter the mixing tank;

[0022] S5. Stirring

[0023] The sheet undergoes the first stage of heating and heat preservation and the second stage of cooling in the mixing tank, and is finally output to the grinding mill for subsequent grinding processing;

[0024] The first stage of heating and heat preservation: hot water is introduced into the interlayer of the material tank through the mold temperature controller to keep the material sheets inside the mixing tank at a temperature of 35-45 degrees for 2-3 hours;

[0025] The second stage of cooling: ice water is introduced into the interlayer of the material tank through a water chiller to reduce the temperature of the material pieces in the mixing tank to below 30 degrees;

[0026] S6, low temperature grinding

[0027] The material is sent to the grinding mill for grinding. The material temperature of the grinding mill is adjusted to 25-32 degrees, the main grinding speed is 25-30Hz, the auxiliary grinding speed is 13-18Hz, and the feeding speed is 18-23Hz. Under the above parameter conditions, the material is crushed into low-temperature solidified powder.

[0028] The production line system of the low-temperature curing powder of the present invention is based on the existing powder coating production line equipment, and the structures of the mixer, screw extruder and roller tablet press on the production line are modified to enable it to have a sandwich water-through structure that is matched with a water chiller, so that the material temperature in each process node is controllable and adjustable, and thus it can be suitable for the production characteristics of low-temperature curing powder. In addition, an additional stirring tank is configured in the production line system to heat and keep the tablets crushed by the roller tablet press in the stirring tank before entering the cooling and quenching process. In the production process of low-temperature curing powder, the material properties of the previous and subsequent processes and the influence of many factors such as operating temperature and time on the finished powder are comprehensively considered, and different temperature settings are made in mixing, extrusion, and tableting, respectively, so that the material always maintains good properties on the above-mentioned process route, and finally the material meets the grinding requirements through the quenching process of first heating and then cooling in the stirring tank, and can be directly ground.

[0029] When low-temperature curing powder is premixed, the premixing temperature is high. When it is higher than 40 degrees, the material is prone to pre-reaction, resulting in changes in the physical and chemical properties of the product. Therefore, the premixing process in the present application needs to ensure that the material temperature is below 40 degrees; during the extrusion process, once the temperature of the extrusion process is not well controlled, the product will gel, resulting in poor final coating performance. Therefore, the extrusion process of the present application is also low-temperature regulated; for conventional powder coatings, the tableting cooling temperature is generally around 40 degrees, and for low-temperature curing powder, when the tableting cooling temperature is higher than 10 degrees, the product will gel, resulting in poor product performance. In view of this characteristic of low-temperature curing powder, the tableting cooling temperature is specifically adjusted to below 10 degrees during the tableting process of the present application, thereby ensuring the normal production characteristics of the product; the material after cyclone separation enters the interior of the mixing tank to achieve material crystallization and change the product crushing performance (conventional products do not have this step); the powder is crushed at a low temperature to achieve the material temperature after the product is crushed, thereby avoiding the problem of product pre-reaction caused by high material temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 : Schematic diagram of the production line system structure of low temperature curing powder;

[0031] In the figure, 1. mixer, 2. screw extruder, 3. roller tablet press, 4. cyclone separator, 5. stirring tank, 6. dust removal box, 7. fan. DETAILED DESCRIPTION

[0032] The present invention will be described in detail below with reference to the accompanying drawings.

[0033] Embodiment 1

[0034] A low-temperature solidified powder production line system comprises a mixer 1, a screw extruder 2, a roller tablet press 3, a cyclone separator 4 and a stirring tank 5 which are sequentially configured according to a production process route, wherein the mixer 1 has a material tank interlayer connected to a water chiller, and ice water is passed through the material tank interlayer to control the material inside the material tank to complete mixing and stirring under a predetermined low temperature condition; the mixer 1 is subsequently connected to a screw extruder 2, and the outer screw sleeve and the inner core shaft of the screw extruder 2 are both connected to the water chiller, and ice water is passed through to extrude the material at a low temperature, and the screw length-to-diameter ratio of the screw extruder 2 is set to 30:1; a roller tablet press 3 is arranged at the lower part of the discharge port of the screw extruder 2, and the pressing roller of the roller tablet press 3 is provided with a water-passing interlayer, which is connected to the water chiller, and ice water is passed through to press the material into a low-temperature tablet for output; the roller The discharge port of the tablet press 3 is connected to the feed port of the cyclone separator 4 via a self-lifting pipeline. The cyclone separator 4 is used to separate the material after tableting. The smoke separated by the cyclone separator 4 enters the dust removal box 6 through the dust removal pipeline and is discharged by the fan 7 after dust removal. The broken pieces separated by the cyclone separator 4 enter the inside of the mixing tank 5 through the discharge port; the tank body of the mixing tank 5 is provided with an interlayer, and the interlayer space is connected to the mold temperature controller through a pipeline on the one hand, and the interlayer space is also connected to the ice water machine through a pipeline on the other hand. Through the connection with the mold temperature controller, high-temperature water can be introduced into the interlayer space, and through the connection with the ice water machine, low-temperature water can be introduced into the interlayer space, so as to control the water temperature inside the interlayer space, and then implement temperature regulation on the material inside the material tank. The sheet is kept warm for a period of time under the predetermined temperature conditions in the mixing tank 5 and then enters cooling and cooling. After the temperature drops to the predetermined temperature index, it is sent to the grinding mill for grinding.

[0035] Embodiment 2

[0036] A production process of low temperature curing powder is implemented based on the production line system of embodiment 1, and includes the following specific steps:

[0037] S1, low temperature mixing

[0038] Put the materials into the material tank of the mixer for premixing, and pass ice water into the interlayer of the material tank through the ice machine. Set the water outlet temperature of the ice machine to 14 degrees. The ice water in the interlayer of the material tank ensures that the materials in the tank are mixed at low temperature in the mixer, reducing the friction heat generated by the materials during the premixing process. The premixing time is controlled within 6 minutes, at which time the temperature of the materials in the tank is 30-35 degrees;

[0039] S2, low temperature extrusion

[0040] The premixed material enters the screw extruder, the screw length-diameter ratio of the screw extruder is 30:1, the extrusion speed is 380r / min, the feeding speed is 25Hz, and the extruder temperature is set to: 40 degrees in zone 1, 55 degrees in zone 2, 55 degrees in zone 3, and 60 degrees in zone 4. The above parameter conditions are controlled to reduce the influence of a large amount of friction heat generated by the high speed of the traditional screw extruder on the material; ice water is introduced into the outer screw sleeve and the inner core shaft of the screw extruder through a water chiller, and the water outlet temperature of the water chiller is 14 degrees, so as to finally ensure that the extrusion temperature is a molten material block below 65 degrees;

[0041] S3, low temperature tableting

[0042] The material blocks extruded at low temperature are sent to the roller tablet press for crushing and tableting. Water is passed into the roller interlayer of the roller tablet press through the ice water machine to ensure that the output sheet temperature is between 6-8 degrees;

[0043] S4. Separation

[0044] The rolled pieces are sent to the cyclone separator via the elevator, and the smoke and dust separated by the cyclone enter the dust removal process, and the pieces separated by the cyclone enter the mixing tank at the bottom;

[0045] S5. Stirring

[0046] The sheet undergoes the first stage of heating and heat preservation and the second stage of cooling in the mixing tank, and is finally output to the grinding mill for subsequent grinding processing;

[0047] The first stage of heating and heat preservation: hot water is introduced into the inner layer of the material tank through the mold temperature controller to keep the material sheets inside the mixing tank at a temperature of 40 degrees for 2 hours;

[0048] The second stage of cooling is to pass ice water into the inner layer of the material tank through the ice machine to reduce the temperature of the material pieces in the mixing tank to 22 degrees before discharging.

[0049] S6, Grinding

[0050] The material is sent to the grinding mill for grinding. The material temperature of the grinding mill is adjusted to 28 degrees, the main grinding speed is 28Hz, the auxiliary grinding speed is 15Hz, and the feeding speed is 20Hz. Under the above parameter conditions, the material is crushed into low-temperature solidified material powder.

[0051] Embodiment 3

[0052] A production process of low temperature curing powder is implemented based on the production line system of embodiment 1, and includes the following specific steps:

[0053] S1, low temperature mixing

[0054] Put the materials into the material tank of the mixer for premixing, and pass ice water into the interlayer of the material tank through the ice water machine. Set the outlet water temperature of the ice water machine to 12 degrees. The ice water in the interlayer of the material tank ensures that the materials in the tank are mixed at low temperature in the mixer, reducing the friction heat generated by the materials during the premixing process. The premixing time is controlled at 8 minutes, at which time the temperature of the materials in the tank is 28-32 degrees;

[0055] S2, low temperature extrusion

[0056] The premixed material enters the screw extruder, the screw length-diameter ratio of the screw extruder is 30:1, the extrusion speed is 360r / min, the feeding speed is 28Hz, and the extruder temperature is set to: 43 degrees in zone 1, 52 degrees in zone 2, 52 degrees in zone 3, and 58 degrees in zone 4. The above parameter conditions are controlled to reduce the influence of a large amount of friction heat generated by the high speed of the traditional screw extruder on the material; ice water is introduced into the outer screw sleeve and the inner core shaft of the screw extruder through a water chiller, and the water outlet temperature of the water chiller is 14 degrees, so as to finally ensure the extrusion of molten material blocks;

[0057] S3, low temperature tableting

[0058] The material blocks extruded at low temperature are sent to the roller tablet press for crushing and tableting. Water is passed into the roller interlayer of the roller tablet press through the ice water machine to ensure that the output sheet temperature is between 5-7 degrees;

[0059] S4. Separation

[0060] The rolled pieces are sent to the cyclone separator via the elevator, and the smoke and dust separated by the cyclone enter the dust removal process, and the pieces separated by the cyclone enter the mixing tank at the bottom;

[0061] S5. Stirring

[0062] The sheet undergoes the first stage of heating and heat preservation and the second stage of cooling in the mixing tank, and is finally output to the grinding mill for subsequent grinding processing;

[0063] The first stage of heating and heat preservation: hot water is introduced into the inner layer of the material tank through the mold temperature controller to keep the material sheets inside the mixing tank at a temperature of 35 degrees for 3 hours;

[0064] The second stage of cooling is to pass ice water into the inner layer of the material tank through the ice water machine to reduce the temperature of the material pieces in the mixing tank to 25 degrees before discharging.

[0065] S6, Grinding

[0066] The material is sent to the grinding mill for grinding. The material temperature of the grinding mill is adjusted to 30 degrees, the main grinding speed is 30Hz, the auxiliary grinding speed is 18Hz, and the feeding speed is 20Hz. Under the above parameter conditions, the material is crushed into low-temperature solidified powder.

[0067] Embodiment 4

[0068] The difference between this embodiment and the second and third embodiments is that the process parameters used are as follows:

[0069]

[0070] The low temperature curing powder obtained in the above example was tested, and its performance data is tabulated as follows:

[0071]

[0072] The above measurement data show that the low-temperature curing powder obtained by the low-temperature curing powder production line system and production process of the present invention can meet the requirements of various physical and chemical indicators, which fully proves that the production line system and production process are very suitable for the industrial production of low-temperature curing powder.

Claims

1. Low temperature curing powder production line system, characterized in that: Including the following configurations in sequence according to the production process route: A mixer, wherein the mixer has a material tank interlayer connected to a water chiller, and ice water is passed into the material tank interlayer to reduce the friction heat generated by the materials during the mixing process; An extruder, wherein the outer screw sleeve and the inner core shaft of the extruder screw are connected to a water chiller, and ice water is introduced to extrude the material at a low temperature, and the length-to-diameter ratio of the screw of the extruder is 30:1; A roller tablet press, wherein the roller of the roller tablet press is connected to a water chiller, and ice water is introduced to press the tablets into low-temperature tablets for output; The cyclone separator separates the material after tableting. The separated tablets enter the mixing tank, and the separated smoke and dust are subjected to subsequent dust removal treatment; A stirring tank is located at the lower discharge port of the cyclone separator, the stirring tank has an interlayer, and the interlayer is respectively connected to the ice water machine and the mold temperature controller. After the material pieces are left to stand for a period of time under a predetermined temperature condition in the stirring tank, they are sent to the grinding mill.

2. A production process for low temperature curing powder, characterized in that: The following steps are involved: S1, low temperature mixing Put the materials into the material tank of the mixer. During the mixing process, ice water is introduced into the interlayer of the material tank through the ice water machine to reduce and cool the friction heat generated by the materials during the mixing and stirring process to ensure that the material temperature is less than or equal to 40°C; S2, low temperature extrusion The mixed materials are fed into the screw extruder. During the extrusion process, ice water is introduced into the outer screw sleeve and inner core shaft of the screw extruder through a water chiller to ensure that the extrusion temperature is a molten material block below 65°C. S3, low temperature tableting The material blocks extruded at low temperature enter the roller tablet press for crushing, and water is passed into the roller of the roller tablet press through the ice water machine to ensure that the output tablet temperature is below 10℃; S4. Separation The rolled pieces are sent to the cyclone separator via the elevator, the dust separated by the cyclone enters the dust removal process, and the pieces separated by the cyclone enter the mixing tank; S5. Stirring The sheet undergoes the first stage of heating and heat preservation and the second stage of cooling in the mixing tank, and is finally output to the grinding mill for subsequent grinding processing; S6, low temperature grinding The material is crushed into low-temperature solidified powder by a grinding machine.

3. A process for producing a low temperature curing powder as claimed in claim 2, characterized in that: In the step S1 of low temperature mixing, the premixing time is 5-8 minutes.

4. A process for producing a low temperature curing powder as claimed in claim 2, characterized in that: In the low-temperature extrusion of step S2, the screw extruder has a screw length-to-diameter ratio of 30:1, an extrusion speed of 350-500 r / min, a feeding rate of 25-32 Hz, and an extruder temperature setting of 38-42°C in zone 1, 52-58°C in zone 2, 52-58°C in zone 3, and 55-60°C in zone 4.

5. A process for producing a low temperature curing powder as claimed in claim 2, characterized in that: In step S5, stirring; The first stage of heating and heat preservation: hot water is introduced into the inner layer of the material tank through the mold temperature controller, so that the material sheets in the mixing tank are kept warm at a temperature of 35-45°C for 2-3 hours; The second stage of cooling is to introduce ice water into the interlayer of the material tank through an ice water machine to reduce the temperature of the material pieces in the mixing tank to below 30°C.

6. A process for producing a low temperature curing powder as claimed in claim 2, characterized in that: In the step S6 of low temperature grinding, the material temperature of the grinding mill is 25-32° C., the main grinding speed is 25-30 Hz, the auxiliary grinding speed is 13-18 Hz, and the feeding speed is 18-23 Hz.

Images