CN109605598B

CN109605598B - Preparation process of powder coating

Info

Publication number: CN109605598B
Application number: CN201811564712.0A
Authority: CN
Inventors: 宋小阳
Original assignee: Chongqing Qicaihong New Material Technology Co ltd
Current assignee: Chongqing Qicaihong New Material Technology Co ltd
Priority date: 2018-12-20
Filing date: 2018-12-20
Publication date: 2020-11-24
Anticipated expiration: 2038-12-20
Also published as: CN109605598A

Abstract

The invention belongs to the technical field of powder coating preparation, and particularly discloses a preparation process of a powder coating, which comprises the following steps of (1) preparing raw materials; (2) pre-melting, namely melting the raw materials treated in the step (1) through melting equipment at each stage; (3) premixing: gradually adding a plurality of molten raw materials into a mixing device according to a proportion, and stirring and mixing while adding the raw materials; (4) extruding; (5) tabletting; (6) crushing; (7) removing impurities; (8) and (4) grading, namely grading the materials by using a screening device to obtain finished products and packaging. Compared with powder premixing, the premixing of the raw materials in the molten state in the scheme is more uniform, so that the components in each prepared powder coating particle are the same, and the quality of the powder coating is ensured.

Description

Preparation process of powder coating

Technical Field

The invention belongs to the technical field of powder coating preparation, and particularly relates to a preparation process of a powder coating.

Background

The powder coating is a formula material which is obtained by taking a novel material as a base material and matching with pigment and filler, is a novel decorative material which is rapidly developed in recent years, has the characteristics of energy conservation, no pollution, high efficiency, high performance, environmental protection and the like, and has high coating efficiency and good corrosion resistance as a solvent-free coating, can form a film once, is convenient to store and transport, and is increasingly popular with people. The preparation process of the existing powder coating mainly comprises the following steps of weighing raw materials → premixing → melt extrusion → tabletting → coarse crushing → fine crushing → grading → packaging, wherein the premixing process is to stir and mix powdery base materials, fillers and pigments, the melt extrusion process is to melt and extrude the mixed raw materials, and the raw materials are mixed together in the melt extrusion process, so that the melting temperature of equipment has to reach the temperature required by the material with the highest melting point in the raw materials, and the temperature is already higher than the melting points of other materials, thereby causing the waste of energy and even destroying the characteristics of certain materials; meanwhile, the premixing of the powder raw materials cannot ensure the uniformity of the raw material mixing, so that the uniformity of the mixed raw materials in the extruder cannot be well ensured.

Disclosure of Invention

The invention aims to provide a preparation process of a powder coating, which aims to solve the problems of energy waste and uneven material mixing.

In order to achieve the purpose, the basic scheme of the invention is as follows: a preparation process of powder coating comprises the following steps of (1) preparing raw materials: respectively weighing the base material, the filler and the auxiliary agent, and then respectively grinding the base material, the filler and the auxiliary agent through grinding equipment; (2) pre-melting: melting the raw materials treated in the step (1) by using melting equipment at all levels, wherein the temperature and the time of the melting equipment at all levels are set according to the melting points and the different melting temperature maintenance of the raw materials in the treatment process; (3) premixing: gradually adding a plurality of molten raw materials into a mixing device according to a proportion, and stirring and mixing while adding the raw materials; (4) extruding: processing the raw materials mixed in the step (3) through an extruder; (5) tabletting: pressing the material extruded in the step (4) into slices by using a tablet press; (6) crushing: grinding the flake material by grinding equipment; (7) removing impurities: removing impurities and coarse powder from the material treated in the step (6) through a dust separation device, and removing dust through a dust removal device; (8) grading: and grading the materials by using a screening device to obtain a finished product and packaging.

The beneficial effect of this basic scheme lies in: in the scheme, the step (2) pre-melts the raw materials respectively, and the temperature and time of each stage of melting equipment are set according to the melting points of the raw materials and the difference of the temperature of the molten state, so that the problem of energy waste caused by the fact that the raw materials need to reach higher temperature when being mixed together for melting can be avoided, and the production cost can be greatly saved in the long-term production process. Then, on the basis of the step (2), several raw materials in a molten state are gradually added into a mixing device in proportion to be mixed, so that the premixing of the raw materials in the molten state is more uniform compared with the premixing of powder, the components in each prepared powder coating particle are the same, and the quality of the powder coating is ensured.

Further, the base material is resin.

Furthermore, the dust separation device is a cyclone separator, so that the separation effect is good, and the production quality is ensured.

Furthermore, the dust removal device is a bag-type dust remover, so that the dust removal effect is good, and a better production environment can be maintained.

Furthermore, the screening device is a vibration grading screen, so that the grading effect is good, the blockage is not easy to happen, and the operation is smooth.

Drawings

FIG. 1 is a longitudinal sectional view of a crushing apparatus in an embodiment;

FIG. 2 is a cross-sectional view A-A of FIG. 1;

fig. 3 is a schematic diagram of the matching of the incomplete gear and the first rack in the embodiment.

Detailed Description

The following is further detailed by way of specific embodiments:

reference numerals in the drawings of the specification include: crushing barrel 1, feeder hopper 2, first grinding roller 3, fixed scraper 4, activity scraper 5, baffle 6, screen cloth 7, spring 8, first guide block 9, link board 10, pivot 11, second grinding roller 12, transfer hopper 13, first rack 14, connecting piece 15, incomplete gear 16, backplate 17, second rack 18, second gear 19, second guide block 20.

A preparation process of a powder coating comprises the following steps:

(1) preparing raw materials: respectively weighing the resin, the filler and the auxiliary agent, and then respectively grinding the resin, the filler and the auxiliary agent through grinding equipment;

(2) pre-melting: melting the raw materials treated in the step (1) by using melting equipment at all levels, wherein the temperature and the time of the melting equipment at all levels are set according to the melting points and the different melting temperature maintenance of the raw materials in the treatment process;

(3) premixing: gradually adding a plurality of molten raw materials into a mixing device according to a proportion, and stirring and mixing while adding the raw materials;

(4) extruding: processing the raw materials mixed in the step (3) through an extruder;

(5) tabletting: pressing the material extruded in the step (4) into slices by using a tablet press;

(6) crushing: grinding the flake material by grinding equipment;

(7) removing impurities: removing impurities and coarse powder from the material treated in the step (6) through a cyclone separator, and removing dust through a bag-type dust remover;

(8) grading: and (5) grading the materials by using a vibration grading sieve to obtain a finished product and packaging.

In the scheme, the step (2) pre-melts the raw materials respectively, and the temperature and time of each stage of melting equipment are set according to the melting points of the raw materials and the difference of the temperature of the molten state, so that the problem of energy waste caused by the fact that the raw materials need to reach higher temperature when being mixed together for melting can be avoided, and the production cost can be greatly saved in the long-term production process. Then, on the basis of the step (2), several raw materials in a molten state are gradually added into a mixing device in proportion to be mixed, so that the premixing of the raw materials in the molten state is more uniform compared with the premixing of powder, the components in each prepared powder coating particle are the same, and the quality of the powder coating is ensured.

The crushing device in the step (1) is basically as shown in the attached drawings 1 and 2, and specifically comprises a crushing barrel 1, wherein the crushing barrel 1 is a square barrel body, and a crushing part is arranged in the crushing barrel 1. The crushing part comprises two first grinding rollers 3 which are arranged in the crushing barrel 1 in parallel, the two first grinding rollers 3 are rotatably arranged on the side wall of the crushing barrel 1, and a grinding gap is arranged between the two first grinding rollers 3. Be equipped with two first grinding roller 3 pivoted power supplies in opposite directions of drive on the outside lateral wall of crushing bucket 1, the power supply is the motor in this embodiment, and the output shaft of motor passes through the shaft coupling with one of them first grinding roller 3's roller and links to each other, is equipped with a pair of meshed drive gear on two first grinding roller 3's the roller, and the during operation, the motor starts to drive two first grinding roller 3 through drive gear and rotates in opposite directions. Be equipped with feeder hopper 2 on the 1 roof of crushing bucket, feeder hopper 2 is big-end-up's taper, and the middle part of feeder hopper 2 welds on 1 roof of crushing bucket, and the lower extreme opening of feeder hopper 2 is located two first grinding gaps between the roller 3 directly over.

Still be equipped with the screening portion in smashing bucket 1, screening portion is including installing screen cloth 7 in smashing bucket 1, and is specific for, and the equal fixed mounting in four sides of screen cloth 7 has baffle 6, has all seted up vertical first guide way on smashing 1 four lateral walls of bucket, be equipped with on the baffle 6 with first guide way sliding fit's first guide block 9, be equipped with spring 8 between first guide block 9 and the first guide way bottom. The screen 7 is positioned below the first grinding roller 3, the screen 7 is a precision screen 7 made of hard metal, and the mesh of the screen 7 can pass through materials meeting the specification.

Two first chutes of level have been seted up on crushing barrel 1 lateral wall, two first chutes are located the upper and lower both sides of first grinding roller 3 roller respectively, equal slidable mounting has first rack 14 in two first chutes, as shown in fig. 3, the teeth of a cogwheel orientation of two first racks 14 is relative, both ends all weld as a whole through connecting piece 15 about two first racks 14, fixed mounting has incomplete gear 16 on the left first grinding roller 3 roller, incomplete gear 16 can mesh with two first racks 14. All seted up the second spout on crushing barrel 1's the front and back lateral wall, the second spout is located the below of first spout, and slidable mounting has grinding portion between two second spouts, and grinding portion includes transfer hopper 13, and both sides all are equipped with the slider with second spout sliding fit around the transfer hopper 13. The transfer hopper 13 is tapered with a wide top and a narrow bottom, and is located right below the grinding gap between the two first grinding rollers 3. The upper end of the transfer hopper 13 is fixed to the first rack 14 on the lower side, and the upper end opening of the transfer hopper 13 is always located below the grinding gap in the process of moving in the second chute. The transfer hopper 13 has a lower opening spaced from the screen 7 to allow material to fall from the transfer hopper 13 onto the screen 7. The equal fixed mounting in both sides has backplate 17 around the transfer hopper 13, rotates between two backplate 17 to install two pivot 11, and two pivot 11 are located the transfer hopper left and right sides respectively, and the equal fixedly connected with in pivot 11 both ends links board 10, links board 10 both ends for the 11 symmetries of pivot, links board 10 and is located backplate 17 inboardly, and two of homonymy link all rotate between the both ends of board 10 and install second grinding roller 12. The front and rear side walls of the crushing barrel 1 are fixedly provided with second racks 18, and both ends of the rotating shaft 11 are fixedly provided with second gears 19 engaged with the second racks 18. Both ends all are equipped with the scraper subassembly about two backplate 17, scrape the material subassembly and include fixed scraper blade 4 and activity scraper blade 5, and fixed scraper blade 4 fixed mounting is between two backplate 17, and second guide way has all been seted up to activity scraper blade 5 and fixed scraper blade 4 slidable mounting, the inboard of two front and back baffles 6, be equipped with on the activity scraper blade 5 with second guide way sliding fit's second guide block 20, the lower extreme and the screen cloth 7 contact of activity scraper blade 5. In the initial state, the screen 7 is pressed against the fixed scraper 4 or the second grinding roller 12 under the action of the spring 8, and the lower second grinding roller 12 is positioned below the lower edge of the fixed scraper 4 when the connecting plate 10 is in the vertical state.

During the use, starter motor drives two first grinding roller 3 through drive gear and rotates in opposite directions, then adds the material gradually in feeder hopper 2, and the material falls into along feeder hopper 2 and grinds in the clearance to first grinding roller 3 grinds the material. Since the upper end opening of the transfer hopper 13 is located below the grinding gap, the material ground by the first grinding roller 3 falls into the transfer hopper 13, and then the material falls onto the screen 7 along the transfer hopper 13. The material that the particle size accords with the specification after grinding can fall to crushing barrel 1 bottom through the sieve mesh, still has simultaneously that partial too big material of particle size can't pass through the sieve mesh and stay on screen cloth 7.

In the process of grinding the material by the first grinding roller 3, the first grinding roller 3 rotates to drive the incomplete gear 16 to rotate, and the incomplete gear 16 rotates to intermittently mesh with the two first racks 14, so that the first racks 14 are driven to move left and right in a reciprocating manner. Since the upper end of the transfer hopper 13 is fixed to the first rack 14 on the lower side, the transfer hopper 13 reciprocates in the left-right direction along with the first rack 14, and the guard plate 17 and the fixed scraper 4 fixed to the transfer hopper 13 also reciprocate in the left-right direction. Because the front and rear side walls of the crushing barrel 1 are fixedly provided with the second rack 18, and the two ends of the rotating shaft 11 are fixedly provided with the second gear 19 meshed with the second rack 18, the rotating shaft 11 can rotate in a reciprocating manner under the action of the second gear 19 and the second rack 18 in the reciprocating left and right movement process. The rotating shaft 11 rotates to drive the connecting plate 10 to rotate, so as to drive the second grinding roller 12 to revolve around the rotating shaft 11, and as the screen 7 abuts against the fixed scraper 4 or the second grinding roller 12 under the action of the spring 8 in the initial state, the second grinding roller 12 can contact with the screen 7 in the process of revolving around the rotating shaft 11 and downwards extrude the screen 7, so that the screen 7 moves downwards. And the second grinding roller 12 can rotate under the action of friction force while revolving round, so that the second grinding roller 12 can grind the materials on the screen 7 again, and the second grinding roller 12 can grind the materials repeatedly in the reciprocating motion process of the transfer hopper 13, so that the particle size of the materials reaches the standard. In the process, the lower end of the movable scraper 5 is always in contact with the screen 7, so that the movable scraper 5 can prevent the material from falling out of the movable range of the second grinding roller 12; meanwhile, the movable scraper 5 can collect materials on two sides of the screen 7 to the middle part, so that the grinding effect is enhanced; and the movable scraper 5 can also clean the screen 7 when moving, so that the screen 7 is prevented from being blocked by materials. When the second grinding roller 12 is contacted with the screen 7 under the action of the spring 8, a large relative acting force exists between the second grinding roller 12 and the screen 7, and the grinding effect of the second grinding roller 12 on the materials can be ensured through the acting force; and the screen 7 can be lifted through the spring 8, so that the falling of the materials can be further accelerated, and the materials are prevented from blocking the screen 7.

The foregoing is merely an example of the present invention and common general knowledge of known specific structures and features of the embodiments is not described herein in any greater detail. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several changes and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.

Claims

1. A preparation process of powder coating is characterized by comprising the following steps: the method comprises the following steps of (1) preparing raw materials: respectively weighing the base material, the filler and the auxiliary agent, and then respectively grinding the base material, the filler and the auxiliary agent through grinding equipment; (2) pre-melting: melting the raw materials treated in the step (1) by using melting equipment at all levels, wherein the temperature and the time of the melting equipment at all levels are set according to the melting points and the different melting temperature maintenance of the raw materials in the treatment process; (3) premixing: gradually adding a plurality of molten raw materials into a mixing device according to a proportion, and stirring and mixing while adding the raw materials; (4) extruding: processing the raw materials mixed in the step (3) through an extruder; (5) tabletting: pressing the material extruded in the step (4) into slices by using a tablet press; (6) crushing: grinding the flake material by grinding equipment; (7) removing impurities: removing impurities and coarse powder from the material treated in the step (6) through a dust separation device, and removing dust through a dust removal device; (8) grading: grading the materials by using a screening device to obtain a finished product and packaging;

the crushing equipment comprises a crushing barrel, a crushing part is arranged in the crushing barrel, the crushing part comprises two first grinding rollers which are arranged in the crushing barrel side by side, the two first grinding rollers are rotatably arranged on the side wall of the crushing barrel, a grinding gap is formed between the two first grinding rollers, a power source for driving the two first grinding rollers to rotate oppositely is arranged on the outer side wall of the crushing barrel, the power source is a motor, an output shaft of the motor is connected with a roller shaft of one of the first grinding rollers, a pair of meshed transmission gears are arranged on the roller shafts of the two first grinding rollers, the motor is started to drive the two first grinding rollers to rotate oppositely through the transmission gears, a feeding hopper is arranged on the top wall of the crushing barrel, and an opening at the lower end of the feeding hopper is positioned right above the grinding gap;

the grinding device is characterized in that a screening part is further arranged in the grinding barrel, the screening part comprises a screen installed in the grinding barrel, baffles are fixedly installed on four sides of the screen, vertical first guide grooves are formed in four side walls of the grinding barrel, first guide blocks in sliding fit with the first guide grooves are arranged on the baffles, springs are arranged between the first guide blocks and the bottoms of the first guide grooves, two horizontal first slide grooves are formed in the side walls of the grinding barrel, the two first slide grooves are respectively located on the upper side and the lower side of a first grinding roller shaft, first racks are installed in the two first slide grooves in a sliding mode, an incomplete gear is fixedly installed on the first grinding roller shaft on the left side, and the incomplete gear can be meshed with the two first racks; the front side wall and the rear side wall of the crushing barrel are respectively provided with a second sliding groove, the second sliding grooves are positioned below the first sliding grooves, a grinding part is arranged between the two second sliding grooves in a sliding manner, the grinding part comprises a transfer hopper, sliding blocks in sliding fit with the second sliding grooves are arranged on the front side and the rear side of the transfer hopper, an upper end opening of the transfer hopper is always positioned below a grinding gap in the process of moving in the second sliding grooves, an interval is reserved between a lower end opening of the transfer hopper and a screen mesh, guard plates are fixedly arranged on the front side and the rear side of the transfer hopper, two rotating shafts are rotatably arranged between the two guard plates and are respectively positioned on the left side and the right side of the transfer hopper, two ends of each rotating shaft are fixedly connected with a connecting plate, two ends of each connecting plate are symmetrical relative to the corresponding rotating;

the front side wall and the rear side wall of the crushing barrel are both fixedly provided with a second rack, both ends of the rotating shaft are both fixedly provided with a second gear meshed with the second rack, both the left end and the right end of the two guard plates are both provided with a scraping component, the scraping component comprises a fixed scraper and a movable scraper, the fixed scraper is fixedly arranged between the two guard plates, the movable scraper is slidably arranged with the fixed scraper, the inner sides of the front baffle and the rear baffle are both provided with a second guide groove, the movable scraper is provided with a second guide block in sliding fit with the second guide groove, and the lower end of the movable scraper is contacted with the screen mesh; in the initial state, the screen props against the fixed scraper or the second grinding roller under the action of the spring, and the second grinding roller below the connecting plate is positioned below the lower edge of the fixed scraper when the connecting plate is in the vertical state.

2. The process for preparing a powder coating according to claim 1, wherein: the base material is resin.

3. A process for the preparation of a powder coating according to claim 2, characterized in that: the dust separating device is a cyclone separator.

4. A process for the preparation of a powder coating according to claim 3, characterized in that: the dust removing device is a bag-type dust remover.

5. The process according to claim 4, wherein: the screening device is a vibration grading screen.