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CN-122008431-A - Melamine resin powder toughening granulation method and granulation equipment thereof

CN122008431ACN 122008431 ACN122008431 ACN 122008431ACN-122008431-A

Abstract

The application provides a melamine resin powder toughening granulation method and granulation equipment thereof, which relate to the technical field of thermosetting resin and comprise the following preparation processes that firstly, thermoplastic resin powder is added into a solvent to prepare a thermoplastic resin solution; coating inorganic rigid particles with thermoplastic resin solution to obtain a mixture, spray-drying the mixture, grinding the mixture into superfine powder, mixing the superfine powder with melamine powder to obtain composite particles, adding carboxymethyl cellulose and zinc stearate into the composite particles, performing twin-roll compression by a granulator to obtain lamellar materials, crushing and granulating the lamellar materials to obtain particles, sieving a particle screen to obtain finished particles, and re-granulating the unqualified materials until qualified uniform melamine resin particles are obtained. The obtained granules have good uniformity when being used for compression molding products on the basis of improving toughness and fluidity through the technical improvement of three steps of coating, spray drying and grinding.

Inventors

  • CUI WEI
  • YANG GUANXING
  • SUN WEILEI
  • SUN HAIPENG
  • Pan Yangqian

Assignees

  • 安徽绿之态秸秆制品有限公司

Dates

Publication Date
20260512
Application Date
20231230

Claims (10)

  1. 1. The melamine resin powder toughening granulation method is characterized by comprising the following steps of: firstly, adding thermoplastic resin powder into a solvent, and stirring until the thermoplastic resin powder is fully dissolved to obtain a thermoplastic resin solution, wherein the raw materials comprise, by weight, 1 part of thermoplastic resin powder and 5-10 parts of solvent; Uniformly wrapping the thermoplastic resin solution obtained in the step one on the surfaces of inorganic rigid particles to obtain a rigid and flexible combined mixture, wherein the mixture ratio of the raw materials is, by weight, 4-8 parts of the thermoplastic resin solution and 5-10 parts of the inorganic rigid particles; step three, spray drying the mixture obtained in the step two, grinding into superfine powder, and uniformly mixing with melamine powder to obtain composite particle materials, wherein the raw materials are 1-3 parts by weight of the mixture and 10-20 parts by weight of the melamine powder; step four, adding carboxymethyl cellulose and zinc stearate into the composite particle material obtained in the step three, then putting the composite particle material into granulating equipment, and performing twin-roll pressing to obtain a lamellar material, wherein the raw materials comprise, by weight, 80-100 parts of the composite particle material, 0.5-1 part of carboxymethyl cellulose and 1-2 parts of zinc stearate; crushing the flake material prepared in the step four by using a crusher, and then finishing granules by using a finishing machine to obtain granules; step six, screening the particles obtained in the step five by using a screen to obtain finished product particles; And step seven, returning the unqualified powder or particles obtained after sieving in the step six to the step four for granulation until all the particles are finally granulated into qualified uniform melamine resin particles, thereby realizing toughening granulation of the melamine resin powder.
  2. 2. The method for toughening and granulating melamine resin powder according to claim 1, wherein the thermoplastic resin in the first step is polystyrene.
  3. 3. The method for toughening and granulating melamine resin powder according to claim 1, wherein the solvent in the first step is toluene.
  4. 4. The method for toughening and granulating melamine resin powder according to claim 1, wherein the inorganic rigid particles in the second step are at least one of nano-scale silica, alumina and montmorillonite.
  5. 5. The method for toughening and granulating melamine resin powder according to claim 1, wherein the particle size of the superfine powder in the third step is 0.1-8 μm, and the particle size of the melamine powder is 0.1-50 μm.
  6. 6. The method for toughening and granulating melamine resin powder according to claim 1, wherein the granulating equipment in the fourth step adopts a twin-roll dry extrusion granulator.
  7. 7. The method for toughening and granulating melamine resin powder according to claim 1, wherein in the step four, the pressure of the twin-roll pressing is 5-15MPa.
  8. 8. The method for toughening and granulating melamine resin powder according to claim 1, wherein the particle size of the finished product particles in the step six is 2-6mm.
  9. 9. A melamine resin powder toughening granulation device, which is suitable for the melamine resin powder toughening granulation method according to any one of claims 1-8, and comprises a granulation assembly (2) for granulating melamine resin powder and a collecting hopper (6) arranged at the top end of the granulation assembly (2), wherein the collecting hopper (6) and the granulation assembly (2) are detachably arranged; The top of collecting hopper (6) is equipped with protection section of thick bamboo (3), protection section of thick bamboo (3) are hollow structure, the one end of protection section of thick bamboo (3) is equipped with limiting plate (5), protection section of thick bamboo (3) are pegged graft inside collecting hopper (6), limiting plate (5) are located the upper surface wall of collecting hopper (6), are used for right protection section of thick bamboo (3) are spacing.
  10. 10. The melamine resin powder toughening granulation equipment according to claim 9, characterized in that the granulation component (2) comprises a granulation box (7) connected with the collecting hopper (6), a plurality of blanking holes (11) are formed in the granulation box (7), a roll shaft (12) is arranged on the upper surface of the inner wall of the granulation box (7), a blanking box (8) is arranged at the bottom end of the granulation box (7), a connecting seat (9) is arranged at the bottom end of the blanking box (8), a starting key (10) is arranged on the side wall of the granulation component (2), a discharging plate (4) is arranged on the side wall of the starting key (10), a base (1) is arranged at the bottom end of the granulation component (2), and a motor is arranged in the base (1) and used for driving the roll shaft (12) to rotate.

Description

Melamine resin powder toughening granulation method and granulation equipment thereof Technical Field The invention relates to the technical field of thermosetting resin, in particular to a melamine resin powder toughening granulation method and granulation equipment thereof. Background Thermosetting plastics are plastics which are formed into products by a cross-linking and curing process by taking thermosetting resin as a main component and combining various necessary additives. At present, thermosetting plastics are widely used in the fields of manufacturing reinforced plastics, foamed plastics, molding compounds for various electricians, casting products, adhesives, coatings and the like. However, with the increasing strict national requirements on safety and environmental protection, when thermosetting resin is used as a raw material, dust pollution is easily caused due to the powder characteristics, so that the 'powder product granulation' has become a necessary trend of the development of powder post-treatment technology, and the 'powder granulation technology' has important significance for reducing the dust pollution, improving the physical properties of products and meeting the requirements of production processes. The powder granulating technology refers to the process engineering of preparing powder raw materials into solid particles with certain shape and size and good fluidity. The powdery melamine resin is easy to generate dust in the process of mould pressing and the like, so that the pollution of processing environment and the inconvenience in use are caused, and therefore, the powdery melamine resin needs to be prepared into particles in advance, so that the further processing and the use are convenient. However, melamine resins, as thermosetting plastics, cannot be extrusion pelletized by a high temperature hot melt method, and therefore, pelletization at a relatively low temperature or room temperature is required. Currently, conventional powder granulation techniques include wet granulation, boiling granulation, pressure forming granulation, spray granulation, hot melt forming, and the like. Although the existing granulation technology is mature, the self-characteristics of melamine resin cause the toughness to be poor after granulation, and the service performance of the melamine resin is affected. Aiming at the problem of poor toughness of thermosetting melamine resin after granulation, a certain toughening method is adopted, so that the method has important significance. The traditional thermosetting resin toughening method mainly comprises the steps of filling rigid inorganic particles, modifying rubber elastomer, blending and modifying thermoplastic resin, mutually penetrating network polymers, modifying liquid crystal polymers and the like, and generally adopts two methods of modifying the rigid inorganic particles and the thermoplastic resin in consideration of cost and convenience in raw material acquisition. Therefore, it is a hot spot problem to investigate and improve the toughening modification at the time of granulating a thermosetting resin. Chinese patent application No. 201710001208.9 discloses a high-toughness melamine resin and a preparation method thereof, wherein an elastomer is added into the melamine resin in the form of powder or emulsion to improve the impact strength of the elastomer, so as to prepare the high-toughness melamine resin. The preparation method of the resin comprises the steps of placing 40-85 parts of melamine-formaldehyde resin prepolymer, 5-50 parts of fiber, 0.1-0.5 part of curing agent, 5-30 parts of elastomer and 0.1-1 part of flowing agent in a 25-80 ℃ kneader for kneading for 30-90min, then placing in a 70-130 ℃ oven for drying and dewatering, and then ball-milling the kneaded material and 3-10 parts of inorganic filler in a ball mill for 4-20h to obtain high-toughness melamine powder. The other preparation method is that the prepolymer, the fiber, the curing agent and the flowing agent are put into a kneader for kneading, then are put into an oven for drying and dewatering to obtain irregular blocky solid, and then the blocky solid, the inorganic filler and the elastomer powder are ball-milled in a ball mill according to the proportion to obtain the high-toughness melamine powder. The method uses a mode of physically blending added fibers and melamine resin to toughen, such as glass fibers, carbon fibers, plant fibers and the like, and as most of melamine plastic products are tableware, the glass fibers and the carbon fibers have a certain influence on the safety of human bodies except the plant fibers, and the plant fibers such as straw wood fibers are added in the existing melamine products, so that the toughness of the formed products after granulation is difficult to further improve by the mode. The patent documents Liu Xin and Chen Duo in the composite material journal disclose that inorganic nano particles and thermoplastic particles