Reaction kettle type foaming device of thermally expandable microspheres and foaming method

Abstract

The invention discloses a reaction kettle type foaming device of thermally expandable microspheres and a foaming method. The foaming device comprises a kettle type foaming tank body, a kettle type foaming tank cover and a steam engine, wherein the kettle type foaming tank body is detachably connected with the kettle type foaming tank cover in a sealed mode, the kettle type foaming tank cover tankcover communicates with the steam engine through a pipeline, the kettle type foaming tank body is of a sandwich structure, and a pressure gauge and a temperature measuring device are arranged on the kettle type foaming tank cover. According to the foaming device and the foaming method, by utilizing a transparent glass foaming kettle with the sandwich structure, the pressure, the temperature and the foaming condition of the microspheres in the kettle can be accurately monitored through the pressure gauge and the temperature measuring device of the kettle type foaming tank cover; cooling water can be rapidly added into the device, so that the shrinkage and sticking conditions of the foamed microspheres are reduced, and dust generated by the foamed microspheres is eliminated; safety foaming of the microspheres at different temperatures or even high-temperature can be carried out by utilizing the characteristics of the temperature resistance and pressure resistance of glass; and the inputvolume of steam can be controlled so as to control the degree of foaming of the microspheres.

Description

technical field [0001] The invention relates to the field of microsphere foaming, in particular to a reactor-type foaming device and a foaming method for thermally expandable microspheres. Background technique [0002] Thermally expandable microspheres are microspheres with a core-shell structure mainly composed of thermoplastic polymers as the shell and expandable substances as the core. When the temperature rises, due to the low boiling point of the blowing agent, the foaming The agent is vaporized, the internal pressure increases, and the temperature increases at the same time, the shell softens, and the microspheres foam under the action of the internal pressure, usually their diameter can increase by 2-5 times. For different types of thermally expandable microspheres, the temperature and pressure of the system have a great influence on the foaming effect. In addition, different heat supply methods will result in different foaming time and foaming results. In the foamin...

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Problems solved by technology

[0003] The following problems are often encountered in the foaming process of heat-expandable microspheres: the shell of the fully foamed heat-expandable microspheres is very soft, and in the process of natural cooling, it is easy to shrink and bond to each other At the same time, the prepared heat-expandable microspheres have low density and light weight. In the absence of effective protective measures, the steam after steam foaming is easy to generate dust, which is harmful to the environment and personnel; due to heat The temperature of the steam is high. In a completely closed system, the final pressure of continuous hot steam will be very high. Under such high temperature and high pressure, it may cause damage to ordinary steam foaming equipment, and in a closed environment, heat There is a certain limit on the amount of steam introduced, which may cause insufficient steaming of some models of microspheres

[0004] Patents US5484815 and US7192989 disclose methods and devices suitable for thermally expandable microsphere dry powder foaming, but the foaming time is slightly too long and dust is easily generated

Patent US4513106 discloses a method and device suitable for microsphere slurry foaming, but it is not suitable for preparing high-temperature and ultra-high-temperature products

Patent EP0348372 discloses a process for making foamed thermoplastic microspheres, where the foaming takes place on a conveyor belt, the process works well, but takes up a lot of space and is relatively expensive

Patents US4722943 and US5342689 disclose methods for foamed microspheres, wherein the microspheres are mixed with a surface barrier coating to prevent caking during the drying step, but the amount of processing aids (such as talc) is very high, and this affects the quenching The possibility of making it difficult to control the degree of microsphere foaming

Patents CN1882638B, CN101263183A and CN1729087A disclose methods for foaming microspheres, the same microspheres are mixed with a surface barrier coating to prevent caking during the foaming step, and the foaming device is complicated to prepare

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