Equipment for continuously preparing polyglycolic acid granules

Abstract

The invention discloses equipment for continuously preparing polyglycolic acid granules. The equipment comprises a molten material storage tank, and further comprises a rotary drum cooling and solidifying device which is horizontally arranged above the molten material storage tank, and the outer wall of the lower part of the rotary drum cooling and solidifying device makes contact with the liquidlevel of a polyglycolic acid molten material in the molten material storage tank; a bottom plate is arranged at one side of the molten material storage tank, and a scraping plate, a first cutter and asecond cutter are arranged on the bottom plate; one end of the scraping plate is connected with the outer wall of the rotary drum cooling and solidifying device, the other end of the scraping plate extends to the bottom plate, and no gap exists between the outer wall of the rotary drum cooling and solidifying device and the scraping plate; and the first cutter and the second cutter are arranged in the extending direction of the bottom plate, and the rotating direction of the first cutter and the rotating direction of the second cutter are opposite to the rotating direction of the rotary drumcooling and solidifying device. According to the equipment, polyglycolic acid is prevented from contacting with cooling water, hydrolytic degradation of the polyglycolic acid in the cooling and solidifying granulation process is avoided, the recovery rate of polyglycolic acid products is improved to 99.95-99.97 wt%, and the technical target of continuous industrial production of the polyglycolic acid products is realized.

Description

technical field [0001] The invention relates to equipment for preparing polyglycolic acid, in particular to an industrial-scale equipment for continuously, stably and efficiently preparing finished polyglycolic acid pellets. Background technique [0002] Polyglycolic acid is a polymer material produced by polymerization of glycolide under the action of an organometallic compound or a Lewis acid catalyst. Polyglycolic acid is a simple linear aliphatic polyester with a simple and regular linear molecular structure and high crystallinity to form a crystalline polymer with a glass transition temperature of 35-40°C and a melting point of 220-240°C. Polyglycolic acid includes two kinds of low molecular weight polyglycolic acid and high molecular weight polyglycolic acid; among them, the molecular weight of low molecular weight polyglycolic acid is more than 100,000, which is easy to hydrolyze, and the degradation products such as lactic acid and glycolic acid are intermediate prod...

AI Technical Summary

Problems solved by technology

As a result, the cooling water flows in the drum, and the outer surface of the drum cools the liquid material, so that the liquid material cools and solidifies on the outer surface of the drum, and the liquid material is cooled evenly, preventing the solid material formed by condensation from wrapping the liquid material; adjust the rotating speed of the drum , can condense on the outer surface of the drum to form solid materials of different thicknesses, and the solid materials fall off from the outer surface of the drum, showing a certain status quo, no further molding treatment is required, but it is only a single cooling device for the cooling and solidification process of liquid materials , cannot be directly applied to the continuous industrial polyglycolic acid production device to make the polyglycolic acid material cold solidified into polyglycolic acid pellet finished product; the invention patent with application number CN201811235288.5 discloses a preparation method of polyglycolic acid, including Reaction of glycolic acid or glycolic acid ester to obtain the step 1 of polyglycolic acid with a weight average molecular weight Mw lower than 20000, and the technical scheme of step 2 of adding a dehydrating agent to the obtained polyglycolic acid for further polymerization, but it is only a laboratory The method of large-scale and intermittent preparation of polyglycolic acid products requires 16 hours of operation to obtain 886-907g of polyglycolic acid, and there is no process of cold solidification and granulation. Once it is applied to a continuous industrial polyglycolic acid production device, there will be a problem of "amplification effect"

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