Manufacturing Method of Polyester
Polyester (Polyester) is an important chemical widely used in fibers, films, containers, insulating materials and other fields. This article will introduce the manufacturing method of polyester, including raw material preparation, esterification reaction, polycondensation reaction, post-treatment and other steps.
I. Raw material preparation
The manufacture of polyester requires two main raw materials: dibasic acid and dibasic alcohol. Commonly used dibasic acids include terephthalic acid (TPA), isophthalic acid (IPA), etc. Commonly used diols include ethylene glycol (EG), propylene glycol (PG), etc. These raw materials are available in the market. These raw materials are available in the market.
II. Esterification reaction
Esterification reaction is the process of reacting dibasic acids and diols to form esters. Esterification reaction generally adopts batch reactor, the reaction temperature is 200-250 ℃, the reaction pressure is 0.1-0.5 MPa. In the esterification reaction, it is necessary to add a catalyst, and the commonly used catalysts include p-toluenesulfonic acid, sulfuric acid and so on. The water generated from the esterification reaction needs to be discharged from the reactor in time to keep the reaction going.
Three, polycondensation reaction
Polycondensation reaction is the process of further reacting the esterified material to generate polyester. The polycondensation reaction generally adopts a continuous reactor, the reaction temperature is 250-300 ℃, the reaction pressure is 0.1-1MPa. In the polycondensation reaction, it is necessary to add a catalyst and stabilizer, commonly used catalysts include tetrabutyl titanate, antimony acetate, etc., and commonly used stabilizers include tricresyl phosphate, triphenyl phosphite and so on. The water generated by the polycondensation reaction needs to be discharged from the reactor in time, and the vacuum of the reactor needs to be controlled to keep the reaction going.
Four, post-processing
After the polycondensation reaction, post-processing is required, including steps such as granulation, drying and packaging. Granulation is to cut polyester into certain lengths of particles to facilitate subsequent processing and use. Drying is to remove the water in the polyester granules to ensure its quality. Packaging is to package the dried polyester pellets for storage and transportation.
In short, the manufacture of polyester needs to go through the steps of raw material preparation, esterification reaction, polycondensation reaction and post-treatment. During the production process, the reaction conditions and raw material quality need to be strictly controlled to ensure the quality and yield of polyester. At the same time, it is also necessary to strengthen the maintenance and repair of production equipment to ensure the stable operation of the production line.
V. Quality control and environmental requirements
In the production process of polyester, need to focus on product quality control and environmental requirements. For quality control, need to establish a perfect quality management system to ensure product quality in line with relevant standards and customer requirements. For environmental protection requirements, it is necessary to take effective measures to reduce the emissions of waste gas, waste water and solid waste in the production process, strengthen the treatment of waste water and waste gas treatment, reduce the impact on the environment.
Six, technological innovation and development trend
With the continuous progress of science and technology, polyester production technology is also constantly innovating and developing. In the future, the production of polyester will pay more attention to environmental protection, high efficiency and sustainable development, and constantly promote technological innovation and product upgrading. At the same time, with the continuous emergence of new materials, polyester applications will continue to expand, injecting new vitality into the development of the field of raw materials for the production of chemicals.
In short, the polyester manufacturing method involves a number of links and processes, requiring strict control of production conditions and raw material quality, focusing on product quality control and environmental requirements. In the future, with the continuous innovation and development of technology, the production of polyester will be more efficient, environmentally friendly and sustainable, and make greater contributions to the development of the field of raw materials for chemicals production.
