The production of PETG (polyethylene terephthalate-co-1,4-cyclohexanedimethanol terephthalate) uses terephthalic acid, ethylene glycol, and 1,4-cyclohexanedimethanol as core raw materials. The core links are esterification reaction and polycondensation reaction, and technological innovations focus on two directions: improving reaction efficiency and optimizing performance controllability. In the esterification stage, traditional batch reactions have problems of long reaction time (8-10 hours) and uneven raw material conversion rate. However, the new continuous esterification device, through the design of a multi-stage reaction tower, realizes continuous feeding of raw materials and real-time separation of reaction products, shortening the reaction time to 4-5 hours, increasing the conversion rate to more than 99.5%, and controlling the product purity fluctuation within ±0.2%, laying a stable foundation for the subsequent polycondensation reaction.

The technological breakthrough in the polycondensation reaction link is the key to improving the performance of PETG. By introducing new titanium-based catalysts to replace traditional antimony-based catalysts, it not only solves the problem of heavy metal residues (residue reduced to less than 1ppm), but also increases the polycondensation reaction rate by 30%, while enabling precise regulation of molecular chain length and branching degree. For example, when producing high-transparency PETG, by reducing the branching degree of molecular chains, the light transmittance of the material reaches more than 92%, close to that of optical-grade PMMA; when producing high-toughness PETG, by appropriately increasing the branched structure, the impact strength is increased to more than 60kJ/㎡, which is 3 times that of ordinary PET. In addition, antioxidants and ultraviolet absorbers added during the reaction can realize in-situ compounding, avoiding performance loss in subsequent processing and simplifying the production process.

The intelligent transformation of equipment provides strong support for PETG production. The online viscosity monitoring system deployed on the production line can feedback the progress of the polycondensation reaction in real time, automatically adjust the reaction temperature and pressure, and ensure the uniform molecular weight distribution of the product (dispersion index controlled at 1.8-2.2); the automated pelletizing and screening equipment can quickly eliminate unqualified particles through infrared detection technology, increasing the product qualification rate to 99.8%. At the same time, the drying system in the raw material pretreatment link adopts heat pump cycle technology, which reduces energy consumption by 35% compared with the traditional electric heating method, conforming to the concept of green production.

At present, the production and manufacturing of PETG has formed a dual-track model of "standardization + customization". The standardized production line can achieve an annual output of 10,000 tons to meet the needs of general fields such as packaging and plates; the customized production line is aimed at high-end fields such as medical care and electronics, and develops PETG products with special properties such as sterilization resistance and antistatic through adjusting raw material ratios and process parameters. This flexible production system enables PETG series materials to quickly respond to changes in market demand and further expand the application boundary.