【Popular Science Tips on Polymers and Materials】--Basic Knowledge for Choosing 40 Resins + Chemical Engineer Yuepeng

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This post was last edited by ljtjbx on 2015-11-26 at 15:50. Nowadays, many industrial clients when choosing resins focus on two main factors: price and performance. However, the resin has been in use well beyond its manufacturer’s expiration date. So what factors determine that resin can still perform well even after exceeding the manufacturer’s shelf life? I’d like to simply share with you some basic knowledge on how to choose resins. 1. Exchange capacity: What we usually refer to is volume exchange capacity, and of course, the higher the better. 2. Mechanical strength: This refers to the fact that the resin does not crack or break apart; it also affects the performance and can contaminate the system. The requirements for resins include resistance to changes in dryness, wetness, cold, and heat, resistance to swelling and contraction caused by acids and alkalis, and resistance to wear due to flow velocity. The manufacturer should provide these experimental data. This also serves as a way to screen resin manufacturers, allowing one to assess their expertise in resin production. If cost efficiency is a priority, resins with a particle size of (20–80 mesh) are generally more convenient to use. 3. Chemical stability is crucial, as it determines the service life of the resin. The key parameters include resistance to organic solvents, dilute acids, dilute bases, as well as oxidizing and reducing agents; for example, foreign-made resins sometimes specify parameters such as the absorption capacity and mechanical strength of the resin after being immersed in a certain percentage of acid for a specific period of time. 4. High selectivity and good regeneration performance: In applications such as concentration and separation, the higher the selectivity of the resin, the better. Recycling precious metals that are used only once has no value. Chelating resins have high selectivity, but their regeneration process is complex; it is essential to clarify exactly how to handle them. 5. Good structural properties: Under operating conditions, the resin has an appropriate void volume and pore size, a narrow pore size distribution, a large specific surface area, and good resistance to contamination. These manufacturers will provide this information to their customers; and if you have high confidence in a manufacturer’s capabilities, they will furnish you with the relevant data as a standard for checking the quality of the resin. This is just my personal opinion; I hope that our country’s resin industry can become more organized, so that price doesn’t become a weapon that manufacturers use to their advantage. This is undoubtedly a significant issue that cannot be ignored for the development of resins in China. Only by becoming more standardized can China’s resins undergo a process of transformation from quantitative change to qualitative change. This is something I’ve observed: abroad, resins achieve the same treatment results as those used in our country. Abroad, such resins cost hundreds of thousands of yuan, while in our country they cost only tens of thousands to a few hundred thousand yuan; yet their market competitiveness still lags behind that of products from foreign markets. I felt heartache immediately; I wanted the manufacturers that usually use resin to impose strict requirements on their resin suppliers, so as to achieve a win-win situation and also contribute to the development of domestic resin!