Simple Solutions That Work! Issue 12

26 I f you have dealt with core / mold making in the metal casting process, then most likely at some point you have dealt with the Phenolic Urethane Cold Box process (PUCB). PUCB is the most popular binder system for coremaking and the most widely organic chemical process in North America. The main key drivers that have propelled the PUCB is its versatility, productivity, and cost of use. Industries such as the automotive, mining, and agricultural depend on PUCB for their core making process. PUCB SYSTEMS OVERVIEW PUCB systems are mainly classified on the solvent package contain the Part 1 and Part 2. The most common systems are: 1. Hydrocarbon or aromatic solvent systems These are the most common systems in the market. They have been in use for more than 50 years. They tend to be lower cost and highly flexible to many cold box materials and methods. AYAX RANGEL HA INTERNATIONAL ARTICLE TAKEAWAYS: • Understanding Phenolic Urethane Cold Box Systems • Benefits of PUCB • Latest developments minimizing the EH&S impact PHENOLIC URETHANE COLD BOX PROCESS 2. Biodiesel or aliphatic systems These are highly regarded for their high performance and lower emissions; VOC (Volatile Organic Content) and HAP (Hazardous Air Pollutant) at core making. The main solvent packaged is plant based (biodiesel). This type of system tends to deliver fast cycle times as well as high mechanical strengths and good bench life for the sand- binder mix. They have been in use for the last 20 years. 3. Silicate Cold Box systems These are PUCB systems furnished with inorganic solvents. This PUCB system is excellent in many respects, offering many environmental and performance advantages. This type of systems deliver the lowest odor and smoke during the core making and casting process and the total VOC profile (*OCMA and PCS). In North America, these systems could be considered as the ideal bridge between PUCB binders and inorganic high productivity binder systems (IOB). *OCMA (Ohio Cast Metals Association) VOC test *PCS (Pouring, Cooling, & Shake-out) GENERAL STEREOTYPES OF PUCB SYSTEMS Aside from its wide use and aforementioned differences, in some sectors of the industry there is still the tendency to generalize the virtues and drawbacks of the PUCB systems as if all PUCB systems display the same characteristics and shortcomings. Some of the main attributes tagged to the majority of the PUCB binder systems can be enunciated as follows: • Faster cycle times • Can be used for ferrous as well as non-ferrous metal casting applications • Can be used with many different sand types and additives • Can produce highly complex and intricate cores • High mechanical strengths relative to binder levels used