U - Foundry Additives Glossary
UFFA TYPE RESINS (See: HOT BOX RESINS-RESINS)
Are resins of a special type commonly used as binders having different setting times, cold-set strengths, hot cured strengths and setting properties.
UNMODIFIED UREA FORMALDEHYDE (See: RESINS-UREA)
Unmodified UF resins, catalyzed, are difficult to control in setting time when used as cold-set resins. Their cold-set strength is medium, but they have a high hot-cured strength. They have poor setting properties and are sensitive to mold-metal reactions, unless a proper coating is given the sand surface.
UREA BINDER (See: LIQUID UREA BINDER)
UREA FORMALDEHYDE CATALYZED (See: UREA RESIN)
When urea resins are catalyzed, they start to cure immediately when used. This can be a bench life problem. The higher the temperature, the faster the curing process.
UREA FORMALDEHYDE RESIN (See: LIQUID UREA BINDER RESINS)
This is a popular resin used by lightweight metal foundries, or those foundries baking cores by the dielectric practice. Urea resin is formed by the combination of urea and formaldehyde. It is a condensed product which is insoluble in water, alcohol, oil, weak acids and alkalis. Urea is a substance with the composition CO(NH2)2. Plaskon is a commercial urea formaldehyde. Urea formaldehyde and other resins of this type were introduced as binders through cores demanding less baking and lower temperatures for curing. The CProcess (Shell Molding) first used urea formaldehyde resin as the binder. Urea formaldehyde resin is a product of the condensation reaction between urea and formaldehyde and may be either a liquid or solid. (See: MODIFIED UREA RESIN.)
Learn more about The Hill and Griffith Company core binders.
UREA-FURAN-FORMALDEHYDE (See: LIQUID UREA BINDER-SELF CURING RESINS)
Are self-setting furan type resins. Furfuryl alcohol modified UF resin, catalyzed by phosphoric acid is used in cold-setting sand mixtures which are easily controllable from ten minutes of setting time. They have high cold-set strengths. No heat is required for curing and the setting properties are excellent. Their mold-metal reaction is medium in comparison with others, but molds utilizing such binders which contain a relatively high proportion of urea formaldehyde and less furfuryl may be subjected to fissure porosity. High nitrogen content must be avoided.
UREA RESIN-FURFURYL ALCOHOL MODIFIED
They cure very fast as binders and higher strengths are developed. The optimum resin addition is about 3% by weight. These usually have higher strengths than unmodified resin.
Review of "Glossary of Foundry Additives" by Clyde A. Sanders, American Colloid Company
Metal Foundry News - From Google and AFS
Hill and Griffith Customer Service
The Hill and Griffith Company's green sand metalcasting foundry supplies help achieve the EPA's M.A.C.T. standards and reduce Benzene emissions. Our variety of environmentally sound release agents, coatings, partings, lubricants, core oils and specialty products will help you meet your metal casting's needs. We're known for our hands on approach. Let us visit your plant and recommend products that suit your needs.
We are pleased to provide samples in quantities large enough to allow you to "try before you buy."
Contact Us »
Technical Services & Support
On-site casting defect investigations, product testing, machine start-ups and much more. Also, lab facilities are available to provide testing upon request.
Contact Us »